Quartz sand physical purification method

The physical method is mainly to remove impurities in quartz sand through water washing-grading desliming, scrubbing, magnetic separation and flotation, and several processes can also be combined to further remove impurities.

1. Water washing - graded desliming and scrubbing

In the quartz sand beneficiation process, the fine-grained grade with a particle size of less than 0.1mm is usually called slime. For quartz sand with a large amount of clay and slime, as the particle size becomes finer, the grade of silica gradually decreases, while impurities such as iron and aluminum increase instead. Its grade can be effectively improved by water washing-grading desliming method.

For the thin film iron and cohesive impurities on the surface of quartz sand, the effect of water washing-grading desliming is poor, which requires the use of mechanical force and the grinding and peeling force between sand particles to remove the thin film iron and cohesive impurities on the surface of the sand. After graded desliming, better impurity removal effect can be achieved.

Studies have shown that the effect of rod scrubbing is ideal. Generally, the scrubbing concentration is 50%-60%. The scrubbing time should be determined according to the nature of the ore to initially meet the product quality requirements. The time should not be too long to avoid excessive energy consumption and Excessive wear and tear on equipment.

In addition, in the process of scrubbing, by adding a rubbing aid (such as water glass), the surface energy of mineral particles can be reduced, the electric repulsion between particles can be increased, and the dispersion of fine particles and the splitting of particles can be produced, thereby helping Scrubbing action

2. Ultrasonic iron removal method

The particle surface of natural quartz sand is easily polluted by the solution containing iron impurities, forming an iron film on the surface, resulting in the problem that the iron content of natural quartz sand is too high and difficult to remove. Under the action of ultrasonic waves, the iron film on the surface of the quartz particles will fall off, so as to achieve the purpose of removing iron and other impurities.

3. Gravity separation, magnetic separation and flotation

For quartz placer, spiral concentrator, chute, shaker and other gravity separation equipment are often used.

Magnetic separation can remove iron and titanium impurities such as hematite, limonite and biotite to a certain extent.

For some iron impurities existing in iron mineral particles or mineral particles such as biotite, garnet and hornblende, and aluminum impurities existing in feldspar, the effective removal method is flotation. At present, flotation mainly adopts acidic conditions, and can be divided into fluorine flotation and fluorine-free flotation according to the different reagents used.

But from the perspective of industrial production, fluorine flotation is still the main flotation method. Its advantages are better purification effect and mature technology, but it has a great corrosion effect on equipment and serious environmental pollution.