河北某铁矿磨矿分级工艺优化试验

Experiment on Process Optimization of Grinding and Grading of an Iron Ore in Hebei Province

为了提高现场旋流器的分级效率,降低循环负荷,针对螺旋分级机溢流粒度粗,一次旋流器沉砂细粒含量高的问题,进行了旋流器代替螺旋分级机及旋流器结构优化试验,并通过现场试验对比了优化效果。研究结果表明:一段磨矿分级采用FX840-P旋流器替代螺旋分级机后,物料中+0.36 mm含量降低,溢流细度提升3.15个百分点,沉砂夹细降低5.95个百分点;二段磨矿分级将原有FX500常规旋流器结构改为平底柱式结构后,溢流细度-0.075 mm达70%左右,分级效率提高9.85个百分点,循环负荷降低100.37个百分点;两段磨矿工艺优化后,二段磨机排矿细度-0.075 mm达45%左右,较优化前提高10个百分点左右。

In order to improve the classification efficiency of the cyclone and reduce the circulating load,aiming at the problems of coarse overflow particle size of the spiral classifier and high content of fine particles in the primary cyclonesand setting,the cyclone instead of the spiral classifier and the structure optimization test of the cyclone is carried out,and the optimization effect was compared through the on-site test.The research results show that the content of+0.36 mm in the material is reduced,the overflow fineness is increased by 3.15 percentage points,and the fine in sand setting is reduced by 5.95 percentage points after the FX840-P cyclone is used to replace the spiral classifier in the primary grinding and classification.After the two-stage grinding and classification changed the original FX500 conventional cyclone structure to a flat-bottom column structure,the overflow fineness of-0.075 mm reached about 70%,the classification efficiency increased by 9.85 percentage points,and the circulating load decreased by 100.37 percentage points.After the optimization of the two-stage grinding process,the ore discharge fineness of the two stage mill is about 45%-0.075 mm,which is about 10 percentage points higher than that of before optimization.