In the dry purification of quartz sand using electromagnetic dry powder
magnetic separators or permanent magnet roller magnetic separators, many
customers have reported that slightly increasing the feeding amount leads to
excessive iron content in the finished product. The problem is not with the
strength of the magnetic system, but with the thickness of the material on the
surface of the magnetic roller.
Dry magnetic separators are highly sensitive to the thickness of the material
layer. When the material layer exceeds 8mm, the quartz sand particles in the
bottom layer are too far away from the surface of the magnetic roller, and the
magnetic field force cannot reach them. Magnetic impurities directly pass
through the sorting area with the sand. It is recommended to control the line
speed of the belt conveyor at 0.6-1.0m/s and install a vibrating feeder in front
of the magnetic separator to evenly spread the material and control 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, rather than
simply increasing the feeding speed.
The moisture content of materials cannot be ignored either. Dry magnetic
separation requires the feed moisture to be controlled below 1%. When this value
is exceeded, fine powder is prone to agglomerate and adhere to the surface of
the magnetic roller, further increasing the effective magnetic field distance
and inevitably reducing the iron removal effect. Hot air drying or online drying
devices can be installed in front of the magnetic separator to ensure that the
moisture content of the feed meets the standard.
Once the stainless steel wear-resistant layer coated on the surface of the
magnetic roller of the permanent magnet roller magnetic separator wears thin,
the effective distance of the magnetic field will be shortened, which will also
reduce the iron removal effect. It is recommended to check the surface magnetic
field strength of the magnetic roller once a month. If it decreases by more than
15% compared to the initial value, it is necessary to check whether the coating
layer of the magnetic roller is worn or whether the magnetic block is
demagnetized.
The thickness of the fabric is controlled, the moisture content meets the
standard, and the surface of the magnetic roller is intact. The iron removal
effect of dry magnetic separation is basically not bad. Shandong Shanlu Heavy
Industry has accumulated rich experience in the field of quartz sand dry
magnetic separation, equipment selection and operation optimization issues.
Welcome to contact Shanlu Heavy Industry's technical team for communication and
exchange: Manager Zhang 13583776655 (same as WeChat).