Alumina melting method

Abstract

The invention discloses an alumina melting method. The melting method comprises the following steps: a. conveying primary ore pulp from a normal-pressure desiliconization process with the temperature of 85-100 DEG C into a vapor preheater for preheating to 200-230 DEG C; b. conveying the ore pulp preheated by the vapor preheater into a molten salt heater for heating to 260-280 DEG C; c. conveyingthe ore pulp heated by the molten salt heater into an insulated melting tank for heat preservation for 30-45 minutes until a melting process is finished; d. conveying the melted ore pulp into a ore pulp self evaporator to decrease temperature and pressure; and e. conveying the ore pulp evaporated and concentrated in the self evaporator into a diluting tank, and diluting and mixing with a primary red mud washing fluid. The invention improves the heating temperature of the ore pulp to 280 DEG C, decreases the alkalinity of the primary ore pulp, saves the construction investment and equipment cost, reduces the energy consumption of an evaporation process, improves the utilization rate of secondary vapor heat, delays the scaring speed of a sleeve and decreases the equipment maintenance cost.

Description

technical field [0001] The invention relates to a dissolution method of alumina. Background technique [0002] In the whole alumina production system, the dissolution workshop is the core workshop in the alumina production process, which affects the alumina production of the whole plant. The main dissolution technologies used in my country's alumina plants are: single casing preheating, autoclave indirect heating dissolution technology, multi-tube preheating and molten salt heating, and pressure cooker insulation dissolution technology. Disadvantages of single-tube preheating and autoclave indirect heating dissolution technology are that high-pressure boilers must be equipped, and autoclaves with steam tube bundles and stirring are used, so the construction investment and equipment costs are relatively high, and the dissolution temperature is only It is 260°C, so the alkali concentration of the raw ore pulp must be increased, so that the amount of steamed water in the evapo...

AI Technical Summary

Problems solved by technology

Disadvantages of single-tube preheating and autoclave indirect heating dissolution technology are that high-pressure boilers must be equipped, and autoclaves with steam tube bundles and stirring are used, so the construction investment and equipment costs are relatively high, and the dissolution temperature is only It is 260°C, so the alkali concentration of raw ore pulp must be increased, so that the evaporation process has a large amount of steamed water and high steam consumption

The disadvantages of multi-tube preheating, molten salt heating, and autoclave heat preservation and dissolution technology are that the number of self-evaporation stages is small, the heat utilization of the secondary steam is low, and the energy consumption is high. Severe casing scarring, frequent cleaning

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