Optimization of Preselection Process of Magnetic Separator

The process of strong magnetic separation of fine ore is two-stage grinding, fine-sieving grading, and coarse-sweeping sorting process, ie, one-stage closed-circuit grinding, fine-sieving (0.20mm) grading, sifting back to the second-stage grinding, and sieving Second-stage closed-circuit grinding products are mixed into strong magnetic separators. Strong magnetic machine for the rough election, rough tooth plate (pitch 3.5mm); the lower plate for the sweep, fine tooth plate (tooth pitch 2.5mm). The rougher and sweeping concentrates were used as strong magnetic concentrates, and the tailings were sifted as strong magnetic separation tailings. After the transformation, the sorting process is as follows: rough sweeping, medium ore enrichment, and a rough two sweeping process, ie, roughing and sweeping operations are separated, and roughing tailings are fed into the sweeping machine after being concentrated in the large well. Strong magnetic machine has a rough selection machine (upper and lower plates are rough selection), coarse tooth plate, sweeping machine (top and bottom plates are sweep selection, fine tooth plate, on the plate for a sweep operation, sweeping the tail The mine feeds into the next plate for the second sweep operation).

The strong magnetic separation system of the slag ore concentrator (-15mm) is now using the SHP-3200 type magnetic separator, which is a rough two-sweep process. When the ore grade is 31.82%, 47.13% of concentrate grade, 17.72% of tailing grade, and actual recovery rate of 70.82% (2003 indicator) can be obtained. The major drawback of this equipment is the low recovery rate for fine-grained grades (-0.037mm).
After the transformation of the strong magnetic separation process, the production of the beneficiation plant has undergone significant changes. The grade of the magnetic concentrate concentrate has slightly decreased from the original 47.41% to 47.17%. The recovery rate of ball mills increased substantially, from 61.24% to 67.01%. This alone increases the amount of iron ore concentrate by about 70,000 to 80,000 tons per year. The economic benefits are very significant.

The selection of magnetic concentrates for the concentrator was approximately -0.075mm for 78% of the grade, -0.037mm for 60%, and -0.037mm for approximately 56% of the roughed tailings. Due to the characteristics of JISCO ore, the grain size distribution of grinding products is uneven. On the one hand, the grain size of difficult-to-grind minerals is relatively coarse and the degree of monomer dissociation is low, which affects the grade of concentrates. On the other hand, some minerals are easily crushed due to muddy formation. The SHP-3200 strong magnetic machine has a low recovery rate for this part of the fine grade, causing metal loss. The 0.037mm fractional loss in the tailings accounted for 65% and the grade was about 22%, while the +0.037mm fractional grade was about 16%. The loss of metal in strong magnetic tailings mainly comes from fine-grained iron ore. In recent years, high gradient magnetic motors have been widely used in industrial applications. SLon type electromagnetic high gradient magnetic separators have been widely used in place of imitated Jones strong magnetic machines. High gradient magnetic field gradient magnetic field, high magnetic field force, effective recovery of the lower limit of particle size is about 10μm.