Beta-semi-hydrated gypsum powder calcination preparation technique and calcination apparatus

Abstract

The invention relates to a beta-semi-hydrated gypsum powder calcination preparation technique and apparatus. The technique comprises the following steps: pulverizing a raw material into 100-140-mesh powder particles; and delivering the powder particles into a rotary kiln through a feed port of the calcination apparatus, calcining, and continuously outputting from a discharge port of the calcination apparatus after sequentially passing through at least two concentric rotating drums, wherein the kiln hood temperature is 450-550 DEG C, the kiln end temperature is 155-190 DEG C, and the powder particle temperature is 150-185 DEG C. The apparatus comprises at least two concentric rotating drums with the same capacity which are sheathed together; and a material delivery part comprises a feed port positioned at one end of the concentric rotating drums, a discharge port arranged at the same or different end of the feed port, and an auxiliary material delivery structure, wherein the auxiliary material delivery structure comprises a helical blade and / or lifting board positioned on the inner wall of the concentric rotating drums. The technique and apparatus have the advantages of massive energy saving and consumption reduction.

Description

Technical field [0001] The invention relates to the technical field of gypsum powder production, in particular to a calcination preparation process and calcination equipment for β-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 medicine and beauty. It is an important industrial raw material. Among them, the gypsum used in the production of building materials includes natural gypsum and chemical gypsum. Natural gypsum includes natural dihydrate gypsum and natural anhydrous gypsum. Natural dihydrate gypsum has a softer texture and natural anhydrous gypsum has a harder texture, so it is also called Anhydrite, natural dihydrate gypsum is commonly used in industry. When the dihydrate gypsum is heated to a certain temperature, the gypsum loses part of its crystal water and obtains hemihydrate gypsum...

AI Technical Summary

Problems solved by technology

In the present invention, the dihydrate gypsum powder is dehydrated using a continuous calcination process. The temperature of the material is gradually raised during the process, and the flue gas is discharged through the flue gas circulation chamber and the flue gas discharge pipe. Compared with the traditional intermittent processing technology, the processing speed is fast and the efficiency is high. High advantages, but there are still the following disadvantages: 1) After the material enters the kiln body, it goes through the preheating, heating and calcination sections in sequence. After the calcination is completed, the material is discharged from the discharge port, so the kiln body is large in length and occupies a large area ;2) The calcination of gypsum powder is carried out by heat exchange rods and heat exchange cones. After a long time of use, the heat exchange oil will crystallize on the inner wall of the heat exchange components, thereby reducing the heat exchange efficiency, and the heat exchange oil needs to be replaced regularly High cost; 3) The flue gas generated during calcination enters the heat exchange pipe through the flue gas inlet, and enters the flue gas circulation chamber from the flue gas pipe outlet. To improve the utilization rate of heat energy, but the flue gas without any purification treatment is directly discharged into the atmosphere, causing serious environmental pollution, which does not meet the requirements of the national environmental protection and emission reduction

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