Effects of TiO2 or ZrO2 addition on corrosion resist; ance of periclase -spinel refractories to copper matte at different temperatures were investigated using static crucible method, and the results were compared with...Effects of TiO2 or ZrO2 addition on corrosion resist; ance of periclase -spinel refractories to copper matte at different temperatures were investigated using static crucible method, and the results were compared with those of fused rebonded magnesite -chrome bricks. The chartges in chemical compositions and microstructure in different zones of the specimens after corrosion tests were studied by means of EDAX and SEM. The results show that ： （ 1 ） the reaction between periclase - spinel refractories and copper matte is very weak with the reaction layer thinner than 1 mm. Penetration is the main cause of copper matte corrosion and the penetration depth increases with temperature rising. When temperature exceeds 1200 ℃ , the penetration depth increases significantly; （2） appropriate TiO2 addition can improve penetration resistance （even better than that of magnesia chrome brick）, the optimum addition is 2 %. But ZrO2 has no remarkable effect on penetration resistance to copper matte of periclase - spinel refractories ; （ 3 ） SEM and EDAX analysis indicates that, Cu2S penetrates much further into the specimens than FeS.展开更多
The precipitation of Fe_(3)O_(4)particles and the accompanied formation of Fe_(3)O_(4)-wrapped copper structure are the main obstacles to copper recovery from the molten slag during the pyrometallurgical smelting of c...The precipitation of Fe_(3)O_(4)particles and the accompanied formation of Fe_(3)O_(4)-wrapped copper structure are the main obstacles to copper recovery from the molten slag during the pyrometallurgical smelting of copper concentrates.Herein,the commercial powdery pyrite or anthracite is replaced with pyrite-anthracite pellets as the reductants to remove a large amount of Fe_(3)O_(4)particles in the molten slag,resulting in a deep fracture in the Fe_(3)O_(4)-wrapped copper microstructure and the full exposure of the copper matte cores.When 1wt%composite pellet is used as the reductant,the copper matte droplets are enlarged greatly from 25μm to a size observable by the naked eye,with the copper content being enriched remarkably from 1.2wt%to 4.5wt%.Density functional theory calculation results imply that the formation of the Fe_(3)O_(4)-wrapped copper structure is due to the preferential adhesion of Cu_(2)S on the Fe_(3)O_(4)particles.X-ray photoelectron spectroscopy,Fourier transform infrared spectrometer(FTIR),and Raman spectroscopy results all reveal that the high-efficiency conver-sion of Fe_(3)O_(4)to FeO can decrease the volume fraction of the solid phase and promote the depolymerization of silicate network structure.As a consequence,the settling of copper matte droplets is enhanced due to the lowered slag viscosity,contributing to the high efficiency of copper-slag separation for copper recovery.The results provide new insights into the enhanced in-situ enrichment of copper from mol-ten slag.展开更多
文摘Effects of TiO2 or ZrO2 addition on corrosion resist; ance of periclase -spinel refractories to copper matte at different temperatures were investigated using static crucible method, and the results were compared with those of fused rebonded magnesite -chrome bricks. The chartges in chemical compositions and microstructure in different zones of the specimens after corrosion tests were studied by means of EDAX and SEM. The results show that ： （ 1 ） the reaction between periclase - spinel refractories and copper matte is very weak with the reaction layer thinner than 1 mm. Penetration is the main cause of copper matte corrosion and the penetration depth increases with temperature rising. When temperature exceeds 1200 ℃ , the penetration depth increases significantly; （2） appropriate TiO2 addition can improve penetration resistance （even better than that of magnesia chrome brick）, the optimum addition is 2 %. But ZrO2 has no remarkable effect on penetration resistance to copper matte of periclase - spinel refractories ; （ 3 ） SEM and EDAX analysis indicates that, Cu2S penetrates much further into the specimens than FeS.
基金supported by the National Natural Science Foundation of China(No.52274349)the National Key Basic Research and Development Program of China(No.2022YFC3900801)+1 种基金the Fujian Province University-Industry Cooperation Research Program,China(No.2023H6007)the Fujian Province Natural Science Foundation,China(No.2023J05024).
文摘The precipitation of Fe_(3)O_(4)particles and the accompanied formation of Fe_(3)O_(4)-wrapped copper structure are the main obstacles to copper recovery from the molten slag during the pyrometallurgical smelting of copper concentrates.Herein,the commercial powdery pyrite or anthracite is replaced with pyrite-anthracite pellets as the reductants to remove a large amount of Fe_(3)O_(4)particles in the molten slag,resulting in a deep fracture in the Fe_(3)O_(4)-wrapped copper microstructure and the full exposure of the copper matte cores.When 1wt%composite pellet is used as the reductant,the copper matte droplets are enlarged greatly from 25μm to a size observable by the naked eye,with the copper content being enriched remarkably from 1.2wt%to 4.5wt%.Density functional theory calculation results imply that the formation of the Fe_(3)O_(4)-wrapped copper structure is due to the preferential adhesion of Cu_(2)S on the Fe_(3)O_(4)particles.X-ray photoelectron spectroscopy,Fourier transform infrared spectrometer(FTIR),and Raman spectroscopy results all reveal that the high-efficiency conver-sion of Fe_(3)O_(4)to FeO can decrease the volume fraction of the solid phase and promote the depolymerization of silicate network structure.As a consequence,the settling of copper matte droplets is enhanced due to the lowered slag viscosity,contributing to the high efficiency of copper-slag separation for copper recovery.The results provide new insights into the enhanced in-situ enrichment of copper from mol-ten slag.
