Gold resources are gradually depleting year by year, and easily extractable gold mines are becoming increasingly scarce. Although arsenic-bearing gold ore are difficult to process, they have huge reserves and high recovery value, and have become important resources for industrial applications. For gold mines with high arsenic content, the ultimate goal is to remove arsenic from the gold mine, as the presence of arsenic not only affects the grade of the gold mine, but also poses challenges for subsequent metallurgy. So, how to deal with arsenic containing gold mines? Here are four processing methods for arsenic-bearing gold ore.
Flotation is an effective method for Arsenic-bearing gold ore. Especially suitable for minerals that do not use arsenic sulfides as carriers. In this process, the selection of agents is crucial, including collectors and inhibitors. Collectors such as thiol anions, thioesters, and amino acids can effectively capture gold containing sulfides; And inhibitors are used to inhibit the flotation of arsenic minerals, such as lime, sodium sulfide, and copper sulfate.
Optimization of flotation process: In the flotation process, adjust the type and amount of reagents to separate gold bearing minerals and arsenic bearing minerals. For example, using a combination of butyl xanthate and SK as a collector can prioritize the flotation of arsenic minerals, thereby improving the recovery rate of gold. In addition, for arsenic antimony containing gold ores, the application of mixed mercury flotation process can achieve comprehensive recovery of gold and antimony.
Oxidation roasting cyanide leaching method is a method of exposing gold by oxidizing and decomposing arsenic sulfides in arsenic-bearing gold ores through high-temperature roasting. This method can effectively improve the cyanide leaching rate of gold and is one of the commonly used techniques for treating arsenic-bearing gold ores.
Classification of roasting techniques: Roasting techniques can be divided into traditional roasting, arsenic fixation roasting, and two-stage roasting. Although traditional roasting can improve the leaching rate of gold, it can produce toxic gases and have an impact on the environment. Solid arsenic roasting, by adding Ca (OH) 2 as a solid arsenic additive, not only improves the leaching rate of gold but also reduces environmental pollution. Two stage roasting is carried out at different temperatures to convert As2O3 into white arsenic, achieving environmental friendliness and comprehensive utilization of resources.
Bacterial oxidation cyanide leaching is a bio metallurgical technology that utilizes bacteria to oxidize sulfides. Through the action of bacteria, mineral desulfurization and arsenic removal are carried out, and the crystal structure is destroyed, thereby exposing fine gold particles and creating conditions for cyanide leaching of gold.
The advantages of bacterial oxidation: Bacterial oxidation pretreatment technology has the advantages of low cost and environmental friendliness. The commonly used bacterial strains include Thiobacillus ferrooxidans, Thiobacillus thiooxidans, etc. They effectively promote the oxidation process of sulfides through direct, indirect, or composite mechanisms.
Non cyanide leaching method is a new gold ore processing technology developed in recent years, mainly including thiosulfate and thiocyanate leaching methods. This method avoids the use of cyanide and reduces environmental risks.
Application of non cyanide leaching: Thiosulfate treatment of gold can effectively dissolve arsenic containing minerals, while thiocyanate treatment of gold uses salt solution oxygen pressure to directly leach arsenic containing gold ore. These methods provide new options for the treatment of high arsenic gold ores.
There are various processing techniques for arsenic-bearing gold ores, and selecting the appropriate method depends on the specific properties of the ore. Whether it is flotation method, oxidation roasting cyanide leaching method, bacterial oxidation cyanide leaching method or non cyanide leaching method, each method has its unique advantages and application scenarios. Xinhai company has rich experience in processing high arsenic gold mines. Researchers have designed processing techniques suitable for specific ore properties through mineral processing experiments and analysis, in order to achieve efficient recovery and sustainable environmental development.
