W.A. Pete sent me some W.A. Ore. I perform a fire assay and a chemical extraction on this ore and share the results. Keywords: Gold Ore, Fire Assay, Gold Extraction, Aqua Regia, Cupel, Cupellation
Geochemist of 35 years here. This is a tough one given all of the iron present in the sample. 1. Trust your fire assay. 2. As another commenter here said, you might consider (getting a taller beaker) and adding additional HCl and Nitric as required in the first go to try to get everything into solution the first time. The trick is to get the iron out of the way. I've never worked at a mine where this was a problem, so I can't definitively point the way. One thing you might try is to soak a small sample (50g?) in oxalic acid until it cleans up, rinse it well and then run it with AR. Oxalic will reduce the Fe2O3 to FeO with some Fe staying in solution so you will still have some Fe to deal with, but not as much and with a weaker bond. 3. You need to filter and wash the slimes left over from filtering the AR solution. I suspect that you will find 'coarse' gold in there. By the way, when you did your math...I could have sworn that was a 250g sample, not a 350g one as you calculated. You are still short at 1039g/t so something is going on. I suspect it's the iron. Overall, a great video and your friend is going to be a happy man if his mine runs that grade for a while! *EDIT: In the beginning, when you did your HCl boil? Replace that with a nitric boil. That should remove the iron, but the nitric MUST be dilute, try 4 parts distilled water and one part of your 30 something percent nitric.
Great video. Your presentation is clear, informative and held my interest. It was pretty darn exciting to see the tiny ball of gold form in the cupel. Also I have really enjoyed reading these comments, and again I learned a lot here. Thank you every one, Pete in USA ( the Pete with no gold bearing ore )
Gold will not go into solution until all of the Iron is dissolved, and since the residue contained undissolved Iron, not all of the Gold was dissolved. Ore from that part of the World is very rich in Iron. Cyanide is consumed by the Iron, thus making that process uneconomical, even with very rich ore.
Would it be possible to seperate the iron on a mechanical way with magnetic fields to reduce the preload. Then mixing with a carbon source to make cast iron. Electroliysing these plates would create iron oxide in water and gold on the stainless electrodes. The Iron reduced material can be then chemicaly stripped for gold.
One thing I liked about your presentation is that you left the viewer with the question "why did you get differing results?". I enjoy being left with a sense of curiosity. It engages my imagination and inspires me to examine what I observed, what I thought I knew, what I believe I understood, and to be critical of each with equal importance. I'm appreciative of this short moment of adventure as I watched you go through the process. W my friend. W
Thanks, Chris. I suspect that there's a lot of gold left on the shaker table floor. I wonder if we can figure out how to recover it. A big joy in life.
Im a novice, chemical refiner (in my rookie year), and I really enjoyed your video. A series on the flux and cupeling "again", and a chalk board going over the mathematical side would be great also. Anyway, I enjoyed watching you do your work.
Great Vid, Awersome viewing we got so much info from all your testing. That red stuff will stain anything. Please keep up the great work and let's see if the remaining material holds the same rewards. Looking forward to Part 2. 😊
When I got into computer scrap recycling many years ago. I would go with the cheapest way I could chemically extract the metals from the parts I was processing. I may have spent too much time concerned about the pieces of scrap that would not contain any silver or gold. I would only include just the parts with the gold pieces exposed I made a makeshift pulverizer. I would always heat up my HCL and then boil some distilled water. That is where the cut the corner comes in. I would dissolve to a 2 to 1 ratio of weight of Urea into the boiling distilled water. I would then strain the dissolved urea in solution to get out the bits and trash that is in the Farmers Co-op urea had in it. I would mix the two together and yes slowly the parts would already in the HCL. I would get all of the metals from the parts. When I dropped the gold. I used SMB. I would use the half the weight of the Parts that I used probably too much. I always ran my slime, and I would get a very consistent result. For every gram of SMB, I used. It would drop almost two thirds the weight of the amount of SMB used. After this I would test the solution and what I ended up with is copper salts trapped in solution I would just hang scrap copper pipe or wire (stripped). The more surface area of copper you have the more copper can be pulled out. I would test the AR I had left after extraction. The stanis test for any trapped gold in solution. I would find all was gone and had been captured. I had child and a wife. I just couldn't keep up my hobby most of my stuff was damaged when a storm wiped out my little shed I was working in. I do think this was a very good video. I did learn a thing or two. Slowly collecting up some more PC scrap. I may decide to get into it again.
A stir bar would be helpful when trying to put the gold in solution with ar.You'll never get all of it to dissolve in that state. The rest of the missing gold is still in the filtrate. (ore sludge)
Losses in the iron removed by magnet and perhaps in the cotton wool. And, what if the bead was heavier than gold because it contained something heavier than gold? Platinum maybe. Wasn't a very golden bead on my screen. And Thank you. Great lessons here. Some insightful comments also.
Great explanation of what you are doing. I would think that some of the rock has neutralized some of the reactions. So letting it cook on heat for more time, keeping it hydrated. Should help that. Very rich ore indeed!
I would like to see the concentration result from running through a simple sluice or maybe a good panning then examining under magnification to see the texture coarseness. With chemical extraction on ore I would roast the fine powder then pour the hot powder into a beaker of ice water which will cause the particulate to crack even finer to release more gold dust.
Gold throughout much of Australia has little silver or other metals in it. especially in the South East but also WA. We alos have had most of the worlds largest specimens here as we never had any glacial movements here whereas other parts of the world did and glacial movements ground up the gold that was in ancient pre glacial river beds as the ice sheet moved over it. The number of nuggets over 450oz that were pulled up during the Victorian gold rush just boggles the mind.
6:47 This my friend is the difference. I put a magnet in my pan I can see gold come up with the iron. Yes, it’s a real thing.( @BiggestKev1960 ) Try a fire assay (or other) on the iron that came off the difference. If you do, call it part two. I want to revisit this story. Much appreciation, Geraldton, Western Australia
Enjoyed your video. If you can locate pockets you can achieve these results. Pete might have salted the pot for promotional purposes. His sales just went off the charts.
I sure would like you to do a fineness assay on the gold bead. The parting solution would tell us the presence of the platinum group. (classically trained assayer 35 years in SF)
Very interesting results. Was this sample raw crushed ore or was it pre-concentrated? Either way, I’d like a slice of that pie. If smelting gives the best results than I would smelt the rest. There may be some other mineral in the ore which is interfering with the chemical recovery process.
My best guess is that the ore is from Nullagine in the Pilbara, an area I'm keen on heading out to some day myself. I enjoyed your video and keen to see what's next.
I would let it sit in 15% HCL for a week, stirring Daily, sitting on a propagation mat to bring the heat up. Replace acid weekly until it runs clear, then do the AR on it. You have potentially not killed off all the nitric which may also be a problem. I haven't seen the use of dropping gold with Stannous before so that's something for me to look into, Cheers.!
It seems like you're dealing with a significant discrepancy between fire assay results and chemical assay results in the context of gold recovery, possibly due to differences in sample preparation processes. Here's a more detailed look at the potential issue: Roasting Before Fire Assay: If you roasted the sample before conducting the fire assay, the roasting process likely helped to break down complex compounds that might otherwise retain the gold, thereby making it more accessible for the assay process. Roasting can convert sulfides and other compounds into oxides, which are easier to deal with in the fire assay. No Roasting Before Leaching: If you did not roast the sample before leaching, the gold might still be locked within these complex compounds, preventing it from being dissolved and recovered during the leaching process. This could lead to significantly lower gold recovery rates. Possible Causes for Discrepancy: - Presence of Sulfides or Other Refractory Materials: The presence of sulfides or other refractory materials in the ore can trap gold and prevent it from being leached effectively unless these materials are broken down by roasting. - Complex Gold Compounds: Gold can form complexes with other elements that are stable under normal leaching conditions but break down upon roasting, releasing the gold. - Inadequate Leaching Conditions: If the leaching conditions (e.g., pH, temperature, reagent concentrations) are not optimized, the gold might not be fully extracted, leading to lower assay values. Recommendations: 1. Roast Samples Before Both Fire Assay and Leaching: To ensure consistency and more accurate comparisons, roast the samples before both the fire assay and the leaching process. This will help to break down any refractory compounds and release the gold. 2. Conduct Diagnostic Leaching Tests: Perform a series of diagnostic leaching tests to identify the specific reasons for the low recovery. This could include varying the roasting conditions, changing leaching reagents, or adjusting other parameters to see what maximizes gold recovery. 3. Characterize the Ore: Use techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), or energy-dispersive X-ray spectroscopy (EDS) to analyze the mineral composition of the ore. Understanding the specific minerals present can help in tailoring the roasting and leaching processes. 4. Optimize Leaching Parameters: Ensure that the leaching conditions are optimized for the specific type of ore you are dealing with. This might involve adjusting the concentration of the leaching agent, temperature, or other parameters. By identifying and addressing the specific factors that are causing the gold loss during the leaching process, you can improve the overall recovery and reduce the discrepancy between fire assay and chemical assay results. The behavior of gold in natural environments and its implications for assay and leaching processes. Here's a more detailed explanation and some additional considerations: Natural Formation of Gold Complexes In nature, the interaction of acidic gold-bearing fluids with alkaline solutions can lead to the formation of water-soluble gold complexes. The pH of the environment plays a crucial role in determining the solubility and stability of these complexes. Acidic Conditions: Under acidic conditions (low pH), gold can form complexes with chloride ions (e.g., AuCl₄⁻) or other ligands that keep it in solution. Alkaline Conditions: When these acidic solutions encounter alkaline conditions (high pH), the chemistry changes, potentially leading to the precipitation of gold complexes. For example, if the pH reaches around 8, certain gold complexes might precipitate out of solution. Resistance to Aqua Regia Some gold complexes that precipitate out under alkaline conditions can become resistant to dissolution by aqua regia. Aqua regia, a mixture of nitric acid and hydrochloric acid, is typically very effective at dissolving gold, but certain complexes might resist this treatment due to their chemical stability. Practical Implications for Assay and Leaching Preserve Leach Solutions: Do not discard your leach solutions prematurely. Since gold can form soluble complexes, especially in the presence of varying pH levels, it is essential to process these solutions thoroughly to recover as much gold as possible. pH Control: Monitor and control the pH of your leaching solutions carefully. Ensure that the pH is optimized to prevent the formation of resistant gold complexes and to maximize gold dissolution. Sequential Leaching: Consider using sequential leaching techniques to break down different gold complexes. This might involve using different leaching agents or adjusting the pH in stages to ensure complete recovery of gold. Advanced Analytical Techniques: Use advanced analytical techniques to understand the nature of gold complexes in your solutions. Techniques such as mass spectrometry, X-ray absorption spectroscopy (XAS), or nuclear magnetic resonance (NMR) can provide insights into the speciation of gold in different environments. Pre-treatment Methods: If you suspect that certain gold complexes are resistant to aqua regia, explore pre-treatment methods that might break down these complexes. This could involve oxidative roasting, pressure oxidation, or other methods to convert resistant complexes into forms that are more amenable to leaching. By understanding the chemistry of gold in different pH environments and taking appropriate steps to manage the leaching process, you can improve gold recovery and reduce losses. Tellurides, such as gold telluride (calaverite) and other gold-tellurium compounds, can be resistant to aqua regia. These compounds often require special treatment to break down the telluride matrix and release the gold for effective recovery. Here are some key points and strategies for dealing with gold tellurides: Characteristics of Gold Tellurides Resistance to Aqua Regia: Gold tellurides are known to be resistant to dissolution by aqua regia due to the strong bond between gold and tellurium. Refractory Nature: These minerals are considered refractory because they do not easily yield gold through conventional leaching or cyanidation processes. Strategies for Processing Gold Tellurides Roasting: Roasting gold tellurides at high temperatures can oxidize the tellurium, converting it into a form that is more easily separated from the gold. This process typically involves heating the ore in the presence of oxygen to break down the telluride matrix. Pressure Oxidation (Autoclaving): This method involves treating the ore under high pressure and temperature with oxygen or air, often in an autoclave. This can effectively oxidize the tellurides and liberate the gold for subsequent recovery by leaching. Alkaline Leaching: Some tellurides may be amenable to alkaline leaching, using reagents such as sodium hydroxide (NaOH) to break down the telluride structure and release gold. Bio-oxidation: Using certain bacteria that can oxidize sulfides and tellurides, bio-oxidation can be a viable method for treating refractory gold telluride ores. Thiosulfate Leaching: An alternative to cyanide, thiosulfate leaching can be effective for some refractory ores, including those containing tellurides. This method uses ammonium thiosulfate as a leaching agent in the presence of a copper catalyst and an ammonia buffer. Ultrafine Grinding: Reducing the particle size of the ore through ultrafine grinding can increase the surface area and make the tellurides more accessible to leaching reagents. This can be combined with other pre-treatment methods to enhance gold recovery. Process Workflow Example Crushing and Grinding: Reduce the ore to a fine particle size to expose the gold tellurides. Roasting: Heat the ground ore to high temperatures in the presence of oxygen to oxidize the tellurium and other sulfides. Leaching: Use a suitable leaching agent, such as cyanide or thiosulfate, to dissolve the gold. Recovery: Recover the dissolved gold from the leach solution through methods such as activated carbon adsorption or electrowinning. Tailings Treatment: Treat the tailings to ensure that any residual gold or harmful byproducts are managed appropriately. Conclusion Processing gold tellurides requires specialized techniques to overcome their refractory nature. By employing methods like roasting, pressure oxidation, or alternative leaching reagents, you can effectively break down the telluride matrix and recover the gold. It's essential to carefully select and optimize these methods based on the specific characteristics of the ore you are dealing with. ~ CHEERS P.S. You should remove your free gold first, but not spend a lot of time doing that. This is because you will lose gold down the line; there is no perfect process. It is paramount to remove the gold in the very earliest stages, and thanks for taking time out of your day to educate the rest of us. 😎
@@Jatslo Really interesting and insightful comments, thank you Jatsio. I try to boil acids in a distillation setup so I can recover acids that would otherwise vent to atmosphere. I have noticed an odd smell that is in these weaker distilled acids that are not present in fresh acids. Makes sense that this could be some sort of gas or plasma. If so, are their any techniques you might suggest that can fix these volatile aspects to increase my yield? Depending, I often add these to the next boil and they eventually end up being cemented out with Copper, then Iron metal, before I eventually recover my nitrates. Developing some sort of semi-closed-system seems prudent tome. Waste not, want not, and all of that.
@@waynoswaynos Discussing plasma states can be a bit extreme for typical metallurgical processes like fire assay. Let's focus on the practical aspects of managing and minimizing the loss of gold during high-temperature processes like fire assay, particularly in relation to the volatilization of lead and its impact on gold recovery. Understanding Lead Volatilization in Fire Assay In the fire assay process, lead is used as a collector for precious metals. However, lead can volatilize at high temperatures, and this volatilization can carry precious metals, including gold, away from the assay sample, leading to losses. Key Points and Strategies to Minimize Losses Proper Temperature Control: Melting Point: Lead has a melting point of 327.5°C and starts to volatilize significantly at temperatures above 600°C. Fire assays typically operate at around 1000-1200°C, increasing the risk of lead volatilization. Controlled Heating: Gradually increasing the temperature and maintaining it at the lower end of the required range can reduce the amount of lead volatilized. Use of Appropriate Fluxes: Flux Composition: Ensure that the flux composition is optimized to bind with impurities and reduce the need for excessively high temperatures. Reducing Agents: Use of reducing agents like carbon or charcoal can help minimize the oxidation of lead, reducing its volatilization. Efficient Furnace Design: Gas Collection Systems: Incorporate systems to collect and condense volatile components, including lead vapors. This can capture both lead and any gold that might be carried with it. Proper Ventilation: Ensure the furnace has adequate ventilation to safely manage gases without losing valuable materials. Sample Handling: Cupellation: In the cupellation stage, where lead is absorbed by the cupel and precious metals are left behind, ensure the process is done at the correct temperature and duration to minimize lead loss while effectively separating the gold. Recycling Lead: Consider recycling the lead collected in gas scrubbing systems to recover any gold that might have been volatilized with it. Analytical Verification: Post-Assay Analysis: Analyze residues and slags post-assay to check for any remaining gold. This can be done using techniques like ICP-MS or AAS. Reprocessing: If significant gold is found in the residues, reprocess these materials to recover the lost gold. Example Procedure Sample Preparation: Mix the sample with fluxes (e.g., litharge, soda ash, borax) and place it in a crucible. Fusion: Heat the mixture in a furnace to around 1000-1200°C. Monitor the temperature closely to avoid excessive lead volatilization. Collection: During the fusion, lead collects the precious metals, forming a lead button at the bottom of the crucible. Cupellation: Transfer the lead button to a cupel and heat it in a cupellation furnace. Lead is absorbed by the cupel or vaporized, leaving behind a precious metal bead. Residue Analysis: Analyze the remaining slag and cupel for any residual gold. Collect and treat any gases and residues to recover volatilized lead and gold. Conclusion Minimizing the loss of gold during fire assay requires careful control of temperature, efficient furnace design, appropriate flux usage, and thorough post-process analysis. By implementing these strategies, you can reduce the volatilization of lead and ensure maximum recovery of precious metals. ~ CHEERS
@@Jatslo Thank you, I have copied and pasted this thread to my metallurgy notes and formatted it. You have shared some things I had not considered. Appreciated.
More about the funnel seal ring. Is it tapered or just stretched to the funnel's cone. I prefer to ask a human and get a real answer, even a relatively simple one. Just never seen those, it is usually the glass frit or ceramic filters that are a quarter the size. Have reservations about the fritt actually being clean after use. Tossng a cotton ball away sounds simpler.
I bought the rubber seal rings as a set on Amazon. you get 6 or 7 different nesting sizes. They are very handy. I think the funnel with cotton is way better than the glass frit type for this work
In your position, for the chemical extraction I would first roast the ore to keep only the oxides, treat with HCl to remove non precious metals, decant and proceed with AR (this to keep all the precious metals for an all encompassing assay), or treat the ore with Nitric for a gold content only assay before I touch the AR. All the other metals will drop the gold from solution so its imperative to remove those first, then your process can continue as it was done in the video. BTW, great Flux recipe!
When you added the 40+ mesh stuff you shook that container making the gold go to the bottom of that container and added that to you r small 100g piles making those possibly hotter then the other piles. That could have made the results different as well .
During your chemical extraction process, you run out of hydrochloric acid and nitric acid, it seems. Boil the sample in hydrochloric acid first, to destroy carbonates and sulfides, then add the nitric acid to form aqua regia. Hope it makes sense, when you think about it... ;)
If the sample is from Kalgoorlie tellurides can inhibit aqua regia recovery. Will require pre roasting to 500 degrees C, or pre treatment with hypochlorite solution to break the Te-Au bond (Emperor Process).
I dont think you stopped all the gold. Firstly you didn't keep adding smb until a white foam appeared on the surface and secondly I didn't see you do a stannous test to see if you dropped it all. My guess is some of the gold is still in solution
Good points! I went back and re-processed the liquid and found a very small amount of gold, about 4% of the original. So, yes, there was more gold but not nearly enough to account for the differences. More experiments to follow.
dissolve the fire assay to see what is making it heavier.. and try to recover what is still held in your chemical process residues to asses what secondary processes may be applied for recovery.
So i am new to this whole thing and have no where near the prestige as commenter's or you, just a question would a H2so4 boil at the beginning help any? Before AR boil.
I am a novice also, with a little experience now. Yes, I think in some cases H2SO4 or HCl may help. I'll have a new video soon, with the continuation of this study.
When you added urea to neutralize nitric the was really no reaction, maybe you just need it more nitric to get the other have, I don't know amazing videos!!
I would say pan a bit a and see what sizes gold there is and then you know the size you need to crush to..for your analysis. There's mineral liberation and then there's mineral exposure. From what I understand you should just need exposure for leaching. But I agree probably rich enough to smelt..could just keep throwing your lead button back in.. to get more gold each smelt ..the lead may decrease in weight each smelt..
I suspect the silver was lost in the flux, chapman flux has a tendency to collect silver. One way to determine that would be to do another 100G smelt with an assay flux vs a smelting flux. You could also fire assay the flux again, or use an XRF on it after it's very finely ground. A local jewellery shop that has an XRF will might be a good option. AguaRegia will not pull silver into solution, or, if the silver/gold ratio is too low, the gold will not go into solution as it's locked up in the silver. Silver is much more of a problem metal than many realize.
Hi Auminer! I have been ignoring the value of silver because I think most gold miners consider it an annoyance. However, if the amount of silver is high and the fire assay does not show it, then we could be mislead into thinking that aqua regia (AR) will work when actually it won't because the silver will block the acid from dissolving the electrum (gold + silver alloy). However, I've done many fire assays with this flux on various ores that contain gold and silver and the silver always shows up in the assay results, sometimes in large quantities, so I don't think we have this problem. Note that the MnO2 content of my flux recipe is low. So, assuming that we don't loose much silver in the fire assay, then this ore contains almost pure gold, which should be easily dissolved in AR. So, I don't yet have a good explanation for the loss of gold in the chemical extraction. I'm learning to be more careful and I'll run more material to see if I can figure it out. As always, I deeply appreciate your comments.
@@orophilia all excellent points. I'd be curious to see what the ore looks like under your microscope, both before and after leaching, also what your shaker table would recover in relation to the size of this gold. There are some good comments posted here, and I think the high iron content might be an issue consuming the acids. Looking forward to solving this mystery on this very rich ore :)
I find that triangular chemists' flask with the tube attached very dangerous. Just too damn ready to accidentally pull it over, could even happen be cause of the weight of the tube itself! One should at least attach the flexible tube to the table so that any accidental pull at the end where you'd handle it would not cause any effect. You wouldn't want to lose that gold by having it spill into the soil or flooring underneath your table, especially when it is not yours...
I didn't see you part the Au/Ag from the fire assay, even though you used Chapman's with MgO2. Fire assay is always more accurate than chemical, unless you Cyanide bottle roll it.
the gold is more then can be held in salutation chemical extraction. Best way for extraction of the gold is smelting and chemical extraction , for 100% removal of gold from the ore. extraction of the gold is smelting should get 100% of the gold.
Could it be as simple as you not dividing the 60+ mesh equally? As in the amount of stratification you’re doing during the handling of the material in the large container? Just a thought 🤷♂️
Well when you consider that most goldmines in WA are only pulling 12 to 15 weights per tonne of ore I would suspect that sample has been heavily salted.
seems fishy being that you found refined gold in ore.....must have been seeded? as far as whats wrong with the chemical vs fire assay? speed.leaching au from ore needs time. time in aqua regia, time slowly adding reducing agent (whether smb or stannous,) time letting it drop. Im certainly no expert but ive seen countless times where what i assumed to be waste solution (after dropping au,) would have a brown precipitate dropping for many days after I thought was done!
@@orophilia i should have said "MAY have been seeded" instead of "must have been," as i dont want to accuse anyone of anything being i dont have all the facts.
@@TerribleShmeltingAccidentWA is some of the purest in the world - also some of the oldest. Normally 98-100% pure. It’s hard to measure volumes at that size accurately.
@@MerchantMarineGuy everything about this sample was unusual....if its too good to be true. Are you familiar with the mining scam that took Charles Tiffany (founder of tiffanys?)
With such a high yield of gold per metric ton, it's possible that the sample contains minerals with significant gold content, including tellurides such as calaverite (AuTe₂), krennerite (Au₈Te₆), sylvanite ((Au,Ag)Te₂), and other gold-bearing minerals. Tellurides are a group of minerals where gold is combined with tellurium. These minerals can contain significant amounts of gold, sometimes in very high concentrations. For example, Calaverite: AuTe₂, typically contains about 44% gold. Testing for tellurium in ore samples can be done using various analytical techniques. Sylvanite ((Au,Ag)Te₂) can be ruled out due to the absence of silver, if that is a true conclusion.
Upwind does not guarantee anything. You make a low pressure zone on the downwind side (the Lee) of your body. Right kinda breeze and distance, you'll get a face full of it. Like campfire smoke, it reaches out for ya. You're alright enough with what you are doing, but if it was something insanely poisonous, ya better not. You'll be haunting people afterwards, not ideal.
I think from watching your process that maybe you didnt drop all the gold that was in solution. And maybe because you still had nitric in the solution . When i have done drops in the past and granted not many i had a lot of problems getting rid of the nitric. From the amount of urea i watched you use it would be very hard to believe the nitric was neutralized. I had to use a lot more than that while at the same time boil the solution and it took a long time . But you probably know a lot more then i do. Good luck .
I think you might be right. Really, the only place all that gold could have disappeared to was into the waste solution after dropping the gold with SnCl2. Take a look at the next video. I use sulfamic acid to kill the nitric and then SMB to drop the gold with perfect results.
I don’t know why you filter the sponge gold after smb. Streetips. Always just lets it settle completely and I see almost clear on top and a brown powder stuff the gold at the bottom to which. He just pours the clear off. I think you filtering it. When it’s not clear. On top. Ur letting half the gold get lost. My opinion. I watch streetips all the time.
You have a scale and a tub there you could have had a MUCH more accurate step of samples by weighing it by subtraction rather than guess work, I find that rather blasie!
Sorry but you need to do something about your audio I would watch it but your when you talked with anything with the letter s in it it's like stabbing a ice pick in my ear your audio is horrible
Geochemist of 35 years here. This is a tough one given all of the iron present in the sample. 1. Trust your fire assay. 2. As another commenter here said, you might consider (getting a taller beaker) and adding additional HCl and Nitric as required in the first go to try to get everything into solution the first time. The trick is to get the iron out of the way. I've never worked at a mine where this was a problem, so I can't definitively point the way. One thing you might try is to soak a small sample (50g?) in oxalic acid until it cleans up, rinse it well and then run it with AR. Oxalic will reduce the Fe2O3 to FeO with some Fe staying in solution so you will still have some Fe to deal with, but not as much and with a weaker bond. 3. You need to filter and wash the slimes left over from filtering the AR solution. I suspect that you will find 'coarse' gold in there.
By the way, when you did your math...I could have sworn that was a 250g sample, not a 350g one as you calculated. You are still short at 1039g/t so something is going on. I suspect it's the iron. Overall, a great video and your friend is going to be a happy man if his mine runs that grade for a while!
*EDIT: In the beginning, when you did your HCl boil? Replace that with a nitric boil. That should remove the iron, but the nitric MUST be dilute, try 4 parts distilled water and one part of your 30 something percent nitric.
Great comment. Thanks
That's a well informed comment!
Great video. Your presentation is clear, informative and held my interest. It was pretty darn exciting to see the tiny ball of gold form in the cupel.
Also I have really enjoyed reading these comments, and again I learned a lot here.
Thank you every one,
Pete in USA ( the Pete with no gold bearing ore )
You are extraordinary, very professional, excellent chemical introduction and mixture excellent way of instructing pure Gold
Thank you! Cheers!
Gold will not go into solution until all of the Iron is dissolved, and since the residue contained undissolved Iron, not all of the Gold was dissolved. Ore from that part of the World is very rich in Iron. Cyanide is consumed by the Iron, thus making that process uneconomical, even with very rich ore.
if it is uneconomic with Cyanide, what it is economic with ??
@@ynalalkhalil6326
A lot of people have asked that question and if someone has the answer, they are not talking.
Would it be possible to seperate the iron on a mechanical way with magnetic fields to reduce the preload. Then mixing with a carbon source to make cast iron. Electroliysing these plates would create iron oxide in water and gold on the stainless electrodes. The Iron reduced material can be then chemicaly stripped for gold.
@@Ordog213
making cast iron consumes a lot of energy !
@@ynalalkhalil6326 Sticky rice will do it
One thing I liked about your presentation is that you left the viewer with the question "why did you get differing results?". I enjoy being left with a sense of curiosity. It engages my imagination and inspires me to examine what I observed, what I thought I knew, what I believe I understood, and to be critical of each with equal importance. I'm appreciative of this short moment of adventure as I watched you go through the process. W my friend. W
Thanks, Chris. I suspect that there's a lot of gold left on the shaker table floor. I wonder if we can figure out how to recover it. A big joy in life.
Im a novice, chemical refiner (in my rookie year), and I really enjoyed your video. A series on the flux and cupeling "again", and a chalk board going over the mathematical side would be great also. Anyway, I enjoyed watching you do your work.
Great Vid, Awersome viewing we got so much info from all your testing. That red stuff will stain anything. Please keep up the great work and let's see if the remaining material holds the same rewards. Looking forward to Part 2. 😊
Thanks, man. I enjoyed it. I still have 500 grams and I'm going to figure this out.
When I got into computer scrap recycling many years ago. I would go with the cheapest way I could chemically extract the metals from the parts I was processing. I may have spent too much time concerned about the pieces of scrap that would not contain any silver or gold. I would only include just the parts with the gold pieces exposed I made a makeshift pulverizer.
I would always heat up my HCL and then boil some distilled water. That is where the cut the corner comes in. I would dissolve to a 2 to 1 ratio of weight of Urea into the boiling distilled water. I would then strain the dissolved urea in solution to get out the bits and trash that is in the Farmers Co-op urea had in it.
I would mix the two together and yes slowly the parts would already in the HCL.
I would get all of the metals from the parts.
When I dropped the gold. I used SMB. I would use the half the weight of the Parts that I used probably too much.
I always ran my slime, and I would get a very consistent result. For every gram of SMB, I used. It would drop almost two thirds the weight of the amount of SMB used. After this I would test the solution and what I ended up with is copper salts trapped in solution I would just hang scrap copper pipe or wire (stripped). The more surface area of copper you have the more copper can be pulled out.
I would test the AR I had left after extraction. The stanis test for any trapped gold in solution. I would find all was gone and had been captured.
I had child and a wife. I just couldn't keep up my hobby most of my stuff was damaged when a storm wiped out my little shed I was working in. I do think this was a very good video. I did learn a thing or two. Slowly collecting up some more PC scrap. I may decide to get into it again.
A stir bar would be helpful when trying to put the gold in solution with ar.You'll never get all of it to dissolve in that state. The rest of the missing gold is still in the filtrate. (ore sludge)
Really enjoyed watching this and look forward to part 2
Losses in the iron removed by magnet and perhaps in the cotton wool. And, what if the bead was heavier than gold because it contained something heavier than gold? Platinum maybe. Wasn't a very golden bead on my screen. And Thank you. Great lessons here. Some insightful comments also.
It did look very pale yellow on my screen to but the process looked perfect, Platinum would be my guess also.
Great explanation of what you are doing. I would think that some of the rock has neutralized some of the reactions. So letting it cook on heat for more time, keeping it hydrated. Should help that. Very rich ore indeed!
I would probably try to run the fire assay on the aqua Regia sample to see if you can extract more gold from it.
Thank you, this an eye-opening ... I have a slight understanding now to a very complex question. Thank you
I would like to see the concentration result from running through a simple sluice or maybe a good panning then examining under magnification to see the texture coarseness.
With chemical extraction on ore I would roast the fine powder then pour the hot powder into a beaker of ice water which will cause the particulate to crack even finer to release more gold dust.
the ice bath shock sounds interesting. thanks
WOW 👌 !! VERY INTERESTING , THANKYOU .
FROM AUSTRALIA 🇦🇺
KIND REGARDS 🇦🇺 🇦🇺
Gold throughout much of Australia has little silver or other metals in it. especially in the South East but also WA. We alos have had most of the worlds largest specimens here as we never had any glacial movements here whereas other parts of the world did and glacial movements ground up the gold that was in ancient pre glacial river beds as the ice sheet moved over it. The number of nuggets over 450oz that were pulled up during the Victorian gold rush just boggles the mind.
Very interesting. You obviously enjoy doing this
6:47 This my friend is the difference.
I put a magnet in my pan I can see gold come up with the iron. Yes, it’s a real thing.( @BiggestKev1960 )
Try a fire assay (or other) on the iron that came off the difference.
If you do, call it part two. I want to revisit this story.
Much appreciation, Geraldton, Western Australia
Yes, I still have that magnetic material saved. I'll test it.
Looks fairly easy, I can’t wait to get home and work on it!
Enjoyed your video. If you can locate pockets you can achieve these results. Pete might have salted the pot for promotional purposes. His sales just went off the charts.
Perhaps. I don't know anything about Pete, but I'd enjoy your take.
Great suggestions from commenters. It sounds like the high iron concentration is the problem.
Dry off the leftovers from the chemical extraction and do a fire assay on it to prove the gold is still there and was not dissolved?
I sure would like you to do a fineness assay on the gold bead. The parting solution would tell us the presence of the platinum group. (classically trained assayer 35 years in SF)
I've never tried it. Any suggestions would be appreciated.
Very interesting results. Was this sample raw crushed ore or was it pre-concentrated? Either way, I’d like a slice of that pie. If smelting gives the best results than I would smelt the rest. There may be some other mineral in the ore which is interfering with the chemical recovery process.
The guy who sent the ore did not make any further comments. I have 500 grams left and I'm going to figure this out. Best to you, Lars.
@@orophiliamanganese can interfere with chemical processing
My best guess is that the ore is from Nullagine in the Pilbara, an area I'm keen on heading out to some day myself. I enjoyed your video and keen to see what's next.
I would let it sit in 15% HCL for a week, stirring Daily, sitting on a propagation mat to bring the heat up. Replace acid weekly until it runs clear, then do the AR on it. You have potentially not killed off all the nitric which may also be a problem. I haven't seen the use of dropping gold with Stannous before so that's something for me to look into, Cheers.!
I get more volume of medal when I dissolve it collaborating and then recipe it with potassium highdropsite side
It seems like you're dealing with a significant discrepancy between fire assay results and chemical assay results in the context of gold recovery, possibly due to differences in sample preparation processes.
Here's a more detailed look at the potential issue:
Roasting Before Fire Assay: If you roasted the sample before conducting the fire assay, the roasting process likely helped to break down complex compounds that might otherwise retain the gold, thereby making it more accessible for the assay process. Roasting can convert sulfides and other compounds into oxides, which are easier to deal with in the fire assay.
No Roasting Before Leaching: If you did not roast the sample before leaching, the gold might still be locked within these complex compounds, preventing it from being dissolved and recovered during the leaching process. This could lead to significantly lower gold recovery rates.
Possible Causes for Discrepancy:
- Presence of Sulfides or Other Refractory Materials: The presence of sulfides or other refractory materials in the ore can trap gold and prevent it from being leached effectively unless these materials are broken down by roasting.
- Complex Gold Compounds: Gold can form complexes with other elements that are stable under normal leaching conditions but break down upon roasting, releasing the gold.
- Inadequate Leaching Conditions: If the leaching conditions (e.g., pH, temperature, reagent concentrations) are not optimized, the gold might not be fully extracted, leading to lower assay values.
Recommendations:
1. Roast Samples Before Both Fire Assay and Leaching: To ensure consistency and more accurate comparisons, roast the samples before both the fire assay and the leaching process. This will help to break down any refractory compounds and release the gold.
2. Conduct Diagnostic Leaching Tests: Perform a series of diagnostic leaching tests to identify the specific reasons for the low recovery. This could include varying the roasting conditions, changing leaching reagents, or adjusting other parameters to see what maximizes gold recovery.
3. Characterize the Ore: Use techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), or energy-dispersive X-ray spectroscopy (EDS) to analyze the mineral composition of the ore. Understanding the specific minerals present can help in tailoring the roasting and leaching processes.
4. Optimize Leaching Parameters: Ensure that the leaching conditions are optimized for the specific type of ore you are dealing with. This might involve adjusting the concentration of the leaching agent, temperature, or other parameters.
By identifying and addressing the specific factors that are causing the gold loss during the leaching process, you can improve the overall recovery and reduce the discrepancy between fire assay and chemical assay results.
The behavior of gold in natural environments and its implications for assay and leaching processes. Here's a more detailed explanation and some additional considerations:
Natural Formation of Gold Complexes
In nature, the interaction of acidic gold-bearing fluids with alkaline solutions can lead to the formation of water-soluble gold complexes. The pH of the environment plays a crucial role in determining the solubility and stability of these complexes.
Acidic Conditions: Under acidic conditions (low pH), gold can form complexes with chloride ions (e.g., AuCl₄⁻) or other ligands that keep it in solution.
Alkaline Conditions: When these acidic solutions encounter alkaline conditions (high pH), the chemistry changes, potentially leading to the precipitation of gold complexes. For example, if the pH reaches around 8, certain gold complexes might precipitate out of solution.
Resistance to Aqua Regia
Some gold complexes that precipitate out under alkaline conditions can become resistant to dissolution by aqua regia. Aqua regia, a mixture of nitric acid and hydrochloric acid, is typically very effective at dissolving gold, but certain complexes might resist this treatment due to their chemical stability.
Practical Implications for Assay and Leaching
Preserve Leach Solutions: Do not discard your leach solutions prematurely. Since gold can form soluble complexes, especially in the presence of varying pH levels, it is essential to process these solutions thoroughly to recover as much gold as possible.
pH Control: Monitor and control the pH of your leaching solutions carefully. Ensure that the pH is optimized to prevent the formation of resistant gold complexes and to maximize gold dissolution.
Sequential Leaching: Consider using sequential leaching techniques to break down different gold complexes. This might involve using different leaching agents or adjusting the pH in stages to ensure complete recovery of gold.
Advanced Analytical Techniques: Use advanced analytical techniques to understand the nature of gold complexes in your solutions. Techniques such as mass spectrometry, X-ray absorption spectroscopy (XAS), or nuclear magnetic resonance (NMR) can provide insights into the speciation of gold in different environments.
Pre-treatment Methods: If you suspect that certain gold complexes are resistant to aqua regia, explore pre-treatment methods that might break down these complexes. This could involve oxidative roasting, pressure oxidation, or other methods to convert resistant complexes into forms that are more amenable to leaching.
By understanding the chemistry of gold in different pH environments and taking appropriate steps to manage the leaching process, you can improve gold recovery and reduce losses.
Tellurides, such as gold telluride (calaverite) and other gold-tellurium compounds, can be resistant to aqua regia. These compounds often require special treatment to break down the telluride matrix and release the gold for effective recovery. Here are some key points and strategies for dealing with gold tellurides:
Characteristics of Gold Tellurides
Resistance to Aqua Regia: Gold tellurides are known to be resistant to dissolution by aqua regia due to the strong bond between gold and tellurium.
Refractory Nature: These minerals are considered refractory because they do not easily yield gold through conventional leaching or cyanidation processes.
Strategies for Processing Gold Tellurides
Roasting: Roasting gold tellurides at high temperatures can oxidize the tellurium, converting it into a form that is more easily separated from the gold. This process typically involves heating the ore in the presence of oxygen to break down the telluride matrix.
Pressure Oxidation (Autoclaving): This method involves treating the ore under high pressure and temperature with oxygen or air, often in an autoclave. This can effectively oxidize the tellurides and liberate the gold for subsequent recovery by leaching.
Alkaline Leaching: Some tellurides may be amenable to alkaline leaching, using reagents such as sodium hydroxide (NaOH) to break down the telluride structure and release gold.
Bio-oxidation: Using certain bacteria that can oxidize sulfides and tellurides, bio-oxidation can be a viable method for treating refractory gold telluride ores.
Thiosulfate Leaching: An alternative to cyanide, thiosulfate leaching can be effective for some refractory ores, including those containing tellurides. This method uses ammonium thiosulfate as a leaching agent in the presence of a copper catalyst and an ammonia buffer.
Ultrafine Grinding: Reducing the particle size of the ore through ultrafine grinding can increase the surface area and make the tellurides more accessible to leaching reagents. This can be combined with other pre-treatment methods to enhance gold recovery.
Process Workflow Example
Crushing and Grinding: Reduce the ore to a fine particle size to expose the gold tellurides.
Roasting: Heat the ground ore to high temperatures in the presence of oxygen to oxidize the tellurium and other sulfides.
Leaching: Use a suitable leaching agent, such as cyanide or thiosulfate, to dissolve the gold.
Recovery: Recover the dissolved gold from the leach solution through methods such as activated carbon adsorption or electrowinning.
Tailings Treatment: Treat the tailings to ensure that any residual gold or harmful byproducts are managed appropriately.
Conclusion
Processing gold tellurides requires specialized techniques to overcome their refractory nature. By employing methods like roasting, pressure oxidation, or alternative leaching reagents, you can effectively break down the telluride matrix and recover the gold. It's essential to carefully select and optimize these methods based on the specific characteristics of the ore you are dealing with.
~ CHEERS
P.S. You should remove your free gold first, but not spend a lot of time doing that. This is because you will lose gold down the line; there is no perfect process. It is paramount to remove the gold in the very earliest stages, and thanks for taking time out of your day to educate the rest of us. 😎
Thanks, Jatslo! As usual, a very useful comment. At least one experiment will include roasting.
@@Jatslo Really interesting and insightful comments, thank you Jatsio. I try to boil acids in a distillation setup so I can recover acids that would otherwise vent to atmosphere. I have noticed an odd smell that is in these weaker distilled acids that are not present in fresh acids. Makes sense that this could be some sort of gas or plasma. If so, are their any techniques you might suggest that can fix these volatile aspects to increase my yield? Depending, I often add these to the next boil and they eventually end up being cemented out with Copper, then Iron metal, before I eventually recover my nitrates. Developing some sort of semi-closed-system seems prudent tome. Waste not, want not, and all of that.
@@waynoswaynos Discussing plasma states can be a bit extreme for typical metallurgical processes like fire assay. Let's focus on the practical aspects of managing and minimizing the loss of gold during high-temperature processes like fire assay, particularly in relation to the volatilization of lead and its impact on gold recovery.
Understanding Lead Volatilization in Fire Assay
In the fire assay process, lead is used as a collector for precious metals. However, lead can volatilize at high temperatures, and this volatilization can carry precious metals, including gold, away from the assay sample, leading to losses.
Key Points and Strategies to Minimize Losses
Proper Temperature Control:
Melting Point: Lead has a melting point of 327.5°C and starts to volatilize significantly at temperatures above 600°C. Fire assays typically operate at around 1000-1200°C, increasing the risk of lead volatilization.
Controlled Heating: Gradually increasing the temperature and maintaining it at the lower end of the required range can reduce the amount of lead volatilized.
Use of Appropriate Fluxes:
Flux Composition: Ensure that the flux composition is optimized to bind with impurities and reduce the need for excessively high temperatures.
Reducing Agents: Use of reducing agents like carbon or charcoal can help minimize the oxidation of lead, reducing its volatilization.
Efficient Furnace Design:
Gas Collection Systems: Incorporate systems to collect and condense volatile components, including lead vapors. This can capture both lead and any gold that might be carried with it.
Proper Ventilation: Ensure the furnace has adequate ventilation to safely manage gases without losing valuable materials.
Sample Handling:
Cupellation: In the cupellation stage, where lead is absorbed by the cupel and precious metals are left behind, ensure the process is done at the correct temperature and duration to minimize lead loss while effectively separating the gold.
Recycling Lead: Consider recycling the lead collected in gas scrubbing systems to recover any gold that might have been volatilized with it.
Analytical Verification:
Post-Assay Analysis: Analyze residues and slags post-assay to check for any remaining gold. This can be done using techniques like ICP-MS or AAS.
Reprocessing: If significant gold is found in the residues, reprocess these materials to recover the lost gold.
Example Procedure
Sample Preparation: Mix the sample with fluxes (e.g., litharge, soda ash, borax) and place it in a crucible.
Fusion: Heat the mixture in a furnace to around 1000-1200°C. Monitor the temperature closely to avoid excessive lead volatilization.
Collection: During the fusion, lead collects the precious metals, forming a lead button at the bottom of the crucible.
Cupellation: Transfer the lead button to a cupel and heat it in a cupellation furnace. Lead is absorbed by the cupel or vaporized, leaving behind a precious metal bead.
Residue Analysis: Analyze the remaining slag and cupel for any residual gold. Collect and treat any gases and residues to recover volatilized lead and gold.
Conclusion
Minimizing the loss of gold during fire assay requires careful control of temperature, efficient furnace design, appropriate flux usage, and thorough post-process analysis. By implementing these strategies, you can reduce the volatilization of lead and ensure maximum recovery of precious metals.
~ CHEERS
@@Jatslo Thank you, I have copied and pasted this thread to my metallurgy notes and formatted it. You have shared some things I had not considered. Appreciated.
More about the funnel seal ring. Is it tapered or just stretched to the funnel's cone. I prefer to ask a human and get a real answer, even a relatively simple one. Just never seen those, it is usually the glass frit or ceramic filters that are a quarter the size. Have reservations about the fritt actually being clean after use. Tossng a cotton ball away sounds simpler.
I bought the rubber seal rings as a set on Amazon. you get 6 or 7 different nesting sizes. They are very handy. I think the funnel with cotton is way better than the glass frit type for this work
a paint brush and dust pan do wonders. love ur expertise though😊
In your position, for the chemical extraction I would first roast the ore to keep only the oxides, treat with HCl to remove non precious metals, decant and proceed with AR (this to keep all the precious metals for an all encompassing assay), or treat the ore with Nitric for a gold content only assay before I touch the AR. All the other metals will drop the gold from solution so its imperative to remove those first, then your process can continue as it was done in the video.
BTW, great Flux recipe!
thanks for the excellent comment
Sreetips, Chief, I think you have a bit of competition here.
You need a ore splitter to obtain a statistically representative sample based on my years of chemical analysis of ore
have you tried the method that I used in the video?
Can you fire the tailings from the chemical assay
Nitric boil to remove all metal and leaves the gold then go into aqua reiga .
Could part of the gold ore be a telluride that during the fire assay process your gold is gping up the chimney as smoke or very fine particles?
Hi Walter. The fire assay process should capture all the gold but I'm not familiar with Telluride ore. I'll do some research.
When you added the 40+ mesh stuff you shook that container making the gold go to the bottom of that container and added that to you r small 100g piles making those possibly hotter then the other piles. That could have made the results different as well .
Yes, the process of spitting ore in an unbiased way can have problems.
very good and detailed
I’m new at this but I heard roasting helps, shouldn’t it help in this case as well
During your chemical extraction process, you run out of hydrochloric acid and nitric acid, it seems. Boil the sample in hydrochloric acid first, to destroy carbonates and sulfides, then add the nitric acid to form aqua regia. Hope it makes sense, when you think about it... ;)
Yeah, I've wondered about this too. The amount of time, heat and chemicals to use. Can we actually destroy sulfides with HCl alone?
It is looking like gold is often found where silver is and getting the 2 apart is the trick.
If the sample is from Kalgoorlie tellurides can inhibit aqua regia recovery. Will require pre roasting to 500 degrees C, or pre treatment with hypochlorite solution to break the Te-Au bond (Emperor Process).
Good info, thanks. It looks like this sample is mostly free mill.
Hello. What materials did you add to the soil during the melting process?
Flux ( Borax, Sodium Carbonate, Manganese Dioxide), Litharge (Lead Oxide), Flour (carbon) and an iron rod.
I dont think you stopped all the gold. Firstly you didn't keep adding smb until a white foam appeared on the surface and secondly I didn't see you do a stannous test to see if you dropped it all. My guess is some of the gold is still in solution
Good points! I went back and re-processed the liquid and found a very small amount of gold, about 4% of the original. So, yes, there was more gold but not nearly enough to account for the differences. More experiments to follow.
Excellent video , just subbed 👍
dissolve the fire assay to see what is making it heavier.. and try to recover what is still held in your chemical process residues to asses what secondary processes may be applied for recovery.
It's likely that you would have to do multiple digestions
So i am new to this whole thing and have no where near the prestige as commenter's or you, just a question would a H2so4 boil at the beginning help any? Before AR boil.
I am a novice also, with a little experience now. Yes, I think in some cases H2SO4 or HCl may help. I'll have a new video soon, with the continuation of this study.
Any updates ?@@orophilia
When you added urea to neutralize nitric the was really no reaction, maybe you just need it more nitric to get the other have, I don't know amazing videos!!
Yeah, I need to be more careful about the amount of HNO3
I would say pan a bit a and see what sizes gold there is and then you know the size you need to crush to..for your analysis. There's mineral liberation and then there's mineral exposure. From what I understand you should just need exposure for leaching.
But I agree probably rich enough to smelt..could just keep throwing your lead button back in.. to get more gold each smelt ..the lead may decrease in weight each smelt..
Does the cotton wool that has disintegrated in the aqua regia turn to guncotton/nitrocellulose?
I don't know but I doubt that there is enough HNO3 to make it.
What about a strong base opposed to an acid? I believe that dirt is quartz sodium hydroxide
can you recommend a method?
Is the red color iron or mercuric oxide?
Iron oxide
Very good!
Over $100,000 in gold per MT? Absolutely incredible! Can I get just one 10 yard dump truck of it? I would be rich!
yeah, incredible. I’d enjoy trying to extract it!
I suspect the silver was lost in the flux, chapman flux has a tendency to collect silver. One way to determine that would be to do another 100G smelt with an assay flux vs a smelting flux. You could also fire assay the flux again, or use an XRF on it after it's very finely ground. A local jewellery shop that has an XRF will might be a good option. AguaRegia will not pull silver into solution, or, if the silver/gold ratio is too low, the gold will not go into solution as it's locked up in the silver. Silver is much more of a problem metal than many realize.
silver should be trapped by the HNO3, no?
@@TerribleShmeltingAccident It would be soluble in nitric alone, but AR produces Ag Chloride which is insoluble.
Hi Auminer! I have been ignoring the value of silver because I think most gold miners consider it an annoyance. However, if the amount of silver is high and the fire assay does not show it, then we could be mislead into thinking that aqua regia (AR) will work when actually it won't because the silver will block the acid from dissolving the electrum (gold + silver alloy).
However, I've done many fire assays with this flux on various ores that contain gold and silver and the silver always shows up in the assay results, sometimes in large quantities, so I don't think we have this problem. Note that the MnO2 content of my flux recipe is low. So, assuming that we don't loose much silver in the fire assay, then this ore contains almost pure gold, which should be easily dissolved in AR.
So, I don't yet have a good explanation for the loss of gold in the chemical extraction.
I'm learning to be more careful and I'll run more material to see if I can figure it out.
As always, I deeply appreciate your comments.
@@orophilia all excellent points. I'd be curious to see what the ore looks like under your microscope, both before and after leaching, also what your shaker table would recover in relation to the size of this gold. There are some good comments posted here, and I think the high iron content might be an issue consuming the acids. Looking forward to solving this mystery on this very rich ore :)
@@AUMINER1 That's a good idea. Will do.
I find that triangular chemists' flask with the tube attached very dangerous. Just too damn ready to accidentally pull it over, could even happen be cause of the weight of the tube itself! One should at least attach the flexible tube to the table so that any accidental pull at the end where you'd handle it would not cause any effect. You wouldn't want to lose that gold by having it spill into the soil or flooring underneath your table, especially when it is not yours...
That is a lot. Try adding more distilled water, as medium for the gold to dissolve into.
Use uniodized salt to get the silver then sodium medabisulfate to get the gold and ammonium chloride to see if there is platinum
Bisakah saya ikut dengan Anda di Australia, saya ingin belajar lebih lanjut terkait pengolahan logam mulia
You will see the gold you have concentrated?
yes, eventually
I think you need to make the particulars 100 mesh or even smaller
Yeah, that's got to be one of the experiments.
Are you wearing a mask or air supply?
I always wear a respirator. Thanks!
I didn't see you part the Au/Ag from the fire assay, even though you used Chapman's with MgO2. Fire assay is always more accurate than chemical, unless you Cyanide bottle roll it.
The gold is almost pure, by density measurement. Yes, I will have to work on parting the gold and silver.
What filter medium are you using?
I use regular lab filters and I use cotton for very fine filtration of colloidal gold.
Thank you for you sir
roast before chemicals?
Yeah, that will be one of the tests.
the gold is more then can be held in salutation chemical extraction.
Best way for extraction of the gold is smelting and chemical extraction , for 100% removal of gold from the ore.
extraction of the gold is smelting should get 100% of the gold.
nice hand writing
Could it be as simple as you not dividing the 60+ mesh equally? As in the amount of stratification you’re doing during the handling of the material in the large container?
Just a thought 🤷♂️
Thanks, Aaron. I don't think I'll ever know what I did wrong.
If you're going to do gold extracting with acids you need to be cleaner about it all and always rinse your glassware super easy to cross-contaminate..
18:19 no, it's out of 250g of ore, not 100g.
The fire assay was with 100 grams of ore and the chemical extraction was with 350 grams of ore. Thanks for the comment.
Cool stuff.
Well when you consider that most goldmines in WA are only pulling 12 to 15 weights per tonne of ore I would suspect that sample has been heavily salted.
seems fishy being that you found refined gold in ore.....must have been seeded?
as far as whats wrong with the chemical vs fire assay? speed.leaching au from ore needs time. time in aqua regia, time slowly adding reducing agent (whether smb or stannous,) time letting it drop. Im certainly no expert but ive seen countless times where what i assumed to be waste solution (after dropping au,) would have a brown precipitate dropping for many days after I thought was done!
Yeah, that's good info. I'm going to check that carefully.
@@orophilia i should have said "MAY have been seeded" instead of "must have been,"
as i dont want to accuse anyone of anything being i dont have all the facts.
@@TerribleShmeltingAccidentWA is some of the purest in the world - also some of the oldest. Normally 98-100% pure.
It’s hard to measure volumes at that size accurately.
@@MerchantMarineGuy everything about this sample was unusual....if its too good to be true.
Are you familiar with the mining scam that took Charles Tiffany (founder of tiffanys?)
@@TerribleShmeltingAccident small sample, big errors. It’s only 1kg. What you want to do is crush a bulk sample of ~1t and then process the cons.
All my chores nd plans put on hold - Latest tape from Orophilia has arrived.
Bloody hell Mo! Is there anyway to escape you? 😂
@@Aaron_Hanson All the best people go to all the best channels
With such a high yield of gold per metric ton, it's possible that the sample contains minerals with significant gold content, including tellurides such as calaverite (AuTe₂), krennerite (Au₈Te₆), sylvanite ((Au,Ag)Te₂), and other gold-bearing minerals. Tellurides are a group of minerals where gold is combined with tellurium. These minerals can contain significant amounts of gold, sometimes in very high concentrations. For example, Calaverite: AuTe₂, typically contains about 44% gold.
Testing for tellurium in ore samples can be done using various analytical techniques. Sylvanite ((Au,Ag)Te₂) can be ruled out due to the absence of silver, if that is a true conclusion.
Thanks, Jatslo.
Maybe there is sulfides in the ore. Roast the ore first then use the chemicals.
Please see the next video. No need to roast the ore. Thanks for the comment!
some of the dirt rock might have been a nugget.
Yes.
Good sir
Suspicious that you don't have silver etc. Perhaps someone has seeded the ore.
Yes
@@orophilia Bre-X is the classic case. When I hear reports of China discovering a mine that is loaded, the alarm bells go off for the same reason.
That is a very strange sample . And i mean off the charts strange. Highly suspect unless thats concentrates from your friend.
Yeah, I don't know anything about it, unfortunately. It was a big surprise and a learning experience.
@orophilia looked like a wild chemistry ride , trying to figure out what was going on under the hood per say.
Upwind does not guarantee anything. You make a low pressure zone on the downwind side (the Lee) of your body. Right kinda breeze and distance, you'll get a face full of it.
Like campfire smoke, it reaches out for ya. You're alright enough with what you are doing, but if it was something insanely poisonous, ya better not. You'll be haunting people afterwards, not ideal.
you are right. it’s always better to wear good protection than to take a chance with these nasty vapors.
I think from watching your process that maybe you didnt drop all the gold that was in solution. And maybe because you still had nitric in the solution . When i have done drops in the past and granted not many i had a lot of problems getting rid of the nitric. From the amount of urea i watched you use it would be very hard to believe the nitric was neutralized. I had to use a lot more than that while at the same time boil the solution and it took a long time . But you probably know a lot more then i do. Good luck .
I think you might be right. Really, the only place all that gold could have disappeared to was into the waste solution after dropping the gold with SnCl2. Take a look at the next video. I use sulfamic acid to kill the nitric and then SMB to drop the gold with perfect results.
👍
no stanus test
Yes, I need to be rigorous about testing.
I don’t know why you filter the sponge gold after smb. Streetips. Always just lets it settle completely and I see almost clear on top and a brown powder stuff the gold at the bottom to which. He just pours the clear off. I think you filtering it. When it’s not clear. On top. Ur letting half the gold get lost. My opinion. I watch streetips all the time.
I'm not sure what you're referring to exactly, but yes, my technique didn't work well, for sure. See the next video.
200 mesh for chemical analysis. You definitely will need a pulverizer.
Good comment. Yes, I think so.
Suspiciously rich in gold and NO silver
Yes
Cool. Im not gonna act like i understand any of apart from it was good pay dirt.
NOVA SCOTIA GOLD IS 97 PERCENT GOLD
Use tare.
You have a scale and a tub there you could have had a MUCH more accurate step of samples by weighing it by subtraction rather than guess work, I find that rather blasie!
Hi David. I don't follow, sorry. Can you explain?
#Sreetips
yep
It's because your chemical process was inferior it should have came out as a white powder at the end you use the wrong chemicals
I'd love some advice. What should I have done?
Average the two together.
Sorry but you need to do something about your audio I would watch it but your when you talked with anything with the letter s in it it's like stabbing a ice pick in my ear your audio is horrible
Yeah, I've tried three different cheap mics. Time for a good one. Thanks for the comment.