Heap leaching process is one of the direct and efficient methods for processing gold ores with low grade. It is widely welcomed by concentrators because of its advantages of gold extraction on the spot, simple process, easy operation and high gold recovery rate. How to apply heap leaching process to extract gold? You can get the detailed gold heap leaching process from the following. Heap leaching process for gold extraction mainly includes: two stages one closed-circuit cruhsing and screening, ore stacking, dosing and spraying, activated carbon adsorption, and gold-loaded carbon desorption and electrolysis. The specific process flow is as follows:
Use the table of contents below to navigate through the guide:
In order to improve the heap leaching efficiency of gold mines, a two-stage closed-circuit screening and crushing process is often used for gold ore pretreatment stage. Its main process is as follows:
The raw gold ore stored in the raw ore bin enters the jaw crusher through the trough feeder for coarse crushing. The crushed products enter the vibrating screen through the belt conveyor for processing. The ore that meets the particle size requirements enters the next heap leaching process, and the oversize materials need to be re-entered into the cone crusher for fine crushing. The ore discharged from the cone crusher and from the jaw crusher enter the screening machine for screening at the same time. Such a two-stage one-closed-circuit crushing and screening process can not only improve the heap leaching efficiency of gold ore, but also separate gold ore concentrate and gangue minerals as much as possible, and improve the recovery rate of gold ore.
Heap building is one of the important factors affecting the heap leaching efficiency of gold mines. When building piles, belt conveyors and bulldozers are used to avoid ore segregation as much as possible. In addition, when choosing a site for gold mines heap leaching, choosing a gully area or a rough slope area can save costs. The height of the stack is a factor that affects the permeability of the drug. Therefore, when stacking, its height should not exceed 5m. It should be noted that in order to avoid the loss of precious liquid, a leak-proof floor mat should be laid at the bottom.
In order to spray the medicine on the ore pile evenly, the pipes of the spraying device should be arranged on the top of the pile. During the spraying process, intermittent spraying can be used. The spray liquid can be composed of cyanide (such as sodium cyanide), alkaline solution (sodium hydroxide), lime water, etc. After these drugs are added to the pharmaceutical agtitaion tank, they are evenly stirred and then sprayed. After a period of spraying, the pregnant solution flows into the pregnant solution tank for further treatment.
The percolated gold pregnant solution is pumped into the stripping column through the pregnant solution pump for activated carbon adsorption. After the adsorption is completed, the gold-loaded carbon enters the carbon storage tank for the next step of desorption. The remaining products of adsorption flow into the lean liquid pool, and then pumped into the pile by the lean liquid pump for re-spraying. This circulation system can improve the recovery rate of gold concentrate.
The gold-loaded carbon in the carbon storage tank enters the stripping column for desorption. The desorption products are filtered by a filter and flows into an electrolytic cell for electrolytic treatment. The gold mud obtained by electrolysis can be smelted. The pregnant solution part of electrolysis and the analytical overflow part are sent to the desorption liquid tank for desorption, and then enter the circulation system. In addition, the desorbed underflow part is washed in the pickling tank and then sent back to the carbon storage tank for the removal of the adsorption column.
The above is the complete gold mine heap leaching process. In the process of heap leaching gold extraction, there are many factors that affect its efficiency, such as ore particle size, heap building effect, pH value, oxygen, spray intensity and cyanide concentration. Therefore, in the design of the gold heap leaching process, there are various consideration. Only in this way can the ore leaching rate be high and the leaching speed be fast. Xinhai has served large, medium and small gold ore dressing plants. We have rich experience in gold ore heap leaching process design. What’s more, we can provide high-quality and high-efficiency gold ore dressing equipment. Welcome to consult.
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