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Method for comprehensively recycling sodium, aluminum and iron from red mud

A technology for red mud and additives, applied in the field of comprehensive recovery of sodium and iron from aluminum and red mud, can solve the problems of secondary pollution and complex red mud treatment process, achieve elimination of environmental hazards, significant industrial application value, and simplify control conditions Effect

Active Publication Date: 2018-12-07
CENT SOUTH UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] Aiming at the problem that the red mud treatment process in the prior art is complex and easily causes secondary pollution, the purpose of the present invention is to provide a method for comprehensively recovering sodium, aluminum and iron from red mud with simple process and no tailings discharge

Method used

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  • Method for comprehensively recycling sodium, aluminum and iron from red mud

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] The Bayer process red mud was taken from a place in Shandong. The raw material of the Bayer process was mainly boehmite. The composition of the processed Bayer process red mud was analyzed, and the main elements in the red mud were obtained as follows:

[0053] Al 2 O 3 Content 21.21%, Fe 2 O 3 Content 26.01%, Na 2 O content 6.48%, TiO 2 Content 4.14%, SiO 2 The content is 18.50%, and the content of CaO is 13.94%.

[0054] According to the molar ratio of CaO / (SiO 2 +TiO 2 )(Calcium ratio) is 2.2, MgO / Fe 2 O 3 Is 0.6, (Na 2 O+K 2 O) / Al 2 O 3 (Alkali ratio) Add a certain amount of limestone (CaCO 3 ), magnesium oxide and sodium carbonate are mixed with Bayer process red mud; put the mixed raw meal in a high-temperature furnace at 1150℃ for 40min; after cooling to room temperature, grind to 80%≤0.074mm; sinter after fine grinding The clinker is Na 2 O k 15g / L, Na 2 O c 5g / L leaching in 80℃ adjusting solution, time is 20min; the ratio of alkaline adjusting solution to clinker liq...

Embodiment 2

[0057] The Bayer process red mud is taken from a place in Henan. The raw materials of the Bayer process are diaspore and boehmite. The composition of the treated Bayer process red mud is analyzed, and the main elements in the red mud are obtained as follows:

[0058] Al 2 O 3 Content 20.57%, Fe 2 O 3 Content 23.17%, Na 2 O content 9.79%, TiO 2 Content 2.55%, SiO 2 The content is 20.58%, and the content of CaO is 10.20%. According to the molar ratio of CaO / (SiO 2 +TiO 2 )(Calcium ratio) is 2.2, MgO / Fe 2 O 3 Is 0.8, (Na 2 O+K 2 O) / Al 2 O 3 (Alkali ratio) Add a certain amount of limestone (CaCO 3 ), magnesium oxide and sodium carbonate are mixed with Bayer process red mud; put the mixed raw meal in a high-temperature furnace at 1150℃ for 60min; after cooling to room temperature, it is ground to 80%≤0.074mm; the sintering after fine grinding The clinker is Na 2 O k 15g / L, Na 2 O c 5g / L leaching in the conditioning solution at 80°C for 20min; the ratio of alkaline conditioning solution...

Embodiment 3

[0061] The Bayer process red mud is taken from a certain place in Guangxi. The Bayer process raw material is mainly diaspore. The composition of the Bayer process red mud is analyzed, and the main elements in the red mud are obtained as follows:

[0062] Al 2 O 3 Content 18.68%, Fe 2 O 3 Content 24.72%, Na 2 O content 5.57%, TiO 2 10.25% content, SiO 2 The content is 22.20%, and the content of CaO is 15.20%.

[0063] According to the molar ratio of CaO / (SiO 2 +TiO 2 )(Calcium ratio) is 2.2, MgO / Fe 2 O 3 Is 0.8, (Na 2 O+K 2 O) / Al 2 O 3 (Alkali ratio) Add a certain amount of limestone (CaCO 3 ), magnesium oxide and sodium carbonate are mixed with Bayer process red mud; put the mixed raw meal in a high-temperature furnace at 1200℃ for 60min; after cooling to room temperature, it is ground to 80%≤0.074mm; after fine grinding, sintering The clinker is Na 2 O k 15g / L, Na 2 O c 5g / L leaching in the conditioning solution at 80°C for 20min; the ratio of alkaline conditioning solution to clin...

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Abstract

The invention discloses a method for comprehensively recycling sodium, aluminum and iron from red mud. The red mud is mixed with an additive to obtain a raw material, the mixed raw material is subjected to calcination to obtain clinker, the clinker is added to an alkaline adjustment liquid for leaching, slid-liquid separation is performed, and leachate containing aluminum and sodium and magnetic leaching residues are obtained; the additive is a mixed additive composed of a calcium-series additive, a magnesium-series additive and a sodium-series additive. According to the technical scheme, no reducing agent needs to be added, hematite or hematite is converted as magnesioferrite with high magnetism through the magnesium-series additive and enters the leaching residues, and then an iron ore concentrate product is obtained through magnetic separating. In the technical scheme, the atmosphere control process and generation of a great quantity of polluting atmosphere in the current iron recycling process are avoided. In the method, the aluminum recycling rate is 85%, the sodium recycling rate is 92% or above, the sodium content in final residues is lowered to 1% or below, the iron grade of the iron ore concentrate is 50-55%, and the recycling rate is about 70%.

Description

Technical field [0001] The invention relates to the fields of industrial waste reuse and environmental protection, and in particular to a method for comprehensively recovering sodium, aluminum and iron from red mud. Background technique [0002] Red mud is a kind of silt-like high-water strong alkali waste generated during the production process of alumina. It is red because of the large amount of iron oxide, so it is called red mud. my country is the world's largest alumina producer. In recent years, the annual alumina output has always accounted for about half of the world's annual alumina output. According to the existing technology and the composition of bauxite, generally 1 to 2.5 tons of red mud are produced for every 1 ton of alumina produced. According to statistics, the annual production of red mud in my country's alumina industry is more than 70 million tons, and the historical accumulated stockpile exceeds 350 million tons. Except for a small number of applications i...

Claims

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Application Information

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IPC IPC(8): C22B7/00C22B1/02
CPCC22B1/02C22B7/008Y02P10/20
Inventor 孙伟胡岳华吕斐王丽高建德孙宁
Owner CENT SOUTH UNIV
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