基于高压电脉冲技术的方铅矿石破碎试验研究

高压电技术破碎技术是一种新型晶界破裂技术,具有选择性破碎、污染小、无粉尘的优势。 为进一步完善高压电脉冲预处理技术体系,针对辽宁某方铅矿石开展高压电脉冲预处理试验,系统考察了球隙间距、输出电压及脉冲次数等参数对矿石破碎效果的影响。结果表明:对 7~ 5 mm、10~ 7 mm、12. 5 ~ 10 mm 这 3 种粒级原料,适宜的高压电脉冲预处理条件为:球隙间距 25 mm、输出电压 25 kV、脉冲次数 150 次,此时破碎产品-2 mm 粒级产率最高,平均破碎比和粒度分布均匀系数最优。此外,给料粒度越细,破碎产品粒度分布均匀系数越大,粒度分布范围越宽,产品粒度均匀性越差。机械破碎主要通过冲击剪切作用力来减小矿石的粒度,以实现矿物单体解离;而高压电脉冲破碎通过介电常数差异,破坏矿石的内部结构,相界面由此产生的大量裂隙和微裂隙有助于矿石的进一步解离破碎。

Research on Galena Ore Comminution Test Based on High-voltage Electrical Pulses Technology

High-voltage electrical pusles technology is a novel grain boundary fracture technology,which has the advantages of selective crushing,less pollution and no dust. In order to further improve the technical system of high-voltage electric pulses pretreatment technology system,high-voltage electric pulse pretreatment test was carried out for a galena in Liaoning Province. The influence of parameters such as ball gap spacing,output voltage and pulse times on ore crushing effect was systematically investigated. The results showed that the suitable high-voltage electric pulse pretreatment conditions for 7 ~ 5 mm, 10~ 7 mm,12. 5~ 10 mm grain size raw materials were as follows:ball gap spacing of 25 mm,output voltage of 25 kV,pulse times of 150 times,in which the grain size yield of -2 mm crushing product was the highest,and the average crushing ratio and particle size distribution uniformity coefficient were the best. In addition,the particle size distribution coefficient is better with the finer feed particle size,indicating the wider the particle size distribution range and the worse the product particle size uniformity. The particle size of ore is reduced mainly through the impact shear force to achieve the dissociation of mineral in mechanical crushing. However,for the high-voltage electrical pusles crushing technology,the internal structure of the ore is destroyed by the difference of dielectric constant,and a large number of cracks and micro-cracks are generated at the phase interface,which contribute to the further dissociation and fragmentation of the ore.