Treatment method for desulfurization, silicon activation and aluminum activation of refractory bauxite

Abstract

The invention discloses a treatment method for desulfurization, silicon activation and aluminum activation of refractory bauxite. The roasting temperature is 820-950 DEG C, the oxidizing atmosphere ina furnace is kept, roasting is conducted for 1-3 seconds, heat preservation is conducted for 10-60 seconds, the pyrite in the bauxite raw material is subjected to a desulfurization reaction, kaolinite is converted into amorphous-phase silicon oxide and gamma-Al2O3, and diaspore is converted into alpha-Al2O3. Deep desulfurization of the bauxite raw material is synchronously completed, wherein thesulfide type sulfur removal rate is higher than 90%, the content of sulfide type sulfur is less than 0.1%, and the content of total sulfur is less than 0.3%. A phase system simultaneously satisfying low-temperature alkali active silicon, low-temperature alkali inert aluminum and high-temperature alkali active aluminum is obtained, the purposes of deep desulfurization, silicon activation and aluminum activation are achieved, and the optimal ore characteristic requirements of solution desilicication and Bayer process dissolution in the next step are met.

Description

technical field [0001] The invention relates to the technical field of bauxite, in particular to a treatment method for desulfurization, live silicon and live aluminum of high-sulfur and high-silicon refractory bauxite. Background technique [0002] my country's bauxite reserves only account for 3-4% of the world's total reserves. It is a country with relatively poor bauxite resources, and nearly 90% of them belong to diaspore sedimentary ores, high-sulfur bauxite with a sulfur content greater than 0.7%. Ores account for about 14%, and medium-to-high-grade resources with an aluminum-silicon ratio of <5 account for about 50%. Due to the hazards of high sulfur and high silicon, the utilization rate is extremely low, and they are basically in a stockpiled and unmined state. With the depletion of high-quality bauxite, the proportion of high-sulfur and high-silicon refractory bauxite in the total domestic reserves is gradually increasing, and the domestic prospective reserves r...

AI Technical Summary

Problems solved by technology

Sulfur is brought into the red mud in the form of FeS, pyrite, etc., because they are easy to adsorb more Al(OH) 4- 、Na + and adsorbed water will make the sedimentation performance of red mud worse, which will affect the technical and economic indicators and product quality

Fourth, increase production energy consumption

The second is to reduce product quality and output

Silicate minerals can cause a large amount of alkali consumption during the dissolution process of alumina; they are precipitated during the semen analysis and separation process, resulting in a reduction in the grade of aluminum hydroxide, lowering the product grade and reducing industrial benefits

The third is to affect equipment safety and ecological issues

Generally speaking, there are many researches on desulfurization and desiliconization involved in high-sulfur bauxite and high-silicon bauxite at home and abroad, but most of the research in the industry only focuses on desulfurization alone or desiliconization alone, and synchronous fusion desulfurization+ The foundation of the overall research on desiliconization is relatively weak, and there is no systematic and mature solution for the beneficiation and processing technology of high-sulfur and high-silicon complex bauxite

[0006] In recent years, the traditional physical process of flotation desulfurization and desiliconization has gradually changed to the chemical process route of roasting alkali-soluble desulfurization and desiliconization at home and abroad. In-depth integration often solves desulfurization and desiliconization at the same time, but brings new problems such as low aluminum dissolution rate and high alkali consumption to subsequent alumina processing, and cannot form a "1+1>2" superimposed promotion effect, resulting in the process It has not been effectively implemented and applied in the industry. The main reason is that the activation temperature of roasting desulfurization is too high (mostly above 1000 degrees), the energy consumption cost is relatively high, and the subsequent solution desilication and Bayer process dissolution are not effectively combined with the mineral phase. system requirements

Due to the inability to obtain a phase system with low sulfur, active silicon and active aluminum at the same time, it cannot better meet the needs of the subsequent alumina dissolution process. Often the front end achieves desulfurization and silicon activation, but it brings about the reduction of the activity of aluminum substances. The new problem greatly reduces the dissolution rate of subsequent alumina, which leads to a substantial increase in cost

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