Waste aluminium slag improved aluminia producing Bayer process with diaspore

A technology of aluminum waste slag and Bayer method, applied in the direction of alumina/hydroxide, etc., can solve the problems of poor decomposition performance and achieve the effect of saving resources and improving production process

Inactive Publication Date: 2007-06-06
上海添瑞环保科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It is a mature technology to produce sandy alumina with diaspore. In order to obtain sandy alumina with diaspore, we can find ways from two aspects. The performance of the semen adopts a decomposition process si

Method used

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  • Waste aluminium slag improved aluminia producing Bayer process with diaspore

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Embodiment 1: the chemical composition (each element content is all converted into oxide, by weight %) of one of aluminum slag aluminum ash used is:

[0018] Alumina (Al 2 o 3 ) 73.56 Silicon oxide (SiO 2 ) 11.17

[0019] Magnesium oxide (MgO) 5.67 Calcium oxide (CaO) 1.06

[0020] Iron oxide (Fe 2 o 3 ) 0.95 Titanium oxide (TiO 2 ) 0.30

[0021] Other 7.29

[0022] Circulating lye concentration: alumina 141.1g / l, caustic alkali 279.8g / l; molecular ratio 3.26.

[0023] Concentration of high-pressure stripping pulp (liquid phase): alumina 279.1g / l, caustic alkali 255.4g / l; molecular ratio 1.51.

[0024] During the dilution process with red mud wash solution per m 3 Add 50kg of the above-mentioned aluminum slag and aluminum ash to the high-pressure stripping slurry, stay for 30 minutes, and separate the liquid from the solid to obtain the semen concentration: alumina 158.3g / l, caustic alkali 143.2g / l; molecular ratio 1.49.

[0025] The obtained semen can be dec...

Embodiment 2

[0026] Embodiment 2: The chemical composition of the aluminum slag and aluminum ash used is the same as in Embodiment 1.

[0027] Circulating lye concentration: alumina 87.9g / l, caustic alkali 192.9g / l; molecular ratio 3.61.

[0028] Concentration of high pressure stripping pulp (liquid phase): alumina 239.4g / l, caustic alkali 229.0g / l; molecular ratio 1.57.

[0029] During the dilution process with red mud wash solution per m 3 Add 50kg of the above-mentioned aluminum slag and aluminum ash to the high-pressure stripping slurry, stay for 30 minutes, and separate the liquid from the solid to obtain the semen concentration: alumina 154.1g / l, caustic alkali 138.4g / l; molecular ratio 1.48.

[0030] The obtained semen can be decomposed for 50-55 hours under the conditions of an initial decomposition temperature of 65-70°C, a final temperature of 45-50°C, and a seed crystal coefficient of 1.5. The decomposition rate can reach 50-52%, and sandy alumina can basically be obtained.

Embodiment 3

[0031] Embodiment 3: the chemical composition (each element content is all converted into oxide, by weight %) of one of aluminum slag aluminum ash used is:

[0032] Alumina (Al 2 o 3 ) 73.56 Silicon oxide (SiO 2 ) 11.17

[0033] Magnesium oxide (MgO) 5.67 Calcium oxide (CaO) 1.06

[0034] Iron oxide (Fe 2 o 3 ) 0.95 Titanium oxide (TiO 2 ) 0.30

[0035] Other 7.29

[0036] Circulating lye concentration: alumina 141.1g / l, caustic alkali 279.8g / l; molecular ratio 3.26.

[0037] Concentration of high-pressure stripping pulp (liquid phase): alumina 279.1g / l, caustic alkali 255.4g / l; molecular ratio 1.51.

[0038] During the dilution process with red mud wash solution per m 3 Add 20kg of the above-mentioned aluminum slag and aluminum ash to the high-pressure stripping slurry, stay for 30 minutes, and separate the liquid from the solid to obtain the semen concentration: alumina 150.3g / l, caustic alkali 145.2g / l; molecular ratio 1.50.

[0039] The obtained semen can be dec...

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Abstract

The present invention discloses waste aluminum slag improved alumina producing Bayer process with diaspore. Specifically, in the diluting step and while adding red mud washing liquid, aluminum slag is added, with the added amount being 20-80 kg for each cubic meter of high pressure leached slurry. The present invention has the advantages of the comprehensive utilization of waste aluminum slag, improved alumina producing process, saving in resource and environment friendship. The method of adding waste aluminum slag is superior to the method of adding gibbsite.

Description

technical field [0001] The invention relates to a process for producing alumina by Bayer process using diaspore as a raw material, in particular to a method of using aluminum waste slag and ash to produce alumina by Bayer process for "sugar addition". Background technique [0002] More than 98% of the aluminum ore resources in my country are diaspore type bauxite, which has low activity and poor solubility. Compared with the Bayer method widely used abroad to treat gibbsite-type bauxite by using it to produce alumina, there is a big difference in terms of production process conditions and technical indicators. When treating diaspore-type bauxite, the dissolution process using the Bayer method requires high temperature, high pressure, and high caustic concentration. Despite this, the semen molecular ratio after dissolution-dilution-separation (α k ) is still high, which is unfavorable to the decomposition of seed crystals, the decomposition period is long, the production ca...

Claims

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Application Information

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IPC IPC(8): C01F7/02
Inventor 杨冠群吴竹成杨升星野滋郎
Owner 上海添瑞环保科技有限公司
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