阅读说明：本技术 高纯铂绿色高效的分离提纯方法 (Green and efficient separation and purification method for high-purity platinum ) 是由 翁永烽 徐攀 江志凌 陈恋 于 2021-10-13 设计创作，主要内容包括：本发明涉及贵金属二次资源回收利用领域,尤其涉及高纯铂绿色高效的分离提纯方法。本发明采用碱性介质中,NaClO氧化分解黄色的(NH-(4))-(2)PtCl-(6)铂盐-FeCl-(3)共沉淀去杂质-NaOH水解-氨化铵沉淀实现铂的绿色高效分离提纯。高纯铂绿色高效的分离提纯方法,按如下步骤依次进行：A、球磨；B、氯化溶解；C、氯化铵沉淀；D、浆化；E、氧化溶解-水解；F、氯化铵沉淀；G、水合肼还原；H、烘干。本发明铂的回收率高,铂的回收率大于99%；生产流程短,生产效率高,经济效益好；高效清洁、绿色、环境友好。(The invention relates to the field of precious metal secondary resource recycling, in particular to a green and efficient separation and purification method for high-purity platinum. The invention adopts NaClO to oxidize and decompose yellow (NH) in an alkaline medium 4 ) 2 PtCl 6 Platinum salt-FeCl 3 Coprecipitation impurity removal, NaOH hydrolysis and ammonium amide precipitation are carried out to realize green and efficient separation and purification of the platinum. The green and efficient separation and purification method of the high-purity platinum comprises the following steps in sequence: A. ball milling; B. chlorination and dissolution; C. ammonium chloride precipitation; D. slurrying; E. oxidative dissolution-hydrolysis; F. ammonium chloride precipitation; G. reducing hydrazine hydrate; H. and (5) drying. The recovery rate of the platinum is high and is more than 99 percent; the production flow is short, the production efficiency is high, and the economic benefit is good; high cleaning efficiency, green and environment-friendly.)

1. The green high-efficiency separation and purification method of the high-purity platinum is characterized by comprising the following steps: the method comprises the following steps:

A. ball mill

Ball-milling platinum ash in a ball mill to 40 meshes, and sampling and analyzing to obtain a noble metal platinum content of more than 10%;

B. dissolving by chlorination

The weight Kg of platinum ash is as follows: volume L of 12M hydrochloric acid: volume L =1 of 45% sodium chlorate solution: 4-6: 0.5 to 5; adding 12M hydrochloric acid into a reactor, starting stirring, slowly adding the platinum ash subjected to ball milling in the step A, heating to 70-90 ℃, then slowly adding a 45% sodium chlorate solution, preserving heat for 4 hours, cooling and filtering; the filtrate is sent to the next platinum refining section, and the platinum is collected and recycled from the filter residue;

C. precipitation of ammonium chloride

Transferring the platinum filtrate obtained in the step B into a reactor, adding a 45% sodium chlorate solution, and mixing the weight Kg of platinum in the platinum filtrate: volume L =1 of 45% sodium chlorate solution: 0.1 to 0.2, heating to 60 to 95 ℃, preserving heat for 1 to 4 hours, and then stirring and adding solid ammonium chlorideThe weight Kg of platinum in the platinum filtrate is as follows: weight Kg of ammonium chloride = 1: 1.2-3; reacting for 1-3 hours, cooling and filtering; yellow (NH)₄)₂PtCl₆The filter cake reaches the next platinum purification section, and the filtrate is collected uniformly to recover platinum; yellow (NH)₄)₂PtCl₆The Pt content in the filter cake is 40-44%;

D. slurrying

The yellow (NH) obtained in step C₄)₂PtCl₆Putting the filter cake and water into a reactor, and adding a small amount of solid ferric trichloride under the stirring state; the material is slurried and has the mixture ratio of (NH)₄)₂PtCl₆Weight Kg of platinum in the filter cake: volume L of deionized water: weight g =1 of ferric chloride: 15-25: 10-30 parts of;

E. oxidative dissolution-hydrolysis

C, slowly adding a sodium hypochlorite solution and a sodium hydroxide solution into the reactor pulped in the step D under the stirring state; the sodium hypochlorite solution has very strong oxidizing property and can make yellow (NH)₄)₂PtCl₆Dissolving the platinum salt to generate H₂PtCl₆Decomposition of sodium hypochlorite solution (NH)₄)₂PtCl₆Reacting according to the formula (1):

(NH₄)₂PtCl₆+3NaClO®H₂PtCl₆+N₂+3H₂O+3NaCl （1）

generation of H₂PtCl₆Hydrolyzed by sodium hydroxide to generate sodium hydroxyplatinate [ Na ]₂Pt(OH)₆]The chemical reaction of the solution is shown in the formula (2):

H₂PtCl₆+8NaOH®Na₂Pt(OH)₆+6NaCl+2H₂O （2）

under the stirring state, respectively and slowly adding a 30% sodium hydroxide solution and a 5% sodium hypochlorite solution into the reactor slurried in the step D, wherein the material ratio is (NH)₄)₂PtCl₆Weight Kg of platinum in salt: volume L of 30% sodium hydroxide solution: volume L =1 of 5% sodium hypochlorite solution: 5-10: 1-10, heating to 50-80 ℃, reacting for 5-8 hours, cooling and filtering; the filtrate goes to the next platinum purification section,uniformly collecting filter residues and recovering platinum;

F. precipitation of ammonium chloride

Hydrochloric acid can react Na₂Pt(OH)₆Reaction to form H₂PtCl₆The chemical reaction is shown in formula (3):

Na₂Pt(OH)₆+8HCl®H₂PtCl₆+6H₂O+2NaCl （3）

ammonium chloride precipitate H₂PtCl₆To form (NH)₄)₂PtCl₆Platinum is yellow (NH)₄)₂PtCl₆The platinum salt and other impurities exist in the solution, so that the separation of the platinum and the other impurities is realized;

and E, putting the platinum filtrate obtained in the step E into a reactor, adjusting the pH of the solution to 0.5-1 by hydrochloric acid, heating to 60-80 ℃, adding hydrogen peroxide, and mixing the weight Kg of platinum in the platinum filtrate: volume L =1 of 35% hydrogen peroxide: 0.1-0.5, reacting for 2-5 hours, adding solid ammonium chloride, and mixing the weight Kg of platinum in the platinum filtrate: weight Kg of ammonium chloride = 1: 1.2-2; the reaction time is 0.5 to 1 hour, and the mixture is cooled and filtered; yellow filter cake (NH)₄)₂PtCl₆Continuously refining platinum by using platinum salt, and uniformly collecting and recycling platinum from filtrate;

repeating the step D-F2-3 times to obtain high-purity yellow (NH)₄)₂PtCl₆A platinum salt;

G. reduction of hydrazine hydrate

Adding deionized water into a platinum reduction reactor, stirring, adding multiple times of purification to obtain qualified high-purity yellow (NH)₄)₂PtCl₆Slurrying, the material slurrying proportion is (NH)₄)₂PtCl₆Weight Kg of platinum in platinum salt: volume L =1 of deionized water: 40-50;

the slurried yellow (NH) is then treated as in step E₄)₂PtCl₆Dissolution-hydrolysis of platinum salts to Na₂Pt(OH)₆Reducing the solution with hydrazine hydrate to obtain high-purity spongy platinum and hydrazine hydrate N₂H₄.H₂Reduction of Na by O₂Pt(OH)₆The chemical reaction of the solution is shown in formula (4):

Na₂Pt(OH)₆+N₂H₄.H₂O®Pt+N₂+5H₂O+2NaOH （4）

mixing Na₂Pt(OH)₆Putting the solution into a reduction reactor, heating to 70-95 ℃, and slowly adding 80% hydrazine hydrate in the proportion of Na₂Pt(OH)₆Weight Kg of platinum in the solution: volume L =1 of 80% hydrazine hydrate: 0.8-2, preserving heat for 2-4 hours, cleaning the reducing solution, cooling, washing and filtering;

H. drying by baking

And D, drying the sponge platinum washed in the step G for 2 hours at 150 ℃, heating to 750 ℃, preserving heat for 1 hour, cooling, weighing and sampling, wherein the recovery rate of the platinum is more than 99%.

Technical Field

The invention relates to the field of precious metal secondary resource recycling, in particular to a green and efficient separation and purification method for high-purity platinum.

Background

The noble metal comprises 8 elements including gold, silver and platinum group metals, wherein the platinum group gold comprises 6 elements including platinum, palladium, rhodium, iridium, ruthenium and osmium. The chemical properties of the platinum group metals are similar, the existing state of the hydrochloric acid medium platinum group metal aqueous solution is very complicated, the chlorine complexes and hydrates of the platinum group metals are very large in amount, and the thermodynamic instability is caused, so that the separation of the platinum group metals in the solution is very difficult. The mutual separation of platinum group metals is carried out by utilizing different oxidation states and reaction kinetics of the platinum group elements, and the separation is usually carried out by adopting methods such as oxidation distillation, ion exchange, solution extraction, chemical precipitation and the like.

The separation and purification of platinum has 2 main processes widely applied in the industry: ammonium chloride precipitation, aqua regia dissolution, ammonium chloride repeated precipitation method and carrier-oxidation hydrolysis method. Wherein, the method of ammonium chloride precipitation, aqua regia dissolution and ammonium chloride repeated precipitation has the defects of uncontrollable water dissolution step, generation of a large amount of NOx and the like, and the method of carrier-oxidation hydrolysis has poor removal effect on impurity palladium and the like. A new process and a new method for efficiently and environmentally separating and purifying platinum are needed to be developed, so that the aims of improving the production efficiency, saving energy, reducing emission and protecting the environment are achieved.

Chinese patent 201711037866.X discloses a preparation method of ultra-pure platinum powder, which comprises the following steps: (1) precipitating platinum by ammonium chloride; (2) controlling potential reduction: precipitating ammonium chloroplatinate with deionized water to prepare a suspension, adding a reducing agent, and controlling the potential of the solution to reduce to obtain an ammonium platinochloride solution; (3) removing impurities by ion exchange: passing the ammonium platinochloride solution through a cation exchange column to further remove cation impurities to obtain a pure platinochloride solution; (4) deep reduction of chloroplatinic acid: adding hydrazine hydrate into the chloroplatinic acid solution for deep reduction, so that the platinum is reduced into a powder form; (6) acid boiling to remove impurities: and boiling and washing the obtained platinum powder with a mixed solution of nitric acid and hydrofluoric acid, fully washing with deionized water, and drying to obtain the high-purity platinum powder. The whole process of the invention adopts the conventional hydrometallurgy process technology, does not relate to the high-temperature calcination process, and has the advantages of low energy consumption, low cost, short process, high product purity and the like.

Chinese patent 201310471954.6 discloses a new process for refining platinum, which comprises the following steps: platinum group metal-containing concentrate (slag, secondary resources and the like), chlorination dissolution, acid adjustment of dissolved solution, ammonium oxalate precipitation of organic reducing agent, and filtration and separation of precious metals. The process has wide material adaptability and simple operation, can efficiently and quickly dissolve and precipitate the ammonium chloroplatinate containing platinum group metal materials containing the ammonium chloroplatinate, has the dissolution efficiency of 95 to 99 percent in the whole refining process, the precipitation rate of 99 percent and the refining direct yield of 90 to 95 percent, effectively solves the problem that nitrogen oxides are difficult to discharge up to the standard compared with the traditional ammonium chloride repeated precipitation method, and can simultaneously solve the problems of high labor intensity and low production efficiency in the nitrate removing process of aqua regia dissolving solution. Meanwhile, the reducing agent ammonium oxalate is an organic reagent, pollution-free gas generated in the reaction process is directly discharged, and a solution system is not changed, so that the influence on the platinum precipitation of ammonium chloride in the next step is avoided, and the yield and the quality of platinum group metal products can be greatly improved.

Chinese patent 201610738573.3 discloses a platinum refining process, which comprises the following process steps: (1) dissolving various platinum-containing feed liquids and crude platinum ammonium salts by aqua regia, driving acid and nitrate, and filtering; (2) pumping the filtrate into a reaction kettle, introducing chlorine gas for hydrolysis while heating, and stopping introducing chlorine gas when the potential is raised to over 1000 mV; (3) stirring, adding liquid alkali to adjust pH, and directly cooling and filtering when pH =8-9 is stable for more than 5min to obtain orange filtrate; (4) returning the filtrate to acid, repeating the step 2 and the step 3 for three times, finally returning the obtained three hydrolyzed solutions to acid to control the acidity of the feed liquid, adding a saturated ammonium chloride solution after boiling to precipitate platinum, cooling and filtering after boiling again; (5) calcining the obtained ammonium chloroplatinate at 680 ℃ to obtain the spongy platinum. The beneficial effects of the invention are as follows: 1. the production cycle is shortened by more than 40 percent; 2. nitrate removal is reduced to one time, which is beneficial to the improvement of the production capacity and the environment improvement; 3. the direct yield of the platinum is improved by 1.94 percent.

Disclosure of Invention

The invention provides a green and efficient separation and purification method of high-purity platinum, which adopts NaClO in an alkaline medium to oxidize and decompose yellow (NH)₄)₂PtCl₆The green and efficient separation and purification of the platinum are realized by platinum salt-NaOH hydrolysis-ammonium amide precipitation.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

the green and efficient separation and purification method of the high-purity platinum comprises the following steps in sequence:

A. ball mill

Ball-milling platinum ash in a ball mill to 40 meshes, and sampling and analyzing to obtain a noble metal platinum content of more than 10%;

B. dissolving by chlorination

The weight Kg of platinum ash is as follows: volume L of 12M hydrochloric acid: volume L =1 of 45% sodium chlorate solution: 4-6: 0.5 to 5; adding 12M hydrochloric acid into a reactor, starting stirring, slowly adding the platinum ash subjected to ball milling in the step A, heating to 70-90 ℃, then slowly adding a 45% sodium chlorate solution, preserving heat for 4 hours, cooling and filtering; the filtrate is sent to the next platinum refining section, and the platinum is collected and recycled from the filter residue;

C. precipitation of ammonium chloride

Transferring the platinum filtrate obtained in the step B into a reactor, adding a 45% sodium chlorate solution, and mixing the weight Kg of platinum in the platinum filtrate: volume L =1 of 45% sodium chlorate solution: 0.1-0.2, heating to 60-95 ℃, preserving heat for 1-4 hours, then stirring and adding solid ammonium chloride, wherein the weight Kg of platinum in the platinum filtrate is as follows: weight Kg of ammonium chloride = 1: 1.2-3; reacting for 1-3 hours, cooling and filtering; yellow (NH)₄)₂PtCl₆Filtering the filter cake to a next platinum purification working section, and uniformly collecting and recovering platinum from the filtrate; yellow (NH)₄)₂PtCl₆The Pt content in the filter cake is 40-44%;

D. slurrying

The yellow (NH) obtained in step C₄)₂PtCl₆Putting the filter cake and water into a reactor, and adding a small amount of solid ferric trichloride under the stirring state; the material is slurried and has the mixture ratio of (NH)₄)₂PtCl₆Weight Kg of platinum in the filter cake: volume L of deionized water: weight g =1 of ferric chloride: 15-25: 10-30 parts of;

E. oxidative dissolution-hydrolysis

C, slowly adding a sodium hypochlorite solution and a sodium hydroxide solution into the reactor pulped in the step D under the stirring state; the sodium hypochlorite solution has very strong oxidizing property and can make yellow (NH)₄)₂PtCl₆Dissolving the platinum salt to generate H₂PtCl₆Decomposition of sodium hypochlorite solution (NH)₄)₂PtCl₆Reacting according to the formula (1):

(NH₄)₂PtCl₆+3NaClO®H₂PtCl₆+N₂+3H₂O+3NaCl （1）

generation of H₂PtCl₆Hydrolyzed by sodium hydroxide to generate sodium hydroxyplatinate [ Na ]₂Pt(OH)₆]The chemical reaction of the solution is shown in the formula (2):

H₂PtCl₆+8NaOH®Na₂Pt(OH)₆+6NaCl+2H₂O （2）

under the stirring state, respectively and slowly adding a 30% sodium hydroxide solution and a 5% sodium hypochlorite solution into the reactor slurried in the step D, wherein the material ratio is (NH)₄)₂PtCl₆Weight Kg of platinum in salt: volume L of 30% sodium hydroxide solution: volume L =1 of 5% sodium hypochlorite solution: 5-10: 1-10, heating to 50-80 ℃, reacting for 5-8 hours, cooling and filtering; the filtrate is sent to the next platinum purification section, and the platinum is collected and recovered from the filter residue;

F. precipitation of ammonium chloride

Hydrochloric acid can react Na₂Pt(OH)₆Reaction to form H₂PtCl₆The chemical reaction is shown in formula (3):

Na₂Pt(OH)₆+8HCl®H₂PtCl₆+6H₂O+2NaCl （3）

ammonium chloride precipitate H₂PtCl₆To form (NH)₄)₂PtCl₆Platinum is yellow (NH)₄)₂PtCl₆The platinum salt and other impurities exist in the solution, so that the separation of the platinum and the other impurities is realized;

and E, putting the platinum filtrate obtained in the step E into a reactor, adjusting the pH of the solution to 0.5-1 by hydrochloric acid, heating to 60-80 ℃, adding hydrogen peroxide, and mixing the weight Kg of platinum in the platinum filtrate: volume L =1 of 35% hydrogen peroxide: 0.1-0.5, reacting for 2-5 hours, adding solid ammonium chloride, and mixing the weight Kg of platinum in the platinum filtrate: weight Kg of ammonium chloride = 1: 1.2-2; the reaction time is 0.5 to 1 hour, and the mixture is cooled and filtered; yellow filter cake (NH)₄)₂PtCl₆Continuously refining platinum by using platinum salt, and uniformly collecting and recycling platinum from filtrate;

repeating the step D-F2-3 times to obtain high-purity yellow (NH)₄)₂PtCl₆A platinum salt;

G. reduction of hydrazine hydrate

Adding deionized water into a platinum reduction reactor, stirring, adding multiple times of purification to obtain qualified high-purity yellow (NH)₄)₂PtCl₆Slurrying, the material slurrying proportion is (NH)₄)₂PtCl₆Weight Kg of platinum in platinum salt: volume L =1 of deionized water: 40-50. The slurried yellow (NH) is then treated as in step E₄)₂PtCl₆Dissolution-hydrolysis of platinum salts to Na₂Pt(OH)₆Reducing the solution with hydrazine hydrate to obtain high-purity spongy platinum and hydrazine hydrate N₂H₄.H₂Reduction of Na by O₂Pt(OH)₆The chemical reaction of the solution is shown in formula (4):

Na₂Pt(OH)₆+N₂H₄.H₂O®Pt+N₂+5H₂O+2NaOH （4）

mixing Na₂Pt(OH)₆Putting the solution into a reduction reactor, heating to 70-95 ℃, and slowly adding 80% hydrazine hydrate in the proportion of Na₂Pt(OH)₆Weight Kg of platinum in the solution: volume L =1 of 80% hydrazine hydrate: 0.8-2, preserving heat for 2-4 hours, cleaning the reducing solution, cooling, washing and filtering;

H. drying by baking

And D, drying the sponge platinum washed in the step G for 2 hours at 150 ℃, heating to 750 ℃, preserving heat for 1 hour, cooling, weighing and sampling, wherein the recovery rate of the platinum is more than 99%.

The invention has the beneficial effects that:

1. the recovery rate of the platinum is high and is more than 99%.

2. The invention has short production flow, high production efficiency and good economic benefit.

3. The invention is efficient, clean, green and environment-friendly.

4. The purpose of chlorination and dissolution in the step B of the invention is to effectively dissolve platinum in the platinum ash and dissolve a small amount of other non-metallic impurities, thereby realizing the dissolution and rough separation of the platinum.

5. FeCl added in the step D pulping process of the invention₃Can be coprecipitated with other small amount of Pd and Rh noble metal impurities and other base metal impurities to realizeSeparation of platinum from other impurities.

Description of the drawings:

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

Example 1

The green and efficient separation and purification method of the high-purity platinum comprises the following steps in sequence:

A. ball mill

Ball-milling platinum ash in a ball mill to 40 meshes, sampling and analyzing, wherein the content of platinum is 35.32%;

B. dissolving by chlorination

Putting 20 liters of 12M hydrochloric acid into a 50 liter glass kettle, stirring, heating to 70 ℃, putting 5 kg of platinum ash subjected to ball milling in the step A into the glass kettle, slowly dropwise adding 2.5 liters of 45% sodium chlorate solution, preserving heat for 4 hours, cooling and filtering; the filtrate is sent to the next platinum refining section, and the platinum is collected and recycled from the filter residue;

C. precipitation of ammonium chloride

B, putting the platinum filtrate obtained in the step B into a PP (polypropylene) barrel of 100 liters, slowly dropwise adding 0.18 liter of 45% sodium chlorate solution, heating to 60 ℃, keeping the temperature for 1 hour, stirring, adding 2.12 kg of solid ammonium chloride, reacting for 1 hour, cooling and filtering; yellow (NH)₄)₂PtCl₆The filter cake reaches the next platinum purification section, and the filtrate is collected uniformly to recover platinum;

D. slurrying

The yellow (NH) obtained in step C₄)₂PtCl₆Putting the filter cake into a reactor of a 150L glass kettle, and adding 26.49L deionized water and 17.66 g solid ferric trichloride while stirring;

E. oxidative dissolution-hydrolysis

C, slowly adding 8.8 liters of 30% NaOH solution and 1.76 liters of 5% NaClO solution into the slurried material obtained in the step D under stirring, heating to 50 ℃, reacting for 5 hours, cooling and filtering; the filtrate is sent to the next platinum purification section, and the platinum is collected and recovered from the filter residue;

F. precipitation of ammonium chloride

Adding Na obtained in the step E₂Pt(OH)₆The solution was placed in a 150 liter glass kettle, the pH of the solution was adjusted to 0.5 with 12M hydrochloric acid, heated to 60 ℃ and added to 0.18Adding 35% hydrogen peroxide, keeping the temperature for 2 hours, adding 2.11 kg of solid ammonium chloride, reacting for 0.5 hour, cooling and filtering; yellow filter cake (NH)₄)₂PtCl₆Continuously refining platinum by using platinum salt, and uniformly collecting and recycling platinum from filtrate;

repeating the step D-F2-3 times to obtain high-purity yellow (NH)₄)₂PtCl₆A platinum salt;

G. reduction of hydrazine hydrate

70.22 liters of deionized water was added to a 200 liter platinum reduction reactor and, with agitation, multiple purifications were added to yield a qualified high purity yellow (NH)₄)₂PtCl₆And slurrying. Following the procedure of step E, yellow (NH)₄)₂PtCl₆Dissolving platinum salt to generate Na₂Pt(OH)₆Heating the solution to 70 ℃, slowly adding 1.4 liters of 80% hydrazine hydrate, preserving the temperature for 2 hours, cooling, washing and filtering when the reducing solution is clear;

H. drying by baking

And F, putting the sponge platinum washed in the step F into an electric furnace, drying for 2 hours at 150 ℃, heating to 750 ℃, preserving heat for 1 hour, cooling, weighing, sampling and analyzing to obtain 1750.46 g of high-purity platinum with the purity of 99.99%, wherein the recovery rate of the platinum is 99.11%.

Example 2

The green and efficient separation and purification method of the high-purity platinum comprises the following steps in sequence:

A. ball mill

Ball-milling platinum ash in a ball mill to 40 meshes, sampling and analyzing, wherein the content of platinum is 35.74%;

B. dissolving by chlorination

Putting 25 liters of 12M hydrochloric acid into a 50 liter glass kettle, stirring, heating to 80 ℃, putting 5 kg of platinum ash subjected to ball milling in the step A into the glass kettle, slowly dropwise adding 15 liters of 45% sodium chlorate solution, preserving heat for 4 hours, cooling and filtering; the filtrate is sent to the next platinum refining section, and the platinum is collected and recycled from the filter residue;

C. precipitation of ammonium chloride

B, putting the platinum filtrate obtained in the step B into a PP (polypropylene) barrel of 100 liters, slowly and dropwise adding 0.27 liter of 45% sodium chlorate solution, heating to 80 ℃, preserving the temperature for 2.5 hours, stirring and adding 2.86 kg of solid ammonium chloride, and reactingCooling for 2 hours, and filtering; yellow (NH)₄)₂PtCl₆The filter cake reaches the next platinum purification section, and the filtrate is collected uniformly to recover platinum;

D. slurrying

The yellow (NH) obtained in step C₄)₂PtCl₆Putting the filter cake into a reactor of a 150L glass kettle, and adding 35.74L deionized water and 35.74 g solid ferric trichloride while stirring;

E. oxidative dissolution-hydrolysis

D, slowly adding 13.36 liters of 30 percent NaOH solution and 9.8 liters of 5 percent NaClO solution into the slurried material obtained in the step D under stirring, heating to 65 ℃, reacting for 6.5 hours, cooling and filtering; the filtrate is sent to the next platinum purification section, and the platinum is collected and recovered from the filter residue;

F. precipitation of ammonium chloride

Adding Na obtained in the step E₂Pt(OH)₆Putting the solution into a 150L glass kettle, adjusting the pH value of the solution to 0.75 by using 12M hydrochloric acid, heating to 70 ℃, adding 0.53L of 35% hydrogen peroxide, preserving the temperature for 3.5 hours, adding 2.84 kg of solid ammonium chloride, reacting for 0.8 hour, cooling and filtering; yellow filter cake (NH)₄)₂PtCl₆Continuously refining platinum by using platinum salt, and uniformly collecting and recycling platinum from filtrate;

repeating the step D-F2-3 times to obtain high-purity yellow (NH)₄)₂PtCl₆A platinum salt;

G. reduction of hydrazine hydrate

79.96L of deionized water was added to a 200L platinum reduction reactor and, with stirring, multiple purifications were added to yield a qualified high purity yellow (NH)₄)₂PtCl₆And slurrying. Following the procedure of step E, yellow (NH)₄)₂PtCl₆Dissolving platinum salt to generate Na₂Pt(OH)₆Heating the solution to 80 ℃, slowly adding 2.49 liters of 80% hydrazine hydrate, preserving the heat for 3 hours, cooling, washing and filtering when the reducing solution is clear;

H. drying by baking

And F, putting the sponge platinum washed in the step F into an electric furnace, drying for 2 hours at 150 ℃, heating to 750 ℃, preserving heat for 1 hour, cooling, weighing, sampling and analyzing to obtain 1771.99 g of high-purity platinum with the purity of 99.99%, wherein the recovery rate of the platinum is 99.15%.

Example 3

The green and efficient separation and purification method of the high-purity platinum comprises the following steps in sequence:

A. ball mill

Ball-milling platinum ash in a ball mill to 40 meshes, sampling and analyzing to obtain 36.16% of platinum content;

B. dissolving by chlorination

Putting 30 liters of 12M hydrochloric acid into a 50 liter glass kettle, stirring, heating to 90 ℃, putting 5 kg of platinum ash subjected to ball milling in the step A into the glass kettle, slowly dropwise adding 25 liters of 45% sodium chlorate solution, preserving heat for 4 hours, cooling and filtering; the filtrate is sent to the next platinum refining section, and the platinum is collected and recycled from the filter residue;

C. precipitation of ammonium chloride

B, putting the platinum filtrate obtained in the step B into a PP (polypropylene) barrel of 100 liters, slowly dropwise adding 0.36 liter of 45% sodium chlorate solution, heating to 95 ℃, preserving the temperature for 4 hours, stirring, adding 5.42 kg of solid ammonium chloride, reacting for 3 hours, cooling and filtering; yellow (NH)₄)₂PtCl₆The filter cake reaches the next platinum purification section, and the filtrate is collected uniformly to recover platinum;

D. slurrying

The yellow (NH) obtained in step C₄)₂PtCl₆Putting the filter cake into a reactor of a 150L glass kettle, and adding 45.2L deionized water and 54.24 g solid ferric trichloride while stirring;

E. oxidative dissolution-hydrolysis

C, slowly adding 18.03 liters of 30 percent NaOH solution and 18.03 liters of 5 percent NaClO solution into the slurried material obtained in the step D under stirring, heating to 80 ℃, reacting for 8 hours, cooling and filtering; the filtrate is sent to the next platinum purification section, and the platinum is collected and recovered from the filter residue;

F. precipitation of ammonium chloride

Adding Na obtained in the step E₂Pt(OH)₆Putting the solution into a 150L glass kettle, adjusting the pH value of the solution to 1.0 by using 12M hydrochloric acid, heating to 80 ℃, adding 0.9L of 35% hydrogen peroxide, preserving the temperature for 5 hours, adding 3.6 kg of solid ammonium chloride, reacting for 1 hour, cooling and filtering; yellow filter cake (NH)₄)₂PtCl₆The platinum salt continues to be refined into platinum,uniformly collecting the filtrate and recovering platinum;

repeating the step D-F2-3 times to obtain high-purity yellow (NH)₄)₂PtCl₆A platinum salt;

G. reduction of hydrazine hydrate

89.94L of deionized water was added to a 200L platinum reduction reactor and, with stirring, multiple purifications were added to yield a qualified high purity yellow (NH)₄)₂PtCl₆And slurrying. Following the procedure of step E, yellow (NH)₄)₂PtCl₆Dissolving platinum salt to generate Na₂Pt(OH)₆Heating the solution to 95 ℃, slowly adding 3.6 liters of 80% hydrazine hydrate, preserving the heat for 4 hours, cooling, washing and filtering when the reducing solution is clear;

H. drying by baking

And F, putting the sponge platinum washed in the step F into an electric furnace, drying for 2 hours at 150 ℃, heating to 750 ℃, preserving heat for 1 hour, cooling, weighing, sampling and analyzing to obtain 1794.26 g of high-purity platinum with the purity of 99.99%, wherein the recovery rate of the platinum is 99.23%.