A method for producing highly active lime by continuous calcination

Abstract

The invention discloses a method for producing high-activity lime through continuous calcination, and belongs to the field of lime preparation. The method comprises the steps that pretreatment and preheating treatment are performed; limestone powder in a storage bin is sequentially loaded to a preheater, a first pressure reduction bin and a second pressure reduction bin; the preheater heats the surface and internal temperature of the limestone powder to 840-860 DEG C; the limestone powder is loaded to the first pressure reduction bin; a channel connected with the preheater is closed after the first pressure reduction bin is filled with the limestone powder; vacuumizing is performed to reach 1E0-1E2 pa; all the limestone powder is loaded to the second pressure reduction bin after vacuumizing operation completion of the first pressure reduction bin; the second pressure reduction bin closes a channel connected with the first pressure reduction bin; vacuumizing is performed to reach 1E-1 to 1E-2 pa; and calcination treatment and cooling treatment are performed to obtain the lime with the activity higher than 360 ml. The method realizes the continuous calcination in a vacuum; the calcination temperature is lower than the normal calcination temperature; and a relation between the activity of the lime and the decomposition speed of limestone is achieved.

Description

technical field [0001] The invention relates to the field of lime preparation, in particular to a method for producing high-activity lime by continuous calcination. Background technique [0002] Activated lime has remarkable characteristics such as large specific surface area, low bulk density, high porosity, and fine grain size. The application of active lime in the steelmaking process will make slagging faster, shorten the smelting time, and the desulfurization and dephosphorization effect will be better. Production practice has proved that: the use of active lime for steelmaking can increase the dephosphorization rate and desulfurization rate by 10% to 60% respectively, reduce the consumption of lime by 10% to 35%, reduce the consumption of calcium fluoride by 30%, and reduce the amount of slag by 10% to 12%. Melting time reduced by 10%. When the limestone is calcined by the traditional process, the particle size range of the limestone is relatively large. During the ca...

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Problems solved by technology

[0004] In the prior art, there is a contradiction between the activity of lime and the decomposition rate of limestone: high calcination temperature, fast decomposition rate of limestone, but low activity of lime, or even loss of activity due to over-burning; and low calcination temperature, although the activity of lime is high, but The decomposition rate of limestone is slow, and the calcination time is long; while the calcination temperature is low, it may cause raw burning, which will also reduce the activity of limestone.

Moreover, the lime activity obtained by most existing processes is generally less than 360ml, and is usually calcined at a temperature of 950-1150°C, which consumes a lot of energy and is prone to overburning

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