Brief introduction of main raw materials of quartz sand precipitation silica

* Source: * Publication time: 2021/09/16 13:59:43 * Browse: 45

Quartz sandbrief introduction

Quartz sand is a kind of quartz particle formed by crushing quartz stone. Quartzite is a non-metallic mineral and a silicate mineral with hard, wear-resistant and stable chemical properties. The color of quartz sand is milky white or colorless translucent, and the Mohs hardness is 7. Quartz sand is an important industrial mineral raw material and non chemical dangerous goods. It is widely used in glass, casting, ceramics and fireproof materials, smelting ferrosilicon, metallurgical flux, metallurgy, construction, chemical industry, plastics, rubber, abrasive, filter materials and other industries. Quartz sand is also the main raw material of precipitated silica！

The article "driven by cost, the price of precipitated silica is about to rise again" mentioned that the recent price rise of major domestic precipitated silica manufacturers is mainly due to the rise in the price of raw materials such as soda ash and sulfuric acid, and did not mention the core raw material quartz sand, because quartz sand is rich in resources, widely distributed and relatively concentrated, and the price is relatively stable, Only around 2021 will there be a certain increase in prices.

Quartz sand is the most common and widely used non-metallic mineral raw material in nature. There are many kinds of quartz sand deposits in China, mainly including quartzite, quartz sandstone, natural quartz sand and vein quartz. However, its quality is not high, mostly quartzite, quartz sandstone and natural quartz sand, which account for 99.07% of China's quartz mineral resources, while high-quality gangue talents account for 0.93% of China's quartz mineral resources.

Domestically, Lianyungang, Jiangsu, Fengyang, Anhui, Lingshou County, Hebei, Heyuan, Guangdong and Linyi, Shandong are the main production plants of quartz raw materials, accounting for 80% of the national market. Their raw materials are famous for their high purity and large output. Fengyang is the most famous producer of quartz sand, while AHU town is the most high-quality quartz sand.

Proportion of different types of quartz resources in China

Due to different metallogenic ages and geographical locations of quartz deposits, their metallogenic periods and representative deposits are shown in the table.

Types of quartz deposits in China

China is rich in quartz sand resources, which are widely distributed and relatively concentrated. Among them, the reserves of quartz sand resources in Northwest China account for 49% of the reserves of quartz sand resources in China.

中国石英砂资源分布图

Distribution of quartz sand resources in China

1. Distribution of quartzite resources

　　Quartzite is formed from siliceous rock or quartz sandstone after a series of metamorphism and thermal contact. The content of quartz minerals in quartzite is generally greater than 85%, which is often associated with tourmaline, zircon, mica, feldspar and clay. Its hardness and density are higher than that of quartz sandstone.

quartzite

　　Quartzite deposits in China are mostly distributed in Qinghai, Anhui, Liaoning, Shaanxi and other places. Qinghai has 289 million tons of quartzite for metallurgy and 1.647 billion tons of quartzite for glass, mainly distributed in Xining city and Haidong area. Fengyang County, Anhui Province is the "100 billion yuan silicon industry base" in the national key planning. It is extremely rich in quartz sand resources, covering an area of 80 square kilometers, with prospective reserves of more than 10 billion tons and silica content of more than 99%. The proved reserves of quartzite in Benxi City, Liaoning Province are about 3.7 billion tons, and the grade is high. The average SiO2 content is greater than 97%, and the SiO2 content of high-quality quartzite can reach 99.4%. The reserves of quartzite for glass in Shaanxi are about 187 million tons.

　　2. Distribution of quartz sandstone

　　Quartz sandstone is a kind of sedimentary sandy rock formed by the consolidation of quartz sand particles by external cement. The content of siliceous rock debris and quartz is more than 95%. The common cements in quartz sandstone include silica cements such as chalcedony and opal, which are often associated with minerals such as tourmaline, rutile, magnetite, mica, feldspar and clay.

Quartz sandstone

　　Quartz sandstone deposits in China are mostly distributed in Sichuan, Hunan, Jiangsu, Zhejiang, Yunnan and Shandong. The source reserves of quartz sandstone in Sichuan are 39 million tons, mainly distributed in Luxian county and other places, and the proved reserves of quartz sandstone in Luxian county are about 20.8 million tons. The reserves of quartz sandstone in Xupu County, Hunan Province reach 1-2 billion tons, and its tanjiawan quartz sandstone mine is one of the high-quality silica sand bases in China.

　　
　　3. Distribution of natural quartz sand

　　Natural quartz sand is a sandy particle formed by weathering, water flow impact and natural aggregation of vein quartz, quartzite, granite and quartz sandstone. Its main mineral composition is quartz, and the associated minerals are mainly ilmenite, feldspar, mica, zircon, clay minerals, tourmaline and amphibole. The variety of impurity components fluctuates greatly.

　　China's natural quartz sand is mainly distributed in the coastal areas of Fujian, Guangdong, the south of Guangxi, the northwest of Hainan and the north of Shandong, as well as the east of Xiliao River, the middle reaches of the Yellow River, Poyang Lake and Luoma Lake.

　　The typical deposit types of natural quartz sand can be divided into two types: marine sedimentary sand deposit and river lake sedimentary sand deposit.

　　4. Distribution of vein quartz

　　Vein quartz is filled in the rock gap by molten magma containing silica and magmatic hydrothermal veins related to granite, and then distributed on the surface of the earth's crust in the form of width of about several meters, thickness of several meters to tens of meters and length of more than ten to hundreds of meters. It is condensed into dense crystalline quartz after rapid cooling. The main producing areas are granite gneiss area and granite area. In most cases, the shape of the ore body is irregular vein form. A single vein quartz mining area can be composed of single or multiple veins. The vein quartz color is pure white, greasy luster, and its purity is very high. The mineral composition is basically quartz, and its SiO2 content reaches more than 99%.

　　Vein quartz deposits in China are mainly distributed in metamorphic rock areas in the East China Sea, Sichuan, Heilongjiang and Hubei of Jiangsu Province. In Qichun County, Hubei Province, the quartz reserves exceed 100 million tons, the silicon content reaches more than 99.98%, and the grade ranks first in the country.

Eight major quartz ore sources in China

According to the metallogenic time of quartz ore, the distribution of quartz resources and main deposits in China, quartz ore resources can be divided into 8 major ore forming areas.

1. Liao Yi Yu quartz (sandstone) distribution area. From the northernmost Hunjiang River in Jilin, through Liaoning, Hebei, Beijing and Shanxi to Fangshan in Henan, it is basically distributed in a north-east direction, and is strictly controlled by the Proterozoic and Sinian ore bearing beds. It is the main ore bearing area in China.

2. Sandstone distribution area in the Yangtze River Basin. It starts from Jiangsu and Zhejiang in the East, passes through Jiangxi to Hubei, extends to Hanzhong, Shaanxi in the north, and extends to Guangxi, Hunan and Guizhou in the south. It is the main metallogenic area in southern China.

3. Distribution area of sand deposits along the south coast. It is mainly distributed along the southeast coast, starting from Jinjiang River in Southern Fujian in the north and Beihai in Guangxi in the south. It is the main sea sand ore distribution area in China.

4. Tongliao placer distribution area. It is a vast area of West Liaohe Liuhe river. At present, the deposits are mainly concentrated along the Zhengzhou Dalian railway. It is one of the main supply bases of siliceous raw materials in northern China.

5. Placer distribution area along the Yellow River. Such as Lanzhou Hewan placer and Inner Mongolia sidaoquan placer.

6. Suqian, Nanning and Dangyang placer distribution areas. Controlled by the original sedimentary basin. The emergence of single encouragement.

7. Yinan quartz sandstone distribution area. Quartz sandstone is widely distributed in Yinan area.

8. Southern Liaoning Fengyang quartzite distribution area. The distribution is relatively stable, the deposit scale is large and the quality is good.

On the whole, there are many kinds of quartz ore raw materials in China with different quality. With the rapid development of national economy, science and technology, the application of quartz sand is no longer limited to the traditional fields of glass and plate construction, but more used in high-tech industries, such as semiconductor, optical fiber communication, aerospace and so on. This also puts forward higher requirements for the quality of quartz sand.

Main classification of quartz sand

Quartz has high fire resistance. In industry, quartz sand is often divided into ordinary quartz sand, refined quartz sand, high-purity quartz sand, molten quartz sand and silicon powder。

1. Ordinary quartz sand

Ordinary quartz sand, i.e. SiO2 ≥ 90-99%, Fe2O3 ≤ 0.06-0.02%, fire resistance 1750 ℃, appearance: some large particles have yellow skin cysts on the surface. Ordinary quartz sand is generally a kind of water treatment filter material made of natural quartz ore through crushing, washing, drying and secondary screening; The filter material has the characteristics of no impurities, no edges and corners, high density, high mechanical strength and long service cycle. It is an ideal material for chemical water treatment. The particle size range is 5-220 mesh, which can be produced according to the user's requirements. Main uses: metallurgy, ink, silicon carbide, glass and glass products, enamel, cast steel, water filtration, bubble alkali (water glass), chemical industry, spray noise and other industries.

2. Refined quartz sand

Also known as pickling quartz sand, SiO2 ≥ 99-99.5%, Fe2O3 ≤ 0.005%, using high-quality natural quartz sand and mortar.

3. High purity quartz sand

SiO2 ≥ 99.5-99.9%, Fe2O3 ≤ 0.001%, high-quality natural quartz stone and mortar are used. (mm is mm)

4. Fused quartz sand

Chemical composition: SiO2: 99.9-99.95%, Fe2O3: 5ppm-25ppm max, Li2O: 1-2ppm max, Al2O3: 20-30ppm max, K2O: 20-25ppm max, Na2O: 10-20ppm max

Physical properties: colorless, transparent block, particle or white powder in appearance, relative specific gravity: 2.21. Mohs hardness: 7.0, pH value: 6.0.

5. Silicon powder

Micro silicon powder: gray or gray white powder in appearance, fire resistance > 1600 ℃. Unit weight: 200 ~ 250kg / m3. See the following table for the chemical composition of silicon powder：

Main uses of quartz sand

The unique physical and chemical properties of quartz sand make it play an important role in aviation, aerospace, electronics, machinery and today's rapidly developing IT industry. In particular, its internal molecular chain structure, crystal shape and lattice change law make it have high temperature resistance, low coefficient of thermal expansion, high insulation, corrosion resistance, piezoelectric effect Resonance effect and its unique optical characteristics play a more and more important role in many high-tech products.

1. Glass industry

Glass is the main raw material of flat glass, float glass, glass products (glass cans, glass bottles, glass tubes, etc.), optical glass, glass fiber, glass instruments, conductive glass, glass cloth and ray proof special glass.

2. Ceramics

Raw materials for ceramics and refractories, porcelain blanks and glazes, high silica bricks, ordinary silica bricks and silicon carbide for kilns; Raw materials or additives for metallurgical silicon metal, ferrosilicon alloy and silicon aluminum alloy, flux concrete, cementitious materials, road building materials, artificial marble, cement physical property inspection materials (i.e. cement standard sand), etc.

3. Chemical industry

Abrasive materials (sand blasting, hard abrasive paper, sandpaper, abrasive cloth, etc.), sand cleaning, rust removal and oxide scale removal;

Electronic high purity metal silicon, optical fiber for communication, etc;

Rubber and plastic fillers (can improve wear resistance);

Coating filler can improve the weather resistance of the coating;

It is used for sand cleaning, rust removal, strengthening, forming, stress relief, surface cleaning and coating of various profiles, roughness (roughening) pretreatment before electroplating, stone cutting, magnetic shot casting, etc As an additive for heavy concrete and blast furnace refractory to increase its wear resistance, high temperature resistance, erosion resistance, electrostatic shielding, radiation protection, oil well filter tank, counterweight, etc;

The surface treatment of granite and marble uses high-quality quartz sand as raw materials. It is a special lawn product specially designed and produced for sports venues. It has the characteristics of high hardness, large ratio, uniform particle size, small edges and corners, natural color and so on. It has little damage to the artificial lawn, forms the role of protecting grass wool, and makes the lawn more durable. Quartz sand is an ideal material for modern track and field fields, football fields, golf courses and other man-made venues.

4. Water treatment filter material

Because the quartz sand particle size of the three-layer filter material filter bed is smaller than that of the double-layer filter material, and there is a finer layer of heavy anthracite filter material under the quartz sand layer, the water quality of the filtered water of the three-layer filter material filter is better than that of the two-layer filter material filter under the same other conditions or even higher filtration speed. When using quartz sand, try to use it together.

5. Quartz sand filter

The tail water of the sewage plant enters the bottom of the filter through the inlet pipe, evenly distributes the water through the water distributor, and then passes through the filter material layer from top to bottom. In this process, the tail water is filtered to remove pollutants in the water. At the same time, the content of pollutants in quartz sand filter material increases, and the degree of pollutants in the lower filter material layer is higher than that in the upper filter material. At this time, open the air lift pump in the center of the filter and lift the quartz sand filter material at the lower layer to the sand washer at the top of the filter for cleaning. The filter sand is returned to the filter bed after cleaning, and the pollutants generated by cleaning are discharged. The quartz sand filter material moves from top to bottom under the action of the lifting pump to stir the tail water. The filter material in the filter can be cleaned in time and has strong resistance to pollutant load impact. The special internal structure and operation characteristics of quartz sand filter make coagulation, clarification and filtration complete in the same tank.

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Brief introduction of main raw materials of quartz sand precipitation silica

1. Ordinary quartz sand

2. Refined quartz sand

3. High purity quartz sand

5. Silicon powder