Pay Attention to These Key Factors When Purifying Quartz ...

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The influence of quartz sand scrubbing, classification and desludging stages

Scrubbing and classification desludging is a process of removing impurity minerals such as film iron, bonding and soil on the surface of quartz sand by mechanical force and the abrasive force between sand particles, and further rubbing the unformed mineral aggregates, and then further purifying the quartz sand through classification operations. Factors affecting the scrubbing and desludging effect include the particle size of quartz sand, the type and content of impurity minerals in the original ore, the structural characteristics of the scrubbing machine, the scrubbing time and the scrubbing concentration. As the quartz particle size becomes finer, the grade of SiO2 decreases, while the content of iron and aluminum impurities increases, which is particularly obvious in quartz sand containing a large amount of clay minerals. However, for removing the film iron and adhesive impurity minerals on the surface of quartz, scrubbing and classification desludging often use spiral scrubbers, drum screens, hydrocyclones, desludging buckets and hydraulic classifiers and other equipment for scrubbing and classification desludging to improve the treatment effect.

Research shows that the scrubbing concentration between 50% and 60% is ideal. The scrubbing time should be based on the product quality requirements to avoid excessive scrubbing that causes equipment wear and increased energy consumption. For quartz sand that does not have an ideal mechanical scrubbing effect, rod scrubbing is a mature solution.

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Factors affecting the magnetic separation stage of quartz sand

The magnetic separation process of quartz sand is designed to remove magnetic impurity minerals such as hematite and limonite, thereby reducing the iron content and improving its use value and product quality. Factors that affect the magnetic separation effect include the number of magnetic separations, magnetic field strength and quartz sand particle size. As the number of magnetic separations increases, the iron content gradually decreases; most of the iron can be removed under a certain magnetic field intensity, but even if the magnetic field intensity increases a lot thereafter, the iron removal rate will not change significantly. In addition, because the amount of iron-containing impurity minerals in fine-grained quartz sand is high, the finer the quartz sand particle size, the better the iron removal effect.

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Factors affecting the quartz sand flotation stage

The flotation method is to remove non-magnetic associated impurity minerals such as feldspar and mica from quartz sand. The properties of raw ore and the selection and dosage of chemicals affect the flotation effect of quartz sand. In the fluorine flotation process, cationic collectors and hydrofluoric acid activators are used. Although the flotation effect is remarkable, fluorine-containing wastewater that is harmful to the environment will be produced and needs to be treated before being discharged. Fluorine-free flotation utilizes the structural differences between quartz and feldspar, rationally mixes anionic and cationic mixed collectors, and uses their different Zeta potentials to preferentially float out feldspar to achieve effective separation. It is a more environmentally friendly purification method. . After scrubbing, desliming, magnetic separation and flotation, the purity of quartz sand can reach 99.3%-99.9%, which can basically meet the needs of industrial sand.

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Factors affecting the acid leaching stage of quartz sand

Acid leaching is a process to further purify quartz sand by taking advantage of the fact that quartz is insoluble in acid (except HF) and other impurity minerals can be dissolved by acid. Its effect is affected by the type, concentration, acid leaching time, temperature and slurry stirring of the acid. Different acids have different removal effects on different metal impurities. Using nitric acid alone for pickling, the iron removal rate is very low; the removal rate of dibasic acid (hydrochloric acid + hydrofluoric acid) is 58.1%, and the removal rate of ternary mixed acid can reach 67.7%. The synergistic effect of mixed acid pickling significantly improves the impurity removal efficiency, but the HF concentration generally needs to be controlled not to exceed 10% to avoid quartz dissolution. Dilute acid has a significant removal effect on Fe and Al, while concentrated sulfuric acid, aqua regia or HF has a better removal effect on Ti and Cr. Using mixed acids such as sulfuric acid, hydrochloric acid, nitric acid and hydrofluoric acid for acid leaching removal can significantly improve the purity of quartz sand. Increasing temperature will accelerate the reaction rate and iron removal rate, but the effect tends to weaken as the temperature increases. Therefore, in the acid leaching process, the concentration, temperature and dosage of acid should be reduced as much as possible, and the acid leaching time should be reduced to achieve efficient purification at lower mineral processing costs.

Quartz sand beneficiation and purification is a systematic project, involving multiple stages such as scrubbing, graded desludging, magnetic separation, flotation and acid leaching. The effect of each stage is affected by many factors, including the nature of the original ore, process parameters, equipment configuration, reagent system, etc. By comprehensively considering these factors, the purification process can be optimized, the purity of quartz sand can be improved, and the high standards of different industrial applications can be met, thereby improving the economic benefits of the beneficiation plant.

A silica sand washing plant is a facility designed to wash, clean, and separate silica sand particles, often used in various industrial applications such as glass manufacturing, casting, hydraulic fracturing (fracking), and water filtration. Silica sand, also known as quartz sand, is composed of silicon dioxide (SiO2) and is one of the most abundant and widely used materials in the world.MINGYUAN can help you solve a variety of problems across silica sand processes, from washing, screening and sizing to tail water management in the sand plant, MINGYUAN can provide you with a solution and supporting facilities to meet your needs.

Here is an introduction to the components and processes typically found in a silica sand washing plant:

1. Feed Hopper: Raw silica sand is typically delivered to the plant in bulk or by conveyor. It is first stored in a feed hopper, where it can be regulated before entering the washing process, for some project it may need stone crushers and sand making machine for silica (quartz)sand making.

2. Screening and Classification: The first step in the washing process is to remove any oversized or undersized particles from the raw sand. This is typically done through a series of screens or classifiers that separate the silica sand into different size fractions.

Contact us to discuss your requirements of quartz sand beneficiation equipment. Our experienced sales team can help you identify the options that best suit your needs.

3. Washing and Scrubbing: The pre-sized silica sand is then subjected to washing and scrubbing to remove impurities such as clay, silt, and organic matter. This process can be accomplished using various equipment, including attrition scrubbers, log washers, or sand screws. Water is often added to aid in the removal of impurities.

4. Hydrocyclones: After washing and scrubbing, the sand is usually directed through hydrocyclones to further separate and classify the sand particles based on their size and density. This helps to achieve a more uniform and clean product.

5. Dewatering: Excess water is removed from the sand slurry using dewatering screens or centrifuges. Dewatering is an essential step to reduce the moisture content of the final product.

6. Stockpiling or Silo Storage: The clean, dewatered silica sand is typically stockpiled or stored in silos for further processing or transport to customers. It is important to prevent recontamination during storage.

7. Water Recycling: Many modern silica sand washing plants incorporate water recycling systems to minimize water usage and reduce environmental impact. This involves treating and recycling the water used in the washing process, making the plant more sustainable.

8. Control Systems: Silica sand washing plants are often equipped with sophisticated control systems to monitor and regulate the various processes, ensuring efficient operation and consistent product quality.

9. Environmental Compliance: Due to environmental regulations and concerns, silica sand washing plants must adhere to relevant environmental standards, including wastewater treatment and dust control measures.

Silica sand washing plants play a crucial role in producing high-quality silica sand that meets the requirements of different industries. They are essential for improving the purity and quality of silica sand, making it suitable for a wide range of applications.

The purpose & aim of silica sand processing plant is to remove the impurities such as iron, aluminum trioxide, mica etc through crushing, scrubbing, washing, classifying and beneficiation.Quartz raw ore or quartz/silica sand needs to be purified to remove impurities so as to obtain high purity silica sand. The SiO2 content of slicasand after processing can reach 99.9% or higher, and the iron content should be reduced to 30 ppm or lower, so as to meet different industrial use. The quartz sand can also be processed into quartz powder through drying and grinding.

Silica sand processing plant technical process

The following is the usual purification process of quartz/silica sand. The raw ore is crushed and screened to remove impurities, then washed and scrubbed to further remove the impurities from quartz sand. Then the symbiotic metal and non-metal impurities are removed by flotation and finally the high purity quartz sand is obtained by rinse.Raw ore treatmentThe common quartz ore is generally quartz lump ore and silica sand. The quartz lump ore needs to be crushed up to 25mm and then ground by rod milling to a certain size, and then enters the subsequent washing, scrubbing, flotation and other processes. The silica sand needs to be screened out the impurities such as soil, organic matter and so on before entering the next stage of processing.Preliminary cleaning and dewateringThe treated raw ore can enter the screw sand washer for preliminary cleaning and dewatering, and some impurities can be removed. At the same time, dewatering is carried out, so that the concentration of quartz sand slurry reaches 60-70%, which is preparation for the subsequent scrubbing operation.ScrubbingThe adjusted slurry of quartz sand is sent to the scrubber for scrubbing. After continuous scrubbing, the soil, impurities covering the surface of quartz sand are separated, and then slurry goes into the washing operation for further treatment.Secondary washingAfter scrubbing, impurities and quartz sand have been separated, impurities exist in the surface of quartz sand and slurry, through the spiral sand washer the purity of quartz sand can be further improved.Silica sand flotationThere are some impurities such as iron oxide, aluminum oxide and mica in the quartz sand after washing. At this time, the impurities can be effectively removed by adding appropriate flotation agents through flotation process, so as to obtain higher purity quartz sand.Further washing and dewateringAfter flotation, quartz sand concentrate can be dewatered by screw sand washer to obtain the final high-purity quartz sand, and its SiO2 content can reach more than 99%.According to the actual production needs, the quartz sand after flotation can be further dewatered and dried, and then through the quartz sand grinding and classifying system the quartz powder can be obtained to meet different industrial needs.

MINGYUAN can provide a complete set of quartz sand processing and purification  solution and equipmets. In addition to the conventional treatment process mentioned above, It can also use particle size classification, strong magnetic separation, acid pickling and other technological processes according to the property of quartz sand to produce high-purity quartz sand products with different requirements.

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