300t/h Capacity Quartz Mining Process Plant Efficiency

Quartz is one of the most common minerals in the Earth’s crust. As a mineral name, quartz refers to a specific chemical compound (silicon dioxide, or silica, SiO2), having a specific crystalline form (hexagonal). It is found in all forms of rock: igneous, metamorphic and sedimentary. Quartz is physically and chemically resistant to weathering. When quartz-bearing rocks become weathered and eroded, the grains of resistant quartz are concentrated in the soil, in rivers, and on beaches. The white sands typically found in river beds and on beaches are usually composed mainly of quartz, with some white or pink feldspar as well.

1. Washing, classifying and desliming process

The grade of SiO2 in the quartz stone is reduced with the thinner of quartz grain size, while the grade of mineral impurities (such as iron and aluminum impurities) is increased, this kind of phenomenon is especially obvious in the quartz stone containing a lot of the clay minerals. Therefore, the spiral washing machine, drum sieve, hydrocyclone, desliming bucket and hydraulic classifier are often used to the water concentration of quartz stone, it is very necessary to carry out the classification and desliming in the quartz processing plant. As a pretreatment method before the ore separation, the washing, classifying and desliming are applied earlier and widely in the quartz washing plant, but this quartz mineral process doesn't have the obvious removal effect for the thin-film iron and adhesive impurity minerals on the surface of quartz stone.

2. Scrubbing process

Scrubbing process is mainly to remove the thin film iron, bond and muddy impurity mineral on the surface of quartz stone with the help of mechanical force and the grinding force among sand particles, and further wipe up the non-monolithic mineral aggregation, and then achieve the further quartz processing effect through the classification operation.

At present, the quartz stone scrubbing process mainly includes rod friction washing and mechanical scrubbing. For the mechanical scrubbing method, the factors affecting the scrubbing effect are mainly the structural characteristics and configuration form of the mineral scrubber, followed by technological factors (scrubbing time and scrubbing concentration).

The study shows that the scrubbing concentration of quartz stone shall be between 50% and 60%, but it also increases the difficulty of quartz processing to some extent. In principle, the scrubbing time shall be based on the requirements of preliminary product quality, not too long. Too long scrubbing time will increase the equipment wear, improve energy consumption, and increase the cost of beneficiation. For some quartz minerals, the mechanical scrubbing and wiping effect are not ideal, adding the reagents when necessary can increase the electrical repulsion on the surface of impurity minerals and quartz particles, enhance the separation effect between impurity minerals and quartz particles.

3. Magnetic separation process

The magnetic separation process can remove the weakly magnetic impurity minerals as possible, such as hematite, limonite and biotite, etc. High-intensity magnetic separation usually adopts the wet high-intensity magnetic separator or high gradient magnetic separator. Generally speaking, the wet high-intensity magnetic separator (large than 10000 Oe) can deal with the quartz containing the weakly magnetic impurity minerals (such as limonite, hematite and biotite). It is better to use a weak magnetic separator or a medium magnetic separator to separate the quartz containing the strong magnetic impurity minerals (magnetite).

4. Flotation process

The flotation process is mainly to remove the non-magnetic associated impurities in quartz sand, such as feldspar, mica. The quartz sand flotation process mainly includes fluorine flotation and fluorine-free flotation process. Among them, the fluoride flotation process is carried out in the acidic pH range with the cationic collector and hydrofluoric acid activator. But the fluorine-containing wastewater causes serious environmental pollution, which needs to be discharged after treatment. The fluorine-free flotation process is to take advantage of the differences in quartz and feldspar structure, rationally mix the ratio and dosage of anion and anion mixed collector, and make use of their different Zeta potentials to preferentially float the feldspar and achieve the separation.

Generally, the purity of quartz can reach 99.3% to 99.9% after scrubbing, desliming, magnetic separation and flotation, which can basically meet the needs of industrial sand.

5. Acid leaching process

Because the quartz is insoluble in acid (except HF), while the other impurity minerals can be dissolved in acid, the acid leaching process can be used as the quartz mining process.