Method for cleaning smelted mixed rare earth concentrate by concentrated sulfuric acid

A technology of mixing rare earth and concentrated sulfuric acid, applied in the direction of improving process efficiency, etc., can solve the problems of large amount of radioactive waste residue, uncontinuous process, uncontinuous roasting, etc., achieve dissolution rate and dissolution rate increase, and high efficiency of the dissolution process The effects of chemicalization and production reduction

Inactive Publication Date: 2016-05-11
BAOTOU RES INST OF RARE EARTHS
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  • Abstract
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  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existing problem is: some impurity components in the mixed rare earth concentrate form a low-temperature eutectic during the roasting process and form rings at the kiln head of the rotary kiln, resulting in the inability to continue the roasting
But there are problems: (1) In the low-temperature roasting section, some impurities in the concentrate are likely to form low-temperature eutectics, resulting in ring formation in the rotary kiln, making the process uncontinuous; (2) In the high-temperature roasting section, the remaining sulfuric acid is partially volatilized In addition, most of them undergo decomposition reactions and release high-concentration SO 2 Gas is difficult to handle; (3) The amount of radioactive waste residue is large, and resources such as phosphorus, iron, sulfur, and calcium are wasted
At present, all wet slag is stored in the special slag warehouse of the environmental protection department, and a storage fee of 250 yuan / ton of wet slag is required

Method used

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  • Method for cleaning smelted mixed rare earth concentrate by concentrated sulfuric acid
  • Method for cleaning smelted mixed rare earth concentrate by concentrated sulfuric acid
  • Method for cleaning smelted mixed rare earth concentrate by concentrated sulfuric acid

Examples

Experimental program
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Effect test

Embodiment 1

[0028] Mix 100g of mixed rare earth concentrate (48.68% by mass of REO, 13.2% by mass of CaO), hydrochloric acid solution with a concentration of 3.5mol / L of hydrogen ion species, and concentrated sulfuric acid solution. The solid-to-liquid volume ratio of mixed rare earth concentrate and hydrochloric acid solution is 1:8; add 15 grams of concentrated sulfuric acid to every liter of hydrochloric acid solution. Stir and dissolve for 180 minutes under the condition of 93°C≤temperature≤95°C. After the dissolution, 67.6 g of chemical separation concentrate and chemical separation waste water with a mass percentage of REO of 69.85% and a mass percentage of CaO of 0.83% were obtained by filtration.

[0029] The chemical separation concentrate and concentrated sulfuric acid are mixed according to the weight ratio of 1:1.4, and roasted in a muffle furnace at 280°C for 1.5 hours. The roasted ore was mixed with water and leached for 1 hour, and the water leaching liquid and water leach...

Embodiment 2

[0039] Mix 100g of mixed rare earth concentrate (58.32% by mass of REO, 13.2% by mass of CaO), hydrochloric acid solution with a concentration of 2.5mol / L of hydrogen ion species, and concentrated sulfuric acid solution. The solid-to-liquid volume ratio of mixed rare earth concentrate and hydrochloric acid solution is 1:5; add 8g of concentrated sulfuric acid to every liter of hydrochloric acid solution. Stir and dissolve for 150 minutes under the condition of 93°C≤temperature≤95°C. After the dissolution, 76.3 g of chemical separation concentrate and chemical separation wastewater with a mass percentage of REO of 74.5% and a mass percentage of CaO of 0.51% were obtained by filtration.

[0040] The chemical separation concentrate and concentrated sulfuric acid are mixed according to the weight ratio of 1:1.2, and roasted in a muffle furnace at 250°C for 3 hours. The roasted ore was mixed with water and leached for 40 minutes, filtered to obtain the water leaching liquid and wa...

Embodiment 3

[0043] Mix 100g of mixed rare earth concentrate (67.96% by mass of REO, 4.55% by mass of CaO), hydrochloric acid solution with a concentration of 1.3mol / L of hydrogen ion substance, and concentrated sulfuric acid solution. The solid-to-liquid volume ratio of mixed rare earth concentrate and hydrochloric acid solution is 1:4; 5g of concentrated sulfuric acid is added to each liter of hydrochloric acid solution. Stir and dissolve at 85°C for 120 min. After the dissolution, 84.1 g of chemical separation concentrate and chemical separation waste water with a mass percentage of REO of 78.4% and a mass percentage of CaO of 1.32% were obtained by filtration.

[0044] The chemical separation concentrate and concentrated sulfuric acid are mixed according to the weight ratio of 1:1.4, and roasted in a muffle furnace at 250°C for 4.5 hours. The roasted ore was mixed with water and leached for 30 minutes, filtered to obtain the water leaching liquid and water leaching residue, the REO co...

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Abstract

The invention relates to a method for cleaning smelted mixed rare earth concentrate by concentrated sulfuric acid. The method is characterized by comprising the following steps of chemically selecting and gathering mixed rare earth concentrate by use of a hydrochloric acid solution and a reinforced impurity remover, mixing the chemically-selected concrete with the concentrated sulfuric acid to roast at a low temperature, carrying out water leaching on roasted concentrate, carrying out resource recovery on a water leaching fluid, carrying out tail gas absorption, and recycling chemical-selected wastewater resources. The method has the advantages that the source of three wastes of a current concentrated sulfuric acid high-temperature roasting process is solved at the front end of concentrate treatment, so that various problems in a low-temperature acid method are solved, the follow-up three-waste treatment difficulty is greatly reduced, the rare earth direct recovery rate is increased, and the purpose of comprehensively recycling various resources in the concentrate and auxiliary materials is finally realized.

Description

technical field [0001] The invention relates to a method for cleanly smelting mixed rare earth concentrates with concentrated sulfuric acid, belonging to the field of hydrometallurgy. Background technique [0002] In the product structure of Baiyun Obo rare earth minerals, concentrates with rare earth grades of 50wt%~65wt% are the main products. At present, concentrates with rare earth grades close to 50wt% (commonly known as "50 concentrates") are mainly processed by concentrated sulfuric acid high-temperature roasting and decomposition process (hereinafter referred to as "high-temperature acid method"), and about 100,000 tons of concentrates are processed by this process every year. This process brings a large number of three industrial wastes such as transformed magnesium sulfate wastewater, sulfur-fluorine-silicon mixed high-temperature acid gas, and thorium-containing radioactive waste, which are extremely difficult to deal with. As a result, P, F, Th, Ca, Fe, undecomp...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B59/00C22B3/08
CPCC22B3/08C22B59/00Y02P10/20
Inventor 崔建国侯睿恩王哲陈天炜马志鸿张丽郝肖丽王艳
Owner BAOTOU RES INST OF RARE EARTHS
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