In nature, mineral symbiosis and association are very common phenomena, some of which are even closely embedded and difficult to separate. This paper introduces a mixed ore of gold, silver, copper, lead and zinc. Xinhai conducted a beneficiation test on its ore sample and finally determined the beneficiation separation process. Through scientific beneficiation process, valuable metal gold and silver have been effectively recovered.
The ore is a low-grade copper lead zinc polymetallic ore, which is associated with a certain amount of gold and silver, and the economic value of gold and silver is greater than that of copper lead zinc. Therefore, the goal of mineral processing and separation is to focus on the recovery of gold and silver minerals and give consideration to the recovery of copper lead zinc minerals.
As the carrier mineral of gold and silver is sulfide ore, when formulating the beneficiation process flow, fully consider the collection of gold and silver minerals in terms of the process structure and reagent system for the recovery of metal sulfide.
The process structure of copper lead first, then zinc, and then copper lead separation is adopted, and collector SK is used to collect gold and silver during copper lead mixed flotation, so that gold and silver can be concentrated in copper lead products as much as possible.
1. Coarse flotation of copper and lead
The monomer dissociation degree of the target mineral is an important factor affecting the separation index. Through the test on the grinding fineness of copper lead mixed flotation roughing, it is determined that the grinding product fineness is -0.075mm, accounting for 70%. One stage grinding is adopted.
Through the test of Na2S dosage, it is determined that the Na2S dosage of copper lead mixed flotation roughing is 500g/t. The flotation process of one roughing, two scavenging and one refining is adopted for copper lead mixed flotation.
The collector SK is used to enrich gold and silver into copper and lead products while copper and lead are mixed and floated. The amount of SK is 35g/t.
2. Copper lead mixed flotation, roughing and refining, regrinding and dressing
The copper lead mixed flotation products were reground and re selected to recover gold and silver. Through the grinding test and the test of the amount of copper lead separation inhibitor, it is determined that the fineness of the reground product in the copper lead mixed flotation coarse and fine regrinding and concentration test is -0.038mm, accounting for 90%, and the amount of separation inhibitor DP is 150g/t.
In this process, 90% of the copper and lead are mixed and refined to -0.038mm, twice mixed and cleaned, and one coarse and one sweep and one refined copper and lead are separated.
3. Determination of beneficiation separation process flow
The beneficiation process flow of the gold, silver and copper lead zinc mixed ore is determined through multiple tests as follows: the raw ore is returned in sequence through 1 stage grinding to 0.075mm, accounting for 70%, 1 coarse, 2 sweeps, 1 fine copper lead zinc mixed flotation, mixed fine regrinding to -0.038mm, accounting for 90%, 2 times of mixed concentration, 1 coarse, 1 sweep, 1 fine copper lead zinc separation, 1 coarse, 2 sweeps, 4 fine zinc flotation, and middling ore.
The project finally obtains copper concentrate with gold recovery rate of 85.92%, silver recovery rate of 50.99%, and lead concentrate with gold recovery rate of 5.5% and silver recovery rate of 17.49%. The total gold recovery rate is up to 91.42%, and the total silver recovery rate is up to 68.48%. The main valuable gold and silver have been effectively recovered.
