Different gold selection processes are suitable for different types of gold mines

Different gold selection processes are suitable for different types of gold mines

So far, China has discovered 98 types of gold minerals, gold bearing minerals, and gold bearing minerals, of which 47 are relatively common. Only 10 types can be directly used in industrial production, and 38 types of gold minerals have extremely low gold content. Therefore, it is necessary to obtain gold from them through beneficiation. Gold beneficiation processes include chemical separation, flotation, magnetic separation, gravity separation, and other different gold beneficiation processes. Moreover, gravity separation and flotation are commonly used methods in gold beneficiation processes, and most gold mines in China use these two methods. Smelting is a process in gold production. Most mines use traditional crucible smelting and converter smelting of gold mud. Non ferrous smelters generally use pyrometallurgical smelting. In actual production, corresponding smelting and gold selection processes should be selected based on the properties of mineral raw materials, the content and storage status of harmful components such as zinc, arsenic, fluorine, and magnesium.

Flotation method for gold separation

80% of China's mineral processing plants choose flotation for gold separation, which is suitable for processing coarse and medium grained natural gold iron ore. The equipment used includes jaw crusher, cone crusher, vibrating screen, ball mill, flotation machine, etc. The crushed gold ore enters the ball mill for grinding and becomes slurry, which then enters the flotation machine for flotation. During the flotation process, sodium carbonate is used as a regulator, while butyl xanthate and amine black are used as collectors. Flotation cannot produce finished gold, and at most, gold can only be enriched into various sulfide concentrates. Therefore, a single flotation process is generally not used, but rather flotation is considered as one of the combined processes.

Reselection method for gold selection

Gravity separation is the most effective and economical method for selecting placer gold, suitable for both placer gold and finely crushed gold. The mineral processing principle is to select according to the difference of mineral density. The main equipment includes chutes, shakers, jigs, and short cone cyclones. Place the gold ore sand into a cylindrical sieve and flow it through high-pressure water. Gravel larger than the sieve hole is transported to the tailings through sliding slag and belt; The ore sand smaller than the sieve size is transported to a jig through public equipment, and then processed by a three-stage jig. The concentrate flows into a shaker for coarse and fine scanning, ultimately producing fine sand ore.

Mixed mercury method for extracting gold

The mixed mercury gold extraction process belongs to the chemical separation method and is an ancient gold extraction process. It is suitable for recovering crude monomer gold with coarse particle size embedded in natural gold and stored in pyrite and other sulfide ores. The beneficiation cost is low, the process flow is simple, but it poses significant environmental hazards. The initial steps of the mixed mercury method, like flotation, are crushing and grinding. Sodium carbonate and caustic soda should be added during grinding to effectively improve the recovery rate of mercury. Afterwards, mercury plates were added to recover gold, with a recovery rate of up to 70%.

Carbon slurry method for gold extraction

In the 1980s, carbon slurry gold extraction process was popular, especially suitable for selecting oxidized ore containing gold Limonite. The carbon slurry method uses activated carbon adsorption on the basis of oxidation leaching, which can improve the leaching rate of gold. The process flow is to crush and grind the ore, overflow the product from the current puller, and then enter the thickener, and then enter the leaching adsorption tank through the buffer tank for leaching operation. At the same time, activated carbon made from coconut shells is adsorbed to obtain the final product, gold charcoal. High frequency complete screening is used to recover gold from crushed activated carbon tailings, and then liquid chlorine is used to treat cyanide containing tailings.

Cyanide extraction of gold

The cyanide gold extraction process includes cyanide leaching, washing and filtration of leached ore slurry, extraction of gold from cyanide solution or cyanide ore slurry, and smelting of finished products.

Heap leaching gold extraction method

Heap leaching is the best method for treating low-grade gold bearing ores, with low cost, simple operation, and simple equipment.

Heap leaching is suitable for large and low-grade gold ores. The technological process is to stack on the underlying materials and spray Sodium cyanide solution circularly to dissolve gold and silver in ores.

The above six gold beneficiation processes are applicable to different types of gold mines. Generally, the gold beneficiation process involves crushing with a crusher, grinding with a ball mill, and then selecting a beneficiation process. In fact, when selecting gold, beneficiation plants usually use a combination of at least two beneficiation techniques to select minerals, as the composition of gold minerals is complex and only after multiple processes can the required concentrate grade be achieved. For detailed process plan customization, please contact Jinqiang Technical Manager.

Different gold selection processes are suitable for different types of gold mines