| Abstract:With the rapid development of modernization, people on the demand for gold is expanding constantly, the development and utilization of poor, fine and mixed refractory resources is one of the most important ways to alleviate the increasing demand of gold. In this paper, the research object is the pyritization gold ore with strong wall rock alterations from Ashley in Xinjiang region. In order to solve the serious sliming, unstable production index and low gold recovery rat, the process mineralogy research, laboratory flotation tests and industrial tests are carried on and finally work out a reasonable agent system and technological process, and through the single mineral tests of five kinds of pure minerals, mixed ore separation tests, Zeta potentials test and CASTEP software calculation to analysis the internal and external factors which influence the flotability of pyritic gold ore.In the raw ore,90%or more of the occurrence of gold are the pyrite lattice, the rest of the gold with the form of silver gold are accrete or package with quartz. The deposit is strongly beresitization, the symbiotic relationship between pyrite and gangue mineral are closely, and the content of slime gangue minerals is high. Using the program of’strengthening the activation and collecting of gold bearing minerals, strengthening pulp dispersion and gangue mineral suppression’, we can obtain a good separation index. The finally closed circuit test gain the gold concentrate of gold grade50.06g/t, gold recovery90.83%.Based on the new technology established in the laboratory, using the process water to the raw ore industrial test, the grade and recovery of gold concentration can be reached at48.70g/t and88.98%with the ore grade of5.17g/t after stable operation, which stays the same with the laboratory test index, inferring the technical route is correct.Single mineral test results show that, the flotability of pyrite is better than auriferous pyrite, the floatability of fine gangue minerals are also very good. Sodium carbonate and sodium silicate have cooperative effect on the auriferous pyrite flotation. The inhibition to the gangue minerals of sodium hexametaphosphate, sodium silicate and sodium carbonate are decreasing in turn. The dolomite is easy to be depressed, quartz is harder, while sericite is hardest to be depressed.Mixed ore separation test results show that, the dolomite can significantly reduce the recovery of two kinds of pyrite, while sericite can significantly reduce the grade of auriferous pyrite, quartz has little effect on the flotability of the two kinds of pyrite. The combination of sodium silicate and sodium carbonate is better than it of sodium hexametaphosphate and sodium carbonate on the separation of mixed ore.The crystal simulation results show that vacancy and gold impurity can change the semiconductor and the cystal structure of pyrite which reduce the pyrite total density of states with negative shift and rise the Fermi level of pyrite, and Au dopant and vacancy are bad for pyrite flotation. |
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