Gold recovery process in magnetron sputtering chamber

Abstract

The invention relates to the technical field of gold recovery of magnetron sputtering, and discloses a gold recovery process in a magnetron sputtering room, during actual use, nickel-gold waste in the magnetron sputtering room is dissolved in an electrochemical dissolution mode, then impurities are removed, chloroauric acid is generated through aqua regia, and the chloroauric acid is reduced into gold powder; and finally, the gold powder is smelted through the cosolvent, pure gold is generated, the whole process is simple, safe, green and low in cost, the high gold recovery rate is achieved, and the gold sputtering cost of the substrate in the magnetron sputtering chamber is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of gold recovery in magnetron sputtering, and in particular to a gold recovery process in a magnetron sputtering chamber. Background Art

[0002] In the semiconductor field, it is often necessary to coat substrates by PVD magnetron sputtering. However, the existing PVD magnetron sputtering coating method has an effective sputtering rate of only 30%, and more than half of the metal in this 30% effective sputtering rate is sputtered onto the tray or chamber anti-deposition plate outside the substrate, resulting in a large amount of waste, especially when plating some precious metals. The large amount of precious metal waste will increase production costs.

[0003] Take the gold plating in the magnetron sputtering chamber as an example. In the actual production process, a layer of nickel base needs to be magnetron sputtered on the substrate before gold plating to meet the bonding requirements between gold and the substrate (molybdenum alloy material). If only a layer of gold is plated on the surface of the molybdenum alloy substrate without nickel as an intermediate transition layer, the bonding strength is poor. Therefore, there are nickel, gold and other large amounts of impurities in the magnetron sputtering chamber for gold plating, and the impurities are mainly oxides, and also include inorganic solid atoms or atomic groups. Therefore, recovering gold from the magnetron sputtering chamber will greatly reduce production costs.

[0004] There are two existing methods for precious metal recovery, as follows:

[0005] Method 1: Extraction by pyrometallurgy. Common pyrometallurgy extraction includes direct smelting. In actual use, although pyrometallurgy extraction has the advantages of simple process, easy operation and high recovery rate, due to the presence of nickel and other metal impurities in the magnetron sputtering chamber, gold cannot be completely extracted by pyrometallurgy alone.

[0006] Method 2: Extraction through wet process. Common wet processes include cyanidation. For example, the patent document with application publication number CN101760625A discloses a cyanidation replacement gold mud pre-calcination and wet metallurgical process, which extracts gold through wet process. However, in actual use, the cyanidation method has the disadvantage that a large amount of oxygen-containing wastewater will be generated during the reaction process, which is difficult to handle. It not only endangers human health, but also pollutes the environment. Summary of the invention

[0007] In view of the shortcomings of the background technology, the present invention provides a gold recovery process in a magnetron sputtering chamber. The technical problem to be solved is the lack of a green and safe gold recovery process in a magnetron sputtering chamber.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a gold recovery process in a magnetron sputtering chamber, comprising the following steps:

[0009] S1: treating the waste in the magnetron sputtering chamber by an electrochemical dissolution process to obtain a waste solution;

[0010] S2: filtering the waste solution to obtain a precipitate;

[0011] S3: removing impurities from the precipitate to obtain secondary waste;

[0012] S4: performing secondary electrochemical dissolution and secondary filtration on the secondary waste in sequence to obtain a secondary precipitate;

[0013] S5: adding aqua regia to the secondary precipitate, thereby dissolving the secondary precipitate to generate chloroauric acid;

[0014] S6: reducing chloroauric acid to generate gold powder;

[0015] S7: purifying, washing and drying the gold powder in sequence;

[0016] S8: adding a solvent to the gold powder obtained in step S7 for smelting.

[0017] In a certain embodiment, step S1 is as follows: placing the waste into an electrolytic cell filled with hydrochloric acid for electrolysis and stirring during the electrolysis process, wherein the hydrochloric acid concentration in the anode chamber of the electrolytic cell is 2 mol / L, the hydrochloric acid concentration in the cathode chamber of the electrolytic cell is 1.5-2 mol / L, and the current density of the electrolytic cell is 250-350A·m -2 , the electrolysis temperature is less than 50°C and the stirring speed is 450-700rmp.

[0018] In certain embodiments, the step of filtering the waste solution in step S2 is as follows:

[0019] The precipitate was filtered using 101-type rapid qualitative filter paper to obtain secondary waste.

[0020] In some embodiments, the process of the secondary electrochemical dissolution in step S4 is as follows:

[0021] The secondary waste is placed in an electrolytic cell filled with hydrochloric acid for electrolysis and stirred during the electrolysis process. The hydrochloric acid concentration in the anode chamber of the electrolytic cell is 2 mol / L, the hydrochloric acid concentration in the cathode chamber of the electrolytic cell is 1.5-2 mol / L, and the current density of the electrolytic cell is 250-350A·m -2 , the electrolysis temperature is less than 50°C and the stirring speed is 450-700rmp.

[0022] In a certain embodiment, in step S6, sodium bisulfite is used as a reducing agent to reduce chloroauric acid, thereby reducing chloroauric acid to generate gold powder.

[0023] In a certain embodiment, the steps of purifying the gold powder in step S7 are as follows: adding the gold powder to 10% hydrochloric acid for multiple times, heating and stirring, and then filtering the gold powder;

[0024] The steps of washing the gold powder in step S7 are as follows: washing the gold powder with distilled water for multiple times, and filtering after washing;

[0025] The steps of drying the gold powder in step S7 are as follows: putting the gold powder into an oven at a temperature of 100° C. for drying.

[0026] In one embodiment, when washing the gold powder in step S7, the distilled water is heated and stirred.

[0027] In a certain embodiment, in step S7, when drying the gold powder, the gold powder is taken out of the oven several times and stirred to fully dry the gold powder.

[0028] In certain embodiments, the co-solvent used in step S8 includes borax and sodium carbonate.

[0029] In one embodiment, the smelting temperature is 1200°C.

[0030] Compared with the prior art, the present invention has the following beneficial effects: the present invention dissolves the nickel-gold waste in the magnetron sputtering chamber by electrochemical dissolution, then removes impurities, generates chloroauric acid by aqua regia, reduces the chloroauric acid to gold powder, and finally melts the gold powder by a solvent to generate pure gold. The whole process is simple, safe, green, low-cost, has a high gold recovery rate, and reduces the gold sputtering cost of the substrate in the magnetron sputtering chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Flowchart of the present invention in an embodiment. DETAILED DESCRIPTION

[0032] Illustrative embodiments of the present application include, but are not limited to, a gold recovery process within a magnetron sputtering chamber.

[0033] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0034] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items. "Include" or "include" and similar words mean that the elements or objects appearing in front of "include" or "include" cover the elements or objects listed after "include" or "include" and their equivalents, and do not exclude other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, and can include electrical connections, whether direct or indirect.

[0035] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0036] like Figure 1 As shown, a gold recovery process in a magnetron sputtering chamber, a gold recovery process in a magnetron sputtering chamber, comprises the following steps:

[0037] S1: treating the waste in the magnetron sputtering chamber by an electrochemical dissolution process to obtain a waste solution.

[0038] Specifically, in step S1, the waste is placed in an electrolytic cell filled with hydrochloric acid for electrolysis and stirred during the electrolysis process, wherein the hydrochloric acid concentration in the anode chamber of the electrolytic cell is 2 mol / L, the hydrochloric acid concentration in the cathode chamber of the electrolytic cell is 1.5-2 mol / L, and the current density of the electrolytic cell is 250-350A·m -2 , the electrolysis temperature is less than 50°C and the stirring speed is 450-700rmp.

[0039] In actual use, by setting the above electrolysis process parameters, the nickel dissolution efficiency can reach 90.8%, which can greatly reduce the nickel content in the waste and facilitate storage.

[0040] For example, the concentration of hydrochloric acid in the cathode chamber of the electrolytic cell is 1.75 mol / L, and the current density of the electrolytic cell is 275 A·m -2, the electrolysis temperature is 40°C, the stirring speed is 500 rpm; or the hydrochloric acid concentration in the cathode chamber of the electrolytic cell is 1.85 mol / L, and the current density of the electrolytic cell is 300 A·m -2 , the electrolysis temperature is 20°C and the stirring speed is 600rmp.

[0041] S2: Filter the waste solution to obtain a precipitate.

[0042] Specifically, in this embodiment, filtration is performed through 101 type rapid qualitative filter paper to obtain a precipitate.

[0043] S3: removing impurities from the precipitate to obtain secondary waste.

[0044] S4: performing secondary electrochemical dissolution and secondary filtration on the secondary waste in sequence to obtain a secondary precipitate.

[0045] Specifically, in this embodiment, the process of secondary electrochemical dissolution in step S4 is as follows: the secondary waste is placed in an electrolytic cell filled with hydrochloric acid for electrolysis and stirred during the electrolysis process, wherein the hydrochloric acid concentration in the anode chamber of the electrolytic cell is 2 mol / L, the hydrochloric acid concentration in the cathode chamber of the electrolytic cell is 1.5-2 mol / L, and the current density of the electrolytic cell is 250-350A·m -2 , the electrolysis temperature is less than 50°C, and the stirring speed is 450-700rmp;

[0046] In addition, the steps of secondary filtration are as follows: Filter using 101 type rapid qualitative filter paper.

[0047] S5: adding aqua regia to the secondary precipitate to dissolve the secondary precipitate to generate chloroauric acid.

[0048] Aqua regia, also known as "royal acid" or "nitrohydrochloric acid", is a highly corrosive liquid that emits a yellow mist. It is a mixture of concentrated hydrochloric acid (HCl) and concentrated nitric acid (HNO 3 ) is a mixture composed of 3:1 by volume.

[0049] S6: Reduce chloroauric acid to generate gold powder.

[0050] Specifically, in step S6, sodium bisulfite is used as a reducing agent to reduce chloroauric acid, thereby reducing chloroauric acid to generate gold powder. The use of sodium bisulfite for reduction does not require the removal of nitrate, and the steps are simple. In addition, before adding sodium bisulfite, the pH of chloroauric acid is adjusted to between 2 and 4, and then the chloroauric acid is heated to 50 degrees Celsius and maintained for a period of time.

[0051] S7: Purify, wash and dry the gold powder in sequence.

[0052] Specifically, in this embodiment, the steps of purifying the gold powder in step S7 are as follows: adding the gold powder to 10% hydrochloric acid for multiple times, heating and stirring, and then filtering the gold powder;

[0053] The steps of washing the gold powder in step S7 are as follows: washing the gold powder with distilled water for multiple times, and filtering after washing; in addition, the distilled water can be heated and stirred in actual use;

[0054] The steps of drying the gold powder in step S7 are as follows: putting the gold powder into an oven at a temperature of 100° C. for drying; in addition, in actual use, when drying the gold powder, take the gold powder out of the oven several times and stir it to fully dry the gold powder.

[0055] S8: adding a solvent to the gold powder obtained in step S7 for smelting.

[0056] Specifically, in this embodiment, the dissolving aids used in step S8 include borax and sodium carbonate, wherein borax can lower the melting point temperature, and sodium carbonate can remove possible sulfide impurities, and the smelting temperature is 1200°C.

[0057] The gold recovery process of the present invention dissolves the nickel-gold waste in the magnetron sputtering chamber by electrochemical dissolution, removes impurities, generates chloroauric acid by aqua regia, reduces the chloroauric acid to gold powder, and finally melts the gold powder by a solvent to generate pure gold. The whole process is simple, safe, green, low-cost, has a high gold recovery rate, and reduces the gold sputtering cost of the substrate in the magnetron sputtering chamber.

[0058] The above is based on the present invention as an inspiration. Through the above description, relevant staff can make various changes and modifications without departing from the technical idea of ​​this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A gold recovery process in a magnetron sputtering chamber, It is characterized in that The steps include: S1: treating the waste in the magnetron sputtering chamber by an electrochemical dissolution process to obtain a waste solution; S2: filtering the waste solution to obtain a precipitate; S3: removing impurities from the precipitate to obtain secondary waste; S4: performing secondary electrochemical dissolution and secondary filtration on the secondary waste in sequence to obtain a secondary precipitate; S5: adding aqua regia to the secondary precipitate, thereby dissolving the secondary precipitate to generate chloroauric acid; S6: reducing chloroauric acid to generate gold powder; S7: purifying, washing and drying the gold powder in sequence; S8: adding a solvent to the gold powder obtained in step S7 for smelting.

2. The gold recovery process in a magnetron sputtering chamber according to claim 1, It is characterized in that Step S1 is as follows: placing the waste into an electrolytic cell filled with hydrochloric acid for electrolysis and stirring during the electrolysis process, wherein the hydrochloric acid concentration in the anode chamber of the electrolytic cell is 2 mol / L, the hydrochloric acid concentration in the cathode chamber of the electrolytic cell is 1.5-2 mol / L, and the current density of the electrolytic cell is 250-350A·m -2 , the electrolysis temperature is less than 50°C and the stirring speed is 450-700rmp.

3. The gold recovery process in a magnetron sputtering chamber according to claim 1, It is characterized in that The steps of filtering the waste solution in step S2 are as follows: The precipitate was filtered using 101-type rapid qualitative filter paper to obtain secondary waste.

4. The gold recovery process in a magnetron sputtering chamber according to claim 1, It is characterized in that The process of secondary electrochemical dissolution in step S4 is as follows: The secondary waste is placed in an electrolytic cell filled with hydrochloric acid for electrolysis and stirred during the electrolysis process. The hydrochloric acid concentration in the anode chamber of the electrolytic cell is 2 mol / L, the hydrochloric acid concentration in the cathode chamber of the electrolytic cell is 1.5-2 mol / L, and the current density of the electrolytic cell is 250-350A·m -2 , the electrolysis temperature is less than 50°C and the stirring speed is 450-700rmp.

5. The gold recovery process in a magnetron sputtering chamber according to claim 1, It is characterized in that In step S6, sodium bisulfite is used as a reducing agent to reduce chloroauric acid, thereby reducing chloroauric acid to generate gold powder.

6. The gold recovery process in a magnetron sputtering chamber according to claim 1, It is characterized in that The steps of purifying the gold powder in step S7 are as follows: adding the gold powder to 10% hydrochloric acid for multiple times, heating and stirring, and then filtering the gold powder; The steps of washing the gold powder in step S7 are as follows: washing the gold powder with distilled water for multiple times, and filtering after washing: The steps of drying the gold powder in step S7 are as follows: putting the gold powder into an oven at a temperature of 100° C. for drying.

7. A gold recovery process in a magnetron sputtering chamber according to claim 6, It is characterized in that When washing the gold powder in step S7, the distilled water is heated and stirred.

8. The gold recovery process in a magnetron sputtering chamber according to claim 6, It is characterized in that In step S7, when the gold powder is dried, the gold powder is taken out of the oven several times and stirred to fully dry the gold powder.

9. The gold recovery process in a magnetron sputtering chamber according to claim 1, It is characterized in that The auxiliary solvent used in step S8 includes borax and sodium carbonate.

10. A gold recovery process in a magnetron sputtering chamber according to claim 1 or 9, It is characterized in that The smelting temperature is 1200°C.

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