Low-grade Sandstone Copper Ore Beneficiation Pilot Study

Copper is an important non-ferrous metals, which is widely used in electrical, light industry, machinery manufacturing, defense industry, building industry and other fields. It is playing a vital important role in the national economic building.It has great significance to rationally developing and utilizing copper resources. With the depletion of mineral resources, copper ore gradually tends to poor, fine and complex, the same time, consumption of copper is increasing year after year now in china. Therefore, rationally utilizing low grade copper ore is becoming increasingly important.In this thesis the object of study is a low grade sandstone copper, with complex composition. Primary sulfide copper minerals are tetrahedrite and chalcopyrite; secondary sulfide copper minerals are bornite, chalcocite and azurite; the main oxide copper mineral is malachite; the main gangue mineral is quartz. The grade of copper is 0.77% and the oxidation rate is 45.45% in the run of mine, it is an oxide copper ore with not thoroughly oxidation. There is a part of disseminated particle size of copper minerals is relatively fine. Mainly sulfide copper minerals are paragenesis with dolomite and pyrite; oxide copper minerals are often blended with limonite. So the key of obtaining the good flotation index is selecting reasonably grinding fineness and making the part of fine-grained disseminated copper full liberation.After further investigating main mineral composition and disseminated relationship in the ore, mineral processing text was carried out. The test scheme is oxide minerals and sulfide minerals bulk flotation, which is a method that oxide minerals and sulfide minerals were floated together after sodium sulfide sulfidization copper oxide. In order to better vulcanizing copper oxide minerals and improve the recovery of mineral processing, the method of piecewise adding sodium sulfide was used, and the roughing times was triple.The results show that the fine grinding was much better than coarse grinding and coarse grinding-regrinding of rougher concentrate. The part of the fine disseminated copper being monomer dissociation before the roughing is the key to improve the separation index. Based on this, two closed-circuit text were carried out, their grinding fineness of which are 85%-200 mesh and 93%-400 mesh. The index of 93%-400 mesh grinding fineness is better. The concentrate grade of copper is increased 6.564% and recovery rate is increased 4.13%.Considering limit of the various factors of the concentrator, the grinding fineness of-200 mesh 85% is recommended finally. Under this condition,after the flotation flowsheet of "triple roughing, once scavenging and twice cleaning", using sodium sulfide as the copper oxide sulfidizer,lime as the pH regulator, butyl xanthate as the collector, and pine camphor oil as the frother,finally copper concentrate grade of 18.006% and the recovery of 80.01% were obtained. This study used source extensively and conventional flotation reagents, the flotation flowsheet with a good maneuverability, so it can provide reference and basis for concentrator production.