Acid-free kaolin bleaching process method

Abstract

The invention discloses an acid-free kaolin bleaching process method, comprising the following steps of: chemical agent mixing: adding rongalite into desanded and graded alkalescent kaolin ore pulp, stirring and mixing evenly to obtain the first sizing agent of the kaolin ore pulp; static bleaching: putting the first sizing agent of the kaolin ore pulp into a pulp storage device and standing still, fully bleaching and reacting to obtain the second sizing agent of the kaolin ore pulp; ion exchange: putting the second sizing agent of the kaolin ore pulp into an ion exchange dasher, and adding solid exchanger, slowly stirring for ion exchange to obtain the third sizing agent of the kaolin ore pulp; solid-liquid separation: putting the third sizing agent of the kaolin ore pulp into a solid-liquid separation device, separating solid ion exchanger capable of adsorbing Fe2+ in the third sizing agent of the kaolin ore pulp so as to obtain separated kaolin ore pulp. The acid-free kaolin bleaching process method has the characteristics of simple processstrong practicality, low cost and environment friendly, is easy for operation and safe and realizes the purpose of acid-free bleaching.

Description

technical field [0001] The invention relates to a kaolin reduction bleaching process technology, in particular to an acid-free kaolin bleaching process. Background technique [0002] Kaolin is widely used in industries such as ceramics, papermaking, refractory materials, coatings, rubber and cables. The whiteness of kaolin is an important indicator that affects its application value and application field, especially in the papermaking and ceramic industries, which have high requirements for the whiteness of kaolin. Therefore, in order to obtain kaolin products with high whiteness, the bleaching process of kaolin is kaolin processing. A very important craft in craft. [0003] In the prior art, the bleaching process of kaolin usually adopts an acid bleaching method, specifically adjusting the kaolin pulp to acidity with sulfuric acid, and then adding a reducing agent—sulfuric acid (chemical name: sodium dithionate, molecular formula: Na 2 S 2 o 4 ), the oxides of ferric ir...

AI Technical Summary

Problems solved by technology

[0006] In the technical scheme of the above-mentioned Chinese invention patent application, although the amount of acid used in the entire bleaching process is reduced compared with the amount of acid used in the acid bleaching method, it is still necessary to add sulfuric acid or other acids in the entire bleaching process. It not only affects the quality of kaolin products, but also has a certain impact on the environment; at the same time, due to Fe 2+ It is necessary to ensure that it is relatively stable under acidic conditions and is not easily oxidized into Fe 3+ , under this condition, because kaolin products contain excessive sulfuric acid and sulfate, etc., the viscosity of kaolin will increase, which is not conducive to the application of kaolin. This will inevitably lead to an increase in production costs, and the particle size of kaolin is relatively small, and the dehydration process of kaolin products after washing is also relatively difficult, which not only increases the process steps, but also directly increases production costs, which is not conducive to the long-term development of the kaolin processing industry.