| The gold has good anticorrosive property,excellent physical, mechanical properties and high thermal stability, Therefore, it is always a metal that people adore all the way.In the domains of people's life and tip field of modern science and technology, gold has been widely applied in the embellishment, monetary and industrial materials. Compared with other sorts of gold, the major characteristics of Calin type of gold ore is sedimentary carbonate.But to pure carbonate, Calin type of gold ore is not included, associated with impure carbonate. These impure carbonate generally contain mud,carbon and powder sandy. The Calin type of gold ore was discovered by our courtry unto 70 age in virtue of special geochemistry and mineral characteristics. The southwest of Guizhou Province is one of the main compact districts of the Calin type of gold ore of our country.There is little visible gold in the mostly Calin type of gold primary ore, which is the distinctive feature.The gold particles are extraordinary fine,they usually distributed in the the surface and the fracture of the pyrite,arsenopyrite and clay minerals,these size is generaly only 0.1μm,some is only 0.01μm. Even under a few ten thousand magnification,they also diffcultly being saw. Only by chemical analysis, can the gold be expected ,which is an important reason of the Calin type of gold ore being not discovered by human. This paper introduces briefly the properties, deposit genesis and characteristic of the Calin type of gold ore in Guizhou Shuiyindong. The analysis has compared relatively domestic and international Calin type of gold ore dressing method, craft and research tendency.This ore gold mainly exists in the form of parcel by sulphide, the occupation rate reaches 79.3%, the main gold-carrying mineral is pyrite and rsenopyrite.The pyrite and rsenopyrite belong to difficult-to-separate micronization embed ore, whose main size is 0.1-0.001mm. So it is very difficult to reach the classification request by the gravity separation. In light of the ore properties,we have carried on three kinds of classifications flowsheets plan comparison to this ore. They are: (1) cyanide leaching of raw ore; (2) Oxidation roasting—cyanide leaching of raw ore; (3) Oxidation roasting—cyanide leaching of flotation concentrate, We Obtained the flotation process is effective concentratesthe method,so we pay attention to investigation of flotation process, in order to search new floatation process and new reagents. Before studying flotation, we carryed on experiment in order to prove sample ore can float.The test shows: the leaching rate does not reach 80% in the cyanide leaching of raw ore or oxidation roasting—cyanide leaching,which proves this kind of Calin type of gold ore belonging to difficult leaching ore,the results indicate that cyanide leaching is inadvisable. Considering this ore gold mainly exists in the form of parcel by sulphide, the occupation rate reaches 79.3%,we propose adopting the flotation procedure.Floatation circuit is simple, easy to operate, the results of classification are very good.Finally , the test research to optimize processing parameters is carried out systematically for flotation of Calin type of gold ore. Based on the research, we get optimum reagent condition of flotation: the fineness of grinding for minus 200 mesh occupy about 96.74%, the dosage of Na2CO3 is 2.5kg/t, the dosage of sodium hexametaphosphate and Na2SiO3 are 1000g/t, the dosage of Pb(NO3)2 and CuSO4 are 600g/t, The final recovery rate of flotation of gold ore is 91.64% and the gold grade of concentrate is 42.6g/t. And we has carried on the oxidation roasting—cyanide leaching of flotation concentrate, the overall recovery rate of gold ore reachs 88%. |
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