In the deep processing of quartz sand, the ball milling classification
closed-loop system is the key to achieving precise control of fine powder
production and particle size. Shanlu Heavy Industry provides a ball mill with
grading machine production line, combined with vertical ring magnetic
separation, scrubbing and dehydration equipment, suitable for the production of
board sand micro powder, coating filler and precision casting sand.
Taking a typical ball milling classification and purification line as an
example: the raw materials are crushed to -5mm and then sent to the ball mill
for classification production line. The ball mill designed by Shanlu Heavy
Industry adopts dry or wet operation, and the cylinder liner is made of silica
or ceramic material. The grinding medium is high alumina balls to avoid iron
pollution. The discharge enters the QF vertical airflow classifier (dry method)
or is connected in series with the hydraulic classifier (wet method) through the
elevator. By adjusting the classifier speed and air volume (or water volume),
narrow particle size products with D90=10 μ m, 20 μ m, 45 μ m and other
specifications can be obtained. Graded coarse particles are returned to the ball
mill for further grinding, forming a closed-loop cycle with minimal over
grinding and concentrated particle size distribution in the finished
product.
If the graded fine powder is used for high whiteness board sand filling,
further iron removal is required. Shanlu Heavy Industry will install an LHC
vertical ring high gradient magnetic separator at this stage. The device adopts
a vertical rotating ring structure, with a background magnetic field strength of
up to 1.5T, and the sorting chamber is filled with magnetic conductive stainless
steel medium. When the slurry or dry powder flows through the medium zone, fine
weakly magnetic iron titanium impurities are adsorbed, and non-magnetic quartz
sand is discharged through the magnetic medium. The LHC magnetic separator can
operate continuously, and after the medium is saturated with adsorption, it
rotates to the non-magnetic zone through a rotating ring to automatically unload
iron, and is equipped with a high-pressure water flushing device for auxiliary
cleaning. After LHC magnetic separation, the content of fine powder Fe ₂ O Ⅲ can
be reduced to below 80ppm, meeting the whiteness requirements of the board sand
filler.
If iron film or mud adheres to the surface of the raw material, a scrubbing
process can be added before magnetic separation. Shanlu Heavy Industry uses CX
scrubbing machine to remove surface pollutants by vigorously rubbing between
sand particles through high-speed stirring. After scrubbing, the slurry enters
the LHC magnetic separator, which can further improve the iron removal rate. The
refined sand after magnetic separation needs to be dehydrated. Shanlu Heavy
Industry uses BK high-pressure diaphragm frame filter press in this process. The
feeding pressure of this equipment can reach 1.2 MPa, supplemented by
high-pressure water diaphragm secondary pressing. The moisture content of the
filter cake is less than 12%, and the filtrate is clear and can be directly
reused. Compared to traditional belt filters, BK filter presses have a smaller
footprint, higher degree of automation, and can achieve unmanned operation.
Shanlu Heavy Industry is located in Shandong and has over 20 years of
experience in mining machinery design. Its products cover a full range of
categories including grinding, grading, magnetic separation, scrubbing, and
dewatering. Shanlu Heavy Industry can provide a parameter matching scheme for a
closed-loop grinding and grading system based on the customer's original sand
particle size and finished product particle size requirements, ensuring the
stability of production and particle size.
In terms of equipment details: The large gear of the ball mill is made of
cast alloy steel, which runs smoothly; The QF classifier spindle bearing adopts
air seal to prevent dust from entering; The excitation coil of the LHC magnetic
separator adopts water electricity separation cooling, with low temperature rise
and long continuous working life; The filter plate of BK filter press is made of
reinforced polypropylene material, which is corrosion-resistant and has a long
replacement cycle. These designs reduce the daily maintenance costs for
customers.
If you need the equipment parameters or incoming material test data for the
ball milling grading production line, please call Manager Zhang at 13583776655
(same as WeChat).