| Mineral resources are important material foundation of the national economy construction and social development, and mining is an important basic industry of the national economy. Currently, high pressure grinding rolls(HPGR) is the mainstream of more crushing less grinding technology and selective grinding technology at home and abroad, and its energy saving effect is very significant. HPGR is widely used in the cement industry and iron ore processing areas, but the application of HPGR in non-ferrous metals processing areas is rarely reported in the domestic. It is very necessary and urgent to carry out the research in this area, and its social significance and economic value is obvious.In this paper, molybdenum-copper ores from Bangpu, Mozhugongka County, Tibet were taken as subject investigated, and the molybdenum-copper ore was crushed by HPGR and jaw crusher(JC). Product characteristics, grinding characteristics of the crushed product and flotation characteristics of the grinding product was investigated with the benefit of the analysis of particle characteristics, metal distribution, Bond work index of ball mill, scanning electron microscope(SEM) and energy dispersive spectroscopy(EDS).The impact mechanism of product characteristics, grinding characteristics and flotation characteristics of the product comminuted by different methods was studied with the help of the analysis of X-ray diffraction(XRD), SEM, EDS, Mineral Liberation Analysis(MLA) and inductively coupled plasma-atomic emission spectrometry(ICP-AES). The main contents and results are as follows:In the closed circuit operation with 3.2mm size, the -0.074 mm content of fine-grained particle in the product crushed by HPGR(HPGR products) were 7.01% higher than that crushed by JC(JC products), and HPGR products had a more uniform size distribution than JC products. With the reducing of target particle size, Bond work index of ball mill of JC products reduceed faster than that of HPGR products. The suitable grinding fineness correction of HPGR products was K5=(P80+15.7)/1.138P80. The graphical user interface(GUI) of Bond work index of ball mill of HPGR products and JC products was designed useing MATLAB7.1, and the GUI could get the Bond work index of ball mill of HPGR products and JC products at any grinding fineness of molybdenum-copper ore from Bangpu. The surface microcracks showed that the innergranular microcracks and intergranular microcracks of HPGR products were more than that of JC products.The effect of grinding kinetic parameters k and m on the grinding speed turned out that the parameter k mainly affected oversized cumulative productivity R when t<<e1/k. The larger parameter k was, the faster grinding speed was. With the increase of the grinding time the parameter m mainly affected oversized cumulative productivity R when t>>e1/k. The larger parameter m was, the faster grinding speed was. The parameter k and m mainly jointly affected oversized cumulative productivity R and grinding speed when t=e1/k. The actual work of the ball mill could be evaluated through the study of grinding kinetic parameters k and m, and the study could also provide the basis for choosing the best comminuted methods, mill structure and operating conditions.The study of grinding characteristics of HPGR products and JC products showed that when the particle size was between 0.105 mm and 3.2 mm, the more coarse the particle was, the faster the grinding speed of HPGR was than JC. The max grinding speed of HPGR products was equal to that of JC products when the particle size was between 0.038 mm and 0.105 mm, and the effect of grinding speed was mainly grinding probability. The grinding speed of HPGR products was much faster than JC products when the particle size was between 0.105 mm and 3.2 mm, and the grinding speed of HPGR products was equal to that of JC products when the particle size was between 0.038 mm and 0.105 mm. According to the difference between grinding speed of HPGR products and JC products, coarse particle of HPGR products was selectively fast grinded by ball mill.The grinding-flotation characteristics of HPGR products and JC products showed that the best grinding fineness of HPGR products was 65%, and the best grinding fineness of JC products was 75%. The flotation reagent system of HPGR products was the same as that of JC products, but the trends was different. Grinding fineness could be enlarged using HPGR process. The test of partial closed circuit showed that molybdenum grade, molybdenum recovery of molybdenum rougher concentrate, copper grade, copper recovery of copper rougher concentrate of HPGR products when the grinding fineness was -0.074 mm content taking 65% compared with JC products when the grinding fineness was -0.074 mm content taking 75%, were respectively 0.83% higher,1.03% higher,0.02% lower,2.66% higher. Molybdenum grade, molybdenum recovery of molybdenum rougher concentrate, copper grade, copper recovery of copper rougher concentrate of HPGR products when the grinding fineness was-0.074 mm content taking 65% compared with JC products when the grinding fineness was-0.074 mm content accounting for 65%, were respectively 0.07% lower, 1.93% higher,0.15% lower,4.05% higher.The product characteristics and flotation characteristics of the product comminuted by final grinding system of HPGR were analyzed, the results showed that the-0.074 mm content of the product under the condition of the V-type separator rotor speed (rotor speed) 200 r/min were 10.85% higher than that of rotor speed 50 r/min, and the product under the condition of rotor speed 200 r/min had a more uniform size distribution. Flotation effect of rotor speed 200 r/min was better than that of rotor speed 50 r/min, and molybdenum recovery and copper recovery of molybdenum rougher concentrate in the product under the condition of rotor speed 200 r/min were 14.28% and 12.39% higher than that of rotor speed 50 r/min. Molybdenum grade, molybdenum recovery of molybdenum rougher concentrate, copper grade, copper recovery of copper rougher concentrate of the product comminuted by final grinding system of HPGR under the condition of rotor speed 200 r/min compared with HPGR products when the grinding fineness was-0.074 mm content taking 65%, were respectively 9.10% higher,11.58% higher,7.67% lower,34.48% higher.The comparison results of energy consumption of different crushing methods showed that the energy consumption of HPGR products when the grinding fineness was-0.074 mm content taking 65% was 23.84% lower than that of JC products when the grinding fineness was-0.074 mm content taking 75%. The energy consumption of the product comminuted by final grinding system of HPGR under the condition of rotor speed 200 r/min was 30.98% lower than that of JC products when the grinding fineness was -0.074 mm content taking 75%.The study results have revealed the differences and correlation of product characteristics, grinding characteristics and flotation characteristics of molybdenum-copper ore comminuted by different crushing methods, and have provided theoretical guidance for the use of HPGR in the areas of non-ferrous metal ore. |
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