CN110668479B - A kind of method for preparing 5N grade magnesium sulfate solution - Google Patents

Abstract

The invention relates to a method for preparing 5N-grade magnesium sulfate solution, which takes industrial-grade magnesium sulfate aqueous solution as feed liquid and P229 as an extracting agent and consists of three steps of full-load fractional extraction separation of NaKMg/MgCaPbAlFe, full-load fractional extraction separation of NaK/Mg and fractional extraction separation of Mg/CaPbAlFe; separating and removing metallic element impurities such as sodium, potassium, calcium, lead, aluminum and iron in the feed liquid, and separating and removing nonmetallic element impurities such as chlorine, silicon and arsenic to prepare a 5N-grade magnesium sulfate solution; the purity of the target product 5N grade magnesium sulfate solution is 99.9991% -99.9997%, and the yield of magnesium in the industrial grade magnesium sulfate 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.

Description

A kind of method for preparing 5N grade magnesium sulfate solution

technical field

The present invention is a method for preparing 5N-level magnesium sulfate solution, which specifically relates to the separation and removal of metal elements such as sodium, potassium, calcium, lead, aluminum, iron and the like in the feed solution by using an industrial-grade magnesium sulfate solution as a feed solution and P229 as an extractant. , and separation and removal of non-metallic elements such as chlorine, silicon, arsenic, etc., to prepare a 5N-grade magnesium sulfate solution. The specific technical field of the present invention is the preparation of 5N grade magnesium sulfate.

Background technique

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

Aiming at that there is no method for preparing 5N-level magnesium sulfate at present, the present invention establishes a method for preparing a 5N-level magnesium sulfate solution by using an industrial-grade magnesium sulfate aqueous solution as a feed liquid. The main impurities in industrial grade magnesium sulfate are sodium, potassium, calcium, lead, aluminum, iron and other metal element impurities, as well as chlorine, silicon, arsenic and other non-metallic element impurities.

SUMMARY OF THE INVENTION

Aiming at that there is no method for preparing 5N-level magnesium sulfate at present, the present invention establishes a method for preparing a 5N-level magnesium sulfate solution by using an industrial-grade magnesium sulfate aqueous solution as a feed liquid.

The present invention is a method for preparing a 5N-level magnesium sulfate solution. The technical-grade magnesium sulfate aqueous solution is used as the feed liquid, and bis(2-ethylhexyl)phosphonic acid (abbreviated as P229) is used as the extractant, and sodium and potassium in the feed liquid are separated and removed. , calcium, lead, aluminum, iron and other metal elements, and separation and removal of non-metallic elements such as chlorine, silicon, arsenic, etc., to prepare 5N grade magnesium sulfate solution.

A method for preparing a 5N-level magnesium sulfate solution of the present invention consists of three steps, namely, full-load fractional extraction and separation of NaKMg/MgCaPbAlFe, full-load fractional extraction and separation of NaK/Mg, and fractional extraction and separation of Mg/CaPbAlFe; full-load fractional extraction and separation of NaKMg/MgCaPbAlFe The extraction section realizes the separation of NaKMg/CaPbAlFe, and the washing section realizes the separation of NaK/MgCaPbAlFe; the full-load fractional extraction and separation of NaKMg/MgCaPbAlFe use the balanced-load P229 organic phase obtained by the full-load fractional extraction and separation of NaK/Mg feed stage as the extraction organic phase, and the fractional extraction and separation The equilibrium aqueous phase obtained from the Mg/CaPbAlFe feed stage is the detergent. The full-load fractional distillation extraction and separation of NaK/Mg is directly connected with the fractional distillation and extraction separation of Mg/CaPbAlFe; the outlet organic phase of the full-load fractionation extraction and separation of NaK/Mg is used as the extraction organic phase of the fractional distillation extraction and separation of Mg/CaPbAlFe, and directly enters the fractional distillation extraction and separation of Mg/CaPbAlFe. 1st stage; the 1st stage outlet water phase of fractional extraction and separation of Mg/CaPbAlFe is used as a detergent for full-load fractional extraction and separation of NaK/Mg.

The 3 steps of a kind of method for preparing 5N grade magnesium sulfate solution of the present invention are as follows:

Step 1: Full-load fractional extraction and separation of NaKMg/MgCaPbAlFe

Step 1 is full-load fractional distillation extraction to separate NaKMg/MgCaPbAlFe, the extraction section realizes NaKMg/CaPbAlFe separation, and the washing section realizes NaK/MgCaPbAlFe separation. Taking the balanced load P229 organic phase obtained from the feed stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, the technical-grade magnesium sulfate aqueous solution as the feed liquid, and the balance obtained from the feed stage of the Mg/CaPbAlFe fractional distillation extraction system in step 3 The aqueous phase is the detergent. The balanced load P229 organic phase obtained from the feed stage of the NaK/Mg full-load fractionation extraction system in step 2 enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the first stage, and the technical-grade magnesium sulfate aqueous solution enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the feed stage. , the equilibrium water phase obtained from the feed stage of the Mg/CaPbAlFe fractionation extraction system in step 3 enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the last stage. The magnesium sulfate solution containing Na, K, Cl, Si and As was obtained from the first-stage outlet aqueous phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system, which was used as the feed liquid for the full-load fractionation extraction and separation of NaK/Mg in step 2; from the NaKMg/MgCaPbAlFe full-load The P229 organic phase loaded with magnesium, calcium, lead, aluminum and iron is obtained from the organic phase at the last stage of the fractional distillation extraction system, which is used as the feed liquid for the fractional distillation extraction and separation of Mg/CaPbAlFe in step 3.

Step 2: Full-load fractional extraction and separation of NaK/Mg

Step 2 is to separate NaK/Mg by full-load fractionation extraction, and to separate and remove the metal element impurities sodium and potassium, and the non-metal element impurities chlorine, silicon and arsenic in the magnesium sulfate solution. Taking the organic phase of ammonia saponification P229 as the extraction organic phase, the magnesium sulfate solution containing Na, K, Cl, Si and As obtained from the first-stage outlet water phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 is the feed liquid, and step 3 The 5N-grade magnesium sulfate solution obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation extraction system is a detergent. The organic phase of saponification P229 is to extract the organic phase from the first stage into the NaK/Mg full-load fractionation extraction system, and the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 contains Na, K, Cl, Si and As obtained from the first-stage outlet water phase. The magnesium sulfate solution enters the NaK/Mg full-load fractionation extraction system from the feed stage, and the 5N-grade magnesium sulfate solution obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation and extraction system in step 3 enters the NaK/Mg full-load fractionation extraction system from the last stage. . A mixture solution containing sodium, potassium, chlorine, silicon and arsenic was obtained from the first-stage outlet aqueous phase of the NaK/Mg full-load fractional distillation extraction system; the balanced-load P229 organic phase of the feed stage of the NaK/Mg full-load fractional distillation extraction system was separated and used as In step 1, the organic phase of extraction of NaKMg/MgCaPbAlFe is separated by full-load fractionation extraction; the magnesium-loaded P229 organic phase is obtained from the organic phase of the last stage of the NaK/Mg full-load fractional distillation and extraction system, which is used as the organic phase of extraction of Mg/CaPbAlFe in step 3 by fractional distillation and extraction. .

Step 3: Fractional extraction and separation of Mg/CaPbAlFe

Step 3 is to separate Mg/CaPbAlFe by fractional distillation, so as to realize the separation of magnesium from calcium, lead, aluminum and iron. Take the magnesium-loaded P229 organic phase obtained in the last stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, and the magnesium-calcium-lead-aluminum-iron P229 obtained in the last stage of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1. The organic phase is the feed liquid, and 3.0 mol/L sulfuric acid is the washing acid. The magnesium-loaded P229 organic phase obtained in the last stage of the NaK/Mg full-load fractionation extraction system in step 2 enters the Mg/CaPbAlFe fractional distillation and extraction system from the first stage, and the magnesium-loaded magnesium obtained in the last stage of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 The P229 organic phase of calcium lead aluminum iron enters the Mg/CaPbAlFe fractionation extraction system from the feed stage, and the 3.0mol/L sulfuric acid washing acid enters the Mg/CaPbAlFe fractionation extraction system from the last stage. The target product 5N-grade magnesium sulfate solution was obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation extraction system, and the 5N-grade magnesium sulfate solution was taken as the detergent of the NaK/Mg full-load fractional distillation and extraction system in step 2; the Mg/CaPbAlFe was taken out The balanced aqueous phase of the feed stage of the fractional distillation extraction system is used as a detergent for the separation of NaKMg/MgCaPbAlFe by full-load fractionation extraction in step 1; the organic phase of P229 loaded with calcium, lead, aluminum and iron is obtained from the organic phase at the last stage of the Mg/CaPbAlFe fractional distillation and extraction system.

The P229 organic phase is a sulfonated kerosene solution of P229, wherein the concentration of P229 is 1.0 mol/L. When in use, ammonia water is used to saponify the P229 organic phase to obtain the ammonia saponified P229 organic phase.

The element concentrations in the industrial-grade magnesium sulfate aqueous solution are respectively: Cl 1.0g/L～3.0g/L, Si 0.0010g/L～0.0030g/L, As 0.00010g/L～0.00030g/L, Na 0.010 g/L～0.030g/L, K0.010g/L～0.030g/L, Mg 65.0g/L～75.0g/L, Ca 0.010g/L～0.050g/L, Pb 0.0010g/L～0.0030g /L, Al 0.0010g/L～0.0030g/L, Fe 0.0010g/L～0.0050g/L.

The element concentrations in the 5N-grade magnesium sulfate solution are: Cl 0.00010g/L～0.00030g/L, Si 0.000010g/L～0.000030g/L, As 0.000010g/L～0.000030g/L, Na 0.000010 g/L～0.000030g/L, K 0.000010g/L～0.000030g/L, Mg 68.0g/L～72.0g/L, Ca 0.00010g/L～0.00050g/L, Pb 0.000010g/L～0.000030g /L, Al 0.000010g/L～0.000030g/L, Fe0.000010g/L～0.000030g/L.

The beneficial effects of the present invention are as follows: 1) 5N-grade magnesium sulfate solution is directly obtained from industrial-grade magnesium sulfate aqueous solution. A series of 5N-grade magnesium-containing compounds such as 5N-grade magnesium sulfate crystals and 5N-grade magnesium phosphate crystals can be obtained by post-processing such as concentrated crystallization or precipitation of 5N-grade magnesium sulfate solution. 2) The product has high purity and high magnesium yield: the purity of the target product 5N-grade magnesium sulfate solution is 99.9991% to 99.9997%, and the yield of magnesium in the technical-grade magnesium sulfate aqueous solution is 96% to 98%. 3) Less reagent consumption: the organic phase at the outlet of the full-load fractional extraction and separation of NaK/Mg is used as the extraction organic phase of the fractional extraction and separation of Mg/CaPbAlFe, and directly enters the first level of the fractional extraction and separation of Mg/CaPbAlFe, saving the fractional extraction and separation of Mg/CaPbAlFe. Saponification base of CaPbAlFe. The first-stage outlet water phase of the fractional distillation extraction and separation of Mg/CaPbAlFe is used as a detergent for the full-load fractionation extraction and separation of NaK/Mg, saving the washing acid for the full-load fractionation extraction and separation of NaK/Mg. 4) High separation efficiency: 3 separation sections (full-load fractionation extraction and separation of NaKMg/MgCaPbAlFe, full-load fractionation extraction and separation of NaK/Mg, and fractional distillation and extraction of Mg/CaPbAlFe) separate and remove the sodium, potassium, calcium, Metal impurities such as lead, aluminum, iron, and non-metallic impurities such as chlorine, silicon, and arsenic. 5) The technological process is short: the method for preparing 5N-grade magnesium sulfate from an aqueous solution of technical-grade magnesium sulfate consists of three separation sections. Full-load fractional extraction and separation of NaKMg/MgCaPbAlFe The balanced load P229 organic phase obtained by full-load fractional extraction and separation of NaK/Mg feed stage is used as the extraction organic phase. Therefore, full-load fractional extraction and separation of NaKMg/MgCaPbAlFe does not require a saponification section; fractional distillation is used to separate Mg/CaPbAlFe. The equilibrium water phase obtained at the feed stage is a detergent, so a stripping section is not required for the separation of NaKMg/MgCaPbAlFe by full-load fractionation extraction. The full-load fractional extraction and extraction of NaKMg/MgCaPbAlFe shares a saponification section with the full-load fractional extraction and extraction of NaK/Mg. The outlet organic phase of the full-load fractional extraction and separation of NaK/Mg is used as the extraction organic phase of the fractional extraction and separation of Mg/CaPbAlFe, so the fractional extraction and separation of Mg/CaPbAlFe does not require a saponification section. The outlet organic phase of full-load fractionation extraction and separation of NaK/Mg is used as the extraction organic phase for fractional distillation and extraction of Mg/CaPbAlFe, so full-load fractionation extraction and separation of NaK/Mg does not require a stripping section. 6) Low production cost: high separation efficiency, short process flow and low reagent consumption.

Description of drawings

Fig. 1: a schematic diagram of the process flow of a method for preparing a 5N-grade magnesium sulfate solution of the present invention. In Figure 1, LOP represents the loaded organic phase; W represents detergent; 5N Mg represents 5N grade magnesium sulfate solution.

Detailed ways

A method for preparing 5N grade magnesium sulfate solution of the present invention will be further described below in conjunction with specific embodiments.

Example 1

The organic phase of P229 is a sulfonated kerosene solution of P229, wherein the concentration of P229 is 1.0 mol/L. When in use, ammonia water is used to saponify the P229 organic phase to obtain the ammonia saponified P229 organic phase.

The element concentrations in the industrial-grade magnesium sulfate aqueous solution are: Cl 1.0g/L, Si 0.0010g/L, As0.00010g/L, Na 0.010g/L, K 0.010g/L, Mg 65.0g/L, Ca 0.010 g/L, Pb 0.0010g/L, Al 0.0010g/L, Fe 0.0010g/L.

Step 1: Full-load fractional extraction and separation of NaKMg/MgCaPbAlFe

Taking the balanced load P229 organic phase obtained at the 32nd stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, the technical grade magnesium sulfate aqueous solution as the feed liquid, and the balance obtained in the 30th stage of the Mg/CaPbAlFe fractional distillation extraction system in step 3 The aqueous phase is the detergent. The balanced load P229 organic phase obtained in the 32nd stage of the NaK/Mg full-load fractionation extraction system in step 2 enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the 1st stage, and the industrial-grade magnesium sulfate aqueous solution enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the 12th stage. , the equilibrium water phase obtained in the 30th stage of the Mg/CaPbAlFe fractional distillation and extraction system in step 3 enters the NaKMg/MgCaPbAlFe full-load fractionation and extraction system from the 26th stage. The magnesium sulfate solution containing Na, K, Cl, Si and As was obtained from the first-stage outlet aqueous phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system, which was used as the feed liquid for the full-load fractionation extraction and separation of NaK/Mg in step 2; from the NaKMg/MgCaPbAlFe full-load The organic phase at the 26th stage of the fractionation extraction system obtains the P229 organic phase loaded with magnesium, calcium, lead, aluminum and iron, which is used as the feed liquid for the fractional distillation extraction and separation of Mg/CaPbAlFe in step 3.

Step 2: Full-load fractional extraction and separation of NaK/Mg

Taking the organic phase of ammonia saponification P229 as the extraction organic phase, the magnesium sulfate solution containing Na, K, Cl, Si and As obtained from the first-stage outlet water phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 is the feed liquid, and step 3 The 5N-grade magnesium sulfate solution obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation extraction system is a detergent. The organic phase of saponification P229 is to extract the organic phase from the first stage into the NaK/Mg full-load fractionation extraction system, and the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 contains Na, K, Cl, Si and As obtained from the first-stage outlet water phase. The magnesium sulfate solution enters the NaK/Mg full-load fractionation extraction system from the 32nd stage, and the 5N-grade magnesium sulfate solution obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation and extraction system in step 3 enters the NaK/Mg full-load fractionation extraction system from the 62nd stage. . A mixture solution containing sodium, potassium, chlorine, silicon and arsenic was obtained from the outlet aqueous phase of the first stage of the NaK/Mg full-load fractionation extraction system; In step 1, the organic phase for extraction of NaKMg/MgCaPbAlFe is extracted by full-load fractionation extraction; the organic phase of magnesium-loaded P229 is obtained from the organic phase at the 62nd stage outlet of the NaK/Mg full-load fractionation extraction system, which is used as the organic phase for extraction of Mg/CaPbAlFe in step 3 by fractional distillation and extraction. .

Step 3: Fractional extraction and separation of Mg/CaPbAlFe

Taking the magnesium-loaded P229 organic phase obtained from the 62nd stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, and the magnesium-loaded P229 of the NaKMg/MgCaPbAlFe full-load fractionation extraction system obtained from the 26th stage of the step 1. The organic phase is the feed liquid, and 3.0 mol/L sulfuric acid is the washing acid. The magnesium-loaded P229 organic phase obtained in the 62nd stage of the NaK/Mg full-load fractionation extraction system in step 2 enters the Mg/CaPbAlFe fractional distillation and extraction system from the first stage, and the magnesium-loaded magnesium obtained in the 26th stage of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 The P229 organic phase of calcium, lead, aluminum and iron enters the Mg/CaPbAlFe fractional distillation and extraction system from the 30th stage, and 3.0mol/L sulfuric acid washing acid enters the Mg/CaPbAlFe fractional distillation and extraction system from the 60th stage. The target product 5N-grade magnesium sulfate solution was obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation extraction system, and the 5N-grade magnesium sulfate solution was taken as the detergent of the NaK/Mg full-load fractional distillation and extraction system in step 2; the Mg/CaPbAlFe was taken out The equilibrium water phase of the 30th stage of the fractional distillation extraction system is used as a detergent for the separation of NaKMg/MgCaPbAlFe by full-load fractionation extraction in step 1; the organic phase of P229 loaded with calcium, lead, aluminum and iron is obtained from the organic phase of the 60th stage of the Mg/CaPbAlFe fractional distillation and extraction system.

The element concentrations in 5N grade magnesium sulfate solution are: Cl 0.00010g/L, Si 0.000010g/L, As 0.000010g/L, Na 0.000010g/L, K 0.000010g/L, Mg 68.0g/L, Ca 0.00010 g/L, Pb 0.000010g/L, Al 0.000010g/L, Fe 0.000010g/L. The purity of the magnesium sulfate solution was 99.9997%, and the yield of magnesium was 96%.

Example 2

The organic phase of P229 is a sulfonated kerosene solution of P229, wherein the concentration of P229 is 1.0 mol/L. When in use, ammonia water is used to saponify the P229 organic phase to obtain the ammonia saponified P229 organic phase.

The element concentrations in the industrial-grade magnesium sulfate aqueous solution are: Cl 2.0g/L, Si 0.0020g/L, As0.00020g/L, Na 0.020g/L, K 0.020g/L, Mg 70.0g/L, Ca 0.030 g/L, Pb 0.0020g/L, Al 0.0020g/L, Fe 0.0020g/L.

Step 1: Full-load fractional extraction and separation of NaKMg/MgCaPbAlFe

Taking the balanced load P229 organic phase obtained at the 28th stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, the technical-grade magnesium sulfate aqueous solution as the feed liquid, and the balance obtained in the 36th stage of the Mg/CaPbAlFe fractional distillation extraction system in step 3 The aqueous phase is the detergent. The balanced load P229 organic phase obtained in the 28th stage of the NaK/Mg full-load fractionation extraction system in step 2 enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the 1st stage, and the industrial-grade magnesium sulfate aqueous solution enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the 26th stage. , the equilibrium water phase obtained in the 36th stage of the Mg/CaPbAlFe fractional distillation and extraction system in step 3 enters the NaKMg/MgCaPbAlFe full-load fractionation and extraction system from the 32nd stage. The magnesium sulfate solution containing Na, K, Cl, Si and As was obtained from the first-stage outlet aqueous phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system, which was used as the feed liquid for the full-load fractionation extraction and separation of NaK/Mg in step 2; from the NaKMg/MgCaPbAlFe full-load The organic phase at the 32nd stage of the fractional distillation extraction system obtains the P229 organic phase loaded with magnesium, calcium, lead, aluminum and iron, which is used as the feed liquid for the fractional distillation extraction and separation of Mg/CaPbAlFe in step 3.

Step 2: Full-load fractional extraction and separation of NaK/Mg

Taking the organic phase of ammonia saponification P229 as the extraction organic phase, the magnesium sulfate solution containing Na, K, Cl, Si and As obtained from the first-stage outlet water phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 is the feed liquid, and step 3 The 5N-grade magnesium sulfate solution obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation extraction system is a detergent. The organic phase of saponification P229 is to extract the organic phase from the first stage into the NaK/Mg full-load fractionation extraction system, and the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 contains Na, K, Cl, Si and As obtained from the first-stage outlet water phase. The magnesium sulfate solution enters the NaK/Mg full-load fractionation extraction system from the 28th stage, and the 5N-grade magnesium sulfate solution obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation and extraction system in step 3 enters the NaK/Mg full-load fractionation extraction system from the 60th stage. . A mixture solution containing sodium, potassium, chlorine, silicon and arsenic was obtained from the outlet aqueous phase of the first stage of the NaK/Mg full-load fractionation extraction system; In step 1, the organic phase of extraction of NaKMg/MgCaPbAlFe is separated by full-load fractionation extraction; the magnesium-loaded P229 organic phase is obtained from the organic phase of the 60th stage outlet of the NaK/Mg full-load fractionation extraction system, which is used as the organic phase of extraction of Mg/CaPbAlFe in step 3 by fractional distillation and extraction. .

Step 3: Fractional extraction and separation of Mg/CaPbAlFe

Taking the magnesium-loaded P229 organic phase obtained from the 60th stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, and the magnesium-calcium-lead-aluminum-iron-loaded P229 obtained from the 32nd stage of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 The organic phase is the feed liquid, and 3.0 mol/L sulfuric acid is the washing acid. The magnesium-loaded P229 organic phase obtained in the 60th stage of the NaK/Mg full-load fractionation extraction system in step 2 enters the Mg/CaPbAlFe fractional distillation and extraction system from the first stage, and the magnesium-loaded magnesium obtained in the 32nd stage of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 The P229 organic phase of calcium, lead, aluminum and iron enters the Mg/CaPbAlFe fractional distillation and extraction system from the 36th stage, and the 3.0mol/L sulfuric acid washing acid enters the Mg/CaPbAlFe fractional distillation and extraction system from the 64th stage. The target product 5N-grade magnesium sulfate solution was obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation extraction system, and the 5N-grade magnesium sulfate solution was taken as the detergent of the NaK/Mg full-load fractional distillation and extraction system in step 2; the Mg/CaPbAlFe was taken out The equilibrium water phase of the 36th stage of the fractional distillation extraction system is used as a detergent for the separation of NaKMg/MgCaPbAlFe by full-load fractionation extraction in step 1; the organic phase of P229 loaded with calcium, lead, aluminum and iron is obtained from the organic phase of the 64th stage of the Mg/CaPbAlFe fractional distillation and extraction system.

The element concentrations in the 5N grade magnesium sulfate solution are: Cl 0.00020g/L, Si 0.000020g/L, As 0.000020g/L, Na 0.000020g/L, K 0.000020g/L, Mg 70.0g/L, Ca 0.00030 g/L, Pb 0.000020g/L, Al 0.000020g/L, Fe 0.000020g/L. The purity of the magnesium sulfate solution was 99.9994%, and the yield of magnesium was 97%.

Example 3

The organic phase of P229 is a sulfonated kerosene solution of P229, wherein the concentration of P229 is 1.0 mol/L. When in use, ammonia water is used to saponify the P229 organic phase to obtain the ammonia saponified P229 organic phase.

The element concentrations in the industrial-grade magnesium sulfate aqueous solution are: Cl 3.0g/L, Si 0.0030g/L, As 0.00030g/L, Na 0.030g/L, K 0.030g/L, Mg 75.0g/L, Ca 0.050 g/L, Pb 0.0030g/L, Al 0.0030g/L, Fe 0.0050g/L.

Step 1: Full-load fractional extraction and separation of NaKMg/MgCaPbAlFe

Taking the balanced load P229 organic phase obtained at the 28th stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, the technical grade magnesium sulfate aqueous solution as the feed liquid, and the balance obtained in the 40th stage of the Mg/CaPbAlFe fractional distillation extraction system in step 3 The aqueous phase is the detergent. The balanced load P229 organic phase obtained in the 28th stage of the NaK/Mg full-load fractionation extraction system in step 2 enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the 1st stage, and the industrial-grade magnesium sulfate aqueous solution enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the 18th stage. , the equilibrium water phase obtained in the 40th stage of the Mg/CaPbAlFe fractional distillation and extraction system in step 3 enters the NaKMg/MgCaPbAlFe full-load fractionation and extraction system from the 34th stage. The magnesium sulfate solution containing Na, K, Cl, Si and As was obtained from the first-stage outlet aqueous phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system, which was used as the feed liquid for the full-load fractionation extraction and separation of NaK/Mg in step 2; from the NaKMg/MgCaPbAlFe full-load The organic phase at the 34th stage of the fractional distillation extraction system obtains the P229 organic phase loaded with magnesium, calcium, lead, aluminum and iron, which is used as the feed liquid for the fractional distillation extraction and separation of Mg/CaPbAlFe in step 3.

Step 2: Full-load fractional extraction and separation of NaK/Mg

Taking the organic phase of ammonia saponification P229 as the extraction organic phase, the magnesium sulfate solution containing Na, K, Cl, Si and As obtained from the first-stage outlet water phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 is the feed liquid, and step 3 The 5N-grade magnesium sulfate solution obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation extraction system is a detergent. The organic phase of saponification P229 is to extract the organic phase from the first stage into the NaK/Mg full-load fractionation extraction system, and the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 contains Na, K, Cl, Si and As obtained from the first-stage outlet water phase. The magnesium sulfate solution enters the NaK/Mg full-load fractionation extraction system from the 28th stage, and the 5N-grade magnesium sulfate solution obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation and extraction system in step 3 enters the NaK/Mg full-load fractionation extraction system from the 62nd stage. . A mixture solution containing sodium, potassium, chlorine, silicon and arsenic was obtained from the outlet aqueous phase of the first stage of the NaK/Mg full-load fractionation extraction system; In step 1, the organic phase for extraction of NaKMg/MgCaPbAlFe is extracted by full-load fractionation extraction; the organic phase of magnesium-loaded P229 is obtained from the organic phase at the 62nd stage outlet of the NaK/Mg full-load fractionation extraction system, which is used as the organic phase for extraction of Mg/CaPbAlFe in step 3 by fractional distillation and extraction. .

Step 3: Fractional extraction and separation of Mg/CaPbAlFe

Taking the magnesium-loaded P229 organic phase obtained from the 62nd stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, and the magnesium-calcium-lead-aluminum-iron-loaded P229 obtained from the 34th stage of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 The organic phase is the feed liquid, and 3.0 mol/L sulfuric acid is the washing acid. The magnesium-loaded P229 organic phase obtained in the 62nd stage of the NaK/Mg full-load fractionation extraction system in step 2 enters the Mg/CaPbAlFe fractional distillation and extraction system from the 1st stage, and the magnesium-loaded magnesium obtained in the 34th stage of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 The P229 organic phase of calcium, lead, aluminum and iron enters the Mg/CaPbAlFe fractional distillation and extraction system from the 40th stage, and the 3.0mol/L sulfuric acid washing acid enters the Mg/CaPbAlFe fractional distillation and extraction system from the 66th stage. The target product 5N-grade magnesium sulfate solution was obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation extraction system, and the 5N-grade magnesium sulfate solution was taken as the detergent of the NaK/Mg full-load fractional distillation and extraction system in step 2; the Mg/CaPbAlFe was taken out The equilibrium water phase of the 40th stage of the fractional distillation extraction system is used as a detergent for the separation of NaKMg/MgCaPbAlFe by full-load fractionation extraction in step 1; the organic phase of P229 loaded with calcium, lead, aluminum and iron is obtained from the organic phase of the 66th stage of the Mg/CaPbAlFe fractional distillation and extraction system.

The element concentrations in the 5N grade magnesium sulfate solution are: Cl 0.00030g/L, Si 0.000030g/L, As0.000030g/L, Na 0.000030g/L, K 0.000030g/L, Mg 72.0g/L, Ca 0.00050 g/L, Pb 0.000030g/L, Al 0.000030g/L, Fe 0.000030g/L. The purity of the magnesium sulfate solution was 99.9991%, and the yield of magnesium was 98%.

Claims (4)

1. a method for preparing 5N grade magnesium sulfate solution, is characterized in that: described method takes technical grade magnesium sulfate aqueous solution as feed liquid, P229 is extraction agent, separates and removes the metal element impurity sodium, potassium, calcium in feed liquid , lead, aluminum and iron, as well as separation and removal of non-metallic element impurities chlorine, silicon and arsenic, to prepare 5N-grade magnesium sulfate solution; it consists of three steps, namely, full-load fractional extraction and separation of NaKMg/MgCaPbAlFe, full-load fractional extraction and separation of NaK/Mg and fractional distillation to separate Mg/CaPbAlFe; the extraction section of full-load fractional extraction to separate NaKMg/MgCaPbAlFe realizes NaKMg/CaPbAlFe separation, and the washing section realizes NaK/MgCaPbAlFe separation; full-load fractional extraction to separate NaKMg/MgCaPbAlFe and full-load fractional extraction to separate NaK/Mg feed grade The obtained balanced load P229 organic phase is the extraction organic phase, and the balanced water phase obtained by fractional extraction and separation of Mg/CaPbAlFe feed stage is the detergent; the full-load fractional extraction and separation of NaK/Mg and the fractional extraction and separation of Mg/CaPbAlFe are directly connected in series; the full-load fractional extraction and separation is directly connected in series; The outlet organic phase for separation of NaK/Mg is used as the extraction organic phase for fractionation extraction and separation of Mg/CaPbAlFe, and directly enters the first stage of fractionation extraction and separation of Mg/CaPbAlFe; the first stage outlet water phase for fractionation extraction and separation of Mg/CaPbAlFe is used as full load Detergent for fractional extraction and separation of NaK/Mg; The 3 steps are as follows: Step 1: Full-load fractional extraction and separation of NaKMg/MgCaPbAlFe Step 1 is to separate NaKMg/MgCaPbAlFe by full-load fractionation extraction, the extraction section realizes NaKMg/CaPbAlFe separation, and the washing section realizes NaK/MgCaPbAlFe separation; the balanced-load P229 organic phase obtained from the feed stage of the NaK/Mg full-load fractional distillation extraction system in step 2 is used for extraction. The organic phase, the industrial grade magnesium sulfate aqueous solution is the feed liquid, the balanced water phase obtained from the feed stage of the Mg/CaPbAlFe fractional extraction system in step 3 is the detergent; the balanced load obtained from the feed stage of the NaK/Mg full-load fractionation extraction system in step 2 The organic phase of P229 enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the first stage, and the industrial-grade magnesium sulfate aqueous solution enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the feed stage, and the equilibrium water obtained from the feed stage of the Mg/CaPbAlFe fractional distillation and extraction system in step 3 The phase enters the NaKMg/MgCaPbAlFe full-load fractionation extraction system from the last stage; the magnesium sulfate solution containing Na, K, Cl, Si and As is obtained from the first-stage outlet water phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system, which is used as the full-load fractionation in step 2 The feed liquid of NaK/Mg is extracted and separated; the P229 organic phase loaded with magnesium, calcium, lead, aluminum and iron is obtained from the organic phase of the last 1-stage outlet of the NaKMg/MgCaPbAlFe full-load fractionation extraction system, which is used as the feed liquid of Mg/CaPbAlFe in step 3 by fractional distillation and extraction; Step 2: Full-load fractional extraction and separation of NaK/Mg Step 2 is to separate NaK/Mg by full-load fractionation extraction, and to separate and remove the metal element impurities sodium and potassium in the magnesium sulfate solution, as well as the non-metallic element impurities chlorine, silicon and arsenic; the organic phase of ammonia saponification P229 is used as the extraction organic phase. The magnesium sulfate solution containing Na, K, Cl, Si and As obtained from the first-stage outlet water phase of the NaKMg/MgCaPbAlFe full-load fractionation extraction system is the feed liquid, and the first-stage outlet water phase of the Mg/CaPbAlFe fractional extraction system in step 3 is 5N grade magnesium sulfate solution is a detergent; the organic phase of saponification P229 is extracted from the first stage into the NaK/Mg full-load fractionation extraction system, and the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 is obtained from the first-stage outlet water phase containing Na. , the magnesium sulfate solution of K, Cl, Si and As enters the NaK/Mg full-load fractionation extraction system from the feed stage, and the 5N-grade magnesium sulfate solution obtained from the first stage outlet water phase of the Mg/CaPbAlFe fractionation extraction system of step 3 is obtained from the last 1 into the NaK/Mg full-load fractional distillation extraction system; obtain a mixture solution containing sodium, potassium, chlorine, silicon and arsenic from the first-stage outlet water phase of the NaK/Mg full-load fractional distillation and extraction system; take the NaK/Mg full-load fractional distillation extraction system feed The balance-loaded P229 organic phase of the first stage is used as the extraction organic phase for the separation of NaKMg/MgCaPbAlFe by full-load fractionation extraction in step 1; the magnesium-loaded P229 organic phase is obtained from the organic phase of the last stage of the NaK/Mg full-load fractionation extraction system and is used as step 3. Fractional extraction to separate the extracted organic phase of Mg/CaPbAlFe; Step 3: Fractional extraction and separation of Mg/CaPbAlFe Step 3 is to separate Mg/CaPbAlFe by fractional distillation, so as to realize the separation of magnesium from calcium, lead, aluminum and iron; take the magnesium-loaded P229 organic phase obtained in the last stage of the NaK/Mg full-load fractionation extraction system in step 2 as the extraction organic phase, The P229 organic phase loaded with magnesium, calcium, lead, aluminum and iron obtained in the last stage of the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 is the feed liquid, and 3.0 mol/L sulfuric acid is the washing acid; The magnesium-loaded P229 organic phase obtained from the first stage enters the Mg/CaPbAlFe fractional distillation extraction system, and the NaKMg/MgCaPbAlFe full-load fractionation extraction system in step 1 The P229 organic phase loaded with magnesium, calcium, lead, aluminum and iron obtained from the last stage Enter the Mg/CaPbAlFe fractional distillation and extraction system, and 3.0mol/L sulfuric acid washing acid enters the Mg/CaPbAlFe fractional distillation and extraction system from the last stage; the target product 5N-grade magnesium sulfate solution is obtained from the first-stage outlet water phase of the Mg/CaPbAlFe fractional distillation and extraction system. Take 5N grade magnesium sulfate solution as the detergent for the NaK/Mg full-load fractional distillation extraction system in step 2; take the equilibrium water phase of the feed level of the Mg/CaPbAlFe fractional distillation and extraction system, and use it as the full-load fractional distillation extraction and separation of NaKMg/MgCaPbAlFe in step 1. Detergent; P229 organic phase loaded with calcium, lead, aluminum and iron is obtained from the organic phase at the last stage of the Mg/CaPbAlFe fractional distillation extraction system. 2. a kind of method of preparing 5N grade magnesium sulfate solution according to claim 1, is characterized in that: described P229 organic phase is the sulfonated kerosene solution of P229, and wherein the concentration of P229 is 1.0mol/L; , using ammonia water to saponify P229 organic phase to obtain ammonia saponified P229 organic phase. 3. a kind of method of preparing 5N grade magnesium sulfate solution according to claim 1 is characterized in that: the element concentration in the described technical grade magnesium sulfate aqueous solution is respectively: Cl 1.0g/L～3.0g/L, Si 0.0010g/L～0.0030g/L, As 0.00010g/L～0.00030g/L, Na 0.010g/L～0.030g/L, K 0.010g/L～0.030g/L, Mg 65.0g/L～ 75.0g/L, Ca 0.010g/L～0.050g/L, Pb 0.0010g/L～0.0030g/L, Al 0.0010g/L～0.0030g/L, Fe 0.0010g/L～0.0050g/L. 4. a kind of method of preparing 5N grade magnesium sulfate solution according to claim 1, is characterized in that: the element concentration in described 5N grade magnesium sulfate solution is respectively: Cl 0.00010g/L～0.00030g/L, Si 0.000010g/L～0.000030g/L, As 0.000010g/L～0.000030g/L, Na 0.000010g/L～0.000030g/L, K0.000010g/L～0.000030g/L, Mg 68.0g/L～ 72.0g/L, Ca 0.00010g/L～0.00050g/L, Pb 0.000010g/L～0.000030g/L, Al 0.000010g/L～0.000030g/L, Fe 0.000010g/L～0.000030g/L.

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