Method and apparatus for decomposing phosphogypsum to produce sulphuric acid, generating electricity power and cement with quiescent state reduction

Abstract

The invention relates to a method for decomposing phosphogypsum by a static reduction method to manufacture sulphuric acid, power cogeneration cement and a device; phosphogypsum, coal and other additives are blended according to the following proportion: 50-80% of the phosphogypsum, 5%-35% of the coal and other additives for the rest, the raw materials are pulverized, formed into small nodules which are sent to the reducing atmosphere in an upper low-temperature reducing zone of a static reducing destruction furnace in the device of the invention for calcining and decomposing the phosphogypsum, and the materials decomposed in the reducing zone at the upper part of the static reducing destruction furnace enters a lower calcining zone with oxidizing atmosphere to form cement clinker; the high-temperature gas discharged from the furnace is firstly used for generating electricity and then turns into low-temperature gas to produce sulphuric acid by resorption. The method of the invention has strong reducibility, high decomposition efficiency, easy formation of the cement clinker, simple technical process and strong maneuverability; moreover, the invention can raise economical benefits,form three-in-one technique in the sulphuric acid production and power cogeneration cement production and can produce high-quality cement.

Description

technical field [0001] The invention relates to the technical field of comprehensive utilization of chemical industry, building materials and solid waste, in particular to a method and equipment for decomposing phosphogypsum to produce sulfuric acid and power generation and co-production of cement by a static reduction method. Background technique [0002] At present, there are various raw materials for industrial sulfuric acid production, but the main methods are sulfur and pyrite. With the dwindling of sulfur resources, researchers began to look for better alternative resources. The cement industry is an industry with high resource consumption and energy consumption, and it also produces a large amount of carbon dioxide, which deteriorates the living environment of human beings. [0003] Phosphogypsum, as a huge amount of solid waste that pollutes the environment seriously, how to turn it into a resource has always been a subject of close attention and research by scholar...

AI Technical Summary

Problems solved by technology

[0011] (2) Phosphogypsum is directly prepared into raw meal. Because cement raw meal contains various impurities, it is easy to form low eutectic minerals. Factors such as the reducing atmosphere in the kiln will often cause phosphogypsum to form rings in the rotary kiln, resulting in high energy consumption. , large investment and small production scale, low output;

[0012] (3) The full combustion of coal and the formation of high-quality clinker require an oxidizing atmosphere; while the decomposition of phosphogypsum requires a reducing atmosphere. This is a pair of contradictions that are difficult to reconcile in the same kiln body. The production control is difficult and the quality of clinker is poor. And the fluctuation is large, the control of the whole process becomes complicated and difficult to control

[0013] (4) The cement firing temperature is high (1450°C), the required gas volume is large, the exhaust gas temperature is high, the energy consumption is high, the process is complex, the equipment investment is large, and the production cost increases

Moreover, the preheater and calciner are frequently blocked, and the decomposition technology outside the cement kiln is difficult to apply

[0017] (2) In the rotary kiln, SO 2 High decomposition temperature leads to ring formation in the rotary kiln and affects production

[0018] (3) SO 2 It is easy to condense on the material in the preheater and return to the rotary kiln, which interferes with the normal production of the kiln.

Images