Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for systematically reducing process alkali consumption and improving process efficiency of Bayer process

A technology of Bayer process and Bayer process red mud, which is applied in the fields of chemical instruments and methods, preparation of alkali metal aluminate/alumina/aluminum hydroxide, inorganic chemistry, etc. Low-level problems, to achieve the effect of improving efficiency and solving high-efficiency utilization problems

Inactive Publication Date: 2018-12-07
GUIZHOU BRANCH CHINA ALUMINUM IND
View PDF2 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to propose a system to reduce the alkalinity in the Bayer process process in view of the low concentration, large quantity and difficulty in effective recycling of the dilute lye produced by the red mud dealkalization process, as well as the large circulation volume and low efficiency of the Bayer process alumina production process. ways to reduce consumption and increase process efficiency

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for systematically reducing process alkali consumption and improving process efficiency of Bayer process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] N k The concentration is 150g / L and α k The decomposed stock solution of 1.45 can get N k The concentration is 160g / L and α k It is the decomposition mother liquor of 2.80. Lower the temperature of the above decomposed mother liquor to 50°C and make it flow at 1.0L / m 2 The flow rate of h (relative to the membrane area, the same below) enters the dialysis chamber of the cationic membrane diffusion dialysis separator to obtain a low α k Sodium aluminate solution, the low alpha k Sodium aluminate solution N k 80g / L, Al 2 o 3 The concentration is 70.14g / L, α k is 1.88; add 2g / L calcium aluminate hydrate to the dilute lye solution of Bayer red mud dealkalized with normal pressure lime as filter aid, and obtain the caustic alkali concentration N k It is 3g / L refined dilute lye, the refined dilute lye is cooled to 50°C, with 1.0L / m 2 The flow rate of h enters the diffusion chamber on the other side of the cationic membrane, and flows countercurrently with the decompo...

Embodiment 2

[0035] N k 158g / L, α k After the decomposed stock solution of 1.40 is decomposed by the Bayer method seed crystal, the caustic alkali concentration N k 169g / L, Al 2 o 3 The concentration is 101.46g / L and α k It is the decomposition mother liquor of 2.74. Lower the temperature of the above decomposed mother liquor to 70°C and make it flow at 2.0L / m 2 The flow rate of h enters the dialysis chamber on the side of the cation membrane in the cation membrane diffusion dialysis separator to obtain low α k Sodium aluminate solution, the low alpha k Sodium aluminate solution N k 62g / L, Al 2 o 3 The concentration is 65.10g / L, α k It is 1.56; add 1g / L calcium aluminate hydrate to the dilute alkaline solution of Bayer red mud and normal pressure lime dealkalization as a filter aid, and obtain the caustic alkali concentration N k It is 20g / L refined dilute lye, and the refined dilute lye is cooled to 70°C, at 3.0L / m 2 The flow rate of h enters the diffusion chamber on the othe...

Embodiment 3

[0037] N k 168g / L, α k After the decomposed stock solution of 1.45 is decomposed by the Bayer method seed crystal, the caustic alkali concentration N k 179g / L, Al 2 o 3 The concentration is 101.19g / L and α k It is the decomposition mother liquor of 2.91. Evaporate the above decomposition mother liquor to the caustic alkali concentration N k 309g / L, after cooling down to 70°C, make it 3.6L / m 2 The flow rate of h enters the dialysis chamber on the side of the cation membrane in the cation membrane diffusion dialysis separator to obtain low α k Sodium aluminate solution, the low alpha k Sodium aluminate solution N k 90g / L, Al 2 o 3 The concentration is 94.62g / L, α k It is 1.56; add 1g / L calcium aluminate hydrate to the dilute alkaline solution of Bayer red mud and normal pressure lime dealkalization as a filter aid, and obtain the caustic alkali concentration N k 20g / L of refined dilute lye, the refined dilute lye is cooled to 70 ° C, with 5.8L / m 2 The flow rate of h...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for systematically reducing process alkali consumption and improving the process efficiency of a Bayer process. The method comprises the following steps: refining diluted alkali liquor generated in a Bayer red mud dealkalization process to obtain refined diluted alkali liquor, and treating the refined diluted alkali liquor with decomposing mother liquor or evaporating mother liquor in the Bayer process in a volume ratio of 1.0-2.0 by adopting a cationic membrane diffusion dialysis separator to obtain a low alpha-k sodium aluminate solution having alpha-k beingless than 2.00 or a high alpha-k sodium aluminate solution having alpha-k being more than 6.50; and decomposing the low alpha-k sodium aluminate solution in a seed precipitation process, and evaporating the high alpha-k sodium aluminate solution for dissolving bauxite, or directly dissolving bauxite in the dissolving process of the Bayer process. According to the method, the diluted alkali liquorgenerated in the red mud dealkalization process can be recycled, the seed precipitation decomposition rate of the Bayer process can be increased by 65 percent or more, and the aim of greatly improvingthe efficiency of the Bayer process is achieved.

Description

technical field [0001] The invention belongs to the technical field of alumina production technology, and in particular relates to a method for systematically reducing alkali consumption in a Bayer process and improving process efficiency. Background technique [0002] Red mud is a strong alkaline solid waste produced in the production process of alumina industry. Due to the difference in production process and bauxite grade, about 1.0-2.0 tons of red mud is produced in the production of 1 ton of alumina. In 2017, China's alumina output was 69.02 million tons, and the red mud discharge exceeded 82 million tons. Red mud has strong alkalinity, high salinity, and is difficult to comprehensively utilize, so it is mainly stockpiled. In recent years, there have been many soil and groundwater pollution accidents caused by red mud stockpiling in China, which have had a major impact on the environmental safety of surrounding areas and the lives of residents. Combined with the alumi...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C01F7/14
CPCC01F7/14C01F7/144
Inventor 尹中林武国宝路晓涛齐利娟
Owner GUIZHOU BRANCH CHINA ALUMINUM IND
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com