阅读说明：本技术 从半导体用废蓝膜片中提取贵金属制备高纯金、铂的方法 (Method for extracting noble metal from waste blue membrane for semiconductor to prepare high-purity gold and platinum ) 是由 衷水平 范大游 苏秀珠 王俊娥 林文贤 刘兴财 唐定 陈杭 朱莞烨 于 2021-10-22 设计创作，主要内容包括：本发明公开了一种从半导体用废蓝膜片中提取贵金属制备高纯金、铂的方法,采用碱液-氧化剂复合溶液强化分离塑料基体和合金料,分离速度快及兼顾脱除杂质铝,避免大量铝进入金、铂浸出液中,减小杂质对后续金、铂高纯化的影响；采用盐酸-硝酸混合浸出剂实现对金选择性浸出,通过焙烧法使得金属钛转化为难溶的二氧化钛,提前除杂,大幅降低铂浸出液中杂质含量,获得高回收率、高纯度铂精炼工艺。解决了现有废蓝膜片中贵金属回收技术存在的环保成本高、药剂耗量大、设备投资成本高、工艺流程长、回收率低的缺点。(The invention discloses a method for extracting precious metals from a waste blue membrane for a semiconductor to prepare high-purity gold and platinum, which adopts alkali liquor-oxidant composite solution to strengthen and separate a plastic matrix and an alloy material, has high separation speed and takes account of removing impurity aluminum, avoids a large amount of aluminum from entering gold and platinum leaching solution, and reduces the influence of impurities on subsequent high purification of gold and platinum; the selective leaching of gold is realized by adopting a hydrochloric acid-nitric acid mixed leaching agent, metal titanium is converted into insoluble titanium dioxide by a roasting method, impurities are removed in advance, the impurity content in the platinum leaching solution is greatly reduced, and the high-recovery-rate and high-purity platinum refining process is obtained. Solves the defects of high environmental protection cost, large medicament consumption, high equipment investment cost, long process flow and low recovery rate in the prior art for recovering the noble metal in the waste blue membrane.)

1. The method for preparing high-purity gold and platinum by extracting noble metals from the waste blue film for the semiconductor is characterized by comprising the following specific steps:

s1, preprocessing:

leaching the waste blue membrane for the semiconductor by using the leaching solution to realize separation of a blue membrane substrate and an alloy material and removal of impurity aluminum;

s2, placing the alloy material obtained by separation in the step S1 into a reaction kettle, and adding a mixed solution of nitric acid and hydrochloric acid to selectively leach out gold; filtering after leaching to obtain a gold separation liquid and gold separation slag;

s3, gold separation and purification:

s3.1, carrying out hydrolysis and impurity removal on the gold separating liquid obtained in the step S2, filtering, adding sodium sulfite into the filtrate for reduction, taking the solution as a reaction end point when the potential of the solution is reduced to 450-550mv, and filtering to obtain gold powder and a gold precipitation liquid;

s3.2, adding hydrazine hydrate into the gold precipitation solution obtained in the step S3.1 for deep reduction, filtering after the reaction is finished to obtain coarse gold powder, returning the coarse gold powder to the step S2, and sending the filtrate to wastewater treatment;

s4, platinum separation and purification: roasting and transforming the separated gold slag obtained in the step S2 to convert Ti into TiO₂And then selectively leaching the Pt.

2. The method according to claim 1, wherein in step S1, the mass concentration of the alkali in the leachate is 1% to 25%, and the volume fraction of the oxidant is 0% to 15%; the leaching condition is that the temperature is 25 ℃, and the time is 15min-3 h.

3. The method as claimed in claim 1, wherein in step S2, the volume ratio of hydrochloric acid to nitric acid in the mixed solution is 3-5: 1, the liquid-solid ratio of the mixed solution to the alloy material is 1.5-3: 1 by volume-mass ratio, and the leaching condition is 60-85 ℃ and the time is 1-2 h.

4. The method according to claim 1, wherein the specific process of step S4 is as follows:

s4.1, placing the gold separation slag in a muffle furnace for roasting;

s4.2, leaching the residue obtained after roasting by using a hydrochloric acid-sodium chlorate solution, filtering after the reaction is finished to obtain primary filtrate and filter residue, and returning the filter residue to carry out secondary leaching to obtain secondary filtrate and secondary filter residue; and combining the primary filtrate and the secondary filtrate to obtain a combined filtrate, adjusting the alkali by using a dilute sodium hydroxide solution until the pH value is 4-5, adding excessive ammonium chloride to obtain a yellow precipitate, washing the yellow precipitate by using a dilute ammonium chloride solution, and reducing the yellow precipitate by using hydrazine hydrate to obtain platinum powder.

5. The method according to claim 4, wherein in step S4.2, the concentration of hydrochloric acid in the hydrochloric acid-sodium chlorate solution is 35g/L-60g/L, and the mass ratio of sodium chloride to gold in the alloy material is 3-6: 1.

6. The method according to claim 4, characterized in that in step S4.2, the leaching temperature is 80-95 ℃ and the time is 2-3 hours.

7. The process according to claim 4, characterized in that in step S4.2, the molar ratio of ammonium chloride to platinum in the combined filtrate is 3: 1, adding excessive ammonium chloride and reacting at room temperature for 1-2 h.

8. The method of claim 4, wherein in step S4.1, the calcination temperature is 700 ℃ to 950 ℃ and the calcination time is 1 to 3 hours.

9. The process according to claim 1, wherein in step S3.1, the reaction conditions for the reduction are controlled at a pH of 4-5 and a temperature of 55-65 ℃.

10. The process according to claim 1, wherein in step S3.2, the deep reduction is carried out under reaction conditions of pH 4-5, time 1-2h, and temperature 50-80 ℃.

Technical Field

The invention relates to the technical field of precious metal extraction and refining in waste materials, in particular to a method for preparing high-purity gold and platinum by extracting precious metals from a waste blue membrane for a semiconductor.

Background

Noble metals have good chemical stability, high electrical and thermal conductivity, and unique electrical, magnetic, optical, etc. properties, and are widely used in microelectronic technologies, such as ohmic contact, wiring, bonding, sealing, etc. of semiconductor devices, and become essential metals for improving the performance of semiconductor devices. The modern electronic industry is rapidly developed, the requirement on materials is higher and higher, and gold has high stability which cannot be replaced by other metals. Meanwhile, electronic products are increasingly miniaturized, the unit gold consumption is small, and the product cost is not threatened. More and more electronic components can therefore use gold as a raw material. The industrial gold accounts for about 10 percent of the total amount, and has the problems of low utilization rate, high material returning rate, complex waste material types and the like. If the utilization rate of gold in electronic products is only 2%, about 98% of gold-containing waste materials are to be recovered, and the gold-containing waste materials mainly comprise poor LED chips, noble metal target material waste materials, waste blue diaphragms, waste gold wires, waste wafers or leftover materials, gold-containing lining plates and the like. Wherein the amount of noble metal in the waste blue membrane is about half of the total waste noble metal. The prior pretreatment methods of the waste blue membrane containing noble metal comprise a roasting method and wet stripping (inorganic solvent and organic solvent). The roasting method has the advantages of short treatment process, direct obtaining of alloy materials after roasting, high investment cost, purchase of an incinerator and a flue gas treatment device (a large amount of harmful gas flue gas generated by roasting needs to be treated), and high environmental protection cost. The organic solvent wet stripping method has the advantages of easiness in large-scale and automatic production, and the defects of long process, high requirements on production equipment, high medicament consumption, easiness in volatilization of medicaments, great harm to human bodies, difficulty in treatment of waste liquid and the like. The inorganic solvent wet stripping method is adopted, and the method also has the problems of long treatment process, low mechanization degree of the treatment process, low efficiency and the like.

The Chinese patent application CN102277497A provides a method for recovering gold, palladium, platinum and silver from waste circuit boards, the idea of the technical scheme is to remove plastic impurities by low-temperature roasting, dissolve and separate silver and palladium by nitric acid, dissolve platinum and gold by hydrochloric acid and perchloric acid after the silver and palladium are dissolved, dissolve gold-platinum alloy by hydrochloric acid-perchloric acid solution system, the time consumption is long, the time is 5-10h, the mixed solution of high-concentration gold and platinum, and the separation and purification are needed for obtaining high-purity platinum powder and gold powder for many times.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a method for preparing high-purity gold and platinum by extracting noble metal from a waste blue membrane for a semiconductor,

in order to achieve the purpose, the invention adopts the following technical scheme:

the method for extracting noble metals from the waste blue film for the semiconductor to prepare high-purity gold and platinum comprises the following specific steps:

s1, preprocessing:

leaching the waste blue membrane for the semiconductor by using the leaching solution to realize separation of a blue membrane substrate and an alloy material and removal of impurity aluminum;

s2, placing the alloy material obtained by separation in the step S1 into a reaction kettle, and adding a mixed solution of nitric acid and hydrochloric acid to selectively leach out gold; filtering after leaching to obtain a gold separation liquid and gold separation slag;

s3, gold separation and purification:

s3.1, carrying out hydrolysis and impurity removal on the gold separating liquid obtained in the step S2, filtering, adding sodium sulfite into the filtrate for reduction, taking the solution as a reaction end point when the potential of the solution is reduced to 450-550mv, and filtering to obtain gold powder and a gold precipitation liquid;

s3.2, adding hydrazine hydrate into the gold precipitation solution obtained in the step S3.1 for deep reduction, filtering after the reaction is finished to obtain coarse gold powder, returning the coarse gold powder to the step S2, and sending the filtrate to wastewater treatment;

s4, platinum separation and purification: roasting and transforming the separated gold slag obtained in the step S2 to convert Ti into TiO₂And then selectively leaching the Pt.

Further, in step S1, the mass concentration of the alkali in the leachate is 1% to 25%, and the volume fraction of the oxidant is 0% to 15%; the leaching condition is that the temperature is 25 ℃, and the time is 15min-3 h.

Further, in step S2, the volume ratio of hydrochloric acid to nitric acid in the mixed solution is 3-5: 1, the liquid-solid ratio of the mixed solution to the alloy material is 1.5-3: 1 by volume-mass ratio, the leaching condition is 60-85 ℃, and the time is 1-2 hours.

Further, the specific process of step S4 is:

s4.1, placing the gold separation slag in a muffle furnace for roasting;

s4.2, leaching the residue obtained after roasting by using a hydrochloric acid-sodium chlorate solution, filtering after the reaction is finished to obtain primary filtrate and filter residue, and returning the filter residue to carry out secondary leaching to obtain secondary filtrate and secondary filter residue; and combining the primary filtrate and the secondary filtrate to obtain a combined filtrate, adjusting the alkali by using a dilute sodium hydroxide solution until the pH value is 4-5, adding excessive ammonium chloride to obtain a yellow precipitate, washing the yellow precipitate by using a dilute ammonium chloride solution, and reducing the yellow precipitate by using hydrazine hydrate to obtain platinum powder.

Furthermore, in step S4.2, the concentration of the hydrochloric acid in the hydrochloric acid-sodium chlorate solution is 35g/L-60g/L, and the mass ratio of the sodium chloride to the gold in the alloy material is 3-6: 1.

Furthermore, in step S4.2, the leaching temperature is 80-95 ℃ and the time is 2-3 hours.

Further, in step S4.2, the molar ratio of ammonium chloride to platinum in the combined filtrate is 3: 1, adding excessive ammonium chloride and reacting at room temperature for 1-2 h.

Furthermore, in step S4.1, the roasting temperature is 700-950 ℃, and the roasting time is 1-3 hours.

Further, in step S3.1, the reaction conditions for the reduction are controlled at pH 4-5 and temperature 55-65 ℃.

Further, in step S3.2, the reaction conditions for the deep reduction are controlled at pH 4-5 for a period of 1-2h and at a temperature of 50-80 ℃.

The invention has the beneficial effects that:

the invention adopts the alkali liquor-oxidant composite solution to strengthen and separate the plastic matrix and the alloy material, has high separation speed, removes impurity aluminum, avoids a large amount of aluminum from entering gold and platinum leaching solution, and reduces the influence of impurities on subsequent gold and platinum high purification. In addition, the invention adopts a hydrochloric acid-nitric acid mixed leaching agent to realize selective leaching of gold, converts metal titanium into insoluble titanium dioxide by a roasting method, destroys an alloy phase, enables Pt to be easy to digest, removes impurities in advance, greatly reduces the impurity content in platinum leaching solution, and obtains a high-recovery and high-purity platinum refining process. The invention solves the defects of high environmental protection cost, large medicament consumption, high equipment investment cost, long process flow and low recovery rate in the existing technology for recovering noble metals in waste blue membranes.

Drawings

FIG. 1 is a schematic flow chart of the method of examples 1 to 4 of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings, and it should be noted that the present embodiment is based on the technical solution, and the detailed implementation and the specific operation process are provided, but the protection scope of the present invention is not limited to the present embodiment.

Example 1

The embodiment provides a method for preparing high-purity gold and platinum by extracting precious metals from waste blue diaphragms for semiconductors, the waste blue diaphragms for the semiconductor industry are prepared by the steps that a matrix is polyvinyl chloride, a layer of acrylic glue is arranged in the middle of the matrix, a layer of alloy coating with the thickness of about 1 micrometer is arranged on a glue surface, and the alloy layer comprises the following components in percentage by mass: 78%, Pt: 10%, Ti: 8%, Al: 4 percent. As shown in fig. 1, the method comprises the following steps:

(1) pretreatment of

The efficient separation of the blue membrane substrate and the alloy material and the removal of impurity aluminum are realized through the enhanced leaching of the leaching solution, the mass concentration of alkali in the mixed solution is 5%, the volume fraction of hydrogen peroxide is 0, the mass ratio of the leaching agent to the waste is 2: 1, the temperature is 25 ℃, the time is 3 hours, the blue membrane substrate and the alloy material are separated, the content of gold and platinum noble metals in the leaching solution is less than 3mg/L, the content of gold and platinum noble metals on the blue membrane substrate is less than 0.05g/t, the removal rate of aluminum impurities is more than 90%, and the leaching solution can be recycled.

(2) Placing the separated alloy material into a reaction kettle, adding a nitric acid-hydrochloric acid mixed solution to selectively leach gold, wherein the volume ratio of hydrochloric acid to nitric acid in the nitric acid-hydrochloric acid mixed solution is 3: 1, the liquid-solid ratio is 1.5: 1 according to the volume-mass ratio, the temperature is 60 ℃, the time is 1h, filtering is carried out after leaching to obtain a gold separation liquid and a gold separation slag, wherein Pt in the gold separation slag is more than or equal to 59%, Ti is more than or equal to 39%, Au is less than or equal to 1.2%, and Al is less than 0.01%;

(3) gold separation and purification

a, carrying out hydrolysis impurity removal on the gold separation solution obtained in the step (2), controlling the pH value to be 4, controlling the temperature to be 55 ℃, filtering, adding sodium sulfite into the filtrate for reduction, taking the reaction end point when the potential of the gold separation solution is reduced to 450mv, and filtering to obtain gold powder and gold precipitation solution; the purity of the gold powder is 99.99 percent, and the direct yield is more than 88 percent;

b. d, adding hydrazine hydrate into the gold precipitation solution obtained in the step a for deep reduction, controlling the pH to be 4, the time to be 1h and the temperature to be 50 ℃, recovering a small amount of platinum and gold in the solution, filtering to obtain crude gold powder, and returning to the step 2; and (5) after secondary reduction, delivering the liquid to wastewater treatment. The direct yield of gold in the two steps of a and b is 98.9 percent in total.

(4) Platinum separation and purification

The gold separating slag obtained in the step (2) is mainly Pt and Ti alloy, and Ti is converted into TiO through roasting and transformation₂And Pt is selectively leached, so that the interference of Ti on Pt purification is avoided. The process conditions are as follows: and (3) roasting the gold separation slag in a muffle furnace at the roasting temperature of 700 ℃ for 3 hours. Leaching the residue after roasting by using hydrochloric acid-sodium chlorate solution, wherein the hydrochloric acid is 35g/L, and chloric acidThe ratio of sodium to gold in the alloy slag is 3: 1, the temperature is 80 ℃, and the time is 3 hours. And after the reaction is finished, filtering to obtain primary filtrate and filter residue, and leaching the filter residue for the second time to obtain secondary filtrate and secondary filter residue. And (3) combining the two filtrates, adjusting the pH to 4 by using a dilute sodium hydroxide solution, adding excessive ammonium chloride, wherein the molar ratio of the ammonium chloride to the platinum in the combined filtrate is 3: 1, reacting for 1h at room temperature to obtain yellow precipitate, washing with dilute ammonium chloride solution for multiple times, and reducing with hydrazine hydrate to obtain platinum powder, wherein the purity of the platinum powder is more than 99%, and the direct yield is more than 85%.

Example 2

The embodiment provides a method for preparing high-purity gold and platinum by extracting precious metals from waste blue diaphragms for semiconductors, the waste blue diaphragms for the semiconductor industry are characterized in that a base body is polyvinyl chloride, a layer of acrylic glue is arranged in the middle of the base body, an alloy coating layer with the thickness of about 1 micrometer is arranged on a glue surface, and the alloy coating layer is formed by Au: 78%, Pt: 10%, Ti: 8%, Al: 4 percent. As shown in fig. 1, the method comprises the following steps:

(1) pretreatment of

The efficient separation of the blue membrane matrix and the alloy material and the removal of impurity aluminum are realized by the enhanced leaching of the leaching solution, and the leaching conditions are as follows: the mass concentration of the alkali liquor is 10 percent, the volume fraction of the hydrogen peroxide is 10 percent, the mass ratio of the leaching solution to the waste is 2: 1, the temperature is 25 ℃, the time is 20min, the blue membrane matrix and the alloy material are separated, the content of gold and platinum noble metal in the leaching agent is less than 4mg/L, the content of gold and platinum noble metal on the blue membrane matrix is less than 0.05g/t, the removal rate of aluminum impurities is more than 98 percent, and the alkali liquor can be recycled.

(2) Placing the separated alloy material into a reaction kettle, adding a nitric acid-hydrochloric acid mixed solution to selectively leach gold, wherein the volume ratio of hydrochloric acid to nitric acid in the nitric acid-hydrochloric acid mixed solution is 4: 1, the liquid-solid ratio is 2: 1 according to the volume-mass ratio, the temperature is 70 ℃, the time is 1.5 hours, filtering is carried out after leaching to obtain a gold separation liquid and a gold separation slag, wherein Pt in the gold separation slag is more than or equal to 60%, Ti is more than or equal to 39%, Au is less than 0.05%, and Al is less than 0.01%;

(3) gold separation and purification

a, carrying out hydrolysis impurity removal on the gold separation solution obtained in the step (2), controlling the pH value to be 4.5, controlling the temperature to be 60 ℃, filtering, adding sodium sulfite into the filtrate for reduction, taking the reaction endpoint when the potential of the gold separation solution is reduced to 500mv, and filtering to obtain gold powder and gold precipitation solution; the purity of the gold powder is 99.99 percent, and the direct yield is more than 88 percent;

b. d, adding hydrazine hydrate into the gold precipitation solution obtained in the step a for deep reduction, controlling the pH to be 4.5, keeping the time to be 1.5h, keeping the temperature at 60 ℃, recovering a small amount of platinum and gold in the solution, filtering to obtain crude gold powder, and returning to the step a; and (5) after secondary reduction, delivering the liquid to wastewater treatment. The direct yield of gold in the two steps of a and b is up to 99.9 percent in total.

(4) Platinum separation and purification

The gold separating slag obtained in the step (2) is mainly Pt and Ti alloy, and Ti is converted into TiO through roasting and transformation₂And Pt is selectively leached, so that the interference of Ti on Pt purification is avoided. The process conditions are as follows: and roasting the gold separation slag in a muffle furnace at the roasting temperature of 850 ℃ for 2 hours. The residue after roasting is leached by hydrochloric acid-sodium chlorate solution, the hydrochloric acid is 45g/L, the ratio of the sodium chlorate to the gold in the alloy residue is 4.5: 1, the temperature is 90 ℃, and the time is 2.5 hours. And after the reaction is finished, filtering to obtain primary filtrate and filter residue, and leaching the filter residue for the second time to obtain secondary filtrate and secondary filter residue. And (3) combining the two filtrates, adjusting the pH to 4.5 by using a dilute sodium hydroxide solution, adding excessive ammonium chloride, wherein the molar ratio of the ammonium chloride to the platinum in the combined filtrate is 3: 1, reacting for 1.5h at room temperature to obtain yellow precipitate, washing with dilute ammonium chloride solution for multiple times, and reducing with hydrazine hydrate to obtain platinum powder, wherein the purity of the platinum powder is more than 99%, and the direct yield is more than 95%.

Example 3

The embodiment provides a method for preparing high-purity gold and platinum by extracting noble metals from waste blue membranes for semiconductors. The waste blue diaphragm for the semiconductor industry is characterized in that a base body is made of polyvinyl chloride, a layer of acrylic glue is arranged in the middle of the base body, an alloy coating layer with the thickness of about 1 micrometer is arranged on a glue surface, and the alloy coating layer is made of Au: 78%, Pt: 10%, Ti: 8%, Al: 4 percent. As shown in fig. 1, the method comprises the following steps:

(1) pretreatment of

The efficient separation of the blue membrane matrix and the alloy material and the removal of impurity aluminum are realized through the enhanced leaching of the leaching solution, the mass concentration of the leaching solution is 25%, the volume fraction of hydrogen peroxide is 15%, the mass ratio of a leaching agent to waste materials is 2: 1, the temperature is 25 ℃, the time is 15min, the blue membrane matrix and the alloy material are separated, the content of gold and platinum noble metals in the leaching agent is less than 5mg/L, the content of gold and platinum noble metals on the blue membrane matrix is less than 0.05g/t, the removal rate of aluminum impurities is more than 98%, and the alkali liquor can be recycled.

(2) Placing the separated alloy material into a reaction kettle, adding a nitric acid-hydrochloric acid mixed solution to selectively leach gold, wherein the volume ratio of hydrochloric acid to nitric acid in the nitric acid-hydrochloric acid mixed solution is 5: 1, the liquid-solid ratio is 2: 1 according to the volume-mass ratio, the temperature is 85 ℃, the time is 2 hours, filtering is carried out after leaching to obtain a gold separation liquid and a gold separation slag, wherein Pt is more than or equal to 60% in the gold separation slag, Ti is more than or equal to 39%, Au is less than 0.05%, and Al is less than 0.01%;

(3) gold separation and purification

a, carrying out hydrolysis impurity removal on the gold separation solution obtained in the step (2), controlling the pH value to be 4.5, controlling the temperature to be 60 ℃, filtering, adding sodium sulfite into the filtrate for reduction, taking the reaction endpoint when the potential of the gold separation solution is reduced to 500mv, and filtering to obtain gold powder and gold precipitation solution; the purity of the gold powder is 99.99 percent, and the direct yield is more than 88 percent;

b. d, adding hydrazine hydrate into the gold precipitation solution obtained in the step a for deep reduction, controlling the pH to be 5, the time to be 2 hours and the temperature to be 80 ℃, recovering a small amount of platinum and gold in the solution, filtering to obtain crude gold powder, and returning to the step 2; and (5) after secondary reduction, delivering the liquid to wastewater treatment. The direct yield of gold in the two steps of a and b is up to 99.9 percent in total.

(4) Platinum separation and purification

The gold separating slag obtained in the step (2) is mainly Pt and Ti alloy, and Ti is converted into TiO through roasting and transformation₂And Pt is selectively leached, so that the interference of Ti on Pt purification is avoided. The process conditions are as follows: and placing the alloy material into a muffle furnace for roasting at the roasting temperature of 950 ℃ for 1 hour. The residue after roasting is leached by hydrochloric acid-sodium chlorate solution, the hydrochloric acid is 60g/L, the ratio of sodium chlorate to gold in the alloy residue is 6: 1, the temperature is 95 ℃, and the time is 2 hours. And after the reaction is finished, filtering to obtain primary filtrate and filter residue, and leaching the filter residue for the second time to obtain secondary filtrate and secondary filter residue. And (3) combining the two filtrates, adjusting the pH to 4.5 by using a dilute sodium hydroxide solution, adding excessive ammonium chloride, wherein the molar ratio of the ammonium chloride to the platinum in the combined filtrate is 3: 1, room temperatureReacting for 2h to obtain yellow precipitate, washing with dilute ammonium chloride solution for multiple times, and reducing with hydrazine hydrate to obtain platinum powder with purity of more than 99% and direct yield of more than 95%.

Example 4

The embodiment provides a method for preparing high-purity gold and platinum by extracting noble metals from waste blue membranes for semiconductors. The waste blue diaphragm for the semiconductor industry is characterized in that a base body is made of polyvinyl chloride, a layer of acrylic glue is arranged in the middle of the base body, an alloy coating layer with the thickness of about 1 micrometer is arranged on a glue surface, and the alloy coating layer is made of Au: 78%, Pt: 10%, Ti: 8%, Al: 4 percent. As shown in fig. 1, the method comprises the following steps:

(1) pretreatment of

The efficient separation of the blue membrane matrix and the alloy material and the removal of impurity aluminum are realized by the enhanced leaching of the leaching solution, the mass concentration of alkali in the leaching solution is 1%, the volume fraction of hydrogen peroxide is 15%, the mass ratio of a leaching agent to waste is 2: 1, the temperature is 25 ℃, the time is 1h, the blue membrane matrix and the alloy material are separated, the content of gold and platinum noble metals in the leaching agent is less than 5mg/L, the content of gold and platinum noble metals on the blue membrane matrix is less than 0.05g/t, the removal rate of aluminum impurities is more than 85%, and the alkali liquor can be recycled.

(2) Placing the separated alloy material into a reaction kettle, adding a nitric acid-hydrochloric acid mixed solution to selectively leach gold, wherein the volume ratio of hydrochloric acid to nitric acid in the nitric acid-hydrochloric acid mixed solution is 4: 1, the liquid-solid ratio is 3: 1 according to the volume-mass ratio, the temperature is 85 ℃, the time is 1 hour, filtering is carried out after leaching to obtain a gold separation liquid and a gold separation slag, wherein Pt is more than or equal to 60 percent in the gold separation slag, Ti is more than or equal to 39 percent, Au is less than 0.16 percent, and Al is less than 0.01 percent;

(3) gold separation and purification

a, carrying out hydrolysis and impurity removal on the gold separation liquid obtained in the step (2), controlling the pH value to be 5, controlling the temperature to be 65 ℃, filtering, adding sodium sulfite into the filtrate for reduction, taking the solution as a reaction end point when the potential of the solution is reduced to 550mv, and filtering to obtain gold powder and gold precipitation liquid; the purity of the gold powder is 99.99 percent, and the direct yield is more than 88 percent;

b, adding hydrazine hydrate into the gold precipitation solution obtained in the step a for deep reduction, controlling the pH to be 4.5, keeping the time to be 1.5h, keeping the temperature at 60 ℃, recovering a small amount of platinum and gold in the solution, filtering to obtain crude gold powder, and returning to the step (2); and (5) after secondary reduction, delivering the liquid to wastewater treatment. The direct yield of gold in the two steps of a and b is up to 99 percent in total.

(4) Platinum separation and purification

In the step (2), the gold slag is mainly Pt and Ti alloy, and Ti is converted into TiO by roasting and transformation₂And Pt is selectively leached, so that the interference of Ti on Pt purification is avoided. The process conditions are as follows: and roasting the gold separation slag in a muffle furnace at the roasting temperature of 850 ℃ for 1 hour. The residue after roasting is leached by hydrochloric acid-sodium chlorate solution, the hydrochloric acid is 60g/L, the ratio of the sodium chlorate to the gold in the alloy residue is 4: 1, the temperature is 80 ℃, and the time is 2 hours. And after the reaction is finished, filtering to obtain primary filtrate and filter residue, and leaching the filter residue for the second time to obtain secondary filtrate and secondary filter residue. And (3) combining the two filtrates, adjusting the pH to 5 by using a dilute sodium hydroxide solution, adding excessive ammonium chloride, wherein the molar ratio of the ammonium chloride to the platinum in the combined filtrate is 3: 1, reacting for 2 hours at room temperature to obtain yellow precipitate, washing the yellow precipitate with dilute ammonium chloride solution for multiple times, and reducing the yellow precipitate with hydrazine hydrate to obtain platinum powder, wherein the purity of the platinum powder is more than 99 percent, and the direct yield is more than 95 percent.

Various corresponding changes and modifications can be made by those skilled in the art based on the above technical solutions and concepts, and all such changes and modifications should be included in the protection scope of the present invention.