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CN-122012957-A - Preparation method of low-impurity ion type rare earth ore magnesium salt concentrate

CN122012957ACN 122012957 ACN122012957 ACN 122012957ACN-122012957-A

Abstract

The invention belongs to the field of rare earth metallurgy, and discloses a preparation method of a low-impurity ion rare earth ore magnesium salt concentrate, which improves the precipitation efficiency by activating magnesium oxide, combines the activated magnesium salt rare earth concentrate with a countercurrent exchange technology to deeply remove aluminum, magnesium and sulfate impurities, and finally obtains the rare earth concentrate with high total rare earth dry agent (REO > 45%), low impurity dry agent (Al <0.9%, mg <3% and SO 4 2‑ < 4%), and the preparation method only improves the magnesium oxide utilization rate by an activation mode, has low production cost, and is simple and easy to operate, and suitable for industrial production.

Inventors

  • LIAO CHUNSHENG
  • HUANG JIN
  • GE LIUSHENG
  • LAN QIAOFA
  • GUO AN
  • KE ZHAOHUA
  • WU DI
  • HUANG DECHENG
  • XIAO XINJIN
  • GUO YONGJUN

Assignees

  • 江西离子型稀土工程技术研究有限公司

Dates

Publication Date
20260512
Application Date
20260227

Claims (7)

  1. 1. The preparation method of the low-impurity ion type rare earth ore magnesium salt concentrate is characterized by comprising the following steps of: (1) Activating magnesium oxide, namely uniformly mixing the magnesium oxide with an activating agent, activating by using mineral activating equipment, and adding a proper amount of water after the activation is finished to prepare MgO slurry with the magnesium oxide concentration of 1-10%; (2) Slowly adding MgO slurry into leaching mother liquor, stirring until the pH value of the liquor reaches 7.8-8.8, stopping adding MgO slurry, standing and settling to obtain supernatant and magnesium salt rare earth enriched material, wherein the leaching mother liquor is obtained when magnesium sulfate leaches ionic rare earth ore; (3) Activating the magnesium salt rare earth enrichment, namely uniformly mixing the magnesium salt rare earth enrichment with an activating agent, and activating by using mineral activating equipment to obtain an activated magnesium salt rare earth enrichment; (4) The countercurrent exchange process of preparing low impurity magnesium salt RE concentrate includes setting RE solution with aluminum concentration less than 20mg/L and fluorine concentration less than 2g/L in a reaction container, regulating pH value to 3.6-4.2 with sulfuric acid or magnesia, adding activated magnesium salt RE concentrate into RE solution, turning on stirring, and filtering with filtering equipment to obtain magnesium salt RE concentrate with low magnesium and low sulfate radical and exchanged liquid.
  2. 2. The method of claim 1, wherein the liquid-solid ratio of magnesium oxide to activator in step (1) is 0.6-4:1, the liquid-solid ratio of magnesium salt rare earth concentrate to activator in step (3) is 0.6-4:1, the activation time is 5-15 minutes, and the units of the liquid-solid ratios are L.kg -1 .
  3. 3. The method of claim 1, wherein the activator comprises a solution of one or both of magnesium sulfate, ammonium sulfate, aluminum sulfate in a concentration range of 0.1-10 g/L.
  4. 4. The method of claim 1, wherein the supernatant in step (2) is used to formulate a magnesium sulfate leaching agent.
  5. 5. The method of claim 1, wherein in step (4) the ratio of liquid to solid of the rare earth solution to the activated magnesium salt rare earth concentrate is 10-100:1, the stirring reaction time is 2-4 hours, and the units of liquid to solid ratio are l.kg -1 .
  6. 6. The method according to claim 1, wherein in step (4) the rare earth solution with an aluminium concentration of <20mg/L and a fluorine concentration of <2g/L is derived from the solution obtained by filtering after the exchange of the magnesium salt rare earth concentrate of step (2) with the leaching mother liquor for the first time and subsequently from the post-exchange liquor obtained in step (4).
  7. 7. The method of claim 1, wherein the post-exchange liquor obtained in step (4) is further used for enriching precipitated rare earth in the added leaching mother liquor in step (2).

Description

Preparation method of low-impurity ion type rare earth ore magnesium salt concentrate Technical Field The invention belongs to the technical field of rare earth ore hydrometallurgy, and particularly relates to a preparation method of a low-impurity ionic rare earth ore magnesium salt concentrate based on magnesium oxide and magnesium salt rare earth concentrate activation and countercurrent exchange impurity removal. Background The ionic rare earth ore occupies an important role in rare earth resources in China, and optimization of exploitation and processing technology has important significance for improving the utilization rate of the rare earth resources, improving the quality of products and reducing the production cost. At present, the magnesium sulfate leaching-magnesium oxide precipitation process is widely applied to the enrichment of the mother liquor of the ionic rare earth mine due to the characteristics of rapid magnesium oxide precipitation, complete rare earth precipitation and the like. However, because magnesium oxide belongs to indissolvable compounds and is insufficient in alkaline release, the magnesium oxide is insufficient in utilization rate and high in magnesium oxide consumption when rare earth mother liquor is precipitated and enriched, the obtained magnesium salt rare earth enriched material has high magnesium and sulfate radical content, and especially the total content of sulfate radicals in the enriched material is even more than 9%, so that the subsequent smelting processes of acid dissolution, impurity removal and the like of the magnesium salt rare earth enriched material are seriously influenced. In the prior art, various researches exist for purifying magnesium salt rare earth enrichment, for example, patent CN202410189265.4 proposes to adjust the pH value of acid solution slag liquid with magnesium salt rare earth enrichment to reduce the acid consumption, but magnesium oxide and rare earth in enrichment are not fully exchanged, and the pH value is limited to rise, so that the purpose of removing aluminum impurities is achieved by continuously adding magnesium oxide to adjust the pH value of acid solution. CN202510090686.6 proposes that magnesium oxide slurry is used for removing aluminum and silicon in acid rare earth leaching solution obtained by mixing and leaching rare earth enrichment pulp and sulfuric acid, the alkaline release of magnesium oxide is insufficient, and the consumption is high. CN202211498901.9 adopts 0.1-1.0mol/L sodium hydroxide solution to remove 85% sulfate radical in carbonate rare earth concentrate, but magnesium oxide enrichment has high impurity content, and when sodium salt is used for removing sulfate radical, the impurity removing efficiency is low, sodium impurity is introduced, rare earth sulfate double salt is easy to form, and rare earth yield is not easy to decompose. Disclosure of Invention The invention aims to develop a preparation method of a low-impurity ion rare earth ore magnesium salt enrichment, which can obviously reduce the content of impurity ions such as aluminum, magnesium, sulfate radical and the like in a product and improve the utilization rate of magnesium oxide and the purity of rare earth products. In order to achieve the above object, the present invention provides the following technical solutions: the preparation method of the low-impurity ion type rare earth mine magnesium salt concentrate comprises the following steps: (1) Activating magnesium oxide, namely uniformly mixing the magnesium oxide with an activating agent, activating by using mineral activating equipment, and adding a proper amount of water after the activation is finished to prepare MgO slurry with the magnesium oxide concentration of 1-10%; (2) Slowly adding MgO slurry into leaching mother liquor, stirring until the pH value of the liquor reaches 7.8-8.8, stopping adding MgO slurry, standing and settling to obtain supernatant and magnesium salt rare earth enriched material, wherein the leaching mother liquor is obtained when magnesium sulfate leaches ionic rare earth ore; (3) Activating the magnesium salt rare earth enrichment, namely uniformly mixing the magnesium salt rare earth enrichment with an activating agent, and activating by using mineral activating equipment to obtain an activated magnesium salt rare earth enrichment; (4) The countercurrent exchange process of preparing low impurity magnesium salt RE concentrate includes setting RE solution with aluminum concentration less than 20mg/L and fluorine concentration less than 2g/L in a reaction container, regulating pH value to 3.6-4.2 with sulfuric acid or magnesia, adding activated magnesium salt RE concentrate into RE solution, turning on stirring, and filtering with filtering equipment to obtain magnesium salt RE concentrate with low magnesium and low sulfate radical and exchanged liquid. Preferably, the liquid-solid ratio of magnesium oxide to activator in the step (1) is 0.6-4:1, the l