High Purity Silica Sand Manufacturing & Washing Process Plant

Silica sand washing plant mainly includes: quartz stone crushing and sand making, washing, grading, desliming, scrubbing, magnetic separation, flotation, acid leaching and other processes to remove the small amount or micro amount of impurities in silica sand and obtain refined silica sand or high-purity silica sand for glass, ceramics, construction, chemical and other industries.

Silica Sand Manufacturing & Washing Process

(i) Crushing & Silica Sand making
Quartz stones are first sent to jaw crusher for coarse crushing, then to the cone crusher for medium and fine crushing after reasonable screening by the circular vibrating screen, and the unqualified materials will be returned to the cone crusher for re crushing after the same screening. The quartz stones that meet the requirements of sand making are driven by the conveyor into the sand making machine for sand making and shaping to obtain 0-5mm silica sand.

(ii) Washing, Grading & Desliming
There are a lot of clay minerals in quartz stone materials, so it is necessary to wash and desliming silica sand.

(iii) Scrubbing
Scrubbing refers to the removal of the film iron, binding and argillaceous impurity minerals on the surface of silica sand by mechanical force and the abrasive force between the sand particles, and the further grinding of the mineral aggregates which are not assembled. The after classification operation, the silica sand will be further purified.

At present, there are mainly mechanical scrubbing, rod scrubbing, high-efficiency strong scrubbing with medicine and ultrasonic scrubbing. The mechanical scrubbing equipment is rotary scrubber, which has strong scrubbing capacity: 200-250T/H.

(iv) Magnetic Separation
Magnetic separation is mainly used to remove the magnetic minerals in silica sand. For example, hematite, limonite, biotite and other weak magnetic minerals can be removed through the strong magnetic separator, while the strong magnetic minerals such as magnetite, titanomagnetite and pyrrhotite can be removed through the weak magnetic separator.

(v) Flotation
The composition of silica sand is complex, except for the iron bearing minerals, there are often mica, feldspar and clay minerals. Some impurities in silica sand, such as feldspar and mica, which cannot be removed by magnetic separation, but can be separated by different collectors. In general, the purity of silica sand can be increased to 99% after scrubbing, desliming, magnetic separation and flotation.

(vi) Acid leaching
The removal of iron from silica sand by acid leaching is based on the fact that silica sand is insoluble in acid (except HF), and the impurity minerals containing Fe can be dissolved by acid solution, so the iron minerals can be removed from silica sand.

After flotation, the purity of silica sand can reach 99.5-99.9%. If the silica sand is further purified, the impurities in the form of spots and inclusions on the surface of silica particles must be treated by acid leaching. According to the requirements of different industrial uses for different impurity minerals (Fe, Al, Ti, Cr) of silica sand, the mixed acid leaching treatment with different concentration and ratio is carried out.

Silica Sand Manufacturing & Washing Process Main Equipments:

Silica Sand Manufacturing & Washing Process Flowchart: