Novel method for processing calx sodica sintered alumina by dry method

Abstract

The invention discloses a processing method for sintering alumina by a novel dry soap lime, which comprises the following steps: (1) raw materials, i.e., broken bauxite, limestone, sodium carbonate and coal are sent to a ball mill to be milled until the oversize product of 100<#> is not lager than 5 percent, and raw meal is made into raw meal balls of 30-50mm; (2) clinker sintering: the raw meal of the step (1) is calcined in a vertical kiln at the temperature of 1150-1250 DEG C to prepare the clinker; (3) clinker leaching: the clinker is leached by the lotion of Bayer process, and then the solution is sent to a desilication groove; (4) decomposition: the desiliconized solution is combined with a Bayer solution, and then the mixture is put into a leaf filter and enters a decomposer to be decomposed by adding seed crystal; and (5) roasting: aluminum hydroxide is roasted into alumina at 950-1200 DEG C. The processing method has the beneficial effect that the water content of the raw meal is reduced to 10-15 percent, thus greatly reducing the specific heat consumption in the sintering process by little change and acquiring higher economic benefits.

Description

technical field [0001] The invention relates to the field of metallurgy, in particular to a novel dry-process soda lime sintered alumina processing method. Background technique [0002] So far, alumina production methods are roughly divided into alkaline method, acid method, acid-base combined method and thermal method. However, only the alkaline method has been applied in industry. Among them, there are Bayer method, soda lime sintering method and so on. The advantage of the Bayer method is that the process is simple, but the disadvantage is that it is not suitable for processing low-grade bauxite. The advantage of soda lime sintering method is that it is suitable for processing low-grade ore, but the disadvantage is high energy consumption. The comprehensive energy consumption per unit product of the soda lime sintering method is about 36GJ / tAO, and the comprehensive energy consumption per unit product of the Bayer process is about 13GJ / tAO. [0003] In soda-lime sinte...

AI Technical Summary

Problems solved by technology

The main disadvantage of clinker kiln as reaction equipment is low heat production efficiency. The calculation of heat consumption is shown in Table 1. The theoretical heat consumption of clinker sintering (that is, the sum of firing reaction heat and water evaporation heat consumption) is 4.62×10 6 kJ / t, so the heat utilization efficiency is only about 50%. In addition, it can be seen from the table that the heat consumption of water evaporation accounts for 44%-45%, and the heat taken away by exhaust gas is 12%-13%. The sum of the two items accounts for 56%-58% of the total heat (the data in the table consumes a lot of water evaporation heat, which is related to the high moisture content of the slurry during the measurement)