The scrubbing machine is responsible for removing surface clay and iron film
in the quartz sand production line, but many customers have reported that the
mud content of the sand material is still high after scrubbing, which affects
the subsequent magnetic separation and flotation effects. The equipment is
running normally and the impeller is not damaged, but the problem often lies in
the coordination of three process parameters: scrubbing time, scrubbing
concentration, and feed particle size.
The cleaning time was not enough, and the clay was drained away before it
could be peeled off. The scrubbing machine relies on intense friction between
sand particles to remove surface attachments, and friction requires time to
accumulate. When dealing with weathered sand with high mud content, if the
scrubbing time is less than 10 minutes, the clay minerals will not have time to
peel off from the surface of the sand particles, and the mud content will
naturally not decrease after being discharged with the slurry. It is recommended
to adjust the scrubbing time according to the mud content of the incoming
materials. When the mud content is 5% -15%, it should be controlled within 10-15
minutes, and when it exceeds 15%, it should be extended to 15-20 minutes. After
adjustment, sample and test the mud content once per shift to gradually find the
optimal time point.
The scrubbing concentration is too low, and the sand particles cannot touch
each other. When the scrubbing concentration is below 60%, the spacing between
sand particles in the slurry is too large, and the frequency and strength of
friction and collision are not enough, which greatly reduces the clay stripping
effect. When the concentration exceeds 75%, the viscosity of the slurry is too
high, the impeller load is increased, and the flowability of the material in the
tank is poor, which also affects the uniformity of scrubbing. It is recommended
to control the scrubbing concentration between 65% and 70% by adjusting the
water and material feeding rates. A concentration meter can be installed at the
feed inlet of the scrubbing machine for real-time monitoring. When the
concentration is too high, water should be added appropriately, and when it is
too low, the amount of water added should be reduced.
The feeding particle size is too coarse, and the mud in the small particles
cannot be washed out. The scrubbing machine has the best scrubbing effect on
-2mm materials. If a large amount of coarse particles larger than 5mm are mixed
into the incoming material, these particles have a smaller specific surface area
and relatively less clay attached to the surface, but they will occupy the space
inside the tank and interfere with the normal scrubbing of fine particles. It is
recommended to set up a vibrating screen in front of the scrubbing machine for
pre grading, to intercept+5mm particles and return them to the crushing process,
and to feed -5mm materials into the scrubbing machine, which will significantly
improve the scrubbing effect.
During daily inspections, the mud content of the sand material after
scrubbing is checked once per shift. If it is found to be consistently high, it
is checked one by one in the order of "checking scrubbing time first, then
concentration, and finally feeding particle size". Encountering problems during
equipment operation, welcome to contact the technical team of Shandong Heavy
Industry for communication: Manager Zhang 13583776655 (same as WeChat).