The Effect Of High Pressure Roller Mill On Pulverization And Sorting Process Of Daye Copper-bearing Iron Ore

Daye copper-bearing iron ore has the problems of low iron grade,many kinds of paragenetic minerals,complex sorting process and high cost.Therefore,it is necessary to explore the efficient and reasonable pulverization and sorting methods.High-pressure roller mill as a kind of crushing equipment,which is widely used in mineral processing plants due to its advantages of high crushing efficiency,low energy consumption,and improved mineral dissociation.In this study,high-pressure roller mill was used to compare with jaw crusher,and MLA,EDS,SEM and optical microscope were applied to examine the crushed and sorted products to investigate the effect of high-pressure roller mill on the crushing and sorting process of copper-bearing iron ore in Daye.In the high-pressure roller mill crushing experiment,the pressure between the rollers is 10 MPa,the revolving speed of the rollers is 0.26m/s,the moisture content of the feed material is 2%,and the closed-circuit crushing and screening process of 3mm is determined.The particle size distribution test of the crushed products found that the roller-pressed products have finer particle size and uniform distribution than the jawcrushed products.The test of Bond ball mill work index shows that when the target particle size is 0.074 mm and 0.15 mm,the rolling product is 2kW·h/t and 1.09 kW·h/t lower than the jaw crushing product,respectively.Grindability testing shows that when the grinding fineness-0.074 mm accounts for 60% and 80%,the grindability increases by 55.00% and 33.30%,respectively.The dissociation degrees of chalcopyrite and magnetite monomers show that when-0.074 mm accounts for 75%,the roll-pressed product is 3.09% and 5.15% higher than the jaw-crushed product,respectively.In the fine-grained dry and wet magnetic separation experiments,the magnetic separation concentrate can effectively recover iron,but the loss rate is more than 30% for the copper.In the first stage flotation roughing experiment where-0.074 mm accounts for75%,the copper grade of the roller press concentrate is 0.03% higher than that of the jaw crusher concentrate,and the recovery rate is increased by 1.57%,when the-0.074 mm accounts for 85%,the copper grade of the ore is 0.09% higher than that of the jaw crusher concentrate,and the recovery rate is 3.1% higher.In the magnetic separation experiment,the iron grade of the roller-pressed concentrate is 64.53%,and the recovery rate is 91.61%,which is 0.43% higher than the jaw crushing concentrate iron grade,and the recovery rate is 0.75% higher.In the magnetic separation experiment,the iron grade of the roller-pressed concentrate is 66.04%,and the iron recovery rate is90.02%,which is 1.11% higher than the jaw crushing concentrate,and the recovery rate is 2.49% higher.High-pressure roller mill crushing is beneficial for Daye copper-bearing iron ore to reduce grinding energy consumption,strengthen mineral dissociation,and improve separation effect.