Effect of Grinding Concentration on Grinding Process

Grinding concentration refers to the weight of the ore (dry weight) in the grinder as a percentage of the weight of the whole pulp (ore + water). The grinding concentration mainly affects the friction between the grinding medium and the material, the effective weight of the medium (the absolute weight of the medium minus the buoyancy of the slurry), the fluidity of the slurry and the transportation capacity of the mill, thus affecting the productivity of the mill. .

The grinding concentration should have a suitable range, which is not good when it is too large or too small. When the grinding concentration is low, the effective specific gravity of the medium increases in the pulp, so the impact force and the grinding force are strong when the medium falls, but the ore particles adhering around the medium are less, and the efficiency of the grinding of the ore particles is reduced; There is a certain grading effect inside, coarse ore is not easy to discharge, and excessive smashing is serious. If the grinding concentration is too low, the slurry flow rate is too fast, the grinding time is short, the running is coarse in the discharge, and the grinding efficiency and productivity are low.

When the grinding concentration increases, the effective specific gravity of the medium decreases, but the viscosity of the slurry increases, the ore particles adhered around the medium increase, the grinding efficiency increases, the fluidity of the slurry is poor, the flow rate is slow, and the impact of the grinding medium is weakened. For an overflow ball mill , the particle size of the discharged product may become coarser, while the lattice type ball mill may cause a "blowing" phenomenon, thereby reducing the productivity of the mill.

The most suitable grinding concentration should be determined by the nature of the material to be ground, the grinding process conditions and the classification efficiency and the overflow concentration. Generally, high concentration grinding and low concentration classification are advocated. For grinding machines operating at medium speeds, coarse grinding (product size is 0.15 mm For the above) or large proportion of ore, the grinding concentration should be controlled between 75 and 83% ; and fine grinding (product size is 0.10 to 0) .074 mm When the ore is small, the grinding concentration should be controlled at 65 to 75% . When the grinding machine rotates at a high speed, the grinding concentration should be slightly lower. Two sections of closed-circuit grinding, the grinding concentration of a section of grinding is generally higher than that of the second section.

The machine adopts front, back, left and right double tilting mechanism to complete casting pouring in the process of variable speed tilting. The technology is conducive to the exhaust of mould and filling of liquid metal in the casting process. It can improve the internal quality of castings and the yield of castings.