Mud kiln, metallurgical and chemical kiln and lime kiln.
Rotary kilns can be divided into cement kilns, metallurgical and chemical kilns and lime kilns according to different materials. Cement kilns are mainly used to calcine cement clinker, which can be divided into dry production kilns and wet production kilns. Metallurgical and chemical furnaces are mainly used for magnetizing roasting of lean iron ore in metallurgical industrial steel mills; Oxidation roasting of chromium and nickel iron ore: high alumina vanadium clay ore is roasted in refractory plant, clinker and aluminum hydroxide are roasted in aluminum plant; Chemical plants roast minerals, such as chrome ore sand and chrome ore powder. Lime kiln (active lime kiln) is used to roast active lime and lightly burned dolomite used in iron and steel plants and ferroalloy plants.
In building materials, metallurgy, chemical industry, environmental protection and many other production industries. Rotary circulating equipment is widely used for mechanical, physical or chemical treatment of solid materials, which is called rotary kiln.
Brick kiln equipment
The application of rotary kiln originated from cement production. 1824, British cement worker J. ASP invented the intermittent soil shaft kiln. 1883, Dietz invented the continuous multi-layer vertical kiln; 1885 British Langsam invented the rotary kiln, which was put into production after being patented in Britain and America, and soon gained considerable economic benefits. The invention of rotary kiln makes the cement industry develop rapidly, and also promotes the research on the application of rotary kiln. Soon rotary kiln was widely used in many industrial fields, and became more and more important in these production, becoming the core equipment of the corresponding enterprises. Its technical performance and operation largely determine the quality, output and cost of enterprise products. The folk proverb "As long as a big kiln turns, there will be tens of millions" vividly describes the importance of rotary kiln in production. In the application field of rotary kiln, the cement industry has the largest number.
The whole production process of cement is summarized as "two grinding and one burning", in which "one burning" is the process of calcining the raw materials that have been ground into mature materials in a rotary kiln at high temperature. Therefore, rotary kiln is the main engine in cement production, commonly known as the "heart" of cement plant. In the building materials industry, in addition to cement clinker, rotary kiln is also used to calcine clay, limestone and slag. In the production of refractories, raw materials are calcined in a rotary kiln to stabilize the size and increase the strength, and then processed and shaped. In the metallurgy of nonferrous metals and ferrous metals, iron, aluminum, copper, zinc, tin, nickel, tungsten, chromium, file and other metals are sintered and roasted in rotary kiln as melting equipment. For example, it is used to roast aluminum hydroxide into alumina in aluminum production; Used to produce pellets for blast furnace ironmaking; Foreign "sl/rn method" and "Krupp method" use it to directly reduce iron ore; Chlorination volatilization roasting method uses it to extract tin and lead. In the process of mineral processing, the poor iron ore is magnetized and roasted in the rotary kiln, which changes the original weak magnetism of the ore into strong magnetism, which is beneficial to magnetic separation. In chemical industry, rotary kiln is used to produce soda ash, calcined phosphate fertilizer and barium sulfide. In 1960s, lapple and others in the United States invented a new process for producing phosphoric acid in rotary kiln. This method has the advantages of low energy consumption, low power consumption, no need for sulfuric acid, and the use of low-grade phosphate rock, and has been rapidly popularized.
In the production of rotary kiln, the phenomenon of ring formation often occurs. At present, manual cleaning mostly adopts shutdown mode, but it affects production and increases production cost. The newly developed rotary kiln ring cleaning machine avoids this phenomenon. Can handle the loop phenomenon well.