Method and device for producing active lime powder from calcined limestone

Abstract

The invention discloses a method for producing active lime powder from calcined limestone. The method comprises the following steps: (1) by taking limestone as a raw material, crushing and grinding the limestone to obtain limestone powder; (2) preheating the limestone powder by a suspension preheating system, and heating the limestone powder after preheating by a combustion decomposition furnace, so that the limestone powder is subjected to further heat absorption and decomposition; and (3) cooling the material subjected to heat decomposition in the step (2) to obtain the active lime powder through a suspension cooling system. The invention discloses a device for employing the method. The preheated limestone powder can be fed from the lower and middle parts of the combustion decomposition furnace, the temperature of the combustion decomposition furnace can be flexibly regulated, and the generated lime powder has high activity; caloric content in primary cyclone waste gas in the suspension preheating system and temperature rise air in the suspension cooling system is fully utilized, and the aim of saving energy in the system is fulfilled; moreover, the degree of automation is high, the production efficiency is high, and the production scale is conveniently enlarged.

Description

technical field [0001] The invention relates to a method and a device for producing lime powder by calcining limestone, in particular to a method and a device for producing lime powder by calcining limestone using a preheating and pre-decomposing system for producing cement. Background technique [0002] Lime (quick lime) is widely used in metallurgy, construction, chemical industry, environment, agriculture and other fields. The production process of lime is essentially calcium carbonate (CaCO 3 ) process of thermal decomposition. [0003] At present, the technology of limestone calcination to produce active lime in my country is mainly rotary kiln and shaft kiln. Most of the rotary kilns are equipped with vertical preheaters and vertical coolers. The active lime obtained by calcination is of good quality, high activity, high output and stable production, and can utilize 10-40mm fine-grained limestone. The vertical preheater preheats the limestone to 800-900°C, and the de...

AI Technical Summary

Problems solved by technology

In the rotary kiln, there is mainly radiation heat exchange with low thermal efficiency, and the surface heat dissipation of the rotary kiln shell is too large, resulting in increased energy consumption of the system

[0004] The active lime produced by the shaft kiln imported from abroad has the advantages of high activity, low raw overburning rate and uniform composition, but at the same time has the disadvantages of high investment, complicated operation, difficult maintenance or high maintenance cost

The activity of active lime calcined by domestic shaft kiln is relatively low, and most of the limestone to be used is more than 40mm in block shape, and the mine utilization rate is low

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