Energy-saving and high-efficiency rare earth ore concentrate sulfuric acid stepped roasting method

A rare earth concentrate, step-by-step roasting technology, applied in the direction of improving process efficiency, can solve the problems of high sulfuric acid consumption, low yield, large waste gas treatment capacity, etc., to reduce sulfuric acid unit consumption, uniform heating, and environmental protection investment. Effect

Inactive Publication Date: 2015-04-29
包头市锦园化工科技有限公司
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  • Abstract
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  • Application Information

AI Technical Summary

Problems solved by technology

[0002] At present, the sulfuric acid roasting of rare earth concentrate adopts the traditional "three-generation acid method" rare earth concentrate treatment process, that is, the rare earth concentrate is mixed with excess sulfuric acid and then roasted and decomposed in the converter, which has the following defects: ① High consumption of sulfuric acid
② During the production and operation process, the converter is easy to be blocked by rings, and the production operation is not smooth
③ Due to the large difference in the shape of the material, the roasting is uneven, the decomposition of the concentrate is also uneven, and the yield is low
④Because the waste gas generated during the decomposition of concentrate, the waste gas generated after sulfuric acid decomposition, combustion waste gas and air are all mixed and then enter the tail gas washing system, the waste gas treatment capacity is very large, and the system is also very complicated. At the same time, the waste water after washing needs to be evaporated Separation, very high operating and investment costs
⑤ Due to many uncertain and uncontrollable factors, the production operation is very unstable and the product quality fluctuates greatly

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] ① Add 500g of Baotou rare earth concentrate (50.8% by mass of REO) to 550g of sulfuric acid (92.5% by mass of sulfuric acid), and stir, mix and granulate.

[0019] ②Then put the mixed and granulated material into a roasting kiln at 260°C for 120 minutes, and detect the F in the ore. + The amount is 150pp.

[0020] ③ During the roasting process, the fluoride ions and water in the rare earth concentrate are completely volatilized, and the vaporized fluoride ions and water are condensed to recover hydrofluoric acid, and the generated HF acid content is 15.3%.

[0021] ④ The fluorine content in the exhaust gas after washing is 0.0053mg / l, meeting the requirements of the national environmental protection standard.

[0022] ⑤ After roasting, the mixture of sulfuric acid and rare earth concentrate pelletized dry ore particles enters the second-stage roasting kiln, and the temperature is raised to 435°C for roasting and decomposition for 120 minutes. The decomposition rate of ...

Embodiment 2

[0030] ① Add 500g of Baotou rare earth concentrate (REO mass percentage 5 0.8%), add 500g sulfuric acid (sulfuric acid percentage 92.5%), stir, mix and granulate.

[0031] ②Then bake at 260°C for 120 minutes to detect the F in the ore + The amount is 230pp.

[0032] ③ After the flue gas produced in the roasting process is washed and absorbed, the content of HF acid produced is 12.13%.

[0033] ④ The fluorine content in the exhaust gas after washing is 0.0039mg / l, meeting the requirements of the national environmental protection standard.

[0034] ⑤ The mixture of sulfuric acid and rare earth concentrate after roasting was heated up to 435°C for roasting and decomposition for 120 minutes, and the decomposition rate of the roasted ore was detected to be 97.22%.

[0035] ⑥ After the waste gas produced in the roasting process is cooled, washed and absorbed, the sulfuric acid content in the washing water reaches 1.89%.

[0036] ⑦The sulfur content of the flue gas after washing a...

Embodiment 3

[0041] ①Add 500g monazite rare earth concentrate (REO mass percentage 51%), add 605g sulfuric acid (sulfuric acid percentage 92.5%) and 50g iron powder (iron content percentage 66%), mix and granulate .

[0042] ② Mix and granulate the mixture of sulfuric acid and rare earth concentrate, heat up to 435°C and roast and decompose for 60 minutes. The decomposition rate of the roasted ore is 99.42%.

[0043] ③ After the waste gas produced in the roasting process is cooled, washed and absorbed, the sulfuric acid content in the washing water reaches 4.47%.

[0044] ④The sulfur content of the flue gas after washing and absorbing is 0.0073mg / l, which meets the requirements of the national standard.

[0045] ⑤ Mix and stir the roasted ore and water according to the ratio of 8:1 for leaching, and the leaching time is 40 minutes.

[0046] ⑥After washing and drying the leached slag, the rare earth content was detected to be 0.64%. 7. The calculated rare earth yield is 98.95%.

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PUM

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Abstract

The invention relates to an energy-saving and high-efficiency rare earth ore concentrate sulfuric acid stepped roasting method, and belongs to the technical field of wet metallurgy and thermometallurgy. The energy-saving and high-efficiency rare earth ore concentrate sulfuric acid stepped roasting method comprises the following steps: mixing rare earth ore concentrate with sulfuric acid with the mass concentration of more than or equal to 92.5% according to weight ratio of 1 : (1.0-1.3); pelletizing, and charging particles into a first-section roasting kiln to roast, so that fluorine ions and water in the rare earth ore concentrate are completely volatilized; condensing the gasified fluorine ions and water, recovering hydrofluoric acid, roasting defluorinated dry ore particles, and charging the roasted particles into a second-section roasting kiln to separate; washing and absorbing separated sulfuric acid gas during roasting, recovering sulfuric acid, and directly leaching roasted ores to obtain a sulfuric acid rare earth solution. According to the energy-saving and high-efficiency rare earth ore concentrate sulfuric acid stepped roasting method, after the stepped roasting process is utilized, waste gas generated in pelletizing step is water vapor and can be directly discharged; compared with the prior art, the stepped roasting method has the advantages that a waste gas washing and absorbing system is reduced to more than 70% and the environmental protection input is reduced to more than 80%.

Description

technical field [0001] The invention relates to an energy-saving and high-efficiency rare earth concentrate sulfuric acid step-by-step roasting method, belonging to the technical fields of hydrometallurgy and pyrometallurgy. Background technique [0002] At present, the sulfuric acid roasting of rare earth concentrate adopts the traditional "three-generation acid method" rare earth concentrate treatment process, that is, the rare earth concentrate is mixed with excess sulfuric acid and then roasted and decomposed in the converter, which has the following defects: ① High consumption of sulfuric acid. In order to ensure the fluidity of the mixed slurry during the operation of the process, sulfuric acid is seriously excessive during the mixing process, and the highest unit consumption of sulfuric acid can reach 1.8 times. ② During the production and operation process, the converter is easy to be blocked by rings, and the production operation is not smooth. ③ Due to the large d...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B3/08C22B1/02C22B59/00
CPCY02P10/20
Inventor 郝胜民史双勤
Owner 包头市锦园化工科技有限公司
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