Gypsum drying and calcining machine

Abstract

The invention discloses a gypsum drying and calcining machine which is characterized by comprising a drying part mechanism and a calcining part mechanism, wherein the drying part mechanism comprises a drying shell capable of being arranged rotatably, a plurality of lifting plates which can rotate along with the shell to drive materials to move forwards are obliquely arranged on the inner wall of the drying shell, a feeding mechanism is arranged at a feed end of the drying shell, and a heating air feed pipe for drying is arranged consequently in the drying shell; the calcining part mechanism comprises a calcining shell capable of being arranged rotatably, and a heating air feed pipe for calcining is arranged at a discharge end of the calcining shell; a vertically-arranged exhaust funnel is arranged between the discharge end of the drying shell and the feed end of the calcining shell, and an intermediate powder discharge shuttle tank and a rotatable transition shuttle tank are arranged in the exhaust funnel. The gypsum drying and calcining machine disclosed by the invention has the advantages of simple structure, capability of ensuring precise control of the reaction process and improving the reaction treatment effect, and capability of obtaining intermediate treatment product powder and higher product powder purity.

Description

technical field [0001] The invention relates to the field of production and reuse of industrial by-product gypsum, in particular to a gypsum drying and calcining machine. [0002] Background technique [0003] Gypsum, whose main component is calcium sulfate, includes natural gypsum and industrial gypsum. Among them, industrial gypsum, also known as industrial by-product gypsum, is a by-product of some industrial production processes, mainly including phosphogypsum and desulfurization gypsum, of which phosphogypsum accounts for more than half of industrial by-product gypsum. At present, the cumulative stockpiles of industrial by-product gypsum in my country have exceeded 500 million tons, of which phosphogypsum is more than 300 million tons. A large amount of industrial by-product gypsum is piled up, which not only occupies land, but also wastes resources. The acid and other harmful substances contained in it are likely to pollute the surrounding environment, which has beco...

AI Technical Summary

Problems solved by technology

[0005] In the prior art, there are two techniques for drying and calcining industrial by-product gypsum powder. The first is the airflow drying method. In this method, drying and calcination are carried out simultaneously in a shell, and the gypsum powder can be dried in a short period of time. Under the action of hot air flow, the powder is heated in all directions to achieve the purpose of drying; but the cost is too high and the continuity is poor

The second is the rotary drum dryer, that is, the gypsum powder runs in the rotary drum, and the powder is dried and calcined by reverse or forward airflow, which has better continuity but poor calcining effect

[0009] 1. The material drying and calcination processes are all carried out in one shell, so the requirements for the control of the reaction process are relatively high. If the control is inaccurate, it will be difficult to obtain a good treatment effect

2. The final product is calcined powder whose main component is hemihydrate gypsum, and the powder with dihydrate gypsum powder as the main component cannot be obtained

3. In the above-mentioned gypsum drying and calcining machine, the material falls directly from the discharge end of the shell into the discharge cylinder after calcination, and then falls from the discharge port into the subsequent cooling, aging and other processes. However, due to long-term open-air stacking of industrial gypsum, Therefore, there are often some large-grained solid residues such as stones that cannot be calcined into powder in industrial gypsum. These large-grained solid residues enter the subsequent process together with the material, which will seriously affect the quality of the final product powder. Separation in the process will increase the difficulty of separation, and at the same time, it is necessary to increase the separation process and a separate separation mechanism, resulting in an increase in cost

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