破碎方式对冀东磁铁矿石微裂纹特性的影响

为考察矿石不同破碎方式对破碎后所得产品颗粒内部微裂纹特性存在的差异,以冀东地区某磁铁矿石为研究对象,对高压辊磨和颚式破碎2种破碎方式所得产品进行对比,分析不同破碎产品的微裂纹差异,并通过Bond球磨功指数的测定,研究微裂纹特性对磨矿产品的影响。结果表明:矿石经高压辊磨机破碎后产生的晶内裂纹和解离裂纹数量均明显高于颚式破碎机破碎后产品,随着粒度逐渐降低,颗粒中微裂纹的长度、宽度以及数量均逐渐增加,同时产品颗粒表面的粗糙度也显著增加;高压辊磨破碎产品比常规破碎产品的Bond球磨功指数(目标粒度-0.15mm和-0.074 mm)分别降低了13.55%和14.14%,采用高压辊磨破碎可有效降低磨矿能耗;在相同磨矿细度条件下,微裂纹数量多的物料,细粒级中铁矿物的含量更多,同时粒度分布也更为合理,但增长趋势随着磨矿细度增加而逐渐减弱。试验结果可以为冀东磁铁矿石降低碎磨成本,实现降本增效提供理论依据。

Effect of Crushing Method on Micro Crack Characteristics of Magnetite Ore in Eastern Hebei Province

To investigate grinding method on micro cracks characteristics in grain of ground products，using a magnetite ore from Eastern Hebei Province area as object，comparison of products from high pressure roller mill and jaw crusher was conducted.Micro cracks characteristics difference was analyzed on different crushing products.Influence of micro cracks on ground products was studied by detection of Bond Ball Mill Work Index.The results show that the number of cracks and cleavage cracks ground by high-pressure roller mill were significantly higher than that of jaw crusher products，with the decrease in particle size range，micro crack length，width and number were increased，while the product particles surface roughness also increased significantly；The Bond Ball Mill Work Index (target particle size -0.15 mm and -0.074 mm) decreased by 13.55% and 14.14% respectively.Using high pressure roller mill can effectively reduce the grinding energy consumption；Under the condition of same grinding fineness，material with more micro cracks，iron mineral content in fine grained is more higher，particle size distribution is more reasonable at the same time，but the growth trend with the increase of grinding fineness gradually lower.The experimental results can provide theoretical basis for reducing the grinding cost of Jidong magnetite to save energy and to reduce the cost and increase the efficiency.