Refractory clay refers to clay with fire resistance greater than 1580℃. According to its physical and chemical properties, ore characteristics and industrial uses, it is generally divided into soft clay, semi-soft clay, hard clay and high alumina clay.
The main minerals commonly found in refractory clay are diaspore, diaspore, gibbsite, pearl clay, kaolinite, dickite, diaspore, halloysite, illite, pyrophyllite and montmorillonite. See table 3-21-1for the chemical composition of these main minerals; The secondary minerals in refractory clay include limonite, hematite, pyrite, siderite, ferrotitanium, rutile, anatase, Yingshi, opal, chalcedony, tourmaline, zircon, garnet, feldspar, amphibole, pyroxene, sphene, calcite, dolomite, gypsum and so on.
Harmful impurities in refractory clay mainly include iron oxides, hydroxides, sulfides, carbonates, free silica, carbonates and sulfates of calcium and magnesium, oxides of manganese, oxides of potassium and sodium, carbon and organic matter. In addition, the function of titanium oxide in refractory clay is often different because of its different content.
Table 3-2 1- 1 Chemical Composition of Common Major Minerals in Refractory Clay
Table 3-2 1-2 Industrial Types of Refractory Clay Ore
Note: high alumina clay and hard clay are not plastic, but semi-soft clay and soft clay are plastic.
The chemical composition of refractory clay is generally unstable. The main components are Al2O3, SiO2 and H2O, and the secondary components are TiO2, Fe2O3, FeO, CaO, MgO, Na2O, K2O, CO2, SO3 and organic matter.
Two. Ore types and industrial requirements
1. Industrial types of refractory clay ore
See table 3-2 1-2.
2. Industrial requirements
See table 3-2 1-3 for general quality requirements of refractory clay, and table 3-2 1-4 for general requirements of mining technical conditions of the deposit.
Table 3-2 1-3 General Quality Requirements of Refractory Clay
Table 3-2 1-4 General requirements for mining technical conditions of refractory clay deposits
The reference indexes for evaluating high impurity refractory clay are as follows. High impurity refractory clay refers to refractory clay with high alkali, high titanium and high iron, and there are four common types.
The industrial index of (1) high-alkali and high-alumina clay (containing K2O+Na2O > 1%) requires K2O+Na2O < 2% and TiO < 4.5%, which can be used to make low-grade high-alumina products and bricks for casting, without the requirement of load softening temperature.
(2) Refer to Table 3-2 1-5 for the reference index of high alkali hard clay (including K2O+NAO > 1%).
Table 3-2 1-5 Reference Industrial Index of High Alkaline Hard Clay
(3) high-titanium refractory clay (TiO 2 >); 4.5%) In addition to the general requirements, its industrial index requires high-titanium and high-alumina clay TiO 2 <15%; For high-titanium and high-alumina clay, TiO 2 < 7.5% is generally required.
(4) The industrial requirement of high-iron refractory clay (Fe2O3 > 3.5%) is Fe2O3 < 5%.
Three. Overview of mineral resources
China is rich in refractory clay resources, which is one of the dominant minerals in China. The types and varieties of ores are complete. There are more than 250 kinds of mineral resources in China, which are distributed in most provinces, municipalities and autonomous regions. Shandong, Shanxi, Hebei, Henan, Liaoning, Inner Mongolia, Jilin and Hubei are relatively concentrated, and the proven reserves account for 76% of the country. High alumina clay is mainly distributed in Shanxi, Henan and Guizhou. Hard clay is mainly distributed in Liaoning, Inner Mongolia, Hebei, Shandong, Henan, Hubei, Anhui and Sichuan. Soft clay is mainly distributed in Heilongjiang, Jilin, Inner Mongolia, Shanxi, Henan and Guangdong.
Refractory clay minerals are mostly distributed in coal storage basins, which is very beneficial to development. At present, the main mineral resources are: Yangquan, Xiaoyi, Shanxi, Gongxian, Xin 'an, Tangshan, Shahe, Zibo, Xiuwen, Guizhou, Zhungeer, Inner Mongolia, Fuxian, Liaoning, Lan Shu, Mudanjiang, Heilongjiang, Huaibei, Anhui, Enshi, Hubei Yicheng, Shaanxi Tongchuan and other refractory clay minerals.
Refractory clay deposits are mostly distributed on the ancient land edge, and some deposits are distributed on the ancient erosion surface. About 80% of the sediments come from Carboniferous to Permian, 65,438+00% from Jurassic and the rest from Tertiary and Quaternary.
Refractory clay minerals are widely distributed in Henan province, with large reserves and complete varieties, which is one of the superior mineral resources in our province. By the end of 199 1, there were 4 refractory clay mines with proven reserves in the province. Among them, there are 5 large ones, 24 medium ones and 2 small ones/kloc-0. The accumulated proven reserves are 294.332 million tons, and the retained reserves are 279.489 million tons, which is second only to Shanxi Province in all provinces, municipalities and autonomous regions in China.
Refractory clay mines in Henan Province are distributed in six cities 15 counties (cities) in western Henan, northern Henan and central Henan, namely Jiaozuo, Zhengzhou, Luoyang, Sanmenxia, Pingdingshan and Xuchang. Among them, Zhengzhou has the most abundant reserves, with 9 mining areas in China sharing114196000t, accounting for 40.86% of the total reserves in the province. Secondly, there are 8 mineral deposits in Luoyang, with an ore reserve of 76.779 million t, accounting for 27.47% of the total reserves in the province. Then there are four mining areas in Jiaozuo,/kloc-0, with an ore reserve of 42.999 million tons, accounting for 15.38% of the whole province. Downward are Sanmenxia, Pingdingshan and Xuchang. The number of ore deposits is 5, 3 and 2 respectively, and the ore reserves are 20.065 million t, 6.5438+09.577 million t and 5.873 million t in turn.
Judging from the degree of geological exploration, of the 4 1 deposit, 23 have been explored in detail, with a reserve of 85.803 million tons, accounting for 30.70% of the total reserves; After preliminary exploration, there are 8 reserves of157.069 million t, accounting for 56.20% of the total reserves; After detailed investigation, there are 8 reserves of 30.744 million tons, accounting for 1 1.00% of the total reserves. There are only two places in the preliminary investigation, with a reserve of 5.873 million t, accounting for only 2. 10% of the total reserve. The above data show that there are 3/kloc-0 clay mineral areas that have reached the level of detailed investigation and pre-investigation, and the ore reserves account for 86.90% of the total. The geological exploration degree of refractory clay ore is relatively high.
In terms of mineral assemblage, there are only seven single refractory clay deposits with a reserve of 20 1.52 million t, accounting for 7.2 1% of the total reserves. The main mineral is refractory clay, and there is 12 deposit coexisting with other minerals. The reserves of refractory clay ore are 129 139000 t, accounting for 46.2 1% of the total reserves. There are 22 clay deposits coexisting with bauxite, hematite, pyrite and other minerals, with a reserve of130198,000 t, accounting for 46.58% of the total reserves. There are few refractory clay minerals produced in the form of single mineral.
Judging from the genesis of the deposit, the types of refractory clay deposits are very simple, both of which belong to chemical and biochemical sedimentary deposit types. The ore-bearing stratum is mainly benxi formation of Middle Carboniferous, which is a set of clay rocks rich in aluminum and iron deposited on the weathering and denudation surface of Ordovician or Cambrian. The reserves of refractory clay minerals in this horizon account for more than 90% of the total reserves, and minerals such as bauxite, hematite and pyrite are often associated with it. Another ore-bearing stratum is the Upper Shihezi Formation of Permian. At present, only a few mining areas have proven reserves.
According to mineral types, there are three kinds of high alumina clay minerals, hard clay minerals and soft clay minerals. Among them, hard clay ore is the most, with a reserve of 6.5438+0.425 million t, accounting for 50.99% of the total reserves. Followed by high alumina clay ore, the reserves are1173.25 million t, accounting for 4 1.98% of the total reserves. Soft clay ore is the least, only 6.5438+0.9664 million t, accounting for only 7.04% of the total reserves. The main component of soft and hard clay minerals is kaolinite, while the main component of high alumina clay minerals is diaspore, and its Al2O3 content is higher than the former, so its refractoriness is also the highest.
In terms of ore grade, I and II are the majority, and the ores above and containing II account for 8 1.47% of the total. Among them, hard clay minerals13.294 million tons, accounting for 4.76% of the total clay minerals; Grade I products were 59.344 million tons, accounting for 265.438+0.23% of the total; 65.295 million tons of Grade II products, accounting for 23.36% of the total; Grade III products are 2.875 million tons, accounting for only 65.438+0.03% of the total. High alumina clay ore is 2.837 million tons, accounting for 65.438 0.02% of the total; Grade II products were 67.875 million tons, accounting for 24.28% of the total; Grade III products reached 42.767 million tons, accounting for 65.438+05.3% of the total. Grade I soft clay ore12.996 million tons, accounting for 4.65% of the total; Grade II products were 6.068 million tons, accounting for 2.17% of the total; The third-class products are only 600,000 t, accounting for only 0.2 1% of the total. In addition, there are some unknown grades in hard and high alumina clay ores.
According to the mining method of the deposit, the ore suitable for open-pit mining is 1 10857 thousand tons, accounting for 39.66% of the total; Underground ore to be mined is 7038 1 10,000 tons, accounting for 25.18% of the total reserves; There are 64 1.97 million tons that can be mixed, accounting for 22.97%. In addition, there are still 34.054 million tons of ore whose mining method is unknown, accounting for 65.438+02. 18% of the total reserves.
The development and utilization of refractory clay mines in Henan Province began as early as 1950s. By the end of 199 1 year, the accumulated stone was mined148.43 million tons. Of the 4 1 deposits in the province, 13 is under exploitation, with a reserve of114.348 million t; Production has stopped at 1 place, with a reserve of 910000t; Closed pit after ore mining 1 piece; There are 26 undeveloped deposits with a reserve of 16423.38+00000 t. Among the 26 undeveloped deposits, 1 1, with a reserve of 601710000t, is recommended for utilization recently. Four places are available for exploration and exploitation, with reserves of 59822438+00000 t; 1 1 is worthy of further work, with an existing reserve of 44.239 million t.
Jiaozuo is the first city in Henan Province to develop and utilize refractory clay minerals. Eight of the 14 deposits in the city have been developed and utilized, with a total of 9.557 million tons of stone mined over the years, accounting for 64.4% of the total stone mined in the province. The main mining units are Jiaozuo clay mine of WISCO, Anyang slope clay mine of Jiaozuo, Xizhangzhuang clay mine of Jiaozuo and Shangliuzhuang clay mine of Jiaozuo. Followed by Zhuangtou mining area in Dengfeng County. Dengfeng clay mine mined 3 16. 1 10,000 t of stone, accounting for 2 1.3% of the total mined stone in the province. Followed by gongyi city Shecun mining area. Gongyi clay mine mined 6.5438+343 million tons of stone, accounting for 9.0% of the total stone mined in the province. In addition, Zhang Yaoyuan, Yushan in Xin 'an County, Qiligou in Sanmenxia City and Dujiagou in Shaanxi County also have a small amount of mining. Henan refractory clay mine has large reserves, good quality, easy mining and convenient transportation, and is an important production base of refractory materials in China.
Four, the main use of refractory clay
Refractory clay is usually used as the raw material of refractories in industry, generally used in clay refractories and high alumina refractories. Mainly used in metallurgy, machinery and other departments, followed by light industry, building materials, chemical industry, national defense and other departments.
Verb (abbreviation of verb) industrial and technical indicators of products
(1) Technical requirements of the standard Technical Conditions for Hard Clay Clinker (YB22 1 1-82) issued by the Ministry of Metallurgy. This standard is applicable to hard clay clinker products for refractory materials.
The products are classified into the following grades according to their physical and chemical indexes, which are listed in Table 3-2 1-6.
Table 3-2 1-6 Physical and Chemical Indicators of Products
(1) The product calcined in contact with coal passes through a 5mm standard sieve, and the discharge does not exceed 5%; The products calcined in rotary kiln and external combustion kiln pass through the screen of 5mm standard screen, and the output is not more than 8%.
(2) Impurity content in products: no more than 3% for superior products and no more than 4% for other grades.
(3) The products shall not be mixed with limestone, loess and other foreign inclusions such as high calcium and high iron.
(2) The technical requirements of Technical Standard for High Alumina Clinker (YB22 12-82) are applicable to high alumina clinker products for refractories.
(1) products are classified into the following grades according to their physical and chemical indexes, as shown in Table 3-2 1-7.
Table 3-2 1-7 Physical and chemical indexes of high-alumina clinker products
(2) The products calcined in contact with coal shall pass through the sieve of 10mm standard sieve, and the discharge shall not exceed10%; The products calcined in rotary kiln and external combustion kiln pass through the screen of 5mm standard screen, and the output is not more than 10%.
(3) The impurity content in the product shall not exceed 4%.
(4) In the same grade, adjacent mixed products are allowed not to exceed 10%.
(5) The products shall not be mixed with limestone, loess and other foreign inclusions such as high calcium and high iron.
(3) Physical and chemical indexes of soft and semi-soft clay are shown in Table 3-21-8 (Yb 2213-78-78).
Table 3-2 1-8 Physical and chemical indexes of soft and semi-soft clay products
(4) See Table 3-2 1-9 for the standard classification of high alumina clay.
Table 3-2 1-9 Standard Classification of High Alumina Clay
(5) Quality requirements of refractory clay for ceramic raw materials.
(1) uniform quality of raw materials; ②Fe2O3 is less than 0.5%; ③ It has appropriate plasticity; (4) after firing, the color is pure white and does not deform; ⑤ When molding and drying, the shrinkage is even and there is no crack.
There is no standard for quality requirements of other uses, but you can refer to the quality requirements of main uses.