Treatment device and method for flue gas of rare earth kiln

Abstract

The invention relates to a treatment device and method for flue gas of a rare earth kiln. The treatment device comprises the kiln, a residue settling tank, a spry tower and a main induced draft fan which are sequentially connected through a pipeline. The treatment device is characterized in that the spray tower comprises a first-stage spray tower, the treatment device further comprises a heat exchanger set arranged on the pipeline between the kiln and the residue settling tank; an induced draft fan is arranged on the pipeline between the residue settling tank and the first-stage spray tower. The invention further relates to the method which comprises the steps as follows: flue gas enters the heat exchanger set to exchange heat with water, water turns into superheated steam, the flue gas subjected to heat exchange enters the residue settling tank and then enters the induced draft fan, and the flue gas passing through the induced draft fan passes through the spray tower and is exhausted into the atmosphere through the main induced draft fan. The water jet amount during cooling is reduced, steam is produced through heat exchange, the flue gas comes out of the kiln, passes through the heat exchanger set and returns to the residue settling tank, heat is recovered, the utilization rate of energy is increased, and the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of flue gas from rare earth furnaces, in particular to a device and method for treating flue gas from rare earth furnaces. Background technique [0002] At present, there are two methods of smelting rare earth concentrates: alkaline method and acid method. Because the alkali method requires high concentrate grade (greater than 60%), only a few factories use the alkaline method for production, and most of them use the acid method to decompose the concentrate , to produce rare earth chloride or rare earth carbonate. At present, the main method of processing rare earth concentrates at home and abroad is concentrated sulfuric acid high-temperature roasting method. Although the wide application of this process has achieved certain economic benefits, a large amount of sulfur, fluorine, strong acid fumes and radioactive waste residues are produced during the high-temperature roasting process. Washing with the spr...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is that due to the current method for processing rare earth furnace flue gas, a large amount of water resources and heat are wasted, and the production cost is increased

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