Method for circulating fluidized bed pyrolysis and deamination of magnesium chloride hexammoniate and equipment thereof

Abstract

The invention relates to a method for circulating fluidized bed pyrolysis and deamination of magnesium chloride hexammoniate. The method comprises the steps of: preheating a magnesium chloride hexammoniate material in a cyclone preheater; subjecting the preheated magnesium chloride hexammoniate to pyrolysis in a circulating fluidized bed pyrolysis furnace, heating the fluidized gas in an indirectheating mode; cooling the pyrolysed and dehydrogenized hot material in a cyclone cooler, conducting sealing reception and preservation to the cooled magnesium chloride material; meanwhile preheating the fluidized gas with the waste heat of the hot material; separating and recycling the ammonia and inert gases in the tail gas. The method of the invention fully makes use of the tail gas of the circulating fluidized bed pyrolysis furnace and the sensible heat of the hot material, thus having high thermal efficiency. Also, the gas and solid contact fully, heat and mass transfer is rapid, and deamination is thoroughly. The invention also provides equipment for realizing the method.

Description

technical field [0001] The invention relates to a pyrolysis method of magnesium chloride hexaammoniate. [0002] The invention also relates to a device for implementing the method described above. Background technique [0003] Magnesium Chloride Hexaammoniate (MgCl 2 6NH 3 ) is bischofite (MgCl 2 ·6H 2 O) (or magnesite (MgCO 3 )) is an important intermediate for preparing high-purity anhydrous magnesium chloride, which is also magnesium silicide (Mg 2 Si) reacts with ammonium chloride in liquid ammonia to prepare silane (SiH 4 ) by-products. Chinese patents CN101462746A, CN1135743A, US6143270A, and CN1978680A disclose a method for preparing anhydrous magnesium chloride by ammonification. First, an ethylene glycol solution of magnesium chloride is prepared from raw materials, and then reacted with ammonia to prepare magnesium chloride hexaammoniate, and finally magnesium chloride hexaammoniate is thermally decomposed. Anhydrous magnesium chloride was obtained. Wherei...

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Problems solved by technology

This method has simple technical requirements and is easy to operate, but it has obvious disadvantages: the temperature field in the fixed bed thermal decomposition furnace is seriously uneven, and there is an obvious temperature difference between the materials in the furnace, resulting in uneven and unstable product quality; The energy consumption of the product is high, which obviously does not meet the requirements of energy saving and emission reduction in the field of industrial production; the production cycle of fixed bed thermal decomposition is long, the production efficiency is low, and the labor intensity is high, which cannot meet the requirements of large-scale and industrial production

[0008] There are few relevant reports about the pyrolysis method of magnesium chloride hexaammoniate. In patents CN101462746A and CN1135743A, only the concept of magnesium chloride pyrolysis is mentioned, and no specific thermal decomposition technology and special equipment are given.

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