Method for carrying out solid-liquid separation on high-temperature alpha gypsum slurry

Abstract

The invention discloses a method for carrying out solid-liquid separation on high-temperature alpha gypsum slurry. The method comprises the following steps: (1) carrying out primary crystallization; (2) carrying out secondary crystallization; (3) carrying out high-temperature dehydration and solid-liquid separation; (4) conveying the material; (5) enabling dehydrated mud-like alpha gypsum to enter a flash dryer. The keys are as follows: heat insulation covers are additionally installed on a vacuum belt conveyor and a belt conveyor, and heat insulation and heating are achieved by injecting high-temperature steam or high-temperature air or directly heating air; the temperature of the high-temperature steam or the high-temperature air is 100-260 DEG C; the material temperature of alpha semi-hydrated gypsum when passing through the vacuum belt conveyor and the belt conveyor is controlled between 97 DEG C and 150 DEG C. Solid-liquid separation of alpha gypsum slurry under the condition of high temperature can be achieved by adopting the method.

Description

technical field [0001] The invention relates to a production and processing method for gypsum, in particular to a solid-liquid separation method for α-gypsum high-temperature slurry. Background technique [0002] At present, the preparation of α-hemihydrate gypsum by the liquid phase method is a new type of high-strength gypsum preparation method. Gypsum powder and dihydrate gypsum powder are mixed with water in the mixing tank to form a gypsum slurry with a concentration of 30-40%, and heated to 30°C-100°C. In the container, under the conditions of temperature 90℃~150℃ and pressure 3.0~5.0MPa, the first crystallization is carried out under the action of crystal transformation agent maleic anhydride, and about 98% of α-gypsum slurry is formed. On the basis of the first crystallization, the generated α-gypsum slurry enters another crystal converter, and under the conditions of temperature 110°C-150°C and pressure 3.0-4.0MPa, secondary crystallization is carried out under the...

AI Technical Summary

Problems solved by technology

The second is to use a vacuum belt conveyor to separate solid-liquid from medium-low temperature (below 97°C) gypsum slurry. At present, no one has used this technology to separate solid-liquid from gypsum slurry at high temperature.

Because the vacuum belt machine does not take heating and heat preservation measures during the solid-liquid separation, the filter cake will cool down rapidly during this process, and α hemihydrate gypsum is easy to undergo chemical reactions in a short period of time under low temperature conditions to become dihydrate gypsum and solidified, resulting in the scrapping of the material

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