| Fireclay is a kind of clays the PCE ( pyrometric cone equivalent ) of which is higher than 1,580??, and which can be used to produce refractories and?? bauxite used to make refractories. In addition to the higher PCE, they can also keep their volume stable at high temperatures, and they possess resistance to slag corrosion, sudden heating and cooling and a certain mechanical strength, so, they are extremely stable after they are calcined.?
Fireclay is an industrial name, and its main minerals are clay mineral and aluminium hydroxides, such as diaspore, boehmite, gibbsite, nacrite, kaolinite, dickite, allophane
non-clay minerals are quartz, feldspar, mica, and then iron and manganese oxide and hydroxide, carbonate, sulfate, sulfide and other oxide and sillicate minerals.?
Fireclay is mainly used in the metallurgical industry as raw materials for production of shaped refractories (bricks of various specifications) and bulk refractories, consumption of which accounts for about 70% of the total refractories. The hard refractory clay is used in producing refractories for blast furnaces, back-up bricks and domed-head stoppers of iron-making furnaces, air heaters and steel vessels. High-alumina clay is used to produce? aluminous firebricks for electric furnaces and blast furnaces, alumina bushing blocks and alumina castable refractories. Hard clay and high-alumina clay are usually calcinated into clinker at high temperatures (1,400~1,800??).?
Fireclay is used to produce high-alumina bricks, phosphate high-alumina refractory bricks and high-alumina melting bricks for cement kilns and glass melting furnaces in the building materials industry. High-alumina clay can be used to produce aluminium cement by calcination at first, and then mixing the resultant with limestone. This kind of cement has the characteristics of flash setting and high corrosion and heat resistance.?
Fireclay has an important application in the grinding, chemical and ceramic industries. High-alumina clay can be used to produce abrasive materials by smelting in arc furnace. Among them the artificial corundum abrasive is the most widely used one at present, accounting for 2/3 of the total abrasive products. High-alumina clay can also be used to produce various aluminium chemical compounds, such as aluminium sulfate, aluminium hydroxide, aluminium chloride and potassium aluminium sulfate. In the ceramic industry? hard clay and semi-hard clay can be used as raw materials of ceramics for daily use, architectural and industrial ceramics. Additionally, high-alumina clay can be used as a backing agent for cleaning oil in the oil well, as a fertilizer accelerating agent in agriculture and paving materials with slip- and abrasive-resistant performances. Hard clay can be used to produce the new type of fire-proof and heat-insulating material--refractory glass fiber with the advantages of resistance to high temperature, a small coefficient of thermal conductivity, acid-and alkali-resistance, acoustic absorption and light weight, which is wildly used in the metallurgical, mechanical, electronic, glass and ceramic industries.?
Large-scale development and application of refractory materials benefit from the modern industry. Since the founding of the People's Republic of China in 1949,due to the needs of the economic construction and development of the iron and steel industry, geological departments have made a great effort to look for the resources of fireclay and have successively explored and developed many fireclay occurrences, such as the Wanshan and Xiaokoushan fireclay deposits in Zibo, Shandong, the Dongshan deposit in Taiyuan, Shanxi, the Baibidian deposit in Tangshan, Hebei, the Shecun deposit in Gong County, Henan, the Zhahuagou deposit in Baotou, Inner Mongolia and the Shuiquliu deposit in Shulan, Jilin. The output of fireclay had been increased from 22,000 tons in 1949 to 3.644 million tons in 1954, and 7.341 million tons in 1997.
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