Method for producing 4A zeolite

Abstract

The invention relates to a method to produce 4A zeolite, in particular to a method to produce the 4A zeolite from a sodium aluminate solution produced in the production process of aluminum oxide. The invention is characterized by producing 4A zeolite from the sodium aluminate solution produced in the production process of aluminium oxide by Bayer process; the producing process is that: an industrial dense sodium metasilicate with a SiO2 weight proportional concentration ranging from 26 percent to 28 percent and Rho density ranging from 1.38 to 1.40 g / cm3 is added into the sodium aluminate solution by Bayer process and well mixed, and stirred for 1 to 3 hours, and the molar proportion of SiO2 / Al2O3 is 1.8 to 2. The method of the invention directly adopts the sodium aluminate solution produced in the production process of aluminum oxide by Bayer process and normal temperature industrial dense sodium metasilicate, 'low temperature and one-step' to produce the 4A zeolite, and good quality cleaning additive 4A zeolite products are obtained after being filtered, cleaned and dried. The invention effectively cuts down the production cost of aluminum oxide by Bayer process, and decreases the ineffective circulation of aluminum in the solution in the production process.

Description

technical field [0001] A method for producing 4A zeolite relates to a method for producing 4A zeolite by using sodium aluminate solution in the alumina production process. Background technique [0002] 4A zeolite is a multi-purpose product, widely used in construction, chemistry, chemical industry and daily life, but the largest amount of 4A zeolite is used as a detergent builder. Different application fields have different performance requirements for 4A zeolite. For example, the adsorption capacity of 4A zeolite used in the chemical industry is the most important performance index, while the two most important performance indexes of 4A zeolite used as detergent builders are Whiteness and calcium exchange capacity. [0003] At present, most of the production methods of 4A zeolite are synthesized by hydrothermal synthesis in an alkaline environment. Hydrothermal synthesis usually has a process of slurrying and crystallization (one-stage crystallization or two-stage crystall...

AI Technical Summary

Problems solved by technology

[0006] Since the "sintering method" sintering method produces alumina after high-temperature sintering (1000-1250 ° C), it is dissolved out, the process is complicated, the energy consumption is high, and the product cost is high, resulting in the production cost of 4A zeolite is still relatively high; in contrast , the production of alumina by the Bayer method is directly dissolved without sintering (dissolution temperature 180-240°C), which has the characteristics of simple production process, low energy consumption and low product cost compared with the sintering method. The sodium aluminate solution in the production process of Bayer method alumina The cost of aluminum oxide is lower than the cost of sodium aluminate solution in the sintered alumina production process; however, in the dissolution process of Bayer alumina production, because the organic matter exists in the form of humus and asphalt in the bauxite, the asphalt does not dissolve In alkaline solution, all discharged with red mud