High-purity quartz sand is a quartz sand with a SiO₂ content of more than 99.9%. It is a milky white powder with no different color and low residual water content. High-purity quartz sand has high heat resistance, good organic chemistry characteristics, high-quality dielectric strength and light transmittance, etc. It is a mineral raw material that cannot be replaced by national high-tech.
High-purity quartz sand is obtained by purification of ordinary quartz sand. Its residual water content is very low, its characteristics are stable, and the manufacturing industry requires a large amount, and it can maintain the flexible use of resources. Therefore, the development trend of high-purity quartz sand is very high. The essential.
Preparation and processing technology of high-purity quartz sand
The key to the purification of quartz sand is to remove small or trace analysis residues in it to obtain high-purity quartz sand. Common processing techniques include cleaning, gravity separation, magnetic separation equipment, heavy medium, and acid leaching.
The mechanical equipment force and the separation force between the sand particles are used to remove the residual iron, bonding and mineral mud on the surface of the quartz sand. Cleaning enables the quartz sand minerals to be reasonably discharged in the early stage to remove a part of the residue, clean the surface of the quartz sand particles, and then smoothly carry out the subsequent purification work.
Reselection is to select minerals based on their different forces. Due to the difference in relative density, the mineral particles are not harmed by the hydrodynamic force and mechanical force in the material, resulting in a loose layer, and then the iron ore particles are separated.
Magnetic separation equipment
Magnetic separation equipment extracts magnetic residue minerals and particles from quartz sand. The calcite in quartz sand is a diamagnetic chemical substance that cannot be magnetized in an electromagnetic field, and most of the residues containing Fe and Ti are paramagnetic substances that can be magnetized. According to the magnetic separation equipment, it can remove Fe containing , Ti residue, get high moisture content of quartz sand.
Magnetic separation equipment generally uses wet test strong wet magnetic separator and high gradient magnetic separator.
The heavy medium is the whole process of separating the mineral particles according to the different physics and physical properties on the surface of the mineral particles. The key role is to remove the related mineral biotite and feldspar from the quartz sand. Scientific research has found that the pH value of the slurry and the type and amount of collectors used have obvious harm to the actual effect of heavy medium purification.
Calcite does not dissolve acid (except hydrochloric acid). According to the melting effect of acid on iron and other harmful elements, the residue is extracted to obtain high-purity quartz sand. Residues in the surface layer and gaps of quartz sand can be removed to a large extent by acid leaching. The only physical methods such as magnetic separation equipment and heavy media are the removal of mineral structure residues.
Scientific research has found that the actual effect of using mixed acid to remove residues during the entire acid leaching process is better. Calcite will be melted by hydrochloric acid, so the concentration of hydrochloric acid in the mixed acid is not suitable to be too high. Time, acid concentration, the entire cleaning process and temperature are all factors that endanger the actual effect of acid leaching.