High purity silica sand refining line and processing system (3N-5N)

High Purity Silica Sand Refining Line and Processing System (3N-5N)

Conceptual Analysis of High Purity Silica Sand

Silica sand (quartz sand) is one of the most widely distributed minerals in the earth's crust, and its main component is SiO₂, which has stable physicochemical properties such as high hardness and high melting point. The so-called high-purity silica sand, currently in the industry usually refers to the purity of SiO₂ to 99.9% to 99.999% (i.e., 3N-5N), and the content of key impurities such as Fe₂O₃ is strictly less than 10 ppm of high-quality silica sand. It is an irreplaceable basic material for the preparation of all kinds of high-end quartz products.

Refining Line System Overview

This production line system is specially designed for the production of 3N-5N grade high purity silica sand. The system integrates various refining processes such as physical beneficiation, chemical purification and high-temperature treatment to remove all kinds of impurities in the raw ore through a series of precise and interlinked processes to realize precise control of the purity of the silica sand, so as to satisfy the stringent requirements of the high-end science and technology industry for basic materials.

Core Application Areas

Quartz glass and products made from high-purity silica sand are indispensable core materials for semiconductor industry (crucibles and diffusion tubes for chip manufacturing), optical communication (fiber optic preforms), photovoltaic (crystal growth furnaces), high-end optics and electric light sources, and other strategic emerging industries. Its purity directly determines the performance and quality of downstream high-end products.

Refining Process Introduction

The system adopts a modular design, which can flexibly combine process units according to the characteristics of raw ore, and its core refining process usually includes:

1. Precision beneficiation and electrowinning: Pre-enrichment of the raw ore through color separation, high-voltage electrowinning and other technologies, efficient separation of minerals based on differences in electrical conductivity, and precise rejection of veins and off-color particles.

2. Thermal crushing (water quenching): The use of high-temperature quenching to produce internal cracks in the ore, which is conducive to the dissociation of monomers and subsequent purification.

3. Deep Magnetic Separation and Superconducting Magnetic Separation: Strong magnetic separation is used to remove strong magnetic impurities initially, and superconducting magnetic separation technology is applied to completely separate weak magnetic impurities such as iron and chromium with its extremely high magnetic field strength.

4. High-efficiency flotation: Remove associated minerals such as mica, feldspar, etc., which have different surface properties with SiO₂ through flotation chemicals.

5. Hot acid leaching (acid leaching): Using mixed acid solution under heated conditions to deeply dissolve metal oxides on the surface of particles and in the fissures.

6. High-temperature purification: High-temperature treatment under vacuum or in a specific atmosphere to effectively vaporize volatile impurities and to induce lattice transformations of certain impurities for subsequent removal.

7. Chlorination Roasting: Chlorine gas is introduced at high temperatures to react with impurities such as alkali metals, which are difficult to remove by pickling, to form gaseous chlorides which are discharged.