Method for producing alumina by coal gangue

Abstract

The invention discloses an alumina making method at raw material of coal gangue, which comprises the following steps: grinding the coal gangue; leaching the coal gangue through sodium hydroxide solution after sintering at high temperature; filtering the residual; producing Al (OH) 3 deposition the residual through carbon dioxide; dewatering Al (OH) 3 to produce Al2O3 at high temperature. The procedure is easy to control to recycle the technological waste water, which realizes zero drainage of industrial production.

Description

technical field

[0001] The present invention relates to the oxide of aluminum, specifically belongs to a kind of production aluminum oxide (Al 2 o 3 )Methods. Background technique

[0002] The method of producing alumina from kaolin and coal gangue has been reported. For example: CN1035505C discloses a method for producing alumina, which is to sinter the raw materials with ammonium sulfate after pre-roasting and dehydration, leaching with dilute sulfuric acid, neutralizing the alum liquid with ammonia gas, and calcining the hydrate to obtain alumina products. CN1083023 discloses the process of producing alumina by the acid analysis method, which is to add the mineral after roasting and dehydration, add ammonium bisulfate to sulfuric acid mixture, i.e. ammonium sulfate solution to leaching to obtain ammonium alum, pass into hydrogen chloride gas to precipitate crystalline aluminum chloride, and obtain after pyrolysis alumina. The salting-out method disclosed in CN1126177 ...