New technology for gas suspension calcination of aluminium hydroxide

Abstract

The invention discloses a new technology for gas suspension calcination of aluminium hydroxide, successively comprising the following steps: feeding, entering a Venturi flash drier, entering a multi-stage preheating drier, entering an aluminium hydroxide roaster, entering a thermal separation cyclone, and entering a cooling mechanism to obtain the finished product aluminium hydroxide. A preheating drier is connected with a pipeline leading to the flash drier, and the cyclone is connected with a pipeline leading to the preheating drier. The new technology is characterized in that the system also comprises a waste heat boiler and a humidifying rotational flow dust collector, wherein the cooler is connected with a pipeline leading to the waste heat boiler; the waste heat boiler is connected with a pipeline leading to the roaster; the roaster is connected with a moisture pipeline leading to the humidifying rotational flow dust collector; and steam from the humidifying rotational flow dust collector and the boiler can serve as a new steam source to be used by an evaporation tool. The invention is characterized in that the invention not only preheats air but also produces steam with high additional value on the utilization of waste heat, provides a valuable evaporation heat source for producing aluminium hydroxide, recovers moisture produced in the roasting process, converts moisture into new steam and greatly lowers production operation cost.

Description

technical field [0001] The invention belongs to the technical field of gaseous suspension roasting of aluminum hydroxide, and specifically relates to a new technology of gaseous suspension roasting of aluminum hydroxide. Industrial roasting or dehydration drying process. Background technique [0002] The purpose of aluminum hydroxide roasting is to remove the attached water and crystal water (about 43% in total) contained in aluminum hydroxide, change the crystal form, and prepare the process of meeting the requirements of alumina. It is the last process in the alumina production process, and its energy consumption accounts for about 23% of the energy consumption of the alumina process. Roasting of aluminum hydroxide is an important link that determines the output, quality and energy consumption of alumina. People have been studying and improving the theory, technology and equipment of the roasting process of aluminum hydroxide. At present, the gaseous suspension roasting ...

AI Technical Summary

Problems solved by technology

The existing heating process adopts the direct heating method. Although the direct heating method has high thermal efficiency, the generated secondary steam and flue gas are mixed, which cannot be separated and reused or the utilization rate of heat energy is low. It is characterized by short process routes and simple equipment, but high energy consumption

[0009] The direct problem existing in the existing aluminum hydroxide gaseous suspension roasting furnace roasting process is: although the thermal energy utilization is reasonable, the thermal energy quality utilization is not scientific enough

However, the situation has changed now. Energy prices, water prices and energy consumption account for high alumina production costs, and energy and water conservation are also related to sustainable development issues.

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