高压电脉冲破碎改善紫金山铜矿石浸出性质的试验研究

Experimental Study on Improvement of the Leaching Properties for Zijinshan Copper Ore with High Voltage Pulse Breakage

为研究高压电脉冲破碎和机械破碎两种破碎方式对紫金山铜矿石颗粒性质和柱浸效率的影响,分别采用机械破碎和高压电脉冲破碎(充电电压分别为110 kV和135 kV)对紫金山铜矿山6.7~9.5 mm粒级铜矿石进行破碎处理。针对不同破碎方式的产品,分别测定了颗粒的表面金属矿物暴露程度与裂缝存在情况、长径比、圆形度和矿堆饱和含水率等性质,并进行了柱浸试验。结果表明,在机械破碎产品中仅有1.6%的颗粒表面有金属矿物暴露,有2.5%的颗粒表面上存在裂缝。而在高压电脉冲破碎产品中,这两类颗粒的占比分别上升为3.4%~3.7%和7.3%~17.2%,使得浸出液更易于接触矿石颗粒内部的金属矿物。高压电脉冲破碎产品的长径比平均值为1.42,低于机械破碎产品的1.51,这使得浸出液在前者的产品颗粒内沿颗粒长径的渗流能力比后者高3.3%~3.5%。此外,高压电脉冲破碎产品还拥有比机械破碎产品略高的圆形度和矿堆饱和含水率,可以轻微提高浸出液在颗粒表面和矿堆内部的流动性。对破碎产品进行柱浸试验,在浸出21 d后,高压电脉冲破碎产品的铜浸出率相比机械破碎产品提高了6.6~11.1个百分点,表明高压电脉冲破碎处理能够有效改善紫金山铜矿石的浸出性质。

In order to investigate the influences of high voltage pulse breakage(HVPB) and mechanical breakage on particles properties and column leaching efficiency of Zijinshan copper ore,mechanical breakage and high voltage pulse breakage with charging voltages of 110 kV and 135 kV,respectively,were used to crush the copper ores with the fraction from 6.7 to 9.5 mm.The properties of progeny particles were measured,including exposure degree of metallic mineral on surface,existence of cracks,aspect ratio,circulartiy and saturated water content of ore heap and the clumn leaching were carried out using the copper ores from different breakage ways.The results indicated that only 1.6% of the particles had metallic minerals exposed on particle surface,and 2.5% of the particles had cracks existed on particle surface for mechanical breakage product.While these two proportions had increased to 3.4%~3.7% and 7.3%~17.2% respectively for HVPB products,which made the leaching solution easier to contact the metallic minerals inside the ore particles.The averaged aspect ratio of HVPB product was 1.42,lower than that of mechanical breakage product of 1.51.As a result,the permeation capacity of leaching solution along the major axis of the progeny particles of HVPB was higher than that of mechanical breakage product for 3.3%~3.5%.In comparison with the mechanical breakage product,the product of HVPB had slightly higher circulartiy and ore heap saturated water content,which could slightly improve the fluidity of the leaching solution on the particle surface and inside the ore heap.Column leaching tests were conducted for the product of different breakage methods and different size fractions.After 21 days for leaching,the copper leaching rate of HVPB product was found to be higher than that of mechanical breakage product by 6.6~11.1 percent,indicating that HVPB can effectively improve the leaching properties for Zijinshan copper ore.