5 Quartz sand purification process, quartz sand processing

Silica ore beneficiation is to increase the content of SiO2 in silica ore and reduce the content of other impurity minerals. Silica after beneficiation and purification is called silica sand. The higher the content of SiO2 in silica sand, the higher its value. Next we will see Take a look at the process of selecting silica ore.

1. Silica pre-selection process

The specific process of silica pre-selection is as follows: the raw silica ore is sent to the jaw crusher for crushing through the vibrating feeder, and the crushed products are sent to the circular vibrating screen by the belt conveyor for screening. Qualified materials enter the crusher again for crushing.

2. Silica scrubbing process

Scrubbing can remove thin film iron and muddy impurities on the silica surface through mechanical force and friction between mineral particles. The main scrubbing methods include mechanical scrubbing, rod scrubbing and ultrasonic scrubbing. The specific process of silica scrubbing is as follows: the crushed silica is sent to the powder bin for storage by the belt feeder, sent to the rod mill for grinding by the feeder, and the qualified boring is pumped from the slurry to the blocked settler to enter the next step. stage.

3. Silica magnetic separation process

Magnetic separation can effectively remove magnetic minerals including conglomerates in silica, such as hematite, etc., and the finer the silica particles, the better the iron removal effect. The silica magnetic separation process should be formulated according to the specific use of the purified silica. There are two common types:

The coarse ore concentrate after grinding and treatment by the first obstructed settler is pumped into the second obstructed settler for secondary settlement, and the part qualified for settlement enters the vibrating screen for treatment. The slurry left by the screening will flow into the slurry pump to be sent to the three-stage sedimentation treatment, and the obtained qualified concentrate will be dehydrated through the dewatering screen to obtain the foundry sand.

Glass sand has higher requirements on the purity of silica, so its selection process will be more complicated than that of foundry sand. As mentioned above, three-stage sedimentation treatment is adopted in the production of foundry sand, and one of the three sedimentation The next part of the process is used to produce sand for glass. The specific process is as follows: the part of the slurry under sedimentation flows into the flat magnetic separator for sorting operation to remove the weak magnetic impurities. Dehydration treatment is carried out to obtain qualified sand and silica concentrate for glass.

4. Silica flotation process

In order to further remove impurities and improve the purity of silica, flotation is usually used. Flotation purification of silica is mainly used to remove non-magnetic associated minerals such as feldspar and mica in ore. The specific process of silica flotation is: use XFb single-cell flotation machine, use H2SO4 as regulator, pH=2.5-3, sodium petroleum sulfonate as collector, pine oil as foaming agent, flotation to obtain quartz, After flotation, about 70% of mica can be removed, and the content of Fe2O3 can be reduced to less than 0.013%.

5. Silica tailings treatment process

The impurity minerals after grinding and sedimentation are directly sent to the concentrator for concentration and dehydration. After dehydration, the product is stirred through the stirring tank, and then pumped into the filter press for dehydration again, so that the water content is lowered to below 20%. To tailings storage.

The above is the process of selecting silica ore. After the above five steps, the purity of SiO2 in silica can be improved. The purity after flotation is conservatively estimated to reach more than 99%. If higher purity silica is required, acid leaching process can also be used. Specific The process should be determined through beneficiation test.