Q. I am an analytical chemist for a recycler. I am new to this area and have a question regarding a selective precipitation of gold from an anolyte solution of 10 by volume aqua regia. The solution also contains PGM. The gold is used to inquart the sample so the PGM materials are soluble. I would like to be able to recover and reuse the gold without contamination from the other materials. Can anyone offer any insight to how to accomplish this gold selective recovery Thanks so much in advance.Get A Quote
Q. I am an analytical chemist for a recycler. I am new to this area and have a question regarding a selective precipitation of gold from an anolyte solution of 10 by volume aqua regia. The solution also contains PGM. The gold is used to inquart the sample so the PGM materials are soluble. I would like to be able to recover and reuse the gold without contamination from the other materials. Can anyone offer any insight to how to accomplish this gold selective recovery Thanks so much in advance.
A. Ferrous Sulfate is commonly used to precipitate gold without precipitating more than traces of the platinum group metals. However this can only be done by first removing any free nitric acid still present in the aqua regia solution. This is usually done by first doing a triple evaporation process on the aqua regia solution. Details of all this can be obtained on the goldrefiningforum.com website.
Q. Thanks Chris. But I thought that using ferrous sulfate will also precipitate out any Pd along with the Au. I was hoping for a straight up gold selective precipitating agent. Can you or anybody else please clarify I may be mistaken on the Pd precipitation. Again many thanks to all for any assistance.
A. You try oxalic acid. If you are trying to know the purity of gold sample you prefer fire assay system. Pd will precipitate by ferrous not ferrous sulphate. Using ferrous reduction takes place. OK consider that FeSO4 contaminate your gold. I suggest that you wash the ppt by hot water to remove acid in it. check by pH paper. Then you add nitric acid to dissolve your ferrous and Pd in it. I hope you will understand the process.
Q. Hi over the past few years I have been recovering gold and silver from ores that contain these metals using aqua regia. I am familiar with CW Amens book as well as CM Hoke. I now have ore concentrates that have gold silver and platinum group metals in it and cant find any detailed information on the correct and complete procedure for precipation of all metals when using Aqua Regia. Any help would be appreciated.
The second thing that I want to know is Can I elecroplate the gold out of AR Or maybe electroplate the gold out of the gold ore by itselfThank you
Q. Hi have a question been plating and recycling for a few years now. But got a small question can zinc powder drop gold from AR after neutralizing nitric and hydrochloric acid Thanks.
A. Yes Zinc dust cementation for gold and silver recovery is one of the best known contact reducing processes in mineral processing. It is also known as Merrill-Crowe process from its founders C.W Merrill of United States of America who started it and T.B Crowe from South Africa who added some important developments Miller 1981.httpswww.911metallurgist.comblogwp-contentuploads201508Merrill-Crowe-Flowsheet-ZINC-PRECIPITATION-ON-GOLD-RECOVERY.pdf
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The addition of gold or silver to an alkaline sodium cyanide solution will cause the gold and silver to react with the cyanide and dissolve into the solution in a process called cyanidation. This process is more frequently referred to as leaching. As well as reacting with the precious metals the cyanide will react with iron copper or zinc that may be in the ore. In order to leach the precious metals efficiently the following leaching conditions must exist
The addition of gold or silver to an alkaline sodium cyanide solution will cause the gold and silver to react with the cyanide and dissolve into the solution in a process called cyanidation. This process is more frequently referred to as leaching. As well as reacting with the precious metals the cyanide will react with iron copper or zinc that may be in the ore. In order to leach the .
Observe any changes to the gold piece. Gold is a stable metal and does not react with oxygen corroding. Because it is stable it will not change colors when exposed to vinegar. If the gold piece changes colors it is not real gold. Gold plate will turn black when exposed to vinegar.
The gold will again take on the appearance of metal. If youve followed the procedure carefully and used filters the gold should be 99.95 pure with negligible losses. Platinum. If you had platinum in your gold it will not dissolve to any appreciable degree in the room temperature aqua regia.
Refining gold from ore or concentrates is done during the smelting process. During this process flux is used to dissolve contaminates such as metal oxides from the gold. The flux is added to a crucible with the gold that is then melted in a furnace. You can make flux for gold refining by first obtaining all of the ingredients and then mixing them together in the proper portions.
We performed experimental tests in order to assess the feasibility of bromine produced in-situ in the leaching reactor to dissolve gold using ore samples from the unexploited Portuguese mine of Castromil. The reagents used in the production of bromine NaBr NaOCl and HCl can be more safely stored than bromine.
Mix the ingredients together in a plastic container. Place the lid on the plastic container and make sure it is completely sealed.
Store the flux in a dry area to prevent moisture penetration.
RECOVERY OF SILVER GOLD AND LEAD FROM A COMPLEX SULFIDE ORE USING FERRIC CHLORIDE THIOUREA AND BRINE LEACH SOLUTIONS By R. G. Sandberg 1 and J. L. Huiatt 2 ABSTRACT The Bureau of Mines investigated a hydrometallurgical procedure to re173 cover gold silver and byproduct lead from a complex lead-zinc sulfide ore.
Q. Hi there I have heard that a mixture of hydrochloric acid and nitric acid can dissolve gold but I am not sure of the percentages. I am a metallurgist with ten years of experience in gold processing from broken ore so feel free to ask me questions if you need help. Thank-you
May 14 2013nbsp018332Gold precious forever but especially lately is a tricky metal. Bound up in consumer electronics jewelry and the ores that it comes from gold is
A. Hi Grant Mix one part by volume concentrated nitric acid to three parts concentrated hydrochloric acid. A good fume hood andface shield affil. link to product info on Amazon are essential. Regards
A. Hi Grant What dissolves gold Aqua Regia isnt it Id ask any assayer i.e. one working in a gold mine and am sure youd get the right percentages.
How To Dissolve Gold From Ore By Acid - archedyl In most gold ores the final process to extract the tiniest gold particles is the use of cyanide to dissolve the gold. Cyanide in the presence of oxygen actually dissolves both gold and silver. It is both efficient and inexpensive so it is widely used in precious metal ore processing.
The gold particle size has a tremendous effect on the time required for dissolution in a cyanide solution. Generally the finer the gold the quicker it will dissolve. A 45 micron particle of gold would dissolve in 10-13 hours while a 150 micron particle might take from 20 to 44 hours to dissolve in the same solution.
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