The zinc powder replacement process for gold extraction develops on the basis of zinc silk replacement process. Nowadays, it is the main method of gold extraction from cyanization pregnant solution which contains gold. Its process can be divided into the following stages: grinding and classification, concentration and dewatering, leaching and washing, pregnant solution purification, pregnant solution deoxidation and zinc powder replacement. You can learn about the detailed process of zinc powder replacement for gold extraction from the following.
Use the table of contents below to navigate through the guide:
01Step1: Gold concentrate grinding and classification
The gold concentrates are fed into agitation tank through spiral feeder. Then add the water into the tank for ore pulp making. The ore pulp is pumped into hydro cyclone for classification process with the action of slurry pump. The overflow prat will be sent to the following process. The mineral particles in the bottom flow part is too large to meet the production requirement. Therefore, they will be delivered to the ball mill machine for grinding process. After grinding, the pulp will flow into hydro cyclone for second classification. This kind of circuit can improve the efficiency of whole ore production line. At the same time, it can improve the utilization rate of mineral materials.
02Step2: Gold ore concentration and dewatering
The graded mineral slurry is pumped by the slurry pump into the single-layer thickener machine for concentration and dehydration operation. In order to improve the concentration efficiency, you can add the agents to accelerate the precipitation speed of gold mine particles. The deposited ore particles flow into the pump tank through the action of the rake at the bottom of the thickener for the next step. The overflow water of the thickener can be treated and recycled.
03Step 3: Gold concentrate leaching and washing
This process can be divided into two steps, respectively, first leaching and washing, second leaching and washing.During the "first-leaching" process, the gold mine slurry stored in the pump box is pumped into the three sets of leaching tanks. The liquid from "one-leaching" is pumped into a three-layer washing thickening machine for "one-washing". The pregnant solution obtained after washing goes to the next process. The lean liquid enters the "second leaching and washing" process, and the equipment used is consistent with the equipment used in "first leaching and washing". The washed products are put into the box filter press for dehydration. The final product is slag, removed water can be sewage treatment and into the circulation system for slurry water.
04Step 4: Gold concentrate pregnant solution purification
After washing and leaching, some solid suspension are exist in pregnant solution. In order to avoid these suspension materials from entering the displacement operation and affecting its effect, the automatic hydraulic chamber filter press is needed to remove the suspension matter. This can also improve the quality of the replaced gold mud. In the actual production, the lower the suspension content in the purified pregnant solution, the better. After the suspension material is removed, the pregnant solution needs to go to the next production process.
05Step 5: Gold concentrate pregnant solution deoxidation
Because the dissolved oxygen in pregnant solution is harmful to the displacement of zinc powder, the deoxygenation is an essential step in the gold extraction process. A vacuum deoxy tower is generally used for the deoxygenation operation of your liquid. Therefore, the deoxygenation process of your liquid is as follows: pregnant liquid flows into the vacuum deoxidation column for deoxygenation operation. After deoxygenation, pregnant liquid pump into the zinc powder mixing device for zinc powder replacement operation.
06Step 6: Gold concentrate zinc powder replacement
This process mainly includes two main steps: zinc powder addition and replacement. When adding zinc powder, attention should be paid to the dose of zinc powder added. In the addition process, zinc powder should be added quickly and continuously to avoid zinc powder oxidation and water absorption agglomeration. In order to avoid manual mistakes and reduce the production efficiency, the concentrators will generally jointly use the spiral zinc powder feeder and the automatic zinc powder mixing device to complete this process.
When the zinc powder is mixed with pregnant, the replacement reaction has already begun. The final replacement reaction and the filtration of the gold mud will be done in the replacement machine. Generally, the concentrator will use the automatic hydraulic chamber filter press as the final zinc powder replacement reaction device. The replaced gold mud will be sent to smelting. The poor liquid part needs to be washed and sewage treated, and the treated water can be recycled.
The above is the whole process flow of zinc powder replacement method to extract the gold. In this process, it should be noted that the purification, deoxygenation and replacement of pregnant liquid are carried out continuously. In order to avoid the interruption of the process flow, the concentrator generally adopts vacuum suction to complete the transfer of pregnant solution from purification to deoxy.
The quality of different gold concentrate requires different processing processes. Therefore, the concentrators in the process design and equipment purchase, should clearly understand the characteristics of their own materials. Xinhai can customize your complete gold concentrate zinc powder replacement process. We have more than 20 years of practical production experience, and will design the appropriate mineral processing process according to the customer plant area, production volume and budget. If you need, welcome to consult Xinhai.