云南镇源难处理金精矿工艺矿物学研究

利用X射线衍射、X射线荧光光谱（XRF）、X射线能谱分析（EDX）和矿物解离分析（MLA）等检测手段对云南镇源难处理金精矿的化学组成、矿物组成、硫化物特征以及金的分布情况进行了详细的工艺矿物学研究。结果显示：该金矿以硫化矿、碳酸盐和硅酸盐类矿物为主，含有3.18%的有机碳和2.37%的无机碳。通过金的诊断浸出发现96.16%的金被硫化物包裹，少量金以单体形式存在。通过对主要载金矿物黄铁矿、辉锑矿和毒砂的粒度、包裹及裸露情况进行分析，得出大部分硫化矿以解离单体的形式存在，少部分与其他矿物共生。根据MLA测试及金的诊断浸出，认为大部分金被硫化矿完全包裹，处理该矿石时应先进行硫化物包裹层的氧化处理，再进行金矿的浸出。

Study on the Process Mineralogy of Refractory Gold Concentrate in Zhenyuan,Yunnan Province

Zhenyuan gold deposit belongs to fine disseminated gold deposits located in Ailao Mountain.This type of gold ore is often associated with sulfide and carbon，which could diminish the gold cyanidation leaching efficiency and reduce the gold recovery efficiency in the next step.In order to guarantee the recovery rate of gold,the process mineralogy has to be proceeded to ensure the gold wasn’t been wasted due to the improper process.X-ray diffraction，X-ray fluorescence，Energy Dispersive X-Ray Spectroscopy，particle size test and mineral liberation analysis have been used to determine the chemical composition，mineral composition，particle size and the characteristic of Zhenyuan refractory gold ore obtained from Zhenyuan gold deposit.The X-ray diffraction，X-ray fluorescence，Energy Dispersive X-Ray Spectroscopy and mineral liberation analysis（MLA） shows that the main phase of the concentrate is sulfide（32.37% of pyrite，0.58% of stibnite and 0.46% of arsenopyrite），carbonate，silicate and the chemical component of concentrate is mainly iron（10.86%），sulfur（12.48%），silicon（18.56%）.Meanwhile 0.87% of arsenic and 5.55% of carbon（3.18% organic carbon and 2.37% inorganic carbon） have been found from the sample，which is harmful to cyanidation process. The particle size，encapsulation and exposure of pyrite，stibnite and arsenopyrite were analyzed with particle size test and MLA test. The particle size of sulfide is mainly between 10~75 μm，about 90%.A large number of sulfide is fully encapsulated（83.6%），only few of them are totally covered with gangue（0.9%）.Gold diagnostic leaching and MLA test were carried out to determine the occurrence state of gold.Sodium cyanide，acetonitrile，nitric acid and fire-assaying method has been used to determine the gold chemical content in native gold，sulfide，carbon and silicate.The gold diagnostic leaching result shows that 96.16% of gold is covered with sulfide and few is in the form of native gold or covered with silicate and carbonate.No gold is wrapped in carbon.MLA test could automatically diagnose different phase of gold ore based on electron software，energy spectrum and MLA software.It also could built standard data base of sample ore and calculate the process mineralogy data automatically.From the MLA test，the electron microscopy （SEM） images of sulfide and native gold has been collected and analyzed，which shows the similar result with gold diagnostic test that most of the gold is wrapped in sulfide. According to the mineralogy process which have proceeded，this gold concentrate is a carbon-baring sulfide gold ore.Since most of the gold is fully covered with sulfide，the sulfide removing process is becoming necessary.It is recommended that oxidation or grinding process should be proceeded before gold leaching process.