Unlock instant, AI-driven research and patent intelligence for your innovation.

A method for non-Bayer process red mud step-by-step deep dealkalization

A Bayer red mud and deep dealkalization technology, which is applied in the field of deep dealkalization of red mud in stages, to avoid alkaline rebound, achieve mineralization fixation, and improve the impact of the surrounding environment

Active Publication Date: 2018-01-05
CHONGQING INST OF GREEN & INTELLIGENT TECH CHINESE ACADEMY OF SCI
View PDF8 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

CN104445844A introduces a method of dealkalizing red mud with flue gas combined with alkaline materials, the essence of which is to first introduce cations to combine with basic anions in red mud to form insoluble solids, and then introduce flue gas to neutralize excess Cations, however, are powerless against the potential calcium, magnesium and other alkaline substances that exist in large quantities in red mud in our country
CN101423318B first uses dilute sulfuric acid to pretreat red mud, and then uses calcium oxide to further dealkalize under pressure. This method also does not further treat alkaline substances such as calcium and magnesium in red mud

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
  • A method for non-Bayer process red mud step-by-step deep dealkalization

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Such as figure 1 As shown, the staged deep dealkalization of non-Bayer process red mud is as follows:

[0032] (1) Prepare the red mud solid and water into a suspension according to a solid-liquid ratio of 1:5, and then introduce it into a stirred reaction device, control the stirring speed to 800 rpm, and introduce carbon dioxide to reach saturation, and control during the reaction The temperature of the reaction system is 25°C, the pressure is maintained at normal pressure, and the reaction time is 200 minutes. After the reaction is over, the suspension is separated into solid-liquid by centrifugation, the obtained liquid is merged into the carbonated mother liquor in the alumina production process for unified treatment and then reused in the dissolution process, and the obtained solid enters the next step for deep dealkalization.

[0033] (2) The acetic acid and water are formulated into an extract with a molar concentration of 6.0 mol / L, and then the red mud solid after...

Embodiment 2

[0036] (1) The red mud solid and water are made into a suspension at a solid-liquid ratio of 1:1, and then introduced into a reaction device with stirring, and the stirring speed is controlled to 800 rpm, and then carbon dioxide is introduced to reach saturation for reaction. During the reaction The temperature of the reaction system was controlled to 50°C, the pressure was maintained at 10 bar, and the reaction time was 600 minutes. After the reaction is over, the suspension is separated into solid-liquid by centrifugation, the obtained liquid is merged into the carbonated mother liquor in the alumina production process for unified treatment and then reused in the dissolution process, and the obtained solid enters the next step for deep dealkalization.

[0037] (2) The citric acid and water are prepared into an extract with a molar concentration of 0.05 mol / L, and then the red mud solids after centrifugation in step (1) are uniformly mixed with the extract at a mass ratio of 1:5 ...

Embodiment 3

[0040] (1) Prepare a suspension of red mud solids and water according to a solid-liquid ratio of 1:15, and then introduce them into a stirred reaction device, control the stirring speed to 800 rpm, and then introduce carbon dioxide to reach saturation for the reaction. The temperature of the reaction system was controlled at 45°C, the pressure was maintained at 8 bar, and the reaction time was 30 minutes. After the reaction is over, the suspension is separated into solid-liquid by centrifugation, the obtained liquid is merged into the carbonated mother liquor in the alumina production process for unified treatment and then reused in the dissolution process, and the obtained solid enters the next step for deep dealkalization.

[0041] (2) The succinic acid and water are formulated into an extract with a molar concentration of 0.1 mol / L, and then the red mud solid after centrifugation in step (1) is uniformly mixed with the extract at a mass ratio of 1:1 to prepare The suspension i...

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 relates to a method for non-Bayer red mud dealkalization in stages, and belongs to the technical field of comprehensive utilization of resources. It mainly includes the following steps: (1) Prepare red mud solid and water into a suspension at a solid-to-liquid ratio of 1:1 to 1:15, stir, and inject CO2 to reach saturation, the temperature is room temperature to 50°C, and the pressure is normal pressure to 10 bar, the time is 30-1000 minutes, and centrifuged; (2) Mix the separated red mud solid with the extract containing monohydric or / and polycarboxylic acid as the extraction agent according to the mass ratio of 1:1 ~ 1:10. Prepare it into a suspension, put it into a high-pressure reaction vessel, stir, and at the same time feed CO2 to carry out deep dealkalization. The present invention conducts deep dealkalization of the red mud in stages, so that the strong alkalinity and sustained alkaline release characteristics of the red mud are weakened, and a stable state with insoluble carbonate as the main form is achieved, greatly affecting the surrounding environment improve.

Description

Technical field [0001] The invention relates to a method for deep dealkalization of red mud in stages, in particular to a method for combining deep dealkalization of non-Bayer red mud with carbon dioxide mineralization and fixation, and belongs to the technical field of comprehensive utilization of resources. Background technique [0002] Red mud is alkaline solid waste produced in the process of producing alumina by alkaline method with bauxite as raw material. Depending on the ore raw materials and production processes, the output of red mud per ton of alumina produced can range from a few hundred kilograms to several tons. Red mud is a typical bulk solid waste, and its comprehensive treatment is still a worldwide problem. [0003] Internationally, there have been attempts to use piled soil and modify it to treat the red mud with plant greening, so that it will gradually return to nature. However, due to the inherent characteristics of the red mud such as strong alkalinity, cont...

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 Patents(China)
IPC IPC(8): C02F11/00
Inventor 陈鸿珍王光伟徐愿坚
Owner CHONGQING INST OF GREEN & INTELLIGENT TECH CHINESE ACADEMY OF SCI