Flotation is widely used in gold processing. In China, 80% rock gold is processed by flotation. Flotation process maximizes the enrichment of gold into sulfide minerals. The tailings can be directly discharged. Flotation in gold mine has low beneficiation cost.
Gold Flotation Process is use to process fine gold, sulfide gold-containing quartz ore, multi metal gold-containing sulfide ore and carbon-containing ore.
Gold mineral flotation normally adopts one stage grinding-flotation process, but stages grinding and flotation for ore with uneven distribution.
For the gold wrapped in sulfide minerals, sulfide ore reaches monomer dissociation; but for the gold with gangue, grinding fineness should reach gold monomer dissociation. Grinding fineness of minerals is determined by test.
Flotation for large density and coarse particle needs thick pulp, whereas for small density and fine particle, need dilute pulp.
In addition to the grinding fineness, process conditions of gold flotation also includes slurry concentration, reagent dosage, aeration quantity, flotation time.
A gold mine in Yunan, capacity was 300t/d; the main mineral was pyrite; fine granularity of gold; the gold had close relationship with metal sulfide mineral. This plant adopted the flotation process—one roughing, two cleaning and two scavenging. But due to surface oxidation of arsenic antimony mineral, it adsorbed amount of flotation reagents, and the flotation effect was poor. So the plant authorized Xinhai to reform the process. Xinhai replaced cyclone tailings with stages grinding & flotation and flotation tailings in accordance with existing problems in production, and Xinhai also changed the number of machine and reagents rules. Finally, this plant obtained excellent indexes. The indexes comparison as follow:
|Products Name||Gold Concentrate Grade/（g/t）||Gold Recovery Rate/%|
|Before Reformation||Gold Concentrate||33.35||90.62|
|After Reformation||Gold Concentrate||34.38||81.80|
The production process flow into stage flotation flowsheet, easy operation, to achieve early harvest, fast charge minerals useful higher impurity minerals; adjust the structure of flotation machine, improve the separation environment, but also improve the flotation pulp mineralization effect, the index of stability and flow.