In the beneficiation of low-sulfur quartz-type gold ore, flotation is often used as the main beneficiation method for this type of ore. For this kind of gold-bearing minerals, it usually has the characteristics of uneven particle size distribution, complex symbiotic relationship between gold minerals and other minerals such as pyrite, which causes certain difficulties in the selection of gold minerals. As a common precious metal, gold minerals are very concerned about the recovery rate. Therefore, how to improve the gold recovery rate has become a widely concerned issue when sorting quartz-type gold ores.
When studying this issue, we can start from three aspects for the more complex embedding and symbiotic relationship of gold minerals in the ore: adjusting gold ore flotation agent system, improving gold ore grinding stage and improving the gold ore beneficiation process flow.
Use the table of contents below to navigate through the guide:
01Adjust gold ore flotation agent system
For the flotation process, the use of flotation agents directly affects the recovery of ore. Therefore, on the issue of improving the recovery rate, adjusting the flotation agent system is an essential aspect.
In the flotation of quartz-type gold ore, xanthate is often used as a collector, and other agents such as black medicine can also be used. In actual production, high-grade xanthate can achieve more considerable recovery effect than lower-grade xanthate. In many concentrators, it is difficult to collect gold ore by using a single collector. Therefore, the use of combined collectors is more extensive. Commonly used combinations of combined collectors include butyl xanthate and butyl ammonium black drug, butyl xanthate and amyl xanthate, etc.
In addition to collector adjustments, adjustments to activators and inhibitors can also improve gold recovery. The activator can increase the flotation speed and ore buoyancy, thereby increasing the recovery rate of gold. The activators used in the flotation of quartz-type gold mines include copper sulfate, lead nitrate, lead sulfate, etc., among which the role of copper sulfate is more obvious. In the selection of inhibitors, it is mainly aimed at arsenopyrite, carbonaceous, bauxite, etc., to eliminate the impact of these minerals on flotation gold ore, thereby improving the recovery rate. Inhibitors commonly used in this type of gold mine include water glass, lime, etc.
Of course, in the practice of adjusting the flotation agent, the use of the agent is closely related to the properties of the ore, and the test should be carried out first, and a reasonable adjustment should be made according to the test results.
02Improve gold ore grinding stage
For quartz-type gold deposits with uneven distribution, improving the grinding stage is one of the effective ways to increase the recovery rate of gold deposits. In production practice, we can draw the conclusion that generally within a certain range, the higher the grinding fineness, the higher the recovery rate.
However, due to the high production cost incurred in the grinding stage, sometimes the production cost of directly grinding fine ore may only obtain a small increase in the gold recovery rate, which cannot meet economic expectations. Therefore, in the production, according to the ore situation, there is also a method to improve the recovery rate by adopting the method of stage grinding to recover the coarse-grained gold ore first, so as to avoid the loss of metal.
03Improve gold ore beneficiation process
In addition to the above two approaches, improving the beneficiation process is also a method to increase the recovery rate of quartz-type gold ore. There are two directions in the improvement of the mineral processing process, one is to improve the flotation process itself, and the other is to add other mineral processing methods to cooperate on the basis of the flotation process.
As far as the flotation process itself is concerned, the use of closed-circuit flotation can achieve higher recovery than open-circuit flotation. On the basis of flotation, a gravity-flotation combined process flow and a flotation-cyanidation combined process flow can be formed to increase the recovery of gold ore in tailings.
We have studied how to improve the recovery rate of gold in quartz-type gold deposits from the above three aspects. Although the mineral composition of quartz-type gold ore is similar, the component content and structure are different. When formulating the process flow for the concentrator, it is not possible to copy it to avoid economic losses. In addition, although the recovery rate is one of the important mineral processing indicators, attention should be paid to recovery At the same time, attention should be paid to the grade of the concentrate, and the goal is to achieve a relative balance between the two indicators.