The permanent magnet dry roller magnetic separator is used for fine powder
iron removal in quartz sand dry purification, but many customers have reported
that the iron removal effect significantly decreases after the equipment runs
for a period of time, and the iron content in the finished product exceeds the
standard. The problem often lies not in the magnetic roller itself, but in the
matching between the magnetic roller speed and the feeding speed.
Low or high magnetic roller speed can affect the iron removal effect. When
the speed is too low, the material stays in the magnetic field zone for too
long, and the material layer is prone to accumulation. The bottom layer of
magnetic material is pressed down by the upper layer of material and cannot be
washed away; When the speed is too high, the material flashes by and weak
magnetic particles are discharged with the sand before they can be adsorbed. It
is usually recommended to control the magnetic roller line speed between
1.5-2.5m/s, with low speed for fine powder materials and high speed for coarse
powder materials. The specific speed needs to be determined based on the
incoming particle size and iron content test.
Uneven feeding can also lead to fluctuations in iron removal efficiency. When
the amount of incoming materials fluctuates, the thickness of the material layer
changes greatly, and the magnetic field penetrates well in thin areas but cannot
reach in thick areas. A vibrating feeder should be installed in front of the
magnetic separator to stabilize the thickness of the material layer at 5-8mm.
When the feeding amount needs to be increased, priority should be given to
widening the effective width of the magnetic roller or increasing the number of
magnetic roller stages. It is not recommended to simply increase the feeding
speed.
The magnetic field distance is shortened after the wear of the surface
coating of the magnetic roller. After the wear and thinning of the stainless
steel coating, the effective range of magnetic field lines decreases, and the
ability to remove iron decreases. Use a Gaussian meter to test the surface
magnetic field strength of the magnetic roller once a month. If it decreases by
more than 15% compared to the initial value, check whether the coating layer is
worn or whether the magnetic block is demagnetized.
During daily inspections, pay attention to observing whether the iron
discharge port is smooth. If the iron powder is discharged intermittently, it is
likely that the surface of the magnetic roller has absorbed too many iron
impurities and has not been cleaned in time. For equipment operation related
issues, please call Manager Zhang at 13583776655 (same as WeChat) at Shandong
Heavy Industry.