Quartz sand beneficiation process

Water washing and graded desliming of quartz sand

Water washing and graded desliming are pretreatment methods before quartz sand is selected. It mainly removes quartz sand containing a large amount of clay and slime, or removes the surface of quartz sand. Film iron and adhesive impurity minerals. Before being selected, the quartz raw ore can be water-separated and deslimed by classification through equipment such as spiral scrubbers, trommel screens, hydrocyclones, desliming hoppers and hydraulic classifiers.

Quartz sand scrubbing and impurity removal

Scrubbing uses mechanical force and the abrasion force between sand grains to remove the thin film iron on the surface of quartz sand. , bonding and muddy impurity minerals and further grinding of mineral aggregates that have not become monomers, and then through classification operations to further purify the quartz sand. At present, there are two main methods of scrubbing: rod friction scrubbing and mechanical scrubbing.

Rod friction scrubbing method:In the scrubbing process, an appropriate amount of chemicals is added to increase the friction between impurity minerals and the surface of quartz particles. Electric repulsion improves its separation effect. On the one hand, this method strengthens the scrubbing effect; on the other hand, due to the presence of an appropriate amount of steel rods, the particle size composition of the original sand can be changed, providing a mineralogical basis for further sorting of quartz sand.

Mechanical scrubbing method: By adding chemicals (water glass) to increase the electrical repulsion between impurities and quartz surface, etc., and then scrubbing to separate quartz and impurity minerals. For mechanical scrubbing, its equipment structural characteristics, configuration form and process factors (scrubbing time and scrubbing concentration) will all affect the scrubbing effect.

Magnetic separation of quartz sand to remove iron and impurities

Magnetic separation is mainly used to remove weak magnetic impurities such as hematite, limonite and biotite contained in quartz sand particles. and highly magnetic minerals, mainly magnetite. The magnetic separation method needs to be selected based on the magnetic separation difference between quartz sand and semi-raw impurity minerals. If magnetite has strong magnetism, a weak magnetic separation method can be used. For weakly magnetic minerals such as hematite and limonite, a weak magnetic separation method needs to be used. Strong magnetic separation method (magnetic field strength needs to be above 10000Oe) is used for selection.

Quartz sand flotation purification

The purpose of flotation is mainly to remove non-magnetic impurities (long Stone, mica, etc.), by adding chemicals to make the minerals adhere to the foam products, and then using specific chemicals to inhibit the feldspar or mica minerals of quartz minerals, etc., to achieve purification. When there are many impurities in the quartz ore and the ideal quartz grade cannot be obtained through scrubbing, desliming, magnetic separation and other methods, the flotation process can be used. Common quartz sand flotation production processes are divided into two types: fluorine flotation and fluorine-free flotation.

Fluorine flotation method: Use cationic collector and hydrofluoric acid activator to float in the acidic pH range. selection operation, but the fluoride-containing wastewater after flotation has a serious impact on the surrounding environment.

Fluorine-free flotation method:Removing the hydrofluoric acid activator, taking advantage of the differences in the structural composition of quartz and feldspar, and the difference in Zeta potential between the two, By adjusting the mixed collector of anions and cations, feldspar is preferentially floated out, allowing the two to be effectively separated.

Quartz sand acid leaching is highly purified

The quartz sand acid leaching production process uses various acid solvents (sulfuric acid, hydrochloric acid, nitric acid and hydrofluoric acid, etc.) The acid-soluble impurity minerals are extracted by acid leaching to realize quartz sand selection. The quartz sand acid leaching process is divided into two types: single acid leaching and mixed acid leaching.

Single acid leaching method: Add quartz sand to an acid solution of a certain concentration, and after heating to a certain temperature (heating for an appropriate time), recover the acid solution and conduct leaching on the quartz sand. Washing, drying and recycling.

Mixed acid leaching method: Add the washed quartz sand minerals into the mixed acid solution, stir and leaching at room temperature for about 24 hours, then wash and dry; if heated, stir and leached After about 2 to 6 hours, wash and dry.