Method of treating sodium-silicon slag by chlorination method

Abstract

The present invention relates to a process for processing sodium white slime through chlorin-ation routeand belongs to the field of non-ferro metals pyrogenic process chlorine metallurgy.Said method comprises the following steps:(1) adding a reducing reagent to sodium white slime, and adding them continuouly to a fluidized bed chlorination furnace to perform a chloridization process to realize a section of selection chloridization of sodium in sodium white slime;(2) washing the chloridized slag with water to get a sodium chloride solution to realize separation of sodium elementand get rinshing slag at the same time;(3) after being washed again and dryed, the rinshing slag being added to a high temperature furnace for a calcinationto get mullite; (4)condensating and separating the chloridized tail gas through a condensatorto get aluminum chloride and silicon tetrachloride solution respectively, wherein the chloridized slags are washed using water and then preserved for making cement. By dealing with waste slags to obtain useful components, the present invention reduces the manufacturing cost of aluminum oxide.

Description

technical field [0001] The invention relates to a method for treating sodium-silicon slag by chlorination, which is used to process waste slag and obtain useful components, and belongs to the field of pyrochlorination metallurgy of nonferrous metals. Background technique [0002] Sodium aluminosilicate hydrate [Na 2 O.Al 2 o 3· wxya 2. (6-2x)H 2 O] is sodium silicon slag, which is the most important reaction product of silicon minerals in alkaline treatment of bauxite. The key to the production of alumina by the alkaline method is the separation of aluminum and silicon. During the high-pressure dissolution of diaspore in the domestic Bayer process, almost all silicon minerals are active, and most of them will react with sodium aluminate solution and mainly use sodium Silicon slag enters red mud; in the process of desiliconization of crude liquid by sintering method, more than 90% of SiO 2 It is also precipitated from the solution in the form of sodium silicate slag. S...

AI Technical Summary

Problems solved by technology

The high-pressure hydration method can comprehensively recover the alumina and sodium oxide in it, and the Na in the waste residue 2 O content is less than 1%, A / S is less than 0.5, but this method has many disadvantages: the concentration of sodium aluminate eluate is high, the caustic ratio is high; the circulation of mother liquor is large; the dissolution conditions are very harsh, and the equipment is required to be able to withstand high temperature and high pressure , processed at high temperature with high a k 1. Nickel-lined equipment should be used for high-alkali-concentration solutions, which increases investment

This method can recover the alkali, the recovery rate reaches 90%, and can also recover a certain amount of alumina, but the recovery rate of alumina is low, and the A / S in the waste residue is greater than 0.7

This method does not require high temperature and high pressure treatment, and has no special requirements for equipment, but the method has a long process, and the purpose of recovering alumina cannot be achieved in one treatment. In addition, there are many uncertain factors in this method