Rotary Kiln is Widely Used in the Ferrous Metallurgy Industry. In the process of Beneficiation, Rotary Kiln can be used for the magnetizing and roasting of lean iron which turns its previous weak magnetism to strong magnetism and is good for beneficiation. According to various types of the ore, there are different roasting methods for the magnetizing and roasting such as reduction roasting, oxidation roasting, reduction & oxidation roasting, and neutral roasting. The most used reducing agent and fuel types are gas and solid. One most important feature of the magnetizing and roasting kiln by the gas reducing agent and fuel is that many gas nozzles are distributed on the kiln and moves with it to add gas reducing agent and fuel to every section of the kiln. When using the solid reducing agent, the gas pipe and air pipe on the kiln can be removed to make it simple in structure.
This reaction takes place at 900C (at which temperature the partial pressure of CO2 is 1 atmosphere), but a temperature around 1000C (at which temperature the partial pressure of CO2 is 3.8 atmospheres) is usually used to make the reaction proceed quickly. Excessive temperature is avoided because it produces unreactive, "dead-burned" lime. variable-speed electric motor. This must have high starting torque in order to start the kiln with a large eccentric load. A 6 x 60 m kiln requires around 800 kW to turn at 3 rpm. The speed of material flow through the kiln is proportional to rotation speed, and so a variable speed drive is needed in order to control this. When driving through rollers, hydraulic drives may be used. These have the advantage of developing extremely high torque. In many processes, it is dangerous to allow a hot kiln to stand still if the drive power fails. Temperature differences between the top and Rotary kilns started to be used for lime manufacture at the start of the 20th century and now account for a large proportion of new installations. The early use of simple...
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