Quartz is everywhere
2 oxygen + 1 silicon, one of the simplest combinations in minerals;It is one of the most widely distributed minerals on the earth’s surface. From the spectacular wonders of the wall to the beautiful coastline, to the vast deserts, there are shadows of quartz;Quartz is one of the main rock-forming minerals, the proportion of quartz group minerals in the crust reaches 12.6%;The various forms of quartz originate from different formation conditions. What we often call “quartz” generally refers to the most common α-quartz.
The types of quartz deposits mainly include vein quartz, quartzite, quartz sandstone, natural quartz sand (marine sand, river sand and lacustrine sand).
Application areas of quartz
Quartz sand is an important industrial mineral raw material, widely used in glass, casting, ceramics and refractory materials, metallurgy, construction, electronics, chemical industry, rubber, abrasives and other industries.The industrial use of quartz is generally to grind them into “quartz sand” of various specifications.
Impurity removal process and equipment for quartz sand
At present, most domestic quartz sands need to be processed by beneficiation before they can be used; therefore, beneficiation technology and equipment are the key.
The common impurity removal processes in China mainly include: magnetic separation, gravity separation, flotation, pickling, intelligent separation (color separation, near-infrared, X-ray, etc.) or a combination of several beneficiation methods to remove impurities in quartz sand Mineral impurities to obtain quartz sand that meets the requirements.
- Magnetic separation
Magnetic separation is an efficient and environmentally friendly way to remove strong and weak magnetic impurities.In recent years, with the gradual maturity of magnetic separation technology and equipment, the application of magnetic separation has become more and more extensive, and has gradually become the main selection method for quartz sand removal.
Because the raw material itself contains a small amount of strong magnetic magnetite and a small amount of weakly magnetic hematite, limonite, biotite, garnet, tourmaline, olivine, chlorite and other impurity minerals, in addition to crushing and grinding A small amount of mechanical iron will be mixed in the mining process; these impurities will seriously affect the quality of quartz sand.
In magnetic separation and impurity removal, the magnetic field strength is weak first and then strong, first remove strong magnetic minerals and mechanical iron, and then remove weak magnetic minerals and some conjoined bodies of weak magnetic minerals.Weak magnetic separation equipment can use Huate CTN series countercurrent permanent magnetic drums, and strong magnetic separation equipment can use Huate SGB series flat-plate magnetic separators, Huate CFLJ strong magnetic roller magnetic separators, and Huate LHGC series vertical ring high Gradient magnetic separator, Huate HTDZ series electromagnetic slurry high gradient magnetic separator.The advantages of magnetic separation are large processing capacity and environmental friendliness. Field application data show that magnetic separation can greatly improve the quality of sand concentrates.
Huate High Gradient Magnetic Separator + Strong Magnetic Plate Magnetic Separator Applied in Anhui Quartz Sand Project
Huate vertical ring high gradient magnetic separator applied in Austrian quartz sand project
2. Reelection
Natural quartz sand (marine sand, river sand, lake sand, etc.) often contains a small amount of heavy mineral impurities (such as zircon, rutile), so the magnetic properties of such impurities are weak, but the specific gravity is significantly higher than that of quartz. Gravity selection can be used to remove.The equipment can adopt spiral chute. The advantage of the spiral chute is low energy consumption, but the disadvantage is that the processing capacity of a single device is low and the area is large.
3.Flotation
Because some quartz ore contains impurity minerals such as muscovite and feldspar, it needs to be removed by flotation. In a neutral or weakly acidic environment, use environmentally friendly agents to remove mica minerals;In a neutral or weakly acidic environment, use environmentally friendly agents to remove feldspar minerals.The advantage of flotation is that it can effectively separate complex ores with close magnetic properties and close specific gravity;The disadvantage of flotation is that the current fluorine-free and acid-free flotation method is not mature enough, the reagents are not friendly to the environment, and the cost of backwater treatment is high. In addition, some quartz sands have requirements for particle size, such as some glass sands. -26+140 mesh, the monomer dissociation degree in this particle size range is low, which is not conducive to flotation operations.
4. Acid washing
Pickling utilizes the characteristics that quartz sand is insoluble in acid (except HF) and other impurity minerals can be dissolved by acid, so that the further purification of quartz sand can be realized.
Commonly used acids include sulfuric acid, hydrochloric acid, nitric acid and hydrofluoric acid, etc.;The reducing agent includes sulfurous acid and its salts.The above-mentioned acids have a good removal effect on non-metallic impurities in quartz, but they have a significant impact on different metal impurities, acid types and their concentrations.Generally, dilute acid has a significant effect on the removal of Fe and Al, while the removal of Ti and Cr requires treatment with concentrated sulfuric acid, aqua regia or HF.The control of various factors of pickling should be based on the final grade requirements of the quartz sand, try to reduce the concentration, temperature and dosage of the acid, and reduce the acid leaching time, so as to achieve impurity removal and purification at a lower cost of beneficiation.
5.Intelligent sorting (color sorting, near infrared, X-ray, etc.)
Intelligent separation is based on the difference in the optical properties of the ore or the difference in the reaction characteristics after X-ray irradiation, and the use of photoelectric detection technology to separate different ore particles.
The available equipment is mainly an intelligent sensor sorting machine, which is mainly composed of a feeding system, an optical detection system, a signal processing system and a separation execution system.
According to the classification of detection light source, it can be divided into fluorescent light source, LED light source, near-infrared light source, X-ray and so on.
The advantage of intelligent sorting is that it can replace manual sorting, accurately control the quality of the selected ore, and increase the production capacity of the processing plant; the disadvantage is that the size range of the selected ore is relatively high, and it is difficult to sort when processing finer materials (-1mm) Higher and lower processing capacity.
Quartz sand is a very important non-metallic mineral resource. It is widely distributed in China, and the quality of quartz sand in various regions is quite different. Before industrial production, it is necessary to do a preliminary study of mineral samples according to the quality requirements of the concentrated sand. Reasonable beneficiation method.
The above-mentioned series of products produced by Shandong Huate Magnetoelectric Technology Co., Ltd. are suitable for the separation of minerals of different particle sizes. They have their own focus on product structure design to meet the requirements of different sorting indexes, and they have been successfully applied. In many mining enterprises, it has played a positive role in saving energy and reducing consumption and improving efficiency.
Mining enterprises should select magnetic separation equipment suitable for their own business conditions according to the nature of the ore and technological conditions to improve production efficiency.
Equipment manufacturers should continuously improve and perfect the performance of their products according to the production requirements of mining enterprises, solve some problems in actual use, produce products more suitable for industrial applications, and promote the technological development of magnetic separation equipment.
Post time: Mar-11-2021