Phosphogypsum circulating fluidized bed reduction roasting comprehensive utilization process and device thereof

Abstract

The invention discloses a phosphogypsum circulating fluidized bed reduction roasting comprehensive utilization process and a device thereof. The device comprises a circulating fluidized bed reactor body provided with a slag discharging opening. An air inlet is formed in the bottom of the circulating fluidized bed reactor. A coal feeding hole, a phosphogypsum/mineral mixture inlet, a circulating material inlet and a secondary air inlet are respectively formed in the lower part of a dense-phase zone; a flue gas outlet is formed in the top of the circulating fluidized bed reactor; a primary cyclone separator is connected with a circulating material inlet and a first-stage fluidized bed cooling device; a flue gas outlet of the primary cyclone separator is connected with a secondary cyclone separator; the lower portion of a second-stage separator is connected with the first-stage fluidized bed cooling device; a flue gas outlet of the secondary cyclone separator is connected with a third-stage cyclone separator; the lower portion of the third-stage cyclone separator is connected with a second-stage fluidized bed cooling device; and meanwhile the first-stage fluidized bed cooling device is connected with the second-stage fluidized bed cooling device. The invention aims to realize activation of a phosphogypsum/tailing mixture under a reduction roasting condition at a temperature of about 850 DEG C by blending phosphogypsum/tailing mixed raw material components. Therefore, the efficient roasting technology and the device are the key to efficient and clean utilization of the phosphogypsum/tailings mixed raw materials. On the other hand, semi-hydrated gypsum is a good building material and has a good application market at present. Therefore, the application value of the phosphogypsum can also be improved by making the existing water-containing gypsum into the semi-hydrated gypsum through processes such as drying and the like.

Description

Technical field [0001] The invention relates to the field of resource utilization of phosphogypsum, in particular to a phosphogypsum circulating fluidized bed reduction roasting process and device. Background technique [0002] Phosphogypsum is a solid waste generated during the production of phosphoric acid. The annual discharge amount is huge. The discharged phosphogypsum occupies a lot of land and forms a slag mountain, which seriously pollutes the environment. Therefore, how to use phosphogypsum as a resource is an urgent problem to be solved. . According to research, the phosphogypsum / tailings mixed raw material contains a variety of mineral components, which can be used as soil improvement fertilizer after activation. By formulating the phosphogypsum / tailings mixed raw material components, the phosphogypsum / tailings mixture can be activated under the reduction roasting conditions at a temperature of about 850°C. Therefore, high-efficiency roasting technology and equipment...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem of resource utilization of phosphogypsum, the present invention provides a process and device for comprehens...

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