阅读说明：本技术 一种制备5n级氯化镁溶液的方法 (Method for preparing 5N-grade magnesium chloride solution ) 是由 曾佳丽 钟学明 王菲 于 2019-11-11 设计创作，主要内容包括：本发明一种制备5N级氯化镁溶液的方法以工业级氯化镁水溶液为料液、P229为萃取剂；由3满载分馏萃取分离NaKMg/MgCaBaPbAlFe、满载分馏萃取分离NaK/Mg和分馏萃取分离Mg/CaBaPbAlFe三个步骤组成；制备5N级氯化镁溶液。目标产品5N级氯化镁溶液的纯度为99.9991%～99.9997%,工业级氯化镁水溶液中镁的收率为96%～98%。本发明具有产品纯度高、镁的收率高、试剂消耗少、分离效率高、工艺流程短、生产成本低等优点。(The invention relates to a method for preparing 5N-grade magnesium chloride solution, which takes industrial-grade magnesium chloride aqueous solution as feed liquid and P229 as an extracting agent; consists of three steps of 3 full-load fractionation extraction separation NaKMg/MgCaBaPbAlFe, full-load fractionation extraction separation NaK/Mg and fractionation extraction separation Mg/CaBaPbAlFe; a 5N grade magnesium chloride solution was prepared. The purity of the target product 5N-grade magnesium chloride solution is 99.9991-99.9997%, and the yield of magnesium in the industrial-grade magnesium chloride aqueous solution is 96-98%. The method has the advantages of high product purity, high magnesium yield, low reagent consumption, high separation efficiency, short process flow, low production cost and the like.)

1. A method for preparing 5N-grade magnesium chloride solution is characterized by comprising the following steps: the method takes industrial-grade magnesium chloride aqueous solution as feed liquid and P229 as an extracting agent, separates and removes metallic element impurities of sodium, potassium, calcium, barium, lead, aluminum and iron in the feed liquid, and separates and removes non-metallic element impurities of bromine, sulfur, arsenic and silicon to prepare 5N-grade magnesium chloride solution; comprises 3 steps, namely full-load fractionation, extraction and separation of NaKMg/MgCaBaPbAlFe, full-load fractionation, extraction and separation of NaK/Mg and fractionation, extraction and separation of Mg/CaBaPbAlFe; the extraction section of full-load fractionation, extraction and separation NaKMg/MgCaBaPbAlFe realizes the separation of NaKMg/CaBaPbAlFe, and the washing section realizes the separation of NaK/MgCaBaPbAlFe; full-load fractionation, extraction and separation of NaKMg/MgCaBaPbAlFe, namely taking a balanced load P229 organic phase obtained by full-load fractionation, extraction and separation of NaK/Mg feeding level as an extraction organic phase, and taking a balanced water phase obtained by fractionation, extraction and separation of Mg/CaBaPbAlFe feeding level as a detergent; full-load fractionation, extraction and separation of NaK/Mg and fractionation, extraction and separation of Mg/CaBaPbAlFe are directly connected in series; the outlet organic phase which is fully loaded with NaK/Mg and is separated by fractional extraction is used as an extraction organic phase for separating Mg/CaBaPbAlFe by fractional extraction, and directly enters the 1 st stage of separating Mg/CaBaPbAlFe by fractional extraction; the 1 st level outlet water phase of the Mg/CaBaPbAlFe separation by fractional extraction is used as a detergent for separating NaK/Mg by full-load fractional extraction;

the 3 steps are as follows:

step 1: full-load fractional extraction separation of NaKMg/MgCaBaPbAlFe

Step 1, full-load fractionation, extraction and separation of NaKMg/MgCaBaPbAlFe, wherein the extraction section realizes the separation of NaKMg/CaBaPbAlFe, and the washing section realizes the separation of NaK/MgCaBaPbAlFe; taking a balanced load P229 organic phase obtained from the feed stage of the NaK/Mg full-load fractionation extraction system in the step 2 as an extraction organic phase, an industrial-grade magnesium chloride aqueous solution as a feed liquid, and taking a balanced water phase obtained from the feed stage of the Mg/CaBaPbAlFe fractionation extraction system in the step 3 as a detergent; the equilibrium loaded P229 organic phase obtained from the feed stage of the NaK/Mg full-load fractionation extraction system in the step 2 enters the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system from the 1 st stage, the industrial-grade magnesium chloride aqueous solution enters the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system from the feed stage, and the equilibrium aqueous phase obtained from the feed stage of the Mg/CaBaPbAlFe fractionation extraction system in the step 3 enters the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system from the last 1 st stage; obtaining a magnesium chloride solution containing Na, K, Br, S, As and Si from the water phase at the 1 st level outlet of the NaKMg/MgCaBaPbAlFe full-load fractional extraction system, and using the magnesium chloride solution As feed liquid for full-load fractional extraction and separation of NaK/Mg in the step 2; obtaining a P229 organic phase loaded with Mg-Ca-Ba-Pb-Al-Fe from the last 1-stage outlet organic phase of the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system, and using the P229 organic phase as feed liquid for fractionating, extracting and separating Mg/CaBaPbAlFe in the step 3;

step 2: full-load fractional extraction for separating NaK/Mg

Step 2, separating and removing NaK/Mg by full-load fractionation and extraction, and separating and removing metallic element impurities of sodium and potassium and non-metallic element impurities of bromine, sulfur, arsenic and silicon in a magnesium chloride solution; taking an ammonia saponification P229 organic phase As an extraction organic phase, taking a magnesium chloride solution containing Na, K, Br, S, As and Si obtained from a 1 st-stage outlet water phase of a NaKMg/MgCaBaPbAlFe full-load fractionation extraction system in the step 1 As a feed liquid, and taking a 5N-stage magnesium chloride solution obtained from a 1 st-stage outlet water phase of a Mg/CaBaPbAlFe fractionation extraction system in the step 3 As a washing agent; the saponified P229 organic phase is an extracted organic phase and enters a NaK/Mg full-load fractionation extraction system from the 1 st level, a magnesium chloride solution containing Na, K, Br, S, As and Si and obtained from a water phase at the 1 st level outlet of the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system in the step 1 enters the NaK/Mg full-load fractionation extraction system from a feeding level, and a 5N-level magnesium chloride solution obtained from a water phase at the 1 st level outlet of the Mg/CaBaPbAlFe fractionation extraction system in the step 3 enters the Mg/CaBaPbAlFe fractionation extraction system from the last 1 st level; obtaining a mixed solution of sodium chloride, potassium chloride and magnesium chloride containing Br, S, As and Si from the water phase at the level 1 outlet of a NaK/Mg full-load fractionation extraction system; separating a balanced load P229 organic phase of a feed grade of a NaK/Mg full-load fractional extraction system, and using the balanced load P229 organic phase as an extraction organic phase for full-load fractional extraction separation of NaKMg/MgCaBaPbAlFe in the step 1; obtaining a P229 organic phase loaded with magnesium from the organic phase at the last level 1 outlet of the NaK/Mg full-load fractionation extraction system, and using the P229 organic phase as an extraction organic phase for fractionating, extracting and separating Mg/CaBaPbAlFe in the step 3;

and step 3: fractionation, extraction and separation of Mg/CaBaPbAlFe

Step 3, fractionating, extracting and separating Mg/CaBaPbAlFe to realize the separation of magnesium from calcium, barium, lead, aluminum and iron; taking a P229 organic phase loaded with magnesium and obtained from the last level 1 of the NaK/Mg full-load fractionation extraction system in the step 2 as an extraction organic phase, taking a P229 organic phase loaded with magnesium, calcium, barium, lead, aluminum and iron and obtained from the last level 1 of the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system in the step 1 as a feed liquid, and taking 6.0mol/L HCl as a washing acid; the P229 organic phase loaded with magnesium and obtained from the last 1 level of the NaK/Mg full-load fractionation extraction system in the step 2 enters into a Mg/CaBaPbAlFe fractionation extraction system from the 1 st level, the P229 organic phase loaded with magnesium, calcium, barium, lead, aluminum and iron and obtained from the last 1 level of the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system in the step 1 enters into the Mg/CaBaPbAlFe fractionation extraction system from a feeding level, and 6.0mol/L HCl washing acid enters into the Mg/CaBaPbAlFe fractionation extraction system from the last 1 level; obtaining a target product 5N-grade magnesium chloride solution from a 1 st-grade outlet water phase of the Mg/CaBaPbAlFe fractional extraction system, and taking the 5N-grade magnesium chloride solution as a detergent of the NaK/Mg full-load fractional extraction system in the step 2; separating a feed-grade equilibrium water phase of the Mg/CaBaPbAlFe fractional extraction system, and using the balance water phase as a detergent for separating NaKMg/MgCaBaPbAlFe through full-load fractional extraction in the step 1; and obtaining a P229 organic phase loaded with calcium, barium, lead, aluminum and iron from the final level 1 outlet organic phase of the Mg/CaBaPbAlFe fractional extraction system.

2. A process for preparing a 5N grade magnesium chloride solution according to claim 1, characterized in that: the P229 organic phase is sulfonated kerosene of P229, wherein the concentration of P229 is 1.0 mol/L; when used, the P229 organic phase is saponified with aqueous ammonia to obtain an ammonolyzed P229 organic phase.

3. A process for preparing a 5N grade magnesium chloride solution according to claim 1, characterized in that: the element concentrations in the industrial grade magnesium chloride aqueous solution are respectively as follows: br 0.010 g/L-0.030 g/L, S0.010.010 g/L-0.030 g/L, As0.010g/L-0.030 g/L, Si 0.010 g/L-0.030 g/L, Na 0.10 g/L-0.30 g/L, K0.010.010 g/L-0.050 g/L, Mg 65.0.0 g/L-75.0 g/L, Ca 0.10.10 g/L-0.50 g/L, Ba0.0010 g/L-0.0030 g/L, Pb0.001g/L-0.0030 g/L, Al 0.0010 g/L-0.0030 g/L, Fe 0.0010.0010 g/L-0.0030 g/L.

4. A process for preparing a 5N grade magnesium chloride solution according to claim 1, characterized in that: the element concentrations in the 5N-grade magnesium chloride solution are respectively as follows: br of 0.000010 g/L-0.000030 g/L, S0.000010 of 0.000010 g/L-0.000030 g/L, As 0.000010.000010 g/L-0.000030 g/L, Si 0.000010.000010 g/L-0.000030 g/L, Na 0.00010 of 0.00010 g/L-0.00030 g/L, K0.000010.000010 g/L-0.000030 g/L, Mg 68.0.0 g/L-72.0 g/L, Ca0.00010g/L-0.00030 g/L, Ba 0.000010.000010 g/L-0.000030 g/L, Pb 0.000010 of 0.000010 g/L-0.000030 g/L, Al 0.000010 of 0.000010 g/L-0.000030 g/L, Fe 0.000010.000010 g/L-0.000030 g/L.

Technical Field

The invention relates to a method for preparing 5N-grade magnesium chloride solution, in particular to a method for preparing 5N-grade magnesium chloride solution by taking industrial-grade magnesium chloride aqueous solution as feed liquid and P229 as an extracting agent, separating and removing metal elements such as sodium, potassium, calcium, barium, lead, aluminum, iron and the like in the feed liquid and non-metal elements such as bromine, sulfur, arsenic, silicon and the like. The invention belongs to the technical field of preparation of 5N-grade magnesium chloride.

Background

The 5N-grade magnesium chloride is one of basic raw materials for preparing other 5N-grade magnesium products, but no method for preparing the 5N-grade magnesium chloride exists at present.

Aiming at the method for preparing 5N-grade magnesium chloride which is not available at present, the invention establishes a method for preparing 5N-grade magnesium chloride solution by taking industrial-grade magnesium chloride aqueous solution as feed liquid. The main impurities in the industrial grade magnesium chloride comprise metallic element impurities such as calcium, sodium, potassium, lead, aluminum, iron and the like, and non-metallic element impurities such as bromine, sulfur, arsenic, silicon and the like.

Disclosure of Invention

The invention aims at the method for preparing 5N-grade magnesium chloride which is not available at present, and establishes a method for preparing 5N-grade magnesium chloride solution by taking industrial-grade magnesium chloride aqueous solution as feed liquid.

The invention relates to a method for preparing 5N-grade magnesium chloride solution, which takes industrial-grade magnesium chloride aqueous solution as feed liquid and di- (2-ethylhexyl) phosphonic acid (P229 for short) as an extracting agent to separate and remove metal elements such as sodium, potassium, calcium, barium, lead, aluminum, iron and the like in the feed liquid and non-metal elements such as bromine, sulfur, arsenic, silicon and the like to prepare the 5N-grade magnesium chloride solution.

The invention relates to a method for preparing 5N-grade magnesium chloride solution, which comprises 3 steps, namely full-load fractional extraction separation of NaKMg/MgCaBaPbAlFe, full-load fractional extraction separation of NaK/Mg and fractional extraction separation of Mg/CaBaPbAlFe; the extraction section of full-load fractionation, extraction and separation NaKMg/MgCaBaPbAlFe realizes the separation of NaKMg/CaBaPbAlFe, and the washing section realizes the separation of NaK/MgCaBaPbAlFe; the method is characterized in that NaKMg/MgCaBaPbAlFe is separated by full-load fractional extraction, a balanced load P229 organic phase obtained by separating NaK/Mg feeding grade by full-load fractional extraction is used as an extraction organic phase, and a balanced aqueous phase obtained by separating Mg/CaBaPbAlFe feeding grade by fractional extraction is used as a detergent. Full-load fractionation, extraction and separation of NaK/Mg and fractionation, extraction and separation of Mg/CaBaPbAlFe are directly connected in series; the outlet organic phase which is fully loaded with NaK/Mg and is separated by fractional extraction is used as an extraction organic phase for separating Mg/CaBaPbAlFe by fractional extraction, and directly enters the 1 st stage of separating Mg/CaBaPbAlFe by fractional extraction; the 1 st stage outlet aqueous phase of the Mg/CaBaPbAlFe separation by fractional extraction is used as a washing agent for full-load fractional extraction and separation of NaK/Mg.

The method for preparing the 5N-grade magnesium chloride solution comprises the following 3 steps:

step 1: full-load fractional extraction separation of NaKMg/MgCaBaPbAlFe

Step 1 is full-load fractionation, extraction and separation of NaKMg/MgCaBaPbAlFe, the extraction section realizes the separation of NaKMg/CaBaPbAlFe, and the washing section realizes the separation of NaK/MgCaBaPbAlFe. And (3) taking a balanced load P229 organic phase obtained from the feed stage of the NaK/Mg full-load fractional extraction system in the step 2 as an extraction organic phase, taking an industrial-grade magnesium chloride aqueous solution as a feed liquid, and taking a balanced water phase obtained from the feed stage of the Mg/CaBaPbAlFe fractional extraction system in the step 3 as a detergent. The equilibrium loaded P229 organic phase obtained from the feed stage of the NaK/Mg full-load fractionation extraction system of the step 2 enters into the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system from the 1 st stage, the industrial grade magnesium chloride aqueous solution enters into the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system from the feed stage, and the equilibrium aqueous phase obtained from the feed stage of the Mg/CaBaPbAlFe fractionation extraction system of the step 3 enters into the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system from the last 1 st stage. Obtaining a magnesium chloride solution containing Na, K, Br, S, As and Si from the water phase at the 1 st level outlet of the NaKMg/MgCaBaPbAlFe full-load fractional extraction system, and using the magnesium chloride solution As feed liquid for full-load fractional extraction and separation of NaK/Mg in the step 2; and (3) obtaining a P229 organic phase loaded with Mg-Ca-Ba-Pb-Al-Fe from the organic phase at the last stage 1 outlet of the NaKMg/MgCaBaPbAlFe full-load fractional extraction system, and using the P229 organic phase as the feed liquid for fractional extraction and separation of Mg/CaBaPbAlFe in the step 3.

Step 2: full-load fractional extraction for separating NaK/Mg

And step 2, full-load fractionation, extraction and separation of NaK/Mg, and separation and removal of metallic element impurities of sodium and potassium and non-metallic element impurities of bromine, sulfur, arsenic and silicon in the magnesium chloride solution. An ammonia saponification P229 organic phase is used As an extraction organic phase, a magnesium chloride solution containing Na, K, Br, S, As and Si, which is obtained from a 1 st-stage outlet water phase of a NaKMg/MgCaBaPbAlFe full-load fractionation extraction system in the step 1, is used As a feed liquid, and a 5N-stage magnesium chloride solution which is obtained from a 1 st-stage outlet water phase of a Mg/CaBaPbAlFe fractionation extraction system in the step 3 is used As a washing agent. The saponified P229 organic phase is an extracted organic phase and enters a NaK/Mg full-load fractionation extraction system from the 1 st level, a magnesium chloride solution containing Na, K, Br, S, As and Si and obtained from a water phase at the 1 st level outlet of the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system in the step 1 enters the NaK/Mg full-load fractionation extraction system from a feeding level, and a 5N-level magnesium chloride solution obtained from a water phase at the 1 st level outlet of the Mg/CaBaPbAlFe fractionation extraction system in the step 3 enters the Mg/CaBaPbAlFe fractionation extraction system from the last 1 st level. Obtaining a mixed solution of sodium chloride, potassium chloride and magnesium chloride containing Br, S, As and Si from the water phase at the level 1 outlet of a NaK/Mg full-load fractionation extraction system; separating a balanced load P229 organic phase of a feed grade of a NaK/Mg full-load fractional extraction system, and using the balanced load P229 organic phase as an extraction organic phase for full-load fractional extraction separation of NaKMg/MgCaBaPbAlFe in the step 1; and obtaining a P229 organic phase loaded with magnesium from the organic phase at the outlet of the last stage 1 of the NaK/Mg full-load fractional extraction system, and using the P229 organic phase as an extraction organic phase for fractional extraction and separation of Mg/CaBaPbAlFe in the step 3.

And step 3: fractionation, extraction and separation of Mg/CaBaPbAlFe

And 3, fractionating, extracting and separating Mg/CaBaPbAlFe to realize the separation of magnesium from calcium, barium, lead, aluminum and iron. Taking a P229 organic phase loaded with magnesium obtained from the last stage 1 of the NaK/Mg full-load fractionation extraction system in the step 2 as an extraction organic phase, taking a P229 organic phase loaded with magnesium, calcium, barium, lead, aluminum and iron obtained from the last stage 1 of the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system in the step 1 as a feed liquid, and taking 6.0mol/L HCl as a washing acid. The P229 organic phase loaded with magnesium and obtained from the last stage 1 of the NaK/Mg full-load fractionation extraction system in the step 2 enters into the Mg/CaBaPbAlFe fractionation extraction system from the stage 1, the P229 organic phase loaded with magnesium, calcium, barium, lead, aluminum and iron and obtained from the last stage 1 of the NaKMg/MgCaBaPbAlFe full-load fractionation extraction system in the step 1 enters into the Mg/CaBaPbAlFe fractionation extraction system from the feeding stage, and 6.0mol/L HCl washing acid enters into the Mg/CaBaPbAlFe fractionation extraction system from the last stage 1. Obtaining a target product 5N-grade magnesium chloride solution from a 1 st-grade outlet water phase of the Mg/CaBaPbAlFe fractional extraction system, and taking the 5N-grade magnesium chloride solution as a detergent of the NaK/Mg full-load fractional extraction system in the step 2; separating a feed-grade equilibrium water phase of the Mg/CaBaPbAlFe fractional extraction system, and using the balance water phase as a detergent for separating NaKMg/MgCaBaPbAlFe through full-load fractional extraction in the step 1; and obtaining a P229 organic phase loaded with calcium, barium, lead, aluminum and iron from the final level 1 outlet organic phase of the Mg/CaBaPbAlFe fractional extraction system.

The P229 organic phase is sulfonated kerosene of P229, wherein the concentration of P229 is 1.0 mol/L. When used, the P229 organic phase is saponified with aqueous ammonia to obtain an ammonolyzed P229 organic phase.

The element concentrations in the industrial grade magnesium chloride aqueous solution are respectively as follows: br 0.010 g/L-0.030 g/L, S0.010 g/L-0.030 g/L, As0.010 g/L-0.030 g/L, Si 0.010 g/L-0.030 g/L, Na 0.10.10 g/L-0.30 g/L, K0.010.010 g/L-0.050 g/L, Mg 65.0.0 g/L-75.0 g/L, Ca 0.10 g/L-0.50 g/L, Ba0.0010g/L-0.0030 g/L, Pb0.0010 g/L-0.0030 g/L, Al 0.0010.0010 g/L-0.0030 g/L and Fe0.0010g/L-0.0030 g/L.

The element concentrations in the 5N-grade magnesium chloride solution are respectively as follows: br of 0.000010 g/L-0.000030 g/L, S0.000010 g/L-0.000030 g/L, As 0.000010.000010 g/L-0.000030 g/L, Si 0.000010.000010 g/L-0.000030 g/L, Na 0.00010.00010 g/L-0.00030 g/L, K0.000010.000010 g/L-0.000030 g/L, Mg 68.0.0 g/L-72.0 g/L, Ca 0.00010.00010 g/L-0.00030 g/L, Ba 0.000010.000010 g/L-0.000030 g/L, Pb 0.000010 g/L-0.000030 g/L, Al 0.000010.000010 g/L-0.000030 g/L, Fe 0.000010.000010 g/L-0.000030 g/L.

The invention has the beneficial effects that: 1) the 5N grade magnesium chloride solution is directly obtained from the industrial grade magnesium chloride aqueous solution. After the 5N-grade magnesium chloride solution is subjected to post-treatment such as concentration crystallization or precipitation, a series of 5N-grade magnesium-containing compounds such as 5N-grade magnesium chloride crystals and 5N-grade magnesium phosphate crystals can be obtained. 2) The product purity is high, and the yield of magnesium is high: the purity of the target product 5N-grade magnesium chloride solution is 99.9991-99.9997%, and the yield of magnesium in the industrial-grade magnesium chloride aqueous solution is 96-98%. 3) The reagent consumption is less: the outlet organic phase which is fully loaded with NaK/Mg and separated by fractional extraction is used as an extraction organic phase for separating Mg/CaBaPbAlFe by fractional extraction, and directly enters the 1 st stage of separating Mg/CaBaPbAlFe by fractional extraction, so that saponification alkali for separating Mg/CaBaPbAlFe by fractional extraction is saved. The water phase at the 1 st stage outlet for fractionating, extracting and separating Mg/CaBaPbAlFe is used as a detergent for separating NaK/Mg by full-load fractionating, extracting and separating, and the washing acid for separating NaK/Mg by full-load fractionating, extracting and separating is saved. 4) The separation efficiency is high: and 3 separation sections (full-load fractional extraction separation NaKMg/MgCaBaPbAlFe, full-load fractional extraction separation NaK/Mg, fractional extraction separation Mg/CaBaPbAlFe) separate and remove metal impurities such as sodium, potassium, calcium, barium, lead, aluminum, iron and the like and non-metal impurities such as bromine, sulfur, arsenic, silicon and the like in the industrial-grade magnesium chloride aqueous solution. 5) The process flow is short: the process for the preparation of 5N grade magnesium chloride from technical grade magnesium chloride aqueous solution consists of 3 separation stages. The method is characterized in that NaKMg/MgCaBaPbAlFe is separated by full-load fractionation and extraction, and a balanced load P229 organic phase obtained by full-load fractionation, extraction and separation of NaK/Mg feed grade is used as an extraction organic phase, so that a saponification section is not needed for full-load fractionation, extraction and separation of NaKMg/MgCaBaPbAlFe; the equilibrium water phase obtained by fractionating, extracting and separating Mg/CaBaPbAlFe feeding level is used as a detergent, so that the NaKMg/MgCaBaPbAlFe full-load fractionating, extracting and separating does not need a back-extraction section. The full-load fractional extraction separation NaKMg/MgCaBaPbAlFe and the full-load fractional extraction separation NaK/Mg share a saponification section. The outlet organic phase which is fully loaded with NaK/Mg and is separated by fractional extraction is used as the extraction organic phase for separating Mg/CaBaPbAlFe by fractional extraction, so that the saponification section is not needed for separating Mg/CaBaPbAlFe by fractional extraction. The outlet organic phase of the full-load fractional extraction for separating the NaK/Mg is used as an extraction organic phase of the fractional extraction for separating the Mg/CaBaPbAlFe, so the fractional extraction for separating the full-load fractional extraction for separating the NaK/Mg does not need a washing section. 6) The production cost is low: high separation efficiency, short process flow and less reagent consumption.

Drawings

FIG. 1: the invention discloses a process flow schematic diagram of a method for preparing 5N-grade magnesium chloride solution. In FIG. 1, LOP denotes the loaded organic phase; w represents a detergent; 5N Mg represents a 5N grade magnesium chloride solution.

Detailed Description

A method for preparing a 5N grade magnesium chloride solution according to the present invention is further described with reference to the following specific examples.