Beneficiation Method of Antimony Gold Mine
Antimony gold mine is an important part of gold resources. Its distinctive feature is that gold is encapsulated in fine particles or impregnated in sulfide, which is a kind of refractory gold ore. The common antimony gold ore beneficiation methods mainly include flotation, pretreatment, and enhanced leaching.
1. Antimony gold ore flotation method
The antimony gold ore flotation method is mostly used to process ores whose antimony minerals are not the carrier minerals of gold. Its essence is the flotation separation of antimony minerals and gold-bearing minerals such as sulfur and arsenic. It can avoid complicated pretreatment links, and at the same time obtain by-product antimony concentrate, and the cost is relatively low.
A. Mixed flotation
The mixed flotation process is relatively simple. However, it is difficult to suppress the floating gold-bearing minerals such as sulfur and arsenic, causing some minerals such as sulfur and arsenic to be mixed into the antimony concentrate, which affects the quality of the antimony concentrate.
B. Priority flotation
The preferential flotation method can be divided into two processes: preferential flotation of gold-loaded minerals such as arsenic and sulfur, and preferential flotation of antimony. Most antimony gold ore flotation plants often use the preferential antimony flotation process. The key to this process is the efficient collection of antimony minerals and the effective suppression of arsenic-sulfur and other gold-bearing minerals. Because the preferential flotation process of arsenic and sulfur will cause some antimony minerals with better floatability to float together, resulting in greater loss of antimony in the gold concentrate.
2. Antimony gold ore pretreatment method
When the grade of antimony in the raw ore is low and does not have recovery value, in order to improve the cyanide leaching environment of antimony-containing gold ores, physical or chemical pretreatment can be used before leaching to achieve high-efficiency leaching of gold. Common pretreatment methods of antimony gold ore mainly include the roasting method and chemical alkaline leaching method.
A. Roasting method
The roasting method is a common method for oxidative pretreatment of antimony-containing gold ore. Roasting changes the physical structure of the ore and produces loose and porous calcine. At the same time, in an oxidizing high-temperature atmosphere, the antimonite is turned into an antimony-containing oxide, thereby eliminating the adverse effects of the package and the antimonite.
The roasting method of antimony-containing gold ore has a high leaching rate and mature technology. However, the co-occurring minerals such as arsenic and sulfur will cause environmental pollution problems, which need to be reprocessed and consume a lot of energy and electricity.
B. Chemical alkaline leaching
The chemical alkaline leaching method is mostly used to treat gold antimony ore with antimonite as the main gold-bearing mineral. The method utilizes the characteristics of antimony minerals that are well soluble in alkali or sodium sulfide, and the products are removed in advance by washing with water to avoid the occurrence of cyanide-consuming and oxygen-consuming reactions during subsequent cyanidation leaching.
Compared with the roasting method, the cyanide leaching rate of the chemical alkaline leaching method will be reduced. But its response is fast, the cycle is short, the pollution is less, and the cost is lower.
3. Enhanced leaching of antimony gold ore
The enhanced leaching method of antimony gold ore is mainly used in the cyanide leaching stage of antimony gold ore. On the one hand, the addition of lead acetate, lead nitrate and other leaching aids can inhibit the occurrence of the cyanide and oxygen consumption reaction of antimonite in the cyanide leaching system, so as to avoid the secondary coverage of the gold particles by the reaction products. On the other hand, by adding potassium permanganate and other oxidants to accelerate the oxidation of antimonite to generate antimonate, destroy the outer coating layer of gold, and at the same time increase the activity of gold cyanide leaching reaction and speed up the leaching rate.
The enhanced leaching method does not require pretreatment of the raw ore. At the same time, it can speed up the leaching rate and improve the leaching efficiency, but it is not suitable for antimony gold mines with serious gangue wrapping.