Xinhai Low-grade Gold Ore Flotation Transformation Project

01Ore Property

The main metals in the ore were natural gold and chalcopyrite, followed by limonite, pyrrhotite and pyrite. Non-metallic minerals were mainly quartz, sericite, chlorite, plagioclase, biotite and carbonate, which accounted for 35.10%. The useful components in ore were mainly gold, copper was the main symbiotic component, and the associated components included silver, sulfur and others. The grain distribution of natural gold was shown in table 1.

(Table1. Grain Components of natural gold)

02Process Before Transformation

The process adopted three-stage one closed-circuit crushing and washing, stage grinding and stage floatation process. According to the change of ore property, different flotation reagents were successively used in the different stage flotation stages: single yellow reagent, ammonium black reagent, yellow reagent and ammonium black reagent. Finally, No. Z-200 was determined.

When adopting stage grinding and stage flotation process, the gold grade remained at 2.2g/t and copper grade was 0.471%. As the lack of resources, the company suffered long-term losses that eventually led to the one-year suspension.

03Process After Transformation

Under the mineral dressing test for the original stage grinding and stage flotation process and production equipment, Xinhai mineral processing institution changed to three-stage closed-circuit crushing, one-stage closed-circuit grinding, one roughing, there scavenging and one cleaning flotation process.

Before the transformation, the grade of gold was 0.9g/t and the grade of copper was 0.322%. Stage grinding and stage separation process didn't improve too much the recovery rate, and increased the cost greatly. Through the comparison of test data and cost analysis, the new ore beneficiation process can add 721200 yuan of profit every year.