Method for regenerating waste gypsum model

Abstract

The invention relates to a method for regenerating a waste gypsum model, and belongs to the field of gypsum. The method comprises the following steps: (1) crushing: crushing the waste gypsum model, and sieving with a sieve of 60-80 mesh to obtain coarse waste gypsum particles; (2) primary purification: adding water into the waste gypsum granules, stirring, and filtering to obtain filter residue A;(3) secondary purification: adding hydrogen peroxide into the filter residue A, stirring, and filtering to obtain filter residue B; (4) tertiary purification: adding water into the filter residue B,adjusting a pH value to 4-6, standing still, and removing supernatant to obtain underlying sediment; (5) autoclaving and drying: autoclaving the underlying sediment, and drying to obtain a drying material; and (6) grinding: mixing the drying material with polyacrylamide for grinding. By adopting the method provided by the invention, impurities in the waste gypsum model can be effectively removed,and the gypsum powder obtained with the regeneration method has relatively high strength when used for preparing the gypsum model.

Description

Technical field [0001] The invention relates to the field of gypsum, in particular to a regeneration method of waste gypsum models. Background technique [0002] Sanitary ceramic products are important supplies in people's lives. One of the main molding methods for the production of sanitary ceramics is grouting, and most of the grouting molding is done in plaster models. Gypsum models are usually used dozens of times before they can be reused and become scrap gypsum models. The production of household porcelain also has a large amount of scrap gypsum models scrapped. According to statistics, every year domestic waste gypsum models only used to make ceramic products are as high as several million tons. At present, the use of waste gypsum models is mainly used by cement companies as part of the raw materials, but the amount of use is limited. Therefore, many waste plaster models in ceramic production areas have become garbage that is not easy to handle. [0003] The main compon...

AI Technical Summary

Problems solved by technology

Special attention should be paid to the fact that the waste gypsum model contains a certain amount of sodium sulfate and anhydrous calcium sulfate, which makes the strength of the regenerated gypsum powder low. Among them, sodium sulfate is easy to absorb water and expand, and the pressure generated by water absorption and expansion is easy to make the model cracked. The strength of the gypsum model made of recycled gypsum powder is reduced, and sodium sulfate will also shorten the initial and final setting time of the gypsum powder. The volume of the gypsum model for sanitary ceramics is usually large, and the pouring time is usually relatively long. If the initial setting time is too short, Then the workers do not have time to operate, making it difficult to complete the grouting

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