High-purity quartz sand production process
High-purity quartz sand is a kind of stone that is made of natural crystal stone, silica, and quartzite after careful selection and fine processing. The production process of high-purity quartz sand includes beneficiation, crushing, screening, cleaning, grinding, impurity removal, drying, and packaging, let’s take a look.
The quartz sand beneficiation process is mainly to remove impurities and purify, remove a small or trace amount of impurities in the quartz sand, and obtain a difficult separation technology of refined quartz sand or high-purity quartz sand.
1. Mineral processing
High-purity quartz sand is generally made of silica, quartzite, or natural crystal stone.
Generally, jaw crushers, impact crushers, and sand-making machines are used for crushing operations. Quartzite is continuously and evenly fed into the jaw crusher by a vibrating feeder for rough crushing. sent to the sand-making machine for fine crushing.
The jaw crusher is mainly used for the coarse crushing of quartzite, the impact crusher is used for the fine crushing, and the sand-making machine fully plays the role of fine crushing and shaping in the production process of high-purity quartz sand, and is the most ideal high-purity quartz sand. crushing equipment.
Use a circular vibrating screen to screen out qualified sand and gravel, and the quartz sand with a particle size of less than 1mm is sent to the sand washing machine to remove the stone powder and dust. The sieving and cleaning system and the crushing system together form a tight and ingenious closed-circuit cycle.
Put the accepted sand and gravel into the cleaning tank according to the process standard and decontaminate with clean water to wash away the impurities attached to the surface of the ore. Operators must wear clean protective water boots when cleaning.
The quartz sand is ground to be used for beneficiation and impurity removal to produce high-purity quartz powder.
6. Impurity removal
(1) Magnetic separation
Using the magnetic difference of various ores or materials, sorting under the action of magnetic force can remove iron-based strong magnetic substances and weak magnetic substances contained in quartz sand.
(2) Acid leaching
The mixed acid of a certain proportion of HCl and HF was soaked for 6 days, mainly to remove acid-soluble metal oxides and part of silicate minerals. Acid leaching is one of the important processes in the purification process of high-purity quartz sand. Whether it is to prepare quartz glass for electric light sources or to prepare quartz raw materials for photovoltaic and semiconductor devices, acid leaching must be used.
According to the different physical and chemical properties of the surface of the mineral particles, the separation is carried out according to the difference in the floatability of the minerals. The main function of flotation is to remove the impurities of mica, feldspar, and iron-bearing minerals in the quartz sand.
The mica content can be effectively reduced by using a shaker and proper water flow for re-selection.