A Method Based on Reduction Roasting-Acid Leaching Fly Ash Recycling

A technology of fly ash and resource utilization, applied in chemical instruments and methods, aluminum sulfate, aluminum compounds, etc., can solve problems such as affecting the extraction of trace metals, achieve good economic benefits, improve the degree of resource utilization, and broad market application prospects Effect

Active Publication Date: 2021-10-22
CENT SOUTH UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the sintering acid leaching process, aluminum and trace metals can be extracted from sintered fly ash, but it will cause a large amount of acid consumption, and silicon will be precipitated in the form of amorphous silica at the same time, resulting in a large amount of waste residue, which will affect the extraction of trace metals extract

Method used

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  • A Method Based on Reduction Roasting-Acid Leaching Fly Ash Recycling
  • A Method Based on Reduction Roasting-Acid Leaching Fly Ash Recycling
  • A Method Based on Reduction Roasting-Acid Leaching Fly Ash Recycling

Examples

Experimental program
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Effect test

Embodiment 1

[0045] Combine fly ash with manganese dioxide and coal with MnO 2 :Al 2 o 3 :C=2.2:2:1 for batching, ball milling, pelletizing and drying. Put the pellets in a corundum crucible and roast at 1000°C for 30 minutes in a reducing atmosphere; grind the obtained clinker with a vibrating mill until the d(0.5) particle size is concentrated at about 48.2 μm, and use 2mol / L sodium hydroxide solution at 90°C For leaching fine clinker, the liquid-solid ratio is 5ml / g, and the leaching time is 90min. The dissolution rate of silicon oxide was 77.4%. After solid-liquid separation, the leaching slag was roasted in an oxidizing atmosphere at 300°C for 30 minutes, then ground until the d(0.5) particle size was concentrated at about 16.6 μm, and leached with 2mol / L sulfuric acid solution at a liquid-solid ratio of 5ml / g for 90 minutes at 20°C . Under these conditions, the leaching rate of aluminum was 81.2%, that of cerium was 64.2%, that of strontium was 65.7%, and that of zirconium was 5...

Embodiment 2

[0047] Combine fly ash with manganese dioxide and coal with MnO 2 :Al 2 o 3 :C=2.35:2:1.1 Perform batching, ball milling, pelletizing and drying. Put the pellets in a corundum crucible and roast at 1100°C for 60 minutes in a reducing atmosphere; grind the obtained clinker with a vibrating mill until the d(0.5) particle size is concentrated at about 35.7 μm, and use 3.5mol / L sodium hydroxide solution at 105 The fine clinker is leached at ℃, the liquid-solid ratio is 10ml / g, and the leaching time is 120min. The dissolution rate of silicon oxide was 95.41%. After solid-liquid separation, the leached slag was roasted in an oxidizing atmosphere at 900°C for 45 minutes, then ground until the d(0.5) particle size was concentrated at about 20.7 μm, and leached at 35°C with 3.5mol / L sulfuric acid solution at a liquid-solid ratio of 10ml / g 105min. Under these conditions, the leaching rate of aluminum was 93.2%, that of cerium was 88.2%, that of strontium was 91.7%, and that of zirc...

Embodiment 3

[0049] Combine fly ash with manganese dioxide and coal with MnO 2 :Al 2 o 3 :C=2.5:2:1.2 Perform batching, ball milling, pelletizing and drying. Put the pellets in a corundum crucible and bake at 1200°C for 90 minutes in a reducing atmosphere; grind the obtained clinker with a vibrating mill until the d(0.5) particle size is concentrated at about 44.6 μm, and use 3.5mol / L sodium hydroxide solution at 120 The fine clinker is leached at ℃, the liquid-solid ratio is 15ml / g, and the leaching time is 180min. The dissolution rate of silicon oxide was 71.21%. After solid-liquid separation, the leached slag was roasted in an oxidizing atmosphere at 1000°C for 60 minutes, then ground until the d(0.5) particle size was concentrated at about 37.86 μm, and then leached with 5mol / L sulfuric acid solution at a liquid-solid ratio of 15ml / g at 50°C for 120 minutes . Under these conditions, the leaching rate of aluminum was 74.1%, that of cerium was 58.2%, that of strontium was 69.6%, and...

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Abstract

The invention relates to a method for recycling fly ash based on reduction roasting-acid leaching. The steps include: ore blending, reduction roasting, alkali leaching, oxidation roasting, and acid leaching. Its advantage is that it can efficiently recycle aluminum-silicon minerals / solid waste, and extract silicon oxide, aluminum oxide and other trace metals. In this method, the activator manganese oxide can be recycled. Compared with the traditional Bayer method and lime / sodium carbonate sintering and leaching method, the closed-circuit circulation of the activator manganese dioxide can be realized, pollution and cost can be reduced, and the extraction rate of silicon dioxide is high. Acid method and leaching route can recover trace metals at the same time.

Description

technical field [0001] The invention relates to the fields of metallurgical engineering and environmental engineering, in particular to a process method based on reduction roasting-acid leaching fly ash resource recovery. Background technique [0002] my country is the world's largest producer and consumer of alumina. Alumina recovery from fly ash can be used as a strategy to mitigate the depletion of high-grade bauxite. Considering that the abundance of rare earth elements in fly ash is higher than the average value of the earth's crust, and there is no mining cost, fly ash is also considered as an alternative resource to deal with the increasing demand and supply risks of rare earths. At present, the main technologies of fly ash recycling are pressurized sulfuric acid leaching / hydrochloric acid leaching, sintering-alkali / acid leaching. The disadvantages of these processes are that a large amount of waste water and residue are generated, corrosion-resistant and pressure-r...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B7/02C22B1/02C22B21/00C22B59/00C22B34/14C22B26/20C01F7/74C01G45/00C01G45/02
CPCC01F7/743C01G45/00C01G45/02C01P2002/72C22B1/02C22B7/007C22B7/008C22B7/02C22B21/0023C22B26/20C22B34/14C22B59/00Y02P10/20
Inventor 夏金兰范晓露聂珍媛刘红昌张多瑞
Owner CENT SOUTH UNIV
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