The chemical composition of quartz sand is silicon dioxide (SiO2), while high-purity quartz sand means that the SiO2 content is higher than 99.9%. As one of the important industrial raw materials, quartz can be widely used in glass, building materials, plastics, electronic materials and other industries. Among them, the fields of electronic technology, aerospace, optical fiber communication and military industry have higher requirements on the purity of quartz sand. The editor of this article will take stock of the mineral processing method and production line process of high-purity quartz sand.
High-purity quartz sand mineral processing method
In industrial production, ordinary quartz sand is usually pretreated first, and then purified into high-purity quartz sand. The purification methods mainly include physical purification, chemical purification and biological purification.
Physical purification of high-purity quartz sand
The common physical purification methods of high-purity quartz sand can include water washing-grading desliming, scrubbing, gravity separation, magnetic separation and flotation, etc., through one or more combinations of them, the impurity minerals in the quartz sand are removed to achieve Purification requirements.
Water washing – graded desliming/scrubbing
In the mineral processing of quartz sand, the particle size less than 0.1mm is usually called slime. As the particle size becomes finer, the grade of silica will be lower and lower, and the impurity ore will be relatively more. Therefore, it can be Through the method of water washing-grading desliming or scrubbing, impurity minerals are removed and the grade of quartz concentrate is improved.
It mainly uses the relative density, particle size, shape, etc. of the particles between the minerals to separate the minerals, so that under the action of water and centrifugal force, they will produce different speeds of movement and distribute in different directions.
Mainly use the magnetic separation difference between quartz and impurity ores to remove hematite, limonite, biotite and other magnetic minerals in the minerals to the greatest extent through magnetic separation equipment.
Use reagents and flotation equipment to change the surface properties of minerals, select high-purity quartz sand from other places under acidic conditions, and remove pure fine-grained hematite, biotite, garnet and aluminum minerals in the minerals.
Chemical purification of high-purity quartz sand
The chemical purification methods of high-purity quartz sand mainly include acid leaching and alkali leaching, and the purification effect of high-purity quartz sand is better.
Commonly used acids are mainly sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, etc. When the acid is relatively dilute, it has a better effect on removing impurities such as iron, aluminum, magnesium, etc., and when the acid is thicker, it has a better effect on removing impurities such as titanium and chromium. .
Alkaline solutions such as sodium hydroxide or sodium carbonate are commonly used to dissolve aluminum-containing silicate impurity minerals to achieve the purpose of purifying quartz sand.
Biological purification of high-purity quartz sand
The biological purification method of high-purity quartz sand mainly adopts microbial leaching and purification, using the physiological functions of microorganisms and their metabolites, through oxidation, dissolution and decomposition, the impurities on the surface of the quartz sand are separated from the quartz matrix to realize the purification of the quartz sand .
High-purity quartz sand production line process
In the mineral processing, the production line process of high-purity quartz sand mainly includes: crushing-grinding-classification-magnetic separation-flotation-acid leaching-or washing and other links.
Production Process1#:Quartz sand crushing
Generally, a two-stage crushing process is adopted. First, the jaw crusher is used for coarse crushing. The crushed products are transported by the belt to the vibrating screen for screening. The unqualified materials are sent to the cone crusher for fine crushing, and the qualified materials are sent to the powder ore bin.
Production Process2#:Grinding and grading
The ore grinding link is mainly to grind the raw ore to a certain particle size to realize the dissociation of quartz sand and gangue minerals. Classification is used in conjunction with grinding equipment to obtain quartz sand materials with qualified particle sizes.
Production Process3#:Magnetic separation
Wet magnetic separators with magnetic field strengths of 3000Oe and 10000Oe were used for primary separation to remove garnet, hematite, limonite, ilmenite and their associated particles in the quartz sand.
It is used to remove mica and Fe2O3 in quartz, using H2SO4 as regulator, pH=2.5~3, sodium petroleum sulfonate as collector, pine oil as foaming agent to realize flotation operation.
Production Process5#:acid leaching
After two separations by magnetic separation and flotation, there are still impurities in the form of spots or inclusions in the quartz. To remove these impurities, acid leaching treatment is required, and different acids are mixed to remove different impurities.
After acid leaching, the surface of the quartz sand has adhering and dissolved soluble impurity residues, which need to be removed by washing. Wash the minerals after acid leaching to make the impurities and residual liquid on the surface of the quartz diffuse to the liquid phase, and then complete the washing.
The above mainly introduces the mineral processing method of high-purity quartz sand and the process of the quartz sand production line. In the actual mineral processing plant, according to the ore properties and impurity types of quartz sand, the mineral processing method and the process of the mineral processing production line are different. If you want to obtain High-purity quartz sand needs to be determined according to its ore properties. Therefore, the editor suggests that through mineral processing test analysis, design and customize a suitable process plan and suitable high-purity quartz sand production line process, in order to obtain quartz sand with a high return on investment .