Pure silica sand processing techniques is a purification
technology, which is mainly to remove small or trace impurities in
the silica sand to obtain refined silica sand or high purity silica
sand. The purification processes of silica sand at home and abroad
mainly include grading, desliming, scrubbing, magnetic separation,
flotation, acid pickling, etc.
Pure silica sand processing techniques
1. Grading
The linear vibrating screen is generally used to complete the
grading process, which is mainly to screen out qualified sand. The
finely crushed silica enters the vibrating screen for grading.
Silica sand that meets the particle size requirements will enter
the subsequent link, and the quartz sand that fails to meet the
standard will be returned to the crushing link and crushed again.
2. Scrubbing
Scrubbing is to remove the thin film iron and muddy impurities on
the surface of silica sand by mechanical force and the abrasive
force between the sand grains and to further grind the
unconsolidated mineral aggregates. At present, there are mainly two
methods of rod scrubbing and mechanical scrubbing.
3. Desliming
The quality of SiO2 in quartz sand decreases with the fineness of
quartz sand, but the quality of impurity minerals is the opposite.
Especially obvious in quartz sand containing a lot of clay
minerals. Therefore, it is very necessary to wash and deslime the
quartz sand ore before being selected.
4. Magnetic separation
In general, the common impurity minerals of silica sand such as
limonite, tourmaline, hematite, and biotite can be removed only by
the magnetic separation process. In actual production, the wet
strong magnetic separator is often used for selection, and the
magnetic field strength is about 13000 Oersted.
5. Flotation
The separation of mica and quartz is difficult. Using anionic
collector under acidic conditions, or anion-cation collector under
alkaline conditions, flotation can obtain good results. Generally,
after scrubbing, desilting, magnetic separation, and flotation, the
purity of silica sand can reach more than 99%, which basically
meets the needs of industrial sand.
6. Acid pickling
Dilute acid has a significant effect on the removal of iron and
aluminum, while the removal of titanium and chromium uses
concentrated sulfuric acid. Generally, the mixed acid composed of
the above acids is used for acid leaching and removal of impurity
minerals. The degree of acid leaching should be based on the final
quality requirements of silica sand. Try to reduce the acid
concentration, temperature, and dosage to achieve silica
purification at a lower beneficiation cost.
7. Wastewater management
Hengyang wastewater treatment system(thickener+filter press) for
process and recovery above 90% water.
