Low-energy-consumption desulfurization, desilicication and high-efficiency aluminum oxide dissolution treatment method for refractory bauxite

Abstract

The invention discloses a low-energy-consumption desulfurization, desilicication and high-efficiency aluminum oxide dissolution treatment method for refractory bauxite. Through integral technologicalintegration of critical coupling control of desulfurization activation and solution desilicication, desilicication liquid regeneration and recyclying, Bayer process elution,silicon slag harmless treatment and red mud comprehensive utilization, an integrated fusion innovative process of double criticality, three cycles, low energy consumption, two times of removal and one time of dissolution is realized, the superposition effect of '1+1>2' is truly realized in the production link, and two-time removal and one-time dissolution-deep desulfurization, critical desilication and efficient aluminum dissolution are synchronously realized. The method has the remarkable advantages of high efficiency, low consumption and environmental protection, is easy for industrial application and popularization,conforms to the direction of accelerated transformation and upgrading and sustainable and healthy development of the aluminum oxide industry in China, and provides a set of green, efficient, value-added and emission-free overall solution for industrial popularization and application of the high-sulfur high-silicon bauxite in China.

Description

technical field [0001] The invention relates to the technical field of bauxite, in particular to an integrated treatment method for high-sulfur and high-silicon refractory bauxite with low energy consumption, desulfurization and desiliconization, and high-efficiency alumina dissolution. Background technique [0002] In view of the current trend of decreasing reserves of high-grade bauxite and declining grade of ore supply, it is imperative to accelerate the development and improvement of high-sulfur and high-silicon type medium and low-grade refractory bauxite utilization technology, so as to expand the available resources of bauxite , improve resource utilization. [0003] Only when the sulfur content in bauxite is less than 0.3% can it meet the industrial production requirements of the Bayer process, otherwise it will cause great harm to production. One is the increase in alkali consumption. Sulfur is mainly composed of pyrite (FeS 2 ) exists in the form of SO in the pr...

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 There are three main technical barriers in the failure of effective implementation and application in the industry: First, the activation temperature of roasting desulfurization is too high (mostly above 1000 degrees), the energy consumption cost is relatively high, and the subsequent solution desiliconization and Bayer process cannot be effectively combined Dissolution Requirements for Mineral Phase System

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

The second is that the solution desiliconization process failed to make good use of the unique phase characteristics of roasted activated ore, and failed to effectively find the reaction mechanism and the optimal critical process system that satisfy both high desiliconization rate and low aluminum loss rate, which eventually led to desiliconization High energy consumption and increased aluminum loss rate

The process system adopted by the existing technology is more about how to obtain a higher desiliconization rate, but fails to balance the aluminum loss and energy consumption.

Often while obtaining high desiliconization rate (desiliconization rate>60%) and high aluminum-silicon ratio (A / S>10), it brings high aluminum loss rate (aluminum loss>5%) and high alkali loss (alkali loss >5%), leading to high energy consumption in comprehensive production

The third is that technical and economically feasible desiliconization liquid regeneration and recycling technologies are not considered, resulting in excessive alkali consumption in the desiliconization process, which ultimately leads to high costs and cannot be applied industrially

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