Process and equipment for preparing alpha and beta mixed semi-hydrated gypsum powder

Abstract

The invention discloses a process for preparing alpha and beta mixed semi-hydrated gypsum powder. The process comprises the following steps of: gathering, wet steaming, airing and frying. The frying step comprises the following flows of: conveying primary powder into an inner drum of a compound rotary kiln through continuous conveyance, wherein the rotary kiln is an internal combustion-type rotary kiln, and the interior of the inner drum is provided with a gas inlet capable of realizing combustible gas conveyance; frying the primary powder by the inner drum and an outer drum or the inner drum, a middle drum and the outer drum in sequence, and then, delivering a finished product out from a discharge hole, wherein the kiln head temperature is 450-550 DEG C, the kiln tail temperature is 155-190 DEG C, the temperature of the finished product is 150-185 DEG C, and the average speed of the axial movement of the primary powder in the kiln is 1m / min; and conveying steam and fume formed during a frying process into an electrostatic precipitator respectively through a steam pipeline and a fume pipeline to perform sedimentation treatment on dust. The invention also discloses equipment used by the process. The invention has the beneficial effects that energy can be saved and the consumption can be reduced to the maximum limit. The gypsum powder is fried by using the process and the equipment, and thus, only 10-12kg of coal is needed when each ton of gypsum powder is produced in the frying step, and compared with the prior art, the power consumption can be reduced by 70 percent.

Description

technical field [0001] The invention relates to the technical field of gypsum powder production, in particular to a preparation process and equipment for α+β mixed type hemihydrate gypsum powder. Background technique [0002] Gypsum powder is widely used in many application fields such as construction, building materials, molds and art models, chemical industry and agriculture, food processing and medical beauty, and is an important industrial raw material. Among them, gypsum used in the production of building materials includes natural gypsum and chemical gypsum. Natural gypsum includes natural dihydrate gypsum and natural anhydrous gypsum. Anhydrite, commonly used in industry is natural dihydrate gypsum. When the dihydrate gypsum is heated to a certain temperature, the gypsum loses part of its crystallization water and obtains hemihydrate gypsum. Hemihydrate gypsum is an air-hardening gelling material, which has two forms of α and β, both of which are diamond-shaped cryst...

AI Technical Summary

Problems solved by technology

This process is intermittent processing. After frying in one pot, it is poured out, and then the frying process in another pot is carried out after loading. In this way, the setting time of the product is unstable, which causes the performance of the gypsum powder to be unstable. Frequent problems, high energy consumption and high cost

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