Research On Balling Characteristic Of Copper Concentrates And Strengthening Technologies

As the first country of copper producing and the first country of copper consuming, the smelting of copper concentrates step into the direction of large-scale, high efficiency and clean production. The demand for raw materials into the furnace is increasingly high. As most copper-containing material is fine grain size, it is easy to be taken away by smelting gas while directly smelted in the furnace, which resulted in material loss, higher dedusting load and lower efficiency of follow-up acid-making with smelting gas. Therefore, the agglomeration of the copper concentrate, which made it have certain size and strength, had great significance for improving the production efficiency of copper smelting.Through research on pelletizing performance and green pellets’ thermal stability of single copper concentrate and blended copper concentrate, the intrinsic relationship between physical and chemical properties of copper concentrate, strength and thermal stability of green pellets is ascertained. Through study on the effect of adding binders on strength of copper concentrate’s green pellets, suitable type of binders for pelletization of copper concentrate was selected, which strengthened the preparation of copper concentrate’s green pellets. Through Potentiodynamic Test, Fourier Transform Infrared Spectroscopy, Environmental Scanning Electron Microscope and so on, the binder’s mechanism of action on the surface of copper concentrate was revealed.The results of copper concentrate pelletizing showed that comparing with the foreign ore, the domestic had lower performance of strength and worse thermal stability of green pellets, which couldn’t meet the requirements of the smelting furnace. Study on the correlation between physicochemical properties and pelletizing performance of materials showed that as the average particle size of raw materials decreased and specific surface area increased, the drop strength and compressive strength of green pellets had an upward trend.The performance of copper concentrate’s green pellets could be improved significantlv by adding calcium bentonites and lipid binder respectively. The improvement became more significant by combination of inorganic binder with organic binder. With1.0%composite binder(the ratio of calcium bentonite:lipid binder was97:3) added, the0.75m drop strength of green pellets increased from1.9times/P to4.5times/P, while the rate of2m drop damage of green pellets reduced from44.15%to13.08%and the rate of green pellets’heat shedding powder reduced from60.28%to23.13%.The lipid binder which contained a large number of functional groups of lipids C-O had the characteristics of good dispersibility, strong viscosity with aqueous solution and forming film’s colloid layer of network structure when contacted with water. The result of the potential of copper concentrate after interaction was unchanged, and the specific absorption peak of the binder’s functional group appeared (lipid-based C-O) in the surface of copper concentrate, which showed that lipid binder was absorbed on the surface of copper concentrate in the form of film by chemisorptions, adsorbed and wrapped the concentrate particles of copper concentrate in the middle by a film of network structure formed by itself. The lipid binder changed the hydrophilicity of copper concentrate’s surface, which was favorable to improve the pelletizing performance of copper concentrate. This dissertation includes43figures,34tables and references of69items.