The gold ore process is usually determined by the physical, chemical and mineralogical properties of the gold ore and gangue. For example, gold ores with large differences in specific gravity and coarse grain size are generally treated by gravity separation; the difference in wettability of the mineral surface Gold ores with large and fine grain size are generally treated by flotation.
For some complex refractory gold ores, in order to maximize the recovery rate of gold and recover other useful components, it is undoubtedly technically necessary and economically reasonable to choose a multi-process combined process.
There are two main types of common gold ore: quartz vein type gold ore and sulfide gold-bearing ore. The technical staff has given the following two common ore processes:
1. Quartz vein type gold ore: The quartz vein type gold ore beneficiation process is mainly cyanidation and flotation. The determination of the process mainly depends on the particle size of gold and the symbiotic relationship with other minerals. In the case where the surface of the ore is contaminated or there is free gold with a thin film, a part of the gold can be recovered by jigging and gravity separation, reducing the grade of tailings and reducing the cyanide leaching time.
When the floatability of the ore is better, the flotation of gold ore containing quartz can produce tailings similar to the cyanidation process. The flotation tailings are ground and then floated, which can improve the flotation recovery rate. In most cases, the cyanidation method is more commonly used in quartz vein type gold ores. The main considerations are the fineness of the ore grinding, the concentration of cyanide in the slurry, and the leaching time. At the same time, in order to reduce the amount of cyanidation operations, the process of flotation concentrate recyanation can be used.
2. Sulphide gold-bearing ore: The vast majority of gold-bearing sulfide ore can be treated by flotation, some can also be treated by cyanidation, or a combined method, or amalgamation, re-selection or their combined process.
The choice of flotation or cyanidation process depends on the recovery rate of gold and the comprehensive utilization degree of associated minerals. Dissolution is more difficult, and the flotation method is also difficult to recycle. When the surface of the gold particles is clean and there are no harmful components in the ore, the mercury mixing method is better than the gravity method. In production practice, the common beneficiation process of gold-bearing sulfide ore is as follows: first flotation, the flotation concentrate can be directly cyanidated, or it can be cyanidated after grinding, or treated by gravity separation and mercury amalgamation.
For gold ore beneficiation plants, mature and simple production processes are used as much as possible. Under this premise, there is room for beneficiation equipment selection and plant construction to provide conditions for future production development and process improvement.