Method for extracting and separating high-purity yttrium

Abstract

The invention discloses a method for extracting and separating high-purity yttrium, which comprises the following steps: 1) separating a YHoErTmYbLu chloride solution by adopting an extracting agent to obtain a calcium-containing crude Y water phase and a YHoErTmYbLu organic phase; 2) separating the YHoErTmYbLu organic phase to obtain a crude Y water phase and a HoErTmYbLu organic phase; 3, hydrochloric acid is adopted for back extraction of the HoErTmYbLu organic phase, and a HoErTmYbLu back extraction water phase is obtained; and 4) separating the crude Y water phase by adopting an extracting agent to obtain a high-purity yttrium solution. The process for extracting and separating the high-purity yttrium is lower in production cost and less in production wastewater.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and particularly relates to a method for extracting and separating high-purity yttrium. Background Art

[0002] High-purity yttrium oxide is widely used in new material fields such as microwave, laser, precision ceramics, semiconductors, and light energy.

[0003] At present, the production process of high-purity yttrium mainly adopts the extraction and separation process. In the P507 extractant system, according to the ionic radius, the distribution ratio of yttrium is between Ho and Er, belonging to the easily extractable components; but in the naphthenic acid extraction system, the distribution ratio of yttrium can be shifted outside the entire rare earth sequence. At present, the naphthenic acid extraction system has become a typical process for extracting and separating yttrium, which can extract and separate and purify yttrium oxide in one step. It is an original process technology with international advanced level in China and has been widely used in various rare earth manufacturers in China. However, the existing naphthenic acid process has a small separation coefficient of naphthenic acid for yttrium and light rare earths such as La, and high-purity yttrium will contain relatively high amounts of lanthanum and calcium. Therefore, the widely used naphthenic acid extraction process can no longer meet the requirements of the high-purity yttrium market. Summary of the Invention

[0004] The present invention discloses a method for extracting and separating high-purity yttrium, aiming to provide an extraction and separation technology for yttrium with low separation cost.

[0005] The method for extracting and separating yttrium of the present invention is as follows:

[0006] 1) The extraction organic phase composed of 10-25% naphthenic acid, 10-20% isooctanol, and the rest being kerosene by volume is saponified with calcium hydroxide slurry into calcium naphthenate, and then the YCl3 solution is extracted to obtain the Y-loaded extractant;

[0007] 2) The Y-loaded extractant obtained in step 1) and the (YHoErTmYbLu)Cl3 solution with a [H + concentration of 0.1-2 mol / L and a [YHoErTmYbLu] concentration of 0.3-2 mol / L are used to separate the YHoErTmYbLu chloride solution to obtain a calcium-containing crude Y aqueous phase and a YHoErTmYbLu organic phase;

[0008] 3) The Y-loaded extractant obtained in step 1) and [H +Separating the organic phase of YHoErTmYbLu in step 2) of the separation process of (HoErTmYbLu)Cl3 solution with a concentration of 0.3 - 2 mol / L and [HoErTmYbLu] concentration of 0.3 - 2 mol / L to obtain a crude Y aqueous phase and a HoErTmYbLu organic phase; taking 70 - 90% of the crude Y aqueous phase as the product and returning 10 - 30% to step 1) for preparing the Y-loaded extractant; diverting 5 - 20% of the aqueous phase during extraction into step (2) to separate the YHoErTmYbLu chloride solution;

[0009] 4) Back-extracting the HoErTmYbLu organic phase with hydrochloric acid at a concentration of 4 - 6 mol / L to obtain a HoErTmYbLu back-extracted aqueous phase; taking 10 - 30% of the HoErTmYbLu back-extracted aqueous phase as an intermediate product for further separation and returning 70 - 90% to step 3) for separating the YHoErTmYbLu organic phase;

[0010] 5) Using the crude Y aqueous phase obtained in step 3), separating it with a P507 extraction organic phase composed of 30 - 50% P507 by volume and the rest being kerosene and hydrochloric acid at a concentration of 4 - 6 mol / L to obtain a high-purity yttrium solution and a solution containing light rare earths and calcium.

[0011] Among them, the number of extraction stages in step 2) is 60 - 100, and the number of washing stages is 10 - 25.

[0012] The number of extraction stages in step 3) is 80 - 110, and the number of washing stages is 110 - 130.

[0013] The number of extraction stages in step 5) is 50 - 70, and the number of washing stages is 10 - 25.

[0014] The technical concept and technical effect of the present invention are as follows:

[0015] The main elements in the yttrium concentrate are Y, Ho, Er, Tm, Yb, Lu and a small amount of La. In the P507 extractant system, the distribution ratio of yttrium is between Ho and Er. To purify yttrium, it is necessary to separate Y from Ho and La first, and then separate Y from Er, Tm, Yb, and Lu, which results in a large consumption of acid and alkali. In the naphthenic acid extraction system, the distribution ratio of yttrium can be shifted outside the entire rare earth sequence. Yttrium is a difficult-to-extract component relative to Ho, Er, Tm, Yb, and Lu, and Y can be separated from Ho, Er, Tm, Yb, and Lu in one step, but it is not easy to separate Y from La. To solve these problems, in the first step of the present invention, naphthenic acid extractant is used to separate yttrium from Ho, Er, Tm, Yb, and Lu. To reduce the extraction amount and washing amount of the separation of yttrium from Ho, Er, Tm, Yb, and Lu, when separating the calcium-containing crude Y aqueous phase and the Ho, Er, Tm, Yb, Lu organic phase from the Y, Ho, Er, Tm, Yb, Lu chloride solution, part of Y enters Ho, Er, Tm, Yb, and Lu, reducing the purification multiple of Ho, Er, Tm, Yb, and Lu. Compared with the traditional extraction separation process of separating the calcium-containing crude Y aqueous phase and the Ho, Er, Tm, Yb, Lu organic phase from the Y, Ho, Er, Tm, Yb, Lu chloride solution, the extraction amount and washing amount are reduced. In the second step, P507 extractant is used to separate Y from La and Ca in the crude yttrium. To save production costs and improve product quality, non-saponified P507 extractant is directly used to extract and separate yttrium from La and Ca to prevent the saponifying agent from contaminating the product. The above process of the present invention improves the product quality, achieves lower acid and alkali consumption, and reduces the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but it does not constitute any limitation to the present invention.

[0017] Figure 1 It is a schematic process flow diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] Example 1

[0019] The components of the rare earth material (i.e., Y, Ho, Er, Tm, Yb, Lu chloride solution) are shown in Table 1 (calculated as oxides).

[0020] Table 1

[0021] Element <![CDATA[La2O3]]> <![CDATA[Ho2O3]]> <![CDATA[Er2O3]]> <![CDATA[Tm2O3]]> <![CDATA[Yb2O3]]> <![CDATA[Lu2O3]]> <![CDATA[Y2O3]]> WRE / % 0.01 2.62 6.60 0.90 5.15 0.86 83.86

[0022] A high-purity yttrium product is separated from the above rare earth material, and the product quality index is: Y2O3 / TREO > 99.999%.

[0023] An extraction organic phase composed of 24% naphthenic acid, 10% isooctanol, and the rest kerosene by volume is first saponified with calcium hydroxide, and then the YCl3 solution is extracted to obtain a Y-loaded extractant. Then, the Y-loaded extractant and [H +(YHoErTmYbLu)Cl3 solution with a concentration of 1.5 mol / L and [YHoErTmYbLu] concentration of 1.0 mol / L is separated by 95 - stage extraction and 12 - stage washing to obtain a calcium - containing crude Y aqueous phase and a YHoErTmYbLu organic phase from the YHoErTmYbLu chloride solution; using a Y - loaded extractant and [H + (HoErTmYbLu)Cl3 solution with a concentration of 1.5 mol / L and [HoErTmYbLu] concentration of 1.0 mol / L is used to separate the YHoErTmYbLu organic phase. After 85 - stage extraction and 125 - stage washing, a crude Y aqueous phase and a HoErTmYbLu organic phase are obtained; 90% of the crude Y aqueous phase is used for the next - stage purification, and 10% is returned to separate calcium from the Y - loaded extractant; 20% of the aqueous phase is split at the 85th stage and enters the separation of the YHoErTmYbLu chloride solution; the HoErTmYbLu organic phase is back - extracted with hydrochloric acid with a concentration of 4.0 mol / L to obtain a HoErTmYbLu back - extraction aqueous phase; 10% of the HoErTmYbLu back - extraction aqueous phase is used as an intermediate product for further separation, and 90% is returned to separate the YHoErTmYbLu organic phase; the crude Y aqueous phase is separated by extraction, washing with a P507 extractant composed of 30% P507 by volume and the rest kerosene and a 4.0 mol / L hydrochloric acid solution to obtain a 5N high - purity yttrium solution and a solution containing light rare earths and calcium.

[0024] Example 2

[0025] The components of the rare - earth materials are shown in Table 1.

[0026] Separate high - purity yttrium products from the above - mentioned rare - earth materials, and the product quality index: Y2O3 / TREO > 99.999%.

[0027] First, saponify calcium hydroxide with an extraction organic phase composed of 10% naphthenic acid, 10% isooctanol by volume, and the rest kerosene, and then extract the YCl3 solution to obtain a Y - loaded extractant. Then use the Y - loaded extractant and [H + (YHoErTmYbLu)Cl3 solution with a concentration of 0.1 mol / L and [YHoErTmYbLu] concentration of 1.5 mol / L is separated by 65 - stage extraction and 24 - stage washing to obtain a calcium - containing crude Y aqueous phase and a YHoErTmYbLu organic phase from the YHoErTmYbLu chloride solution; using the Y - loaded extractant and [H +The organic phase of (HoErTmYbLu)Cl3 solution with a concentration of 0.3 mol / L and [HoErTmYbLu] concentration of 1.5 mol / L is used to separate the YHoErTmYbLu organic phase. After 110 - stage extraction and 110 - stage washing, a crude Y aqueous phase and a HoErTmYbLu organic phase are obtained. 70% of the crude Y aqueous phase is used for further purification, and 30% is returned to separate calcium in the Y - loaded extractant. At the 110th stage, 5% of the aqueous phase is diverted into the separation of YHoErTmYbLu chloride solution. The HoErTmYbLu organic phase is back - extracted with hydrochloric acid with a concentration of 6.0 mol / L to obtain a HoErTmYbLu back - extraction aqueous phase. 30% of the HoErTmYbLu back - extraction aqueous phase is used as an intermediate product for further separation, and 70% is returned to separate the YHoErTmYbLu organic phase. The crude Y aqueous phase is separated by extraction, washing with an extraction organic phase composed of 50% P507 by volume and the rest kerosene and a 6.0 mol / L hydrochloric acid solution to obtain a 5N high - purity yttrium solution and a solution containing light rare earths and calcium.

[0028] Example 3

[0029] The components of the rare - earth material are shown in Table 1.

[0030] A high - purity yttrium product is separated from the above - mentioned rare - earth material, and the product quality index is: Y2O3 / TREO > 99.999%.

[0031] The extraction organic phase composed of 15% naphthenic acid, 15% isooctanol by volume and the rest kerosene is first saponified with calcium hydroxide and then used to extract the YCl3 solution to obtain a Y - loaded extractant. Then, the Y - loaded extractant and [H + The (YHoErTmYbLu)Cl3 solution with a concentration of 0.1 mol / L and [YHoErTmYbLu] concentration of 1.5 mol / L is separated from the YHoErTmYbLu chloride solution by 85 - stage extraction and 14 - stage washing to obtain a calcium - containing crude Y aqueous phase and a YHoErTmYbLu organic phase. The Y - loaded extractant and [H +The organic phase of (HoErTmYbLu)Cl3 solution with a concentration of 0.3 mol / L and [HoErTmYbLu] concentration of 1.5 mol / L is used to separate the YHoErTmYbLu organic phase. After 90 - stage extraction and 120 - stage washing, a crude Y aqueous phase and a HoErTmYbLu organic phase are obtained; 80% of the crude Y aqueous phase is used for further purification, and 20% is returned to separate calcium in the Y - loaded extractant; 5% of the aqueous phase is shunted at the 90th stage and enters the separation of YHoErTmYbLu chloride solution; the HoErTmYbLu organic phase is back - extracted with hydrochloric acid with a concentration of 5.0 mol / L to obtain a HoErTmYbLu back - extraction aqueous phase; 20% of the HoErTmYbLu back - extraction aqueous phase is used as an intermediate product for further separation, and 80% is returned to separate the YHoErTmYbLu organic phase; the crude Y aqueous phase is extracted, washed and separated with a P507 extraction organic phase composed of 40% P507 and the rest kerosene and a 5.0 mol / L hydrochloric acid solution to obtain a 5N high - purity yttrium solution and a solution containing light rare earths and calcium.

Claims

1. A method for extracting and separating high-purity yttrium, characterized in that, Comprising the following steps: 1) Extract the organic phase of naphthenic acid, saponify it with calcium hydroxide slurry to calcium naphthenate, and then extract the YCl3 solution to obtain the loaded Y extractant; 2) Extract the supported Y extractant obtained in step 1) and + a (YHoErTmYbLu)Cl3 solution with a [H]] concentration of 0.1 - 2 mol / L and a [YHoErTmYbLu] concentration of 0.3 - 2 mol / L to extract and wash and separate the YHoErTmYbLu chloride solution to obtain a calcium-containing crude Y aqueous phase and a YHoErTmYbLu organic phase; 3) Extract the loaded Y extractant obtained in step 1) and + a (HoErTmYbLu)Cl3 solution with a [H]] concentration of 0.3 - 2 mol / L and a [HoErTmYbLu] concentration of 0.3 - 2 mol / L, and the YHoErTmYbLu organic phase from step 2) through extraction and washing to obtain a crude Y aqueous phase and a HoErTmYbLu organic phase; combine the crude Y aqueous phase with the crude Y aqueous phase from step 2), use 70 - 90% as the crude product for further preparation of high-purity yttrium, and return 10 - 30% to step 1) for the preparation of the loaded Y extractant; divert 5 - 20% of the aqueous phase during extraction into step (2) to separate the YHoErTmYbLu chloride solution; 4) Back-extract the HoErTmYbLu organic phase with hydrochloric acid solution to obtain the HoErTmYbLu back-extracted aqueous phase; 10 - 30% of the HoErTmYbLu back-extracted aqueous phase is used as an intermediate product for further separation, and 70 - 90% is returned to step 3) for separating the YHoErTmYbLu organic phase; 5) For the crude Y aqueous phase obtained in step 3), use the P507 extraction organic phase and hydrochloric acid solution for extraction, washing and separation to obtain a high-purity yttrium solution and a solution containing light rare earths and calcium.

2. The method according to claim 1, characterized in that, The naphthenic acid extraction organic phase described in step 1) is a naphthenic acid extraction organic phase composed of 10 - 25% naphthenic acid, 10 - 20% isooctanol, and the rest is kerosene by volume.

3. The method according to claim 1, wherein The extraction stage number described in step 2) is 60 - 100 stages, and the washing stage number is 10 - 25 stages.

4. The method according to claim 1, wherein The extraction stage number described in step 3) is 80 - 110 stages, and the washing stage number is 110 - 130 stages.

5. The method according to claim 1, characterized in that The hydrochloric acid solution described in step 4) is a hydrochloric acid solution with a concentration of 4 - 6 mol / L.

6. The method according to claim 1, characterized in that, The P507 extraction organic phase described in step 5) is a P507 extraction organic phase composed of 30 - 50% P507 by volume and the rest is kerosene.

7. The method according to claim 1, characterized in that The hydrochloric acid solution described in step 5) is a hydrochloric acid solution with a concentration of 4 - 6 mol / L.

8. The method according to claim 1, wherein The extraction stage number described in step 5) is 50 - 70 stages, and the washing stage number is 10 - 25 stages.

Images