关键词: 工艺矿物学　, 金矿　, 浮选　, 黄铁矿　, 载金矿物

Abstract: To promote the efficient development and utilization of the Jiutiaogou Gold Deposit in Gansu Province,this
study conducted systematic process mineralogy research to characterize the ore and guide the optimization of mineral processing
technology. Methods including mineral liberation analyzer (BPMA),optical microscopy,X-ray diffraction (XRD),and scanning
electron microscopy with energy dispersive spectroscopy (SEM-EDS) were employed to investigate the chemical composition,
mineral composition,occurrence state,and dissemination characteristics of gold. The results show that the major valuable
element in the ore is gold with a grade of 1. 28 g/ t. Gold mainly occurs in petzite (distribution rate of 77. 36%) and native
gold (distribution rate of 22. 64%). The primary metallic mineral is pyrite (content of 1. 37%),and the main gangue minerals
include muscovite,quartz,and dolomite. Gold minerals are fine-grained and unevenly distributed,closely associated with pyrite,
wherein enclosed gold accounts for 51. 77% and fissure gold accounts for 33. 93%. Pyrite exhibits relatively coarse dissemination
size,which favors liberation. Based on the mineralogical characteristics,a closed-circuit flotation flowsheet consisting of one
roughing,two cleaning,and one scavenging stages was adopted. Under the optimal conditions with grinding fineness of 70%
passing -0. 074 mm and a reagent regime,a gold concentrate assaying 75. 60 g/ t Au with a recovery of 92. 80% was obtained,
while the tailings grade was reduced to 0. 09 g/ t. This study provides reliable mineralogical basis and technical support for formulating
beneficiation processes for such finely disseminated gold ores.