Gold Leaching Agent Compared to Cyanide in Gold Processing

Gold leaching agent gets widely applied in gold processing plants in recent years. But why did the gold processing plants choose gold leaching agent instead of sodium cyanide in the end? You will find the answer in this article.

What is Gold Cyanidation Process?

Cyanidation is an economical and simple method of extracting gold from raw ore, concentrate or tailings and even extract gold from industrial waste. A hydrometallurgical process in which cyanide selectively dissolves gold from a gold-containing material in an alkaline slurry or solution in the presence of an oxidant to separate gold from other metal minerals and gangue.

Cyanide leaching is a process in which solid natural gold in ore or beneficiation product forms a gold-cyanide complex dissolved in water under the combined action of a leaching agent, an oxidizing agent and a base, that is, a phase transformation process of solid phase gold. Chemical reaction formula for gold leaching: 4Au+8KCN+2H2O→4KAu(CN)2+4KOH.

In short, the cyanidation process is to dissolve the gold in the ore through cyanide, then adsorb it through activated carbon, use electrowinning, become gold mud, and finally get the gold bar.

Why not Cyanide Sodium?

One of the biggest problem of gold cyanidation process is it will cause strict environment pollution. The state has a variety of environmental protection policies, and has strict requirements for the treatment of wastewater, leaching of gold waste, and waste slag. The use of cyanide will cause lots of problem. And some countries have banned on using cyanide to extract gold. So is there anything else that can extract gold instead of cyanide? In fact, there are many chemicals that can replace cyanide. The most widely used is the new environmentally friendly gold leaching reagent. Some gold mining plants have been applied, and the effect is good.

What is Eco-friendly Gold Leaching Agent?

CNLITE eco-friendly gold leaching reagent is a kind of leaching reagent that can replace sodium cyanide without changing the original equipment and cyanide process. It can be used directly for gold ore beneficiation and refining. Compared with the traditional gold leaching reagent, it can truly achieve targets of green and environmental protection with no severe accidents. And for different kind of gold ore, we also provide different kind of samples for gold leaching test in lab.

Many customers who are interested in CNLITE eco-friendly gold leaching reagent are confused of the question, that is how effective the CNLITE eco-friendly gold leaching reagent is compared to cyanide in gold mining plant? As we all know, cyanide is used as the most effective and economy leaching reagent in gold mining plant for many years. However, for its high toxicity, we have produced a new kind of gold leaching reagent called CNLITE eco-friendly gold leaching reagent to replace cyanide’s function on leaching gold. And the CNLITE eco-friendly gold leaching reagent also has higher leaching efficiency and more efficient leaching rate compared to cyanide in gold mining plant. The biggest advantages of CNLITE gold leaching reagent is its low toxicity compared to cyanide, which is good for environment and human.

What's the Differences Between Cyanide and Eco-friendly Gold Leaching Agent?

In order to investigate the difference of NaCN leaching reagent and CNLITE gold leaching reagent in the leaching effect on gold ore, we choose six kind of gold ore samples which are oxidized gold ore in Sultan Kush, oxidized gold ore in Tanzania (Busolwa Mining Ltd), oxidized ore and mixed ore of gold mine (ie containing both oxidized ore and primary ore) in Tanzania (MMG GOLD LIMITED), oxidized gold ore gravity separation tailings in Tanzania(T5) for leaching comparison test.

With same other cyanide leaching conditions, the research focused on the difference of the leaching agent dosage, leaching rate, gold adsorption rate when using NaCN or CNLITE as the leaching reagent, and also carried out the economic benefit analysis of the comparable projects as the followings.

According to the test result, the leaching rate, final dosage, carbon adsorption rate and the leaching cost is similar between the cyanide and CNLITE gold leaching reagent. For leaching different kind of gold ore, the leaching effect of the cyanide and CNLITE gold leaching reagen is also different.

Conclusion

Nowadays, more than 80% gold mines in the world use gold cyanidation process, while 85% of them use sodium cyanide to extract gold. However, cyanide is a highly poisonous and dangerous chemical, and many accidents in transportation, storage and usage will result in serious consequences. Therefore, many countries and states have explicitly banned or restricted the use of sodium cyanide in gold extraction and the global gold extraction industry urgently needs an environmental gold leaching agent that can completely replace cyanide. So using CNLITE gold leaching agent to replace cyanide is a good choice.