Quartz sand, seasonal sandstone and quartzite in nature are collectively referred to as siliceous raw materials and are widely distributed. Timely is the main mineral component of siliceous raw materials and a mineral resource with stable physical and chemical properties, which is widely used in optics, glass, electronics, chemistry, refractories and other industries.
Second, the characteristics of rock mineralogy
The main mineral composition of siliceous primary ore is quartz, and the secondary minerals are feldspar, cuttings, heavy minerals (garnet, tourmaline, pyroxene, amphibole, refined stone, topaz, epidote, ilmenite, etc.). ) and mica, chlorite and clay minerals. Synchronism is the most common mineral formed by SiO2 _ 2 alone in nature, including low-temperature synchronism (α-synchronism) in triangular system and high-temperature synchronism (β-synchronism) in hexagonal system. The most common is low temperature response time, which is usually called response time. The timely aggregate is clustered or granular, massive, stalactite-like, nodular, cleavage-free, conchoidal fracture, glassy, and the fracture is often greasy. Pure colorless and transparent, but mostly gray, yellow to orange, purple, deep purple, pink, grayish brown, brown, black, because it contains trace pigment ions or finely dispersed inclusions, or because of colored centers, the transparency is reduced. The stripes are white. The density is 2.65 ~ 2.66g/cm3. Mohs hardness 7. Refractive index1.533 ~1.541,birefringence difference of 0.009 and dispersion of 0.0 13. Its chemical, thermal and mechanical properties are obviously anisotropic, insoluble in acid and slightly soluble in KOH solution. Timely crystals have optical activity, pyroelectricity and piezoelectricity. Timely crystals often contain solid, liquid and gas inclusions.
Quartz sand refers to all kinds of sand mainly in time, such as sea sand, river sand and lake sand. Timely sandstone is a kind of consolidated sandstone, and its content of timely and siliceous debris is generally above 95%. The accessory minerals are mostly feldspar, mica and clay minerals, and the content of heavy minerals is very small. Common heavy minerals are tourmaline, rutile, magnetite and ilmenite. Cement is usually silica. Quartzite is a metamorphic rock formed by the metamorphism of sandstone or other siliceous rocks.
The grade of siliceous raw ore in China is not high. Generally speaking, the quality of rock ore is better than placer, quartzite is better than timely sandstone, northern sandstone is better than southern sandstone, and sea sand is better than continental sand. The chemical composition of sandstone and quartzite ore is relatively stable, with the content of SiO2 _ 2 generally greater than 97%, Al2O3 generally 0.4% ~ 1.3% and Fe2O3 generally 0.04% ~ 0.39%. The chemical composition of quartz sand ore varies from place to place, with SiO2 content of 82% ~ 99%, Al2O3 content of 0.2% ~ 6% and Fe2O3 content of 0.07% ~ 1.38%. The main harmful impurities in siliceous raw ore are iron compounds. The content of Fe2O3 in quartzite is 0. 12% ~ 1%, most of which is less than 0.2%. The Fe2O3 content in seasonal sandstone is 0.06% ~ 1. 12%, most of which is less than 0.3%. The content of Fe2O3 in quartz sand is 0. 1% ~ 2.5%, most of which is less than 0.6%. Al2O3 content is related to feldspar content, ranging from 0. 1%- 10%.
Third, use.
Siliceous raw materials are widely used in glass, refractories, ceramics, casting, petroleum, chemical industry, environmental protection, grinding and other industries.
1) Metallurgical industry: It has high timely fire resistance, and is mainly used for manufacturing refractory materials (silicon bricks), smelting silicon alloys (ferrosilicon, silicomanganese, silicochromium) and as a flux. Pure crystalline silicon. Crystalline silicon is the main raw material for producing monocrystalline silicon, and it can also be used for producing silicon, aluminum and silicone. Molding sand for foundry industry. Metallurgical industry can be used as smelting additive, flux and various ferrosilicon alloys. Refractory industry can be used as refractory for high temperature bricks, ordinary bricks and kilns.
2) Glass industry: it is the main raw material for making glass, and can also be made into refractory bricks as the kiln lining of glass melting furnaces. Glass products are made of siliceous rocks (sand) as the main raw material, accounting for about 70% of the raw material composition, adding dolomite, limestone, feldspar, soda ash, mirabilite, carbon powder and other ingredients, and then melting, molding, annealing, cutting and other processes.
3) Cement industry: it can be used as the calibration material of portland cement, and sand can also be used as cement ingredients, aerated concrete and ordinary products.
4) Construction industry: it can be used as an important building cornerstone, used as road rockfill and railway ballast.
5) Chemical industry: all kinds of silicides, silicates and nitrates can be made, and the good quality can be used as the packing of acid-resistant sulfuric acid tower. It can also produce lead silicate, potassium silicate, sodium silicate, water glass, silica gel, desiccant, petroleum refining catalyst, exterior wall coating, road coating and so on.
6) Grinding materials: quartzite and timely sandstone can be used as grinding materials such as grindstone, oilstone, sandpaper and carborundum; Quartz sand is also commonly used for sawing stone, polishing glass, polishing the surface of metal products and stone products, and polishing jewelry.
7) Abrasive sand blasting: Quartz sand can be used as abrasive sand blasting to remove the oxide scale on the surface of various aluminum alloy parts and to carry out surface treatment on granite and marble.
8) Other industries: It can be used as raw materials for enamel ceramics and water treatment. Pure products are widely used in insulation materials, decorative materials, radio industry, optical instruments, resonators, oscillators, filters, communication networks, wireless data transmission, high-speed digital data transmission, infrared detectors, thermoelectric laser calorimeters, night vision devices, spectrometer receivers, medical quartz lamp, ultrasonic technology, modern national defense and cutting-edge technology.
Four. geologic feature
There are five main types of siliceous raw material deposits in China.
1) sedimentary metamorphic quartzite deposit. Most of them are generated in the tectonic subsidence zone at the edge of the platform, belonging to coastal-foreshore deposits, which were formed by late diagenesis and slight metamorphism. This kind of Shi Ying deposits include, for example, Xiaomingding Mountain in Benxi, Liaoning Province and Laoqingshan Mountain in Fengyang, Anhui Province, and most of them are large. The ore body is layered, tens to hundreds of meters thick, with no or few interlayers, and the interlayers are regularly distributed. It accounts for more than 95% ~ 99% of the mineral composition of the ore, and contains almost no feldspar, clay minerals and cuttings. Common trace minerals are mica, tourmaline, zircon, rutile, magnetite and apatite. Siliceous cementation and secondary pig iron dyeing are not serious. Chemical composition of ore: 96.42% ~ 99.78% of SiO 2, generally less than 97%; al2o 30. 14% ~ 1.5%； Generally less than1%; Fe2o 30.08% ~ 0.2% ~ 0.5%, generally less than 0. 15%. The ore quality is good, and the particle size is mainly fine, generally between 0.2 and 0.4 mm.
2) Sedimentary quartz sandstone deposits. It is generated in the coastal areas of continental margin on the edge of ancient land or ancient uplift, and mostly belongs to intertidal-supratidal deposition. Quartz sandstone deposits belonging to this type are Qingming Mountain in Suzhou, Jiangsu, Lei Zi Pai in Xiangtan, Hunan and Wan Chao in Kaili, Guizhou, all of which are large in scale. The ore bodies are layered, generally with 2 ~ 3 or 4 ~ 5 layers of ore, with a thickness of tens of meters, but rarely more than 50 meters. The shape of the ore bodies is still stable, and most of them contain irregular layered or lenticular interlayers. It accounts for more than 95% of the mineral composition of the ore, and the particle size is mainly 0.2 ~ 0.5 mm, which is angular-sub-circular and contains a small amount of feldspar, clay minerals and cuttings. Common trace minerals are mica, tourmaline, zircon, rutile, magnetite, ilmenite, hematite and apatite. Siliceous and clayey cementation, with different degrees of secondary pig iron dyeing. Chemical composition of ore: SiO 2 95.58% ~ 99.75%, generally greater than 96%; al2o 3 0.29% ~ 3%； Generally less than1.5%; Fe2O3 0.0 1%~0.24% ~ 0.24%, generally less than 0.2%. The raw ore quality of this kind of ore is generally not as good as quartzite ore, and the ore quality of different deposits is also different, but the ore washability is generally good, and high-quality concentrate can be obtained after beneficiation. In addition, the Mesozoic sandstone distributed in Jiangjin, Yongchuan, Sichuan and Dangyang, Hubei belongs to continental lake deposits.
3) Marine sedimentary quartz sand ore. The deposit is distributed along the coast and belongs to the coastal foreshore subtidal-intertidal sedimentary placer. Quartz sand mines belonging to this type include Fujian Dongshan Wulong, Guangdong Huidong Jiabi, Yangdong Donggou, Guangdong Leizhou Qishui, Dongfang Bawei, Guangxi Beihai, Shandong Baihutou and Shandong Xukou. Most deposits are large. Deposits are generally tens of centimeters above sea level to about 1m, and the beach surface or mine plane is inclined at a small angle to the sea surface. The bottom of coal seam is sandy clay rich in organic matter in coastal intertidal zone. The ore body is layered, several meters to more than ten meters thick, containing lenticular interlayer, mostly organic clay sand. It accounts for more than 90% ~ 99% of the mineral composition of the ore, with fine particles, uniform particle size and good sorting, and contains a small amount of feldspar, clay minerals and cuttings. Common trace minerals are mica, tourmaline, zircon, rutile, magnetite, ilmenite, white titanium ore, garnet, monazite and so on. And secondary pig iron dyeing of some chromium-containing spinel in different degrees. Chemical composition of ore: SiO 2 92. 12% ~ 98.45%, generally greater than 92%; Al2O3 0. 1% ~ 3.5%, generally less than 2.5%; Fe2O3 0.0 1% ~ 0.2 1%, generally less than 0.2%. The ore quality is good, although there are changes in each producing area, there are certain regularity, and there is a close relationship between mineral composition, chemical composition and particle composition.
4) Quartz sand deposits in rivers and lakes. Quartz sand deposits distributed on both sides of the middle reaches of the Yellow River, such as Hujingzui in Lanzhou, Gansu and Sidaoquan in Otog Banner, Inner Mongolia, belong to floodplain deposits. Quartz sand deposits such as Baimajian in Suqian, Jiangsu Province and Chenggang in Xinyi are distributed at the junction of yi river, Shuhe and Luoma Lake in Jiangsu Province, at the foot of Maling Mountain, and belong to river delta facies deposits. High-grade quartz sand concentrate can be obtained by cross bedding development, complex structure, great thickness variation, poor ore quality, weak clay cementation, sand-mud separation after elutriation, further mineral processing and feldspar separation. Quartz sand deposits, such as Tuerjishan, Ganqika and Zhanggutai, distributed in Tongliao Basin in Northeast China, belong to fluvial-lacustrine deposits, with stable distribution, uniform mineral composition and particle size, simple internal structure and black and gray clay sand layers containing organic matter as interlayers. After the Holocene basin rose, aeolian deposits were formed, forming today's aeolian landscape. The scale of deposits is from small to large. The ore bodies are irregular or lenticular, generally several meters thick, and contain lenticular interlayers composed of different ore bodies or clay layers, with irregular distribution. It accounts for 80% ~ 95% of the mineral composition of the ore, and contains more feldspar, clay minerals and cuttings. Common trace minerals are mica, tourmaline, zircon, rutile, magnetite, ilmenite, garnet, epidote and chlorite, all of which are dyed with secondary pig iron to varying degrees. Chemical composition of ore: SiO2 8 1.70% ~ 98.46%, Al2O3 1.5% ~ 9.29%, Fe2O3 0.07% ~ 1.03%.
5) Lacustrine sedimentary quartz sand ore. Modern lakeside sedimentary quartz sand deposits are mainly distributed in Hukou, Yongxiu and other places on the east bank of Poyang Lake in Jiangxi Province, and are still receiving lacustrine deposits. The scale of deposits is from small to large. The ore body is layered and several meters thick, and the distribution law between layers is regular. It accounts for more than 90% of the mineral composition and contains more feldspar and cuttings. Common trace minerals are mica, tourmaline, rutile, magnetite, garnet, epidote and chlorite. Dyed with different degrees of pig iron. Chemical composition of ore: 92% ~ 95.54% of SiO 2, generally 93%; Al2O3 0. 1% ~ 5.5%, generally 2.5%; Fe2O3 is 0.07% ~ 0.32%, generally 0. 16%.
Verb (abbreviation of verb) mineral distribution
1) quartz sand ore. Distributed in Hainan, Jiangxi, Guangdong, Fujian, Inner Mongolia, Jilin, Guangxi, Jiangsu, Shandong, Liaoning, Gansu, Heilongjiang, Xinjiang, Ningxia and other provinces. Hainan accounts for 49.69%, Jiangxi accounts for 1 1.38%, and Guangdong accounts for114%. Most quartz sand mines in China are distributed in the eastern Quaternary modern littoral sediment and the coastal areas of Jiaodong Peninsula. The main metallogenic belt is the quartz sand mine distribution belt along the southern coast, which starts from southern Fujian, including Huidong, Yangxi, Leizhou and Hainan in Guangdong, and ends in Beihai in Guangxi. It is the main development and utilization object of China's sea sand mines. Quartz sand deposits in rivers and lakes are mainly distributed in the Quaternary system of Tongliao Basin at the junction of Inner Mongolia, Jilin and Liaoning. The distribution of Tongliao quartz sand deposits includes Xiliaohe-Liuhe area, and the deposits are mainly concentrated along Dazheng Railway, which is one of the main supply bases of Shi Ying raw materials for glass in northern China. River alluvial quartz sand (rock) deposits are mainly distributed in the middle reaches of the Yellow River and the Neogene in Suqian, Anhui Province. Lacustrine quartz sand deposits were found in Quaternary in the first or second terrace on the east bank of Poyang Lake in Hukou-Yongxiu area, Jiangxi Province, and some deposits have been used by nearby glass factories.
2) Quartz sandstone deposit. Distributed in Shandong, Sichuan, Hebei, Jiangxi, Hunan, Jiangsu, Zhejiang, Guizhou, Shanxi, Hubei, Yunnan, Ningxia, Jilin, Guangxi, Shaanxi, Beijing, Xinjiang, Gansu, Inner Mongolia and other provinces (autonomous regions and municipalities). Shandong accounts for 28. 16%, Sichuan accounts for 1 1.83%, and Hebei accounts for 9.03%.
Yingshi sandstone deposit in China is mainly located in the sedimentary cover of Yangtze platform, and the occurrence horizon is mainly Devonian, followed by Sinian, Cambrian, Jurassic, Triassic and Neogene. The ore beds are often located in shallow sea facies or sea-land sedimentary facies. The main metallogenic area is the distribution area of seasonal sandstone in the Yangtze River basin, starting from Jiangsu and Zhejiang in the east, reaching Hubei in the west, Hanzhong in Shaanxi in the north and Hunan and Guizhou in the south. There are many mineral deposits, large scale and good quality. In addition, many large quartz sandstone deposits have been found in Cambrian in Yinan and Cangshan, forming another timely sandstone metallogenic area.
3) Quartzite deposit. Distributed in Qinghai, Liaoning, Shaanxi, Anhui, Shandong, Henan, Gansu, Fujian, Shanxi, Zhejiang, Beijing, Inner Mongolia, Jiangsu, Xinjiang, Jiangxi, Jilin and other provinces (autonomous regions and municipalities). Qinghai accounts for 69.25%, Liaoning accounts for 12.45%, and Shaanxi accounts for 7.80%.
The Shi Ying deposit in China is mainly located in the secondary subsidence zone of North China platform and Qilian fold zone, and also distributed in Yangtze platform. The ore-bearing strata are mostly Precambrian, and some are Silurian and Devonian. The main metallogenic areas are quartzite (seasonal sandstone) in Liaoning, Hebei and Henan, starting from Baishan, Jilin, passing through Liaoning, Hebei, Beijing and Shanxi, and ending in Henan. Generally distributed in the northeast, strictly controlled by Sinian ore-bearing strata. Another metallogenic area is the distribution zone of quartzite (seasonal sandstone) in Xining-Bohai Bay. The ore belt is distributed in the western margin of China-Korea platform, and the scale and quality of the deposit are not as good as the former, but it is the main object of development and utilization in northwest China. The main metallogenic belt of sedimentary metamorphic quartzite is the southern Liaoning-Fengyang quartzite distribution belt, and the deposits are distributed in Zhuanghe, Liaoning, Pixian, Jiangsu and Fengyang, Anhui. See Figure 2-46- 1 for details.
Fig. 2-46- 1 Schematic diagram of distribution of siliceous raw material deposits in China.
The available resources of intransitive verbs
By the end of 2005, 228 mineral deposits have been discovered in China, with a resource reserve of 47× 108t (Table 2-46- 1). In terms of quantity, the supply of siliceous raw materials in China exceeds demand, and some of them are exported besides meeting domestic demand; From the variety point of view, the shortage of high-quality siliceous raw materials has affected the stability and improvement of the quality of flat glass products to some extent.
Table 2-46- 1 Distribution of proven resources and reserves of different types of siliceous raw material deposits in China (104t, ore).
(According to Notice of Ministry of Land and Resources on National Mineral Resources Reserves, 2005)