Hydrometallurgy: Leaching in Heap, Vat, CIL, CIP, Merrill–Crowe, SX Solvent Extraction

Hydrometallurgy: Leaching in Heap, Vat, CIL, CIP, Merrill–Crowe, SX Solvent Extraction 2017-04-04T06:57:36+00:00
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Replacement for Cyanide (6 replies)

Maya Rothman
2 years ago
Maya Rothman 2 years ago

Is there any replacement for cyanide during gold extraction? If yes,then how safe is that chemical? Can it have higher extraction than cyanide? If yes, then can someone share any testwork or research that has been conducted so far.

Can you please share with us some test works that have been done using other chemicals to replace NaCN? I will appreciate if you include some research on that chemical.

Alan Carter
2 years ago
Alan Carter 2 years ago

Try a literature search for thiosulphate, thiourea, thicyanate, chloride, bromide processes for gold. At worst, read the relevant chapter from Gold Ore Processing edited by Adams, your library should have a copy.

Bill Fraser
2 years ago
Bill Fraser 2 years ago

If the gold is liberated or this is an oxide ore then direct leaching of the gold is likely possible. Yes there are many options other then cyanide. Some of these options are safer then cyanide, some are not (Note: Cyanide is reusable and under proper mining conditions can be fairly safe). Are you going to get higher extraction, probably not without further liberation of gold but similar extractions can be expected. All the work we do at Hazen Research is confidential so I can not share specific research programs, however I can say that the use of thiosulfate and chloride have both been successful in extracting gold.

I would personally suggest reading this book https://books.google.com/books/about/The_Chemistry_of_Gold_Extraction.html?id=OuoV-o_Xf-EC 

Victor Bergman
2 years ago
Victor Bergman 2 years ago

Following on the note that chloride has also been successful in extracting gold, one of the compounds at EarthGold is C3H3N3O3 - cyanuric acid = 1,3,5-triazine-2,4,6-triol (which is also used in swimming pools as a chlorine stabilizer)


EarthGold offers a number of operational advantages when compared to a cyanide reagent:

  • Environmentally-friendly product
  • Safer product
  • Lower costs for waste water treatment
  • Transportation costs are lower
  • Storage costs are lower
  • Cost of operation is lower
  • Similar extraction rate as cyanide

In summary EarthGold is an environmentally-friendly solution for the leaching of gold ores and using EarthGold offers a viable alternative that when considered as an overall cost in the processing of gold ores offers a very attractive option to sodium cyanide.

Also there is a new product that can substitute Cyanide in gold leaching. its called Gold Dressing Agent. Visit at http://lutcol.co.tz/company_profile/ for details but the following are attributes for this reagent

High recovery rate: It can effectively leach the gold ionized atom, increase the recovery rate and it is suitable for large scale -oriented production.

Good stability: With addition of effective additives, reduce the disturbance caused by other present elements such as high arsenic, high sulfur and lead, copper, zinc, iron, antimony and others which the traditional sodium cyanide process technology of gold extraction is very difficult to extract the gold from ore with those elements.

Faster recovery: Heap leaching method saves 50% of time than traditional time. Tank leaching method saves 28.6% of time than traditional time. Carbon leaching method, leaching time could be as low as 6 hours.

Less consumption: This product saves 60% dosage than competitive products.

Higher recycling rate: The highest leaching rate of raw ore with residue GDA is 99.6%, Cyanide residue will be able to leach another 30-78%.

Lower cost: It helps the enterprise to save the costs of transportation, safekeeping, safety reduction, rehabilitation of the environment, poison destruction (detoxification) and production (less time is used in production).

Low-toxicity and environment-friendly: It is easy to use, green, human and animal harmless. As an ordinary chemical product, it can greatly appease the contamination and hazard of poisoning caused by production upset.

Convenient to use: It is convenient to use, as it is used in the same manner as ordinary sodium cyanide.

It is convenient to transport: Highway, railway, aviation and ocean transportation are possible and available.

Bob Mathias
2 years ago
Bob Mathias 2 years ago

I used a new reagent the rate recovery was good Au 89%. The same raw ore with the traditional NaCN was Au 88°% ( CN-500 ppm) those in bottle test 72hrs.

I will like more information the new reagent.

Victor Bergman
2 years ago
Victor Bergman 2 years ago

May you please share with us some information regarding your bottle test, information like dissolved oxygen,pH and other stuffs? This will help us to know if the new reagent might change your recovery or not.

2 years ago
David 2 years ago

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