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针对碳酸盐脉石对氧化铜矿酸浸动力学的影响进行探讨,研究了温度、酸度、矿石粒径、液固质量比、振荡速度等因素对含碳酸盐脉石氧化铜矿浸出的影响.结果表明,高温、高酸度、高液固质量比、小粒径和高振荡速度利于矿石的浸出,但碳酸盐脉石使得酸耗增加.考虑浸出成本确定合理的浸出条件为温度303 K、酸度35 g·L~(-1)、矿石粒径0.074~0.125 mm、液固质量比3∶1以及振荡速度180 r·min~(-1),浸出180 min后铜浸出率达53.6%.对浸出前后矿石表面形貌进行分析.结果显示碳酸盐脉石与酸反应后在矿石表面形成CaSO_4·2H_2O沉淀,覆盖在颗粒表面,限制了矿石颗粒孔裂隙的发育.基于收缩未反应核模型对浸出动力学进行分析,发现碳酸盐脉石反应生成的沉淀阻碍了浸出反应,固体产物层扩散为浸出反应的控制步骤,反应的表观活化能为8.65 k J·mol~(-1).
The influence of carbonate gangue on acid leaching kinetics of copper oxide ores was studied. The effects of temperature, acidity, ore particle size, liquid-solid mass ratio, oscillation speed and other factors on leaching kinetics of copper oxide ores The results show that high temperature, high acidity, high liquid-solid mass ratio, small particle size and high oscillation speed are good for the leaching of ore, but the carbonate gangue makes the acid consumption increase.According to the leaching cost, the reasonable leaching conditions are determined as 303 K, acidity 35 g · L -1, particle size 0.074 ~ 0.125 mm, liquid-solid mass ratio 3:1 and oscillation rate 180 r · min -1. After leaching for 180 min, the leaching rate of copper reached 53.6 % .The surface morphology of ore before and after leaching was analyzed.The results showed that carbonate gangue and acid react to form CaSO 4 · 2H 2 O precipitates on the surface of ore and cover the surface of the ore and thus restrict the development of ore particle pores.According to the uncoordinated Kinetic model was used to analyze the leaching kinetics. It was found that the precipitate formed by carbonate gangue reaction hindered the leaching reaction and the diffusion of solid product layer as the control step of leaching reaction. The apparent activation energy of reaction was 8.65 kJ · mol ~ (- 1).