Technique for extraction separation of quadravalence cerium, thorium, fluorine and cerium less tervalence rare earth from sulphuric acid rare earth solution

Abstract

The invention relates to a technological method for extracting and separating quadrivalent cerium, thorium, fluorine and less-cerium trivalent rare-earth from rare earth sulfate solution. The rare earth sulfate solution, which is obtained through processing the rare-earth ores and contains high-valence cerium, the fluorine, the thorium and ferrum, is used as raw material; synergistic extraction agent basing on P507 and P204 is adopted for extracting and separating; the cerium (1V), the thorium, the fluorine, and the ferrum are extracted into an organic phase, then selective washing and back extraction are performed step by step to obtain three products that are the cerium, the fluorine, and the thorium, the trivalent rare-earth is left in a water phase, and then unsaponifiable P507 or thesynergistic extraction agent basing on P507 is adopted to perform multistage fractional extraction to separate single rare earth elements. The technological method has the characteristics that the synergistic extraction agent basing on P507 and P204 is adopted, the thorium is easy to perform the back extraction, and extraction capacity is large, and the emulsification is not generated during the extraction process; the cerium (1V), the thorium, the fluorine, the ferrum and the trivalent rare-earth are extracted and separated in the same extraction system; both extraction and the separation adopt unsaponifiable extraction agent, and ammonia-nitrogen wastewater is not generated; in addition, the thorium and the fluorine are recovered as products, and the pollutions caused by thorium-containing waste residue, fluoride-containing wastewater and the ammonia-nitrogen wastewater are eliminated from headstream. Therefore, the technological method has the advantages of simple procedures, greenenvironmental protection, and low manufacturing cost.

Description

technical field

[0001] The invention relates to a process for extracting and separating cerium (IV), thorium, fluorine and cerium-less trivalent rare earth from a rare earth sulfate solution containing thorium, fluorine and high-valent cerium. Rare earth sulfate solution with high valence cerium is used as raw material, and the non-saponification co-extractant based on P507 or P204 is used for extraction and separation. The invention belongs to the field of rare earth hydrometallurgy. Background technique

[0002] my country is a big country with rare earth resources, and the rare earth industry has occupied a leading position in the world. With the continuous expansion of the scale of the rare earth industry, the low utilization rate of resources and the pollution of three wastes generated in the process of rare earth smelting and separation are becoming more and more serious. For example, Sichuan bastnaesite is the second largest rare earth resource in my country. At pre...

Examples

Embodiment 1

[0034] The mixed ore of bastnaesite and monazite is roasted with sodium carbon and leached with sulfuric acid, and the rare earth sulfate solution containing high valence cerium, fluorine, thorium and iron is used as raw material, and Ce in the raw material 4+ / ∑Ce is 93% (weight percent), the rare earth concentration REO is 0.3 mol / liter, H + Concentration is 0.5 mol / L, F - at a concentration of 0.1 mol / L, ThO 2 The concentration of Fe is 0.1 g / L, and the concentration of Fe is 0.1 g / L. The extraction agent is a mixed extraction agent of 90% P507 and 10% TBP, the concentration is 1.0 mol / liter, the diluent is sulfonated kerosene, and the flow ratio used is organic phase: material liquid = 2: 1, after 3 stages of countercurrent extraction, Obtain the raffinate containing cerium (IV), fluorine, thorium and iron organic phase and trivalent rare earth;

[0035] The loaded organic phase after extraction is washed with 1 mol / L sulfuric acid through three stages of countercurrent...

Embodiment 2

[0041] Its process method and operation steps are the same as in Example 1. Rare earth sulfate solution containing high valence cerium, fluorine, thorium and iron after oxidative roasting-sulfuric acid leaching of bastnaesite is used as raw material, and the rare earth concentration REO in the raw material solution is 0.4 mol / liter , Ce 4+ / ∑Ce is 97%, H + At a concentration of 1.0 mol / L, ThO 2 The concentration is 0.50 g / L, F - The concentration of Fe is 0.8 mol / L, and the concentration of Fe is 3 g / L. The extractant is a mixed extractant of 95% P507 and 5% TRPO, the concentration is 1.5 mol / liter, the diluent is sulfonated kerosene, and the flow ratio is organic phase:material liquid=3:1. The loaded organic phase after extraction was washed with 5 stages of countercurrent with 3 mol / L sulfuric acid. Fluorine is washed with a nitric acid solution containing 2 mol / liter of aluminum salt and acidity of 1 mol / liter, so that 99% of the fluorine in the organic phase enters the...

Embodiment 3

[0043] Its processing method and operating steps are the same as in Example 1, and the rare earth concentration REO is 0.6 mol / liter in the raw material liquid, and the H + At a concentration of 1.0 mol / L, ThO 2 The concentration is 0.30 g / L, F - The concentration of Fe is 0.4 mol / L, and the concentration of Fe is 0.5 g / L. The extractant is a synergistic extractant prepared by 85% P204 and 15% TRPO, the concentration is 1.25 mol / L, and the loaded organic phase after extraction is washed with 2.5 mol / L sulfuric acid through three stages of countercurrent washing. Fluorine is washed with 1.5 mol / liter of aluminum salt nitric acid solution, the acidity is 0.5 mol / liter, and 99% of the fluorine in the organic phase enters the water phase. The loaded organic phase after fluorine washing is back-extracted cerium from the cerium-containing organic phase with 2.5% hydrogen peroxide and 4 mol / liter hydrochloric acid, and 6-stage countercurrent back-extraction, the tetravalent cerium ...

technical field

[0001] The invention relates to a process for extracting and separating cerium (IV), thorium, fluorine and cerium-less trivalent rare earth from a rare earth sulfate solution containing thorium, fluorine and high-valent cerium. Rare earth sulfate solution with high valence cerium is used as raw material, and the non-saponification co-extractant based on P507 or P204 is used for extraction and separation. The invention belongs to the field of rare earth hydrometallurgy. Background technique

[0002] my country is a big country with rare earth resources, and the rare earth industry has occupied a leading position in the world. With the continuous expansion of the scale of the rare earth industry, the low utilization rate of resources and the pollution of three wastes generated in the process of rare earth smelting and separation are becoming more and more serious. For example, Sichuan bastnaesite is the second largest rare earth resource in my country. At pre...

Examples

Embodiment 1

[0034] The mixed ore of bastnaesite and monazite is roasted with sodium carbon and leached with sulfuric acid, and the rare earth sulfate solution containing high valence cerium, fluorine, thorium and iron is used as raw material, and Ce in the raw material 4+ / ∑Ce is 93% (weight percent), the rare earth concentration REO is 0.3 mol / liter, H + Concentration is 0.5 mol / L, F - at a concentration of 0.1 mol / L, ThO 2 The concentration of Fe is 0.1 g / L, and the concentration of Fe is 0.1 g / L. The extraction agent is a mixed extraction agent of 90% P507 and 10% TBP, the concentration is 1.0 mol / liter, the diluent is sulfonated kerosene, and the flow ratio used is organic phase: material liquid = 2: 1, after 3 stages of countercurrent extraction, Obtain the raffinate containing cerium (IV), fluorine, thorium and iron organic phase and trivalent rare earth;

[0035] The loaded organic phase after extraction is washed with 1 mol / L sulfuric acid through three stages of countercurrent...

Embodiment 2

[0041] Its process method and operation steps are the same as in Example 1. Rare earth sulfate solution containing high valence cerium, fluorine, thorium and iron after oxidative roasting-sulfuric acid leaching of bastnaesite is used as raw material, and the rare earth concentration REO in the raw material solution is 0.4 mol / liter , Ce 4+ / ∑Ce is 97%, H + At a concentration of 1.0 mol / L, ThO 2 The concentration is 0.50 g / L, F - The concentration of Fe is 0.8 mol / L, and the concentration of Fe is 3 g / L. The extractant is a mixed extractant of 95% P507 and 5% TRPO, the concentration is 1.5 mol / liter, the diluent is sulfonated kerosene, and the flow ratio is organic phase:material liquid=3:1. The loaded organic phase after extraction was washed with 5 stages of countercurrent with 3 mol / L sulfuric acid. Fluorine is washed with a nitric acid solution containing 2 mol / liter of aluminum salt and acidity of 1 mol / liter, so that 99% of the fluorine in the organic phase enters the...

Embodiment 3

[0043] Its processing method and operating steps are the same as in Example 1, and the rare earth concentration REO is 0.6 mol / liter in the raw material liquid, and the H + At a concentration of 1.0 mol / L, ThO 2 The concentration is 0.30 g / L, F - The concentration of Fe is 0.4 mol / L, and the concentration of Fe is 0.5 g / L. The extractant is a synergistic extractant prepared by 85% P204 and 15% TRPO, the concentration is 1.25 mol / L, and the loaded organic phase after extraction is washed with 2.5 mol / L sulfuric acid through three stages of countercurrent washing. Fluorine is washed with 1.5 mol / liter of aluminum salt nitric acid solution, the acidity is 0.5 mol / liter, and 99% of the fluorine in the organic phase enters the water phase. The loaded organic phase after fluorine washing is back-extracted cerium from the cerium-containing organic phase with 2.5% hydrogen peroxide and 4 mol / liter hydrochloric acid, and 6-stage countercurrent back-extraction, the tetravalent cerium ...

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