This kind of light-burned magnesia ball is common in the steel enterprises in the northeast and coastal areas, because the northeast is rich in magnesite resources, and the coastal areas are rich in brucite, etc., especially in certain chemical enterprises, which use electrolysis to prepare chlorine. The remaining residue is basically a kind of industrial waste. It is cheap and good to prepare magnesium balls. The ranking of magnesium balls is higher, which can reach more than 65%. Other companies use the middle of the magnesium balls. The content of magnesium oxide is basically between 45% and 65%. With the intensified smelting of blast furnaces, the use of titanium ore or titanium balls to protect the furnace has become one of the main means for many steel plants to stabilize production and extend the life of the blast furnace. With the increase in demand, the prices of titanium ore and titanium balls continue to rise. Ironmaking and cost have a great impact. Pellets have the advantages of high grade, low gangue content, high strength, and good reducibility. They are one of the main raw materials for blast furnace ironmaking.
In August 2010, two super-large blast furnaces with a capacity of 5,500 cubic meters were supporting the construction of a large belt roaster pellet production line with an annual output of 4 million tons. The iron ore powder used for the pellet production of Jingtang Company was Peruvian magnetic Iron ore powder, but due to its low silicon and high alkali metal content, if other high-silica ore powder is not added, the reduction expansion rate of pellets is abnormally high, which cannot meet the requirements of large blast furnaces.
In order to control the reduction expansion rate of pellets, the SiO2 content in the initial stage of pellet production is controlled above 3.5%, which affects the principle of further refinement of the blast furnace. In addition, sintering requires the addition of magnesium-containing fluxes such as dolomite to ensure the fluidity of the slag. However, sintering has the problem of reduced drum strength and particle size after adding too much magnesium-containing solvent. Rotary kiln-type incinerator, also known as rotary kiln, is a slightly inclined steel hollow cylinder lined with refractory bricks. Most of the waste materials are heated by the gas generated during the combustion process and the heat transmitted by the kiln wall.
The solid waste is sent from the front end to the kiln for incineration, and it is rotated to achieve the purpose of mixing the waste. It is necessary to maintain a proper tilt when rotating to facilitate the solid waste to slide down. In addition, waste liquid and exhaust gas can be sent from the kiln head or the second combustion chamber, and even the whole barrel of waste can be sent to the rotary kiln incinerator for combustion. Rotary kiln incineration technology is currently the most mainstream technology in hazardous waste incineration technology. It is the most widely used furnace type. It is a highly adaptable multi-purpose incinerator that can incinerate a variety of solid, semi-solid, liquid and gaseous wastes. Combustible wastes of various types and shapes (granules, powders, blocks and barrels) can be sent to the rotary kiln for incineration. Hazardous wastes are incinerated in rotary kilns, and generally go through several stages such as drying, pyrolysis, burning and burnout. After these stages, the harmful components in the hazardous waste are fully decomposed and destroyed under the action of high temperature, forming high-temperature flue gas and slag. These high-temperature flue gas and slag will cause corrosive damage to the refractory materials built in the rotary kiln.