Mineral Processing Experiments on Fine-disseminated Gold Ore from Shaanxi Province

Fine-disseminated type gold deposits often pose significant challenges due to their high content of arsenic, mercury, antimony, carbon, and other refractory minerals. In such deposits, fine-grained gold is typically associated with sulfide minerals like pyrite, classifying these ores as refractory.

Characteristics of the Shaanxi Gold Deposit

The gold deposit in Shaanxi Province is characterized by extremely small gold mineral particle sizes, primarily consisting of sub-micro gold. As a result, traditional flotation methods struggle to produce high-grade gold concentrates. To enable the effective extraction of gold from this fine-grained ore, technological mineralogy studies and mineral processing tests were carried out.

Process mineralogy research reveals that pyrite is the main gold-bearing mineral in this deposit. At a fineness where -0.074 mm particles account for 60% of the sample, the dissociation degree of pyrite reaches 93.48%. Natural gold exists in the form of sub-micro gold and lattice gold, firmly classifying this ore as a fine-grain disseminated type refractory ore.

Mineral Processing Test Results

A comprehensive comparison of mineral processing tests indicates that the “grinding-roasting-grinding-cyanide” process suits this gold mine. The optimal conditions involve grinding the ore to a fineness where -0.075 mm particles account for 80%, followed by roasting at 650 °C for 2 hours. The calcined ore is then ground to a fineness where -0.075 mm particles account for 95%. With a NaCN dosage of 4 kg/t and a cyanide leaching time of 36 hours, the gold leaching rate can reach 73.36%.

Conclusion

This test scheme demonstrates its suitability for the flotation of fine-disseminated gold ores, yielding relatively ideal mineral processing results. Further research and optimization may lead to even more efficient extraction methods, contributing to the sustainable development of the gold mining industry.