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

Method for producing sodium aluminate by treating Bayer-process red mud through andradite one-step alkali thermal method

A technology for Bayer process red mud and calcium iron garnet, which is applied to the field of sodium aluminate production from Bayer process red mud by one-step alkaline heat treatment of calcium iron garnet, can solve the problems of waste of raw materials, high cost, low removal efficiency and the like

Inactive Publication Date: 2017-10-13
NORTHEASTERN UNIV
View PDF1 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above-mentioned dealkalization methods all have problems in varying degrees. The effect of the lime dealkalization method under normal pressure is unsatisfactory and the cost is high under high pressure; Alkali is ineffective; chloride ions in magnesium chloride and ammonium chloride dealkalization will corrode equipment and is not conducive to the subsequent application of red mud; CO 2 Suspension dealkalization, in which CO 2 Only for Na in red mud 2 O·Al 2 o 3 、Na 2 SiO 3 and Na 2 CO 3 works, but for Na 2 O·Al 2 o 3 1.7SiO2 2 ·nH 2 O does not work, and most of the sodium in red mud is in the form of Na 2 O·Al 2 o 3 1.7SiO2 2 ·nH 2 The form of O exists, so the removal efficiency of this method is not high; in the lime-sulfuric acid combined dealkalization method, the acid method and the alkali method coexist, and it is easy to waste raw materials.

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 producing sodium aluminate by treating Bayer-process red mud through andradite one-step alkali thermal method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] In this embodiment, diaspore Bayer process red mud is used, and the main chemical composition (mass percentage, wt%) is: alumina (Al 2 o 3 ) 21.62%, silicon dioxide (SiO 2 )16.11%, sodium oxide (Na 2 O) 7.08%, calcium oxide (CaO) 16.50%, total iron (TFe) 14.80%, and its aluminum-silicon ratio is 1.34;

[0038] Sodium ferrite is sintered from iron-containing raw materials and industrial caustic soda;

[0039] The caustic concentration in the circulating mother liquor is 240g / L, and the molecular ratio is 25;

[0040] F / A=0.6:1;

[0041] C / S=2.5:1.

[0042] according to this figure 1 The method for the production of sodium aluminate by the one-step alkali-thermal process of the present invention with andradite red mud of Bayer process as shown:

[0043] S1: After mixing red mud, sodium ferrite and active lime, mix it with circulating mother liquor according to the ratio of L / S=4:1 to prepare raw material slurry;

[0044] S2: The raw material pulp is subjected to alk...

Embodiment 2

[0056] This embodiment adopts Bayer process red mud, and its main chemical composition (mass percentage, wt%) is: alumina (Al 2 o 3 ) 23.35%, silicon dioxide (SiO 2 ) 23.23%, sodium oxide (Na 2 O) 15.61%, calcium oxide (CaO) 0.51%, total iron (TFe) 16.16%, titanium dioxide (TiO 2 )5.37%, and its aluminum-silicon ratio is 1.01;

[0057] Calcium ferrite is sintered from iron-containing raw materials and lime;

[0058] The caustic concentration in the circulating mother liquor is 240g / L, and the molecular ratio is 25;

[0059] F / A=0.5:1;

[0060] C / S=3:1.

[0061] according to this figure 1 The method for the production of sodium aluminate by the one-step alkali-thermal process of the present invention with andradite red mud of Bayer process as shown:

[0062] S1: After mixing red mud, sodium ferrite and lime, mix them with circulating mother liquor according to the ratio of L / S=5:1 to prepare raw material slurry (note: the iron contained in red mud is not included in the...

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 producing sodium aluminate by treating Bayer-process red mud through an andradite one-step alkali thermal method. The method comprises the following steps: S1: mixing the red mud, sodium ferrite or calcium ferrite, active lime and a circulating mother solution to prepare raw material ore pulp; S2: carrying out alkali thermal dissolution reaction on the raw material ore pulp; after reacting, obtaining dissolved-out ore pulp; S3: diluting the dissolved-out ore pulp to obtain a diluting solution; carrying out liquid-solid separation on the diluting solution to obtain dissolved-out dreg and a dissolved-out solution; S4: after evaporating the dissolved-out solution, adding a crystal seed, crystallizing and carrying out solid-liquid separation to obtain a sodium aluminate solid and a high-molecular-ratio sodium aluminate solution; S5: blending the high-molecular-ratio sodium aluminate solution to prepare the circulating mother solution used in step S1. According to the method provided by the invention, aluminum oxide and sodium oxide in the red mud are recycled so that the alkali content in the dissolved-out dreg is reduced to be 0.5 percent or below and the red mud can be used as raw materials including cement, concrete, an iron-melting adhesive and the like; the method provided by the invention can be used for consuming a lot of the red mud so that the recycling of the red mud is realized and the green utilization effect of resources is realized.

Description

technical field [0001] The invention belongs to the technical field of sodium aluminate production, and in particular relates to a method for producing sodium aluminate by treating Bayer process red mud with one-step alkali-thermal treatment of andandroid. Background technique [0002] Red mud is the waste residue produced during the production of alumina. It is red because it contains a large amount of iron oxide, so it is called red mud. The output of red mud varies with ore grade, production method and technical level. Every time 1 ton of alumina is produced in my country, 1.0 to 1.7 tons of red mud will be produced. At present, the cumulative accumulation of red mud exceeds 300 million tons. A large amount of red mud cannot be effectively used and can only be stacked in a large area, which not only takes up a lot of land, but also causes serious pollution to the environment due to the high alkalinity of the red mud. As of 2016, the cumulative stockpiles reached more th...

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): C01F7/04C01B33/20C01F7/066
CPCC01B33/20C01F7/04C01F7/066
Inventor 于海燕潘晓林杨再明赵成明涂赣峰吴艳
Owner NORTHEASTERN UNIV
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