At present, 98 kinds of gold minerals and gold-bearing minerals have been found, only 47 kinds are common, and only more than 10 kinds of minerals are directly used by industry. There are nearly 38 kinds of gold-bearing substances in China, and the gold content of gold mines is generally relatively small.

Gravity separation and flotation are commonly used in gold ore processing methods, most of the gold mines in China are using the above methods to extract gold, and there have been great improvements in mineral processing technology and equipment.

According to the structural state and gold content of gold in minerals, gold deposit minerals can be divided into three categories: gold minerals, gold bearing minerals and gold carrying minerals. The so-called independent mineral of gold refers to the gold produced in the form of gold minerals and gold-bearing minerals, which is the most important form of gold occurrence in nature and the main object of industrial development and utilization.

At present, the mainstream gold selection process is generally broken through the crusher, and then crushed into the ball mill, and then through the gravity separation, flotation process, extract the concentrate and tailings, and then through chemical methods, and finally through smelting, its products eventually become finished gold.

Gold ore dressing process can be understood as:
The raw ore enters the double-layer vibrating screen after the first stage of crushing, and the upper layer product is crushed together with the middle layer product for the second stage of crushing, and the second stage of crushing product is returned to combine the first stage of crushing product for screening.
The sieving product is grinded by the first stage ball mill and formed closed circuit grinding with the grading mechanism, and the grading overflow is classified by the cyclone and then entered the second stage ball mill and then formed closed circuit grinding with the cyclone.
The cyclone overflow is first priority flotation, and the foam products are twice and three times selected and finally become concentrate products. The tailings after preferential flotation go through the sorting process of one rough selection, one clean selection, two clean selection, three clean selection and one sweep selection. The tailings of one clean selection and the foam products of one sweep are entered into the cyclone for re-classification and re-sorting. Second selection and first selection constitute closed circuit selection, and third selection and second selection constitute closed circuit selection.

Crushing and grinding
The crushing process uses the jaw crusher for coarse crushing, the standard cone crusher for medium crushing, and the short head cone crusher and the roll crusher for fine crushing. Medium and small gold processing plants mostly use two-stage and closed-circuit crushing, and large gold processing plants use three-stage and closed-circuit crushing process. In order to increase the yield and equipment utilization coefficient, the concentrator generally follows the principle of more crushing and less grinding to reduce the granularity of the ore.

reselection
Gravity separation is a method of separating ore according to mineral density difference. The main equipment used are chute, shaking table, jig and short cone cyclone.

flotation
80% of gold processing plants in China use flotation method for gold processing, and the output concentrate is mostly sent to non-ferrous smelters for treatment. Due to the increasing development of cyanide gold extraction and in order to improve economic benefits and reduce the loss of concentrate transportation, the flotation process has been greatly developed and occupies an important position in gold extraction production.

Beneficiation method of gold ore – chemical separation
At present, the main chemical separation methods are amalgamation process and cyanide process for gold extraction. Amalgamation process is an ancient gold extraction process, which is simple, economical and suitable for recovery of coarse monomer gold, but it has great pollution to the environment, and has been gradually replaced by gravity separation, flotation and cyanide process.
The process of cyaniding gold extraction includes cyanide leaching, washing and filtration of leaching pulp, extraction of gold from cyanide liquid or cyaniding pulp and smelting of finished product.

Beneficiation method of gold ore – smelting
Smelting is the last process of extracting gold, smelting has rough smelting and refining. Gold smelting has developed rapidly in China, and most of them use the traditional crucible smelting method to produce synthetic gold, or are sent to non-ferrous metal smelters for processing and refining of finished gold.

Beneficiation method for gold ore – heap leaching
The amount of low-grade oxidized ore occupies a certain proportion in China’s gold resources, and it is not economical to use the conventional cyaniding process for gold extraction, but the heap leaching process is still economical.