Plate quartz silica sand washing processing line machine high purity China

1.Quartz sand quality grade

Silica sand / Quartz sand is one of the indispensable raw materials in the manufacturing process of quartz plates. According to the characteristics of particle size, chemical composition, and loss on ignition of Silica sand, it can be divided into multiple grades.
The commonly used grade standards are as follows:

Grade	particle size(mm)	SiO2(%)	Fe2O3 (%)	loss on ignition(%)
Level 1	0.5-1.0	≥99.5	≤0.015	≤0.2
Level 2	0.5-1.0	≥99.0	≤0.02	≤0.3
Level 3	0.5-2.0	≥97.0	≤0.03	≤0.5
Level 4	0.5-2.0	≥95.0	≤0.04	≤1.0
Level 5	0.5-3.0	≥93.0	≤0.05	≤1.5

2.High purity silica sand washing processing line 

2.1 preprocessing - washing

Firstly, it is necessary to crush and screen the original quartz ore to a suitable particle size, usually between tens to hundreds of microns, and ensure particle uniformity through screening. This step lays the foundation for subsequent processing. 

The next step is water washing and scrubbing, which aims to preliminarily remove soluble impurities such as soil and dust, as well as some attachments on the surface of quartz sand. Using a scrubber, such as a strong stirring scrubbing machine or a spiral clarifier machine, can enhance the scrubbing effect by removing thin films and loose impurities on the surface of sand and gravel through the friction between particles.

2.2 Magnetic separation & flotation

In order to further purify quartz sand, physical sorting is required. There are various methods for physical sorting, such as gravity and magnetic sorting, which can remove mechanical and magnetic impurities from quartz sand and improve purity.

At this stage, the purpose of magnetic separation is to remove ferromagnetic impurities such as magnetite and iron filings, as well as weak magnetic impurities from quartz sand. The best effect is achieved by using a high-intensity magnetic separator.

The purpose of flotation is to remove non-magnetic impurities in quartz sand that have a density similar to or coexist with quartz. The commonly used flotation method is reverse flotation.

2.3 ACID washing treatment

The purity and quality of quartz sand can be effectively improved through chemical cleaning and acid leaching treatment.

In this step, the following acids are commonly used: hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, etc. Through the synergistic effect of different acids, various impurities that are difficult to separate can be removed. For example, hydrofluoric acid can dissolve silicate minerals and deeply etch the surface of quartz particles, but due to its high toxicity and corrosiveness, caution should be exercised during operation.

The acid washing operation methods include atmospheric pressure leaching, pressure leaching, mixed acid system, and multi-stage acid washing to ensure efficient impurity removal while minimizing the dissolution loss of quartz.