A method for extracting and refining platinum using N-methylaminosulfonic acid

Abstract

The invention discloses a method for extracting and refining platinum by using N-methylaminosulfonic acid. The method comprises the following steps: using N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate to form an organic extraction phase; using a pulse sieve plate extraction tower device, feeding an organic phase from the bottom of the tower, feeding a feed liquid to be extracted from the top of the tower, performing stripping on the obtained platinum-carrying organic extraction phase, dripping diketoxime into the stripping liquid until no bright yellow precipitate is generated; adding ammonium chloride solid to the obtained platinum-containing stripping liquid, precipitating platinum to obtain ammonium chloroplatinate, and calcining to obtain a platinum product; using a pulse extraction column, which has the advantages of short equilibrium time and short feed liquid residence time, and using a new high-efficiency N-methylaminosulfonic acid extractant with synergistic effect, further improving the extraction rate and separation efficiency of platinum, and improving the stripping process compared with the existing process, solving the problem of low stripping efficiency; improving the direct recovery rate of platinum as a whole, shortening the process flow, and saving reagents, and can be applied to the extraction process of precious metal platinum.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical process, in particular to a method for extracting and refining platinum with N-methylaminosulfonic acid. Background Art

[0002] Platinum has excellent physical and chemical properties such as high catalytic activity, good conductivity, high temperature resistance, and corrosion resistance, and is widely used in the chemical, electronic, pharmaceutical, and oil refining industries. With the technological innovation of these industries, the demand for high-purity platinum is increasing. However, since platinum group metals have similar physical and chemical properties, the separation and purification of platinum group metals is challenging.

[0003] The ammonium chloride repeated precipitation method currently in common use has undergone many studies and improvements, but in essence it is still to use ammonium chloride to precipitate platinum in the form of ammonium chloroplatinate, and then separate it from other elements by washing. This method is simple to operate and the technical conditions are easy to control, but when the operation is repeated, the ammonium chloroplatinate must first be transferred into the solution. Whether it is dissolved after calcination into sponge platinum or directly dissolved in aqua regia, there are disadvantages such as high cost, long time consumption, high labor intensity of repetitive work, slow filtration speed, and environmental pollution.

[0004] Platinum is a precious metal known for its chemical properties and wide range of applications. Platinum waste recycling is of great significance for reducing resource waste and protecting the environment. Common methods for platinum waste recycling include chemical recycling methods, smelting recycling methods, precipitation recycling methods, biological recycling methods, ion exchange recycling methods, carbon polymer composite recycling methods, and electrolytic recycling methods. Among them, chemical recycling methods are the most common, including pyrometallurgy and hydrometallurgy. The application scope of platinum waste recycling includes the automotive industry, electronic waste, medical equipment, and chemical industry. When recycling platinum waste, sustainability and environmental protection must be considered, and appropriate safety measures and waste treatment methods must be taken to prevent harm to the environment. Platinum waste recycling technology will continue to improve and contribute to sustainable development and resource protection.

[0005] Compared with the traditional precipitation method, solvent extraction technology simplifies the process flow, shortens the production cycle, reduces platinum accumulation, and improves direct output rate, which has significant advantages in industrial production. At present, various large platinum group metal refineries have developed a variety of solvent extraction processes, which are gradually replacing the traditional precipitation separation process. Summary of the invention

[0006] In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a method for extracting and refining platinum with N-methylaminosulfonic acid.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a method for extracting and refining platinum with N-methylaminosulfonic acid, comprising: using N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate to form an organic extraction phase; using a pulse sieve plate extraction tower device, the organic phase is fed from the bottom of the tower, the feed liquid to be extracted is fed from the top of the tower, the obtained platinum-carrying organic extraction phase is stripped, diketoxime is added dropwise to the stripping solution until no bright yellow precipitate is generated; ammonium chloride solid is added to the obtained platinum-containing stripping solution, platinum is precipitated to obtain ammonium chloroplatinate, and calcination is performed to obtain a platinum product.

[0008] As a further improvement of the present invention: the platinum concentration in the liquid to be extracted is 4-12 g / L.

[0009] As a further improvement of the present invention: the platinum concentration in the liquid to be extracted is 5 g / L.

[0010] As a further improvement of the present invention: after diketoxime is added dropwise to the stripping solution until no bright yellow precipitate is generated, the pH of the obtained platinum-containing stripping solution is adjusted to 1.

[0011] As a further improvement of the present invention: the obtained platinum-loaded organic extract phase is back-extracted with 38% analytically pure hydrochloric acid, and the ratio of the two phases is controlled to be 1:1.

[0012] As a further improvement of the present invention: the pulse sieve plate extraction tower is a KH-HG211-pulse sieve plate extraction tower.

[0013] As a further improvement of the present invention: the feed flow rate is controlled at a flow rate of 0.5-3 L / h, and the organic phase flow rate is maintained at 2-6 L / h.

[0014] As a further improvement of the present invention: the feed flow rate is controlled at 1 L / h, and the organic phase flow rate is maintained at 4 L / h.

[0015] As a further improvement of the present invention: the ammonium chloroplatinate obtained by precipitation of platinum is washed with a 17% ammonium chloride solution.

[0016] As a further improvement of the present invention: in the platinum liquid to be extracted, the Pt concentration is 10g / L, the pH is ≤1, N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed in a ratio of 1:1 to form an organic phase, the organic phase is selected as the dispersed phase, the tower body is filled, the feed pump is turned on, the feed flow rate is controlled at 1L / h, the organic phase flow rate is maintained at 4L / h, the flow ratio is 1:2, the pump is turned on for 5h, 20L of extract in the extraction phase tank is collected, and the platinum-carrying organic phase collected in the extraction tank is stripped with a freshly prepared 0.01mol / L thiourea-0.5mol / L HCl solution, and the Pt content of the organic phase after extraction is measured to be 6mg / L, the organic phase after extraction is washed with water for recycling, the pH of the platinum-containing stripping solution is adjusted to about 1, ammonium chloride solid is added until no precipitation is generated, the generated ammonium chloroplatinate is washed 3 times with a 17% ammonium chloride solution, and a platinum product is obtained by calcination.

[0017] As a further improvement of the present invention: in the platinum liquid to be extracted, the Pt concentration is 5 g / L, and the pH is ≤1. N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed in a ratio of 1:1 to form an organic phase, the organic phase is selected as the dispersed phase, and the tower body is filled with the feed pump. The feed flow rate is controlled at 1 L / h, the organic phase flow rate is maintained at 4 L / h, the flow ratio is 1:4, and the pump is turned on for 5 hours. 20 L of extract in the extraction phase tank is collected, and the platinum content in the extract is measured to be 1.256 g / L. The platinum-carrying organic phase collected in the extraction tank is stripped with 0.01 mol / L thiourea-0.5 mol / L HCl solution, and the Pt content of the organic phase after extraction is measured to be less than 4 mg / L. The organic phase after extraction is washed with water for recycling, the pH of the platinum-containing stripping solution is adjusted to about 1, and ammonium chloride solid is added until no precipitation is generated. The generated ammonium chloroplatinate is washed 3 times with 17% ammonium chloride solution, and a platinum product is obtained by calcination.

[0018] As a further improvement of the present invention: the Pt concentration in the platinum solution to be extracted is 5 g / L, N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are prepared in a ratio of 2:1 to form an organic phase, the organic phase is selected as the dispersed phase, the tower body is filled, the feed pump is turned on, the feed flow rate is controlled at a flow rate of 1 L / h, the organic phase flow rate is maintained at 4 L / h, the platinum-loaded organic phase collected in the extraction tank is stripped with a 0.001 mol / L thiourea-0.5 mol / L HCl solution, the organic phase after extraction is washed with water for recycling, the pH of the platinum-containing stripping solution is adjusted to 1, ammonium chloride solid is added until no precipitate is generated, the generated ammonium chloroplatinate is washed 3 times with a 17% ammonium chloride solution, and a platinum product is obtained by calcining.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The pulse extraction column has the advantages of short equilibrium time and short liquid residence time. In combination with a new high-efficiency N-methylaminosulfonic acid extractant with synergistic effect, the extraction rate and separation efficiency of platinum are further improved. At the same time, compared with the existing process, the stripping process is improved and the problem of low stripping efficiency is solved.

[0021] (2) The overall direct recovery rate of platinum is improved, the process flow is shortened, and reagents are saved, and it can be applied to the extraction process of precious metal platinum. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution, the drawings required for use in the implementation will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 It is a schematic diagram of the extraction structure of the present invention.

[0024] Figure 2 It is a schematic diagram of the extraction process of the present invention.

[0025] Figure numerals: 1. Pulse sieve plate extraction tower; 2. Extractant tank; 3. Tank for the agent to be extracted; 4. Vibration motor; 5. Flow meter for the agent to be extracted; 6. Flow meter for the extractant. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] The existing method of refining platinum generally uses the ammonium chloride repeated precipitation method. Although many studies and improvements have been made, the essence is still to use ammonium chloride to precipitate platinum in the form of ammonium chloroplatinate and separate it from other elements by washing. This method is simple to operate and the technical conditions are easy to control, but when repeated, the ammonium chloroplatinate must be transferred into the solution first. Whether it is dissolved after calcination into sponge platinum or directly dissolved in aqua regia, there are disadvantages such as high cost, long time, high labor intensity of repetitive work, slow filtration speed, and environmental pollution. The limitations of the current extractant: there are few types of extractants, poor extraction ability, poor selectivity, weak stripping ability, and insufficient load capacity resulting in large consumption. Compared with traditional recovery methods such as precipitation method and displacement method, solvent extraction method replaces traditional methods. Solvent extraction method has the advantages of simple process, short cycle, high recovery rate of precious metals, and safe production. The process technology for extracting and separating precious metals is still under development and improvement. The current extractant is subject to extraction ability, selectivity, stripping ability and load capacity. All are not ideal, and there have been few studies in recent years.

[0029] The present invention is further described with reference to the accompanying drawings and embodiments: Figure 1-2 The method for extracting and refining platinum with N-methylaminosulfonic acid includes preparing an organic extraction phase with N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate; using a pulse sieve plate extraction tower device, the organic phase is fed from the bottom of the tower, the liquid to be extracted is fed from the top of the tower, the obtained platinum-loaded organic extraction phase is stripped, diketoxime is added dropwise to the stripping solution until no bright yellow precipitate is generated; ammonium chloride solid is added to the obtained platinum-containing stripping solution, platinum is precipitated to obtain ammonium chloroplatinate, and calcined to obtain a platinum product.

[0030] The invention discloses a method for extracting and refining platinum by using N-methylaminosulfonic acid, which adopts a pulse extraction column and has the advantages of short equilibrium time and short liquid residence time. The method is combined with a novel high-efficiency N-methylaminosulfonic acid extractant with synergistic effect, thereby further improving the extraction rate and separation efficiency of platinum and improving the stripping process.

[0031] As an embodiment of the present invention, the platinum concentration in the liquid to be extracted is 4-12 g / L.

[0032] Furthermore, it is preferred that the platinum concentration in the solution to be extracted is 5 g / L.

[0033] As an embodiment of the present invention, diketoxime is added dropwise to the stripping solution until no bright yellow precipitate is generated, and then the pH of the obtained platinum-containing stripping solution is adjusted to 1.

[0034] As an embodiment of the present invention, the obtained platinum-loaded organic extract phase is back-extracted using 38% analytical pure hydrochloric acid, and the ratio of the two phases is controlled to be 1:1.

[0035] Furthermore, by controlling the two-phase flow rate during the extraction process of the pulse sieve plate extraction tower, the extraction capacity can be explored and the optimal production conditions can be determined.

[0036] As an embodiment of the present invention, N-methylaminosulfonic acid and di(2-ethylhexyl)phosphate are prepared in a 1:1 ratio to form an organic extraction phase.

[0037] Furthermore, the extractant has high selectivity, large capacity, shortened process flow, is green and environmentally friendly, and can be reused repeatedly.

[0038] As an embodiment of the present invention, the pulse sieve plate extraction tower is a KH-HG211-pulse sieve plate extraction tower.

[0039] Furthermore, the use of the pulse sieve plate extraction tower device has a high extraction efficiency and can fully reflect the effect of the extractant. At the same time, the flow rate is adjustable, which is convenient for determining the optimal experimental conditions.

[0040] As an embodiment of the present invention, the feed flow rate is controlled at 0.5-3 L / h, and the organic phase flow rate is maintained at 2-6 L / h.

[0041] Furthermore, it is preferred that the feed flow rate is controlled at 1 L / h and the organic phase flow rate is maintained at 4 L / h.

[0042] As an embodiment of the present invention, ammonium chloroplatinate obtained by precipitation of platinum is washed with a 17% ammonium chloride solution.

[0043] Furthermore, stripping is usually performed by acid or alkali washing, and the problem of metal residue in the extract is serious. Adding a certain amount of thiourea can effectively improve the stripping efficiency and the stripping effect.

[0044] Working principle of the present invention:

[0045] like Figure 1 As shown, a pulse sieve plate extraction tower device is used, the organic phase is fed from the bottom of the tower, and the feed liquid to be extracted is fed from the top of the tower. In order to improve the extraction efficiency, the feed liquid to be extracted is selected as the dispersed phase and the organic extraction phase is selected as the continuous phase, so that the continuous phase fills the tower body, the extraction equipment is turned on, the liquid in the tower is subjected to pulse motion, and then the dispersed phase is broken into small droplets by the action of the filler, so as to increase the mass transfer contact area and improve the extraction efficiency; the obtained platinum-loaded organic extraction phase is stripped, and a newly prepared 0.01 mol / L thiourea-0.5 mol / L HCl solution is used to control the ratio of the two phases to 1:1, and 10% dimethylglyoxime is added dropwise to the stripping solution until no bright yellow precipitate is generated; the pH of the obtained platinum-containing stripping solution is adjusted to about 1, and ammonium chloride solid is added to precipitate platinum to obtain ammonium chloroplatinate, which is calcined to obtain a platinum product.

[0046] The method for extracting and refining platinum with N-methylaminosulfonic acid of the present invention is used to refine platinum, and the effects of different residence times on the extraction rate, the effects of different concentrations on the extraction rate, and the effects of stripping solutions with different ratios on the extraction rate under the control of feed flow rate are explored.

[0047] Embodiment 1:

[0048] In the platinum solution to be extracted, the Pt concentration is 10 g / L, the Pd concentration is 2 g / L, the Ir concentration is 5 g / L, the Zn concentration is 5 g / L, the concentrations of other metals such as Cu, Fe, Ni are about 200 mg / L, the pH is ≤ 1, N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed in a 1:1 ratio to form an organic phase, the organic phase is selected as the dispersed phase, and the tower body is filled with the feed pump, the feed flow rate is controlled at 1 L / h, the organic phase flow rate is maintained at 4 L / h, the flow ratio is 1:2, and it is turned on for 5 hours, and 20 L of extract is collected in the extraction phase tank. The platinum content in the extract is measured to be 2.488 g / L, and the resulting platinum extraction recovery efficiency is 99.5%. The platinum-loaded organic phase was collected in a stripping extraction tank using a newly prepared 0.01 mol / L thiourea-0.5 mol / L HCl solution, and the Pt content of the organic phase after extraction was measured to be 6 mg / L. The organic phase after extraction was washed with water for recycling, the pH of the platinum-containing stripping solution was adjusted to about 1, and solid ammonium chloride was added until no more precipitate was generated. The generated ammonium chloroplatinate was washed three times with 17% ammonium chloride solution, and the quality of the platinum product obtained after calcination was 99.99%, and the platinum recovery rate of the whole process reached 99.3%.

[0049] Embodiment 2:

[0050] In the platinum solution to be extracted, the Pt concentration is 10g / L, the Pd concentration is 1g / L, the Ru concentration is 5g / L, the Zn concentration is 5g / L, the concentrations of other metals such as Cu, Fe, Ni are about 200mg / L, the pH is ≤1, N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed in a 1:1 ratio to form an organic phase, the organic phase is selected as the dispersed phase, and the tower body is filled with the feed pump, the feed flow rate is controlled at 2L / h, the organic phase flow rate is maintained at 4L / h, the flow ratio is 1:2, and it is turned on for 5h, 20L of extract is collected in the extraction phase tank, and the platinum content in the extract is measured to be 4.515g / L, and the resulting platinum extraction recovery efficiency is 90.3%. The platinum-loaded organic phase was collected in a stripping extraction tank using a newly prepared 0.01 mol / L thiourea-0.5 mol / L HCl solution, and the Pt content of the organic phase after extraction was measured to be 5 mg / L. The organic phase after extraction was washed with water for recycling, the pH of the platinum-containing stripping solution was adjusted to about 1, and solid ammonium chloride was added until no more precipitate was generated. The generated ammonium chloroplatinate was washed three times with 17% ammonium chloride solution, and the quality of the platinum product obtained after calcination was 99.99%, and the platinum recovery rate of the whole process reached 90.2%.

[0051] Embodiment three:

[0052] In the platinum solution to be extracted, the Pt concentration is 5 g / L, the Pd concentration is 2 g / L, the Ir concentration is 5 g / L, the Zn concentration is 5 g / L, the concentrations of other metals such as Cu, Fe, Ni are about 200 mg / L, and the pH is ≤ 1. N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed in a 1:1 ratio to form an organic phase, and the organic phase is selected as the dispersed phase to fill the tower body. Then the feed pump is turned on, and the feed flow rate is controlled at 1 L / h, the organic phase flow rate is maintained at 4 L / h, the flow ratio is 1:4, and it is turned on for 5 hours. 20 L of extract is collected in the extraction phase tank, and the platinum content in the extract is measured to be 1.256 g / L, and the obtained platinum extraction rate is 99.6%. The platinum-loaded organic phase was collected in a stripping extraction tank using a 0.01 mol / L thiourea-0.5 mol / L HCl solution, and the Pt content of the organic phase after extraction was measured to be less than 4 mg / L. The organic phase after extraction was washed with water for recycling, the pH of the platinum-containing stripping solution was adjusted to about 1, and solid ammonium chloride was added until no more precipitate was generated. The generated ammonium chloroplatinate was washed three times with a 17% ammonium chloride solution, and the quality of the platinum product obtained after calcination was 99.99%, and the platinum recovery rate of the whole process reached 99.3%.

[0053] Embodiment 4:

[0054] In the platinum solution to be extracted, the concentration of Pt is 5g / L, the concentration of Pd is 2g / L, the concentration of Ir is 5g / L, the concentration of Zn is 5g / L, the concentration of other metals such as Cu, Fe, Ni is about 200mg / L, and the pH is ≤1. N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed into an organic phase at a ratio of 1:1. The organic phase is selected as the dispersed phase to fill the tower body, and then the feed pump is turned on. The feed flow rate is controlled at 1L / h, and the organic phase flow rate is maintained at 4L / h. It is turned on for 5h, and 20L of the extract in the extraction phase tank is collected. The platinum content in the extract is measured to be 1.244g / L, and the platinum extraction rate is 99.5%. The organic phase containing platinum collected in the extraction tank is stripped with 0.5mol / L HCl solution, and the Pt content of the organic phase after extraction is measured to be 179.88mg / L, and the platinum recovery rate is 84.3%. The stripping effect is not good, and more platinum remains in the extractant.

[0055] Embodiment five:

[0056] In the platinum solution to be extracted, the Pt concentration is 5g / L, the Pd concentration is 2g / L, the Ir concentration is 5g / L, the Zn concentration is 5g / L, the concentrations of other metals such as Cu, Fe, Ni are about 200mg / L, the pH is ≤1, N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed in a 1:1 ratio to form an organic phase, the organic phase is selected as the dispersed phase, and the tower body is filled with it. Then the feed pump is turned on, the feed flow rate is controlled at 1L / h, the organic phase flow rate is maintained at 4L / h, and it is turned on for 5h. 20L of extract is collected in the extraction phase tank, and the platinum content in the extract is measured to be 1.250g / L, and the obtained platinum extraction rate is 99.5%. The platinum-loaded organic phase was collected in a stripping extraction tank using 0.02 mol / L thiourea-0.5 mol / L HCl solution, and the Pt content of the organic phase after extraction was measured to be 5 mg / L. The organic phase after extraction was washed with water for recycling, the pH of the platinum-containing stripping solution was adjusted to about 1, and solid ammonium chloride was added until no more precipitate was generated. The generated ammonium chloroplatinate was washed 3 times with 17% ammonium chloride solution, and the quality of the platinum product obtained after calcination was 99.99%, and the platinum recovery rate of the whole process reached 99.5%.

[0057] The extraction effects of Examples 1-5 are shown in the following table:

[0058]

[0059] Among them, Comparative Example 1 corresponds to Example 4, Comparative Example 2 corresponds to Example 5, Example 2 and Example 1 explore the influence of different residence times on the extraction rate by controlling the feed flow rate, Example 3 and Example 1 explore the extraction effects of different concentrations, and Example 4 and Example 5 explore the extraction effects of stripping solutions with different ratios in the previous examples.

[0060] The main functions of the present invention are:

[0061] 1) N-methylaminosulfonic acid, which has a synergistic extraction effect on platinum, is used as an extractant. It has good selectivity for platinum group metals and can be purified at very few stages. In addition, it has a large extraction capacity. The extraction capacity of the extractant directly affects the factory investment. The larger the extraction capacity, the smaller the amount of extractant used, which can reduce costs. Secondly, it has good chemical stability and does not degrade during the extraction cycle. It has good stripping regeneration ability, and the loaded metal is easy to strip, and the regenerated extractant does not require special treatment.

[0062] 2) The extraction device uses a pulse sieve plate extraction tower device, which can better reflect the extraction capacity of N-methylaminosulfonic acid by enhancing the degree of interfacial turbulence to enhance mass transfer;

[0063] 3) The stripping process is improved. Thiourea is added to hydrochloric acid to form a coordination reaction, which makes the stripping process more thorough, solves the problem of low stripping efficiency, and uses less stripping solution, does not affect the regeneration of the extract, and has low toxicity and low pollution;

[0064] 4) The overall process further improves the extraction rate and separation efficiency of platinum. Compared with the existing process, the present invention improves the direct recovery rate of platinum as a whole, shortens the process flow and saves reagents, and can be applied to the extraction production of precious metal platinum.

[0065] In summary, after reading the present invention document, ordinary technicians in this field can make various other corresponding transformation schemes based on the technical scheme and technical concept of the present invention without creative mental work, which all fall within the scope of protection of the present invention.

Claims

1. A method for extracting and refining platinum with N-methylaminosulfonic acid, characterized in that: The method comprises the following steps: using N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate to prepare an organic extraction phase; using a pulse sieve plate extraction tower device, feeding an organic phase from the bottom of the tower, feeding a feed liquid to be extracted from the top of the tower, performing stripping of the obtained platinum-carrying organic extraction phase, dripping diketoxime into the stripping solution until no bright yellow precipitate is generated; adding ammonium chloride solid to the obtained platinum-containing stripping solution, precipitating platinum to obtain ammonium chloroplatinate, and calcining to obtain a platinum product; The platinum concentration in the liquid to be extracted is 4-12 g / L; The organic extraction phase was prepared by mixing N-methylaminosulfonic acid and di(2-ethylhexyl)phosphate in a ratio of 1:

1.

2. The method for extracting and refining platinum with N-methylaminosulfonic acid according to claim 1, characterized in that: The platinum concentration in the solution to be extracted is 5 g / L.

3. The method for extracting and refining platinum with N-methylaminosulfonic acid according to claim 1, characterized in that: Diketoxime was added dropwise to the stripping solution until no bright yellow precipitate was generated, and then the pH of the obtained platinum-containing stripping solution was adjusted to 1.

4. The method for extracting and refining platinum with N-methylaminosulfonic acid according to claim 1, characterized in that: The obtained platinum-loaded organic extract phase was back-extracted using 38% analytical pure hydrochloric acid, and the ratio of the two phases was controlled to be 1:

1.

5. The method for extracting and refining platinum with N-methylaminosulfonic acid according to claim 1, characterized in that: The feed flow rate is controlled at 0.5-3 L / h, and the organic phase flow rate is maintained at 2-6 L / h.

6. The method for extracting and refining platinum with N-methylaminosulfonic acid according to claim 5, characterized in that: The feed flow rate was controlled at 1 L / h, and the organic phase flow rate was maintained at 4 L / h.

7. The method for extracting and refining platinum with N-methylaminosulfonic acid according to claim 1, characterized in that: The ammonium chloroplatinate obtained by precipitating platinum is washed with 17% ammonium chloride solution.

8. The method for extracting and refining platinum with N-methylaminosulfonic acid according to claim 1, characterized in that: The following steps are involved: The platinum solution to be extracted has a Pt concentration of 10 g / L and a pH of ≤1. N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed in a ratio of 1:1 to form an organic phase. The organic phase is selected as the dispersed phase and filled with the tower body. The feed pump is turned on, the feed flow rate is controlled at 1 L / h, the organic phase flow rate is maintained at 4 L / h, the flow ratio is 1:2, and the pump is turned on for 5 hours. 20 L of extract in the extraction phase tank is collected, and the platinum-loaded organic phase collected in the extraction tank is stripped with a freshly prepared 0.01 mol / L thiourea-0.5 mol / L HCl solution. The pH of the platinum-containing stripping solution is adjusted to 1, and ammonium chloride solid is added until no precipitation is generated. The generated ammonium chloroplatinate is washed 3 times with a 17% ammonium chloride solution, and a platinum product is obtained by calcination.

9. The method for extracting and refining platinum with N-methylaminosulfonic acid according to claim 1, characterized in that: The following steps are involved: The platinum solution to be extracted has a Pt concentration of 5 g / L and a pH of ≤1. N-methylaminosulfonic acid and di(2-ethylhexyl) phosphate are mixed in a ratio of 1:1 to form an organic phase. The organic phase is selected as the dispersed phase and filled with the tower body. The feed pump is turned on, the feed flow rate is controlled at 1 L / h, the organic phase flow rate is maintained at 4 L / h, the flow ratio is 1:4, and the pump is turned on for 5 hours. 20 L of extract in the extraction phase tank is collected, and the platinum content in the extract is measured to be 1.256 g / L. The platinum-containing organic phase collected in the extraction tank is stripped with 0.01 mol / L thiourea-0.5 mol / L HCl solution, the organic phase after extraction is washed with water for recycling, the pH of the platinum-containing stripping solution is adjusted to 1, and ammonium chloride solid is added until no precipitation is generated. The generated ammonium chloroplatinate is washed 3 times with 17% ammonium chloride solution, and a platinum product is obtained by calcination.

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