Preparation method of sodium gold sulfite solution

Abstract

The invention relates to a preparation method of a sodium gold sulfite solution. The preparation method comprises the following steps: S1, preparing chloroauric acid; s2, slowly dropwise adding the prepared chloroauric acid into a sodium sulfite solution, when the solution becomes light yellow, temporarily stopping dropwise adding the chloroauric acid, adjusting the pH value, and after the solution becomes colorless and transparent, continuously dropwise adding the chloroauric acid until the chloroauric acid is completely dropwise added to obtain a crude sodium gold sulfite solution; s3, ethanol is added into the crude sodium gold sulfite solution, a crystal product is precipitated through an anti-solvent, after solid-liquid separation, the crystal product is washed multiple times with ethanol, and a sodium gold sulfite crystal is obtained; and S4, dissolving the obtained sodium gold sulfite crystals in a sodium sulfite solution to prepare a sodium gold sulfite solution, thereby obtaining the sodium gold sulfite solution.

Description

Technical Field

[0001] The invention relates to the field of sodium gold sulfite preparation, and in particular to a method for preparing a sodium gold sulfite solution. Background Art

[0002] Sodium gold sulfite is the main gold salt used in the sulfite gold plating system. It has a strong resistance to discoloration of the gold plating layer and can be used as a decorative plating layer. At the same time, the gold plating layer of sodium gold sulfite has excellent properties such as corrosion resistance, wear resistance, low contact resistance, and good solderability. It can also be used as a functional and protective plating layer and is widely used in printed circuit boards, semiconductor electronic components manufacturing, and cutting-edge military equipment.

[0003] In terms of the preparation of sodium gold sulfite solution, patent CN113046800A discloses a sodium gold sulfite electroplating solution and a preparation method thereof, comprising the following steps: adding gold to aqua regia and dissolving it at 90-100°C for 1-3 hours; continuing to keep warm at 90-100°C for 3-5 hours, concentrating chloroauric acid into a syrupy state, and adding concentrated hydrochloric acid to the concentrated chloroauric acid several times to drive out nitrate; placing the fixed solution in an ice water bath, and dripping saturated sodium hydroxide into the chloroauric acid solution while stirring under the ice water bath condition to adjust the pH to 6-7; adding the chloroauric acid solution after the pH adjustment to the sodium sulfite solution while stirring, and continuing to stir for 1-

[0004] 1.5h; wait for the solution to fade from yellow to colorless and transparent, filter, and obtain sodium gold sulfite electroplating solution. This patent does not wash the chloride ions, and the chloride ions entrained and adsorbed by gold will still accompany the product. This patent is completely different from the electrolytic method for preparing gold hydroxide in this patent. Patent CN105568269A discloses a method for preparing sodium gold sulfite, a cyanide-free gold plating reagent, using a method of gold rolling-cleaning gold nuggets-gold dissolving-driving nitrate-alkalization-cleaning-complexation reaction-concentration and crystallization. By controlling the pH, an intermediate product Au(OH)3 precipitate is prepared, and the chloride ions in the product are removed by washing with deionized water. The Au(OH)3 precipitate is complexed with a sodium sulfite solution to prepare a sodium gold sulfite solution, which is concentrated to obtain sodium gold sulfite crystals. This method has problems such as low yield and chloride ion corrosion of electroplating hangers and tanks.

[0005] And, in the preparation process, the yield of sodium sulfite gold in the reaction is related to the pH value of the reaction solution. When the pH value is controlled at a specific value, the yield is the highest. When the pH changes, the incomplete reaction of chloroauric acid will cause the reaction solution to present the light yellow color of chloroauric acid. Since chloroauric acid is a strong acid, in the process of adding sodium sulfite solution, it is necessary to continuously add sodium hydroxide solution to adjust the pH value of the reaction solution so that the pH value is maintained at the target value. The prior art is to judge the pH value of the reaction solution by observing the color change in the reaction container by the operator. When the reaction solution presents a light yellow color after adding chloroauric acid, sodium hydroxide solution is added to return the pH to the target value and make the chloroauric acid fully react, so that the reaction solution presents a transparent color again. On the one hand, this technical means can only be roughly observed or operated by the operator, and there is human error; on the other hand, the sodium hydroxide solution has a certain viscosity. In the process of outputting sodium hydroxide, sodium hydroxide is easily adsorbed at the opening of the dropper and gathered into droplets of different sizes before dripping, so that it is difficult to control the amount of sodium hydroxide added.

[0006] The purpose of the present invention is to design a method for preparing a sodium gold sulfite solution in view of the problems existing in the prior art. Summary of the invention

[0007] In view of the problems existing in the above-mentioned prior art, the present invention provides a method for preparing a sodium gold sulfite solution, which can effectively solve at least one problem existing in the above-mentioned prior art.

[0008] The technical solution of the present invention is:

[0009] A method for preparing a sodium gold sulfite solution comprises the following steps:

[0010] S1, preparing chloroauric acid;

[0011] S2. Slowly drop the prepared chloroauric acid into the sodium sulfite solution. When the solution turns light yellow, temporarily stop dropping the chloroauric acid, adjust the pH, and continue to drop the chloroauric acid after the solution turns colorless and transparent, until the chloroauric acid is completely added, to obtain a crude sodium gold sulfite solution;

[0012] S3, adding ethanol to the crude sodium gold sulfite solution, precipitating a crystalline product with an anti-solvent, and washing the crystalline product with ethanol for multiple times after solid-liquid separation to obtain sodium gold sulfite crystals;

[0013] S4, dissolving the obtained sodium gold sulfite crystals in a sodium sulfite solution to prepare a sodium gold sulfite solution, thereby obtaining a sodium gold sulfite solution.

[0014] Furthermore, in step S2, the pH is adjusted to 7.5-9.

[0015] Furthermore, in step S1, chloroauric acid is prepared by dissolving gold in aqua regia.

[0016] Furthermore, in step S3, after obtaining the sodium gold sulfite crystals, the crystals are left to stand to allow the ethanol to evaporate.

[0017] Further, step S2 is based on a preparation device, and the preparation device includes:

[0018] A reaction bottle, provided with a stirring element, and used for storing sodium sulfite;

[0019] a first receiving bottle and a first pump body, wherein the first receiving bottle is used to store chloroauric acid, and the first pump body outputs chloroauric acid to the reaction bottle through a first pipeline;

[0020] a second containing bottle and a second pump body, wherein the second containing bottle is used to store sodium hydroxide, and the second pump body outputs sodium sulfite to the reaction bottle through a second pipeline;

[0021] A droplet size adjustment mechanism, comprising a spring and a driving member, wherein the bottom end of the spring is fixedly connected to the liquid outlet end of the second pipe, and the end of the spring extends to the lower side of the liquid outlet end of the second pipe. After the liquid is discharged from the second pipe, the droplets are attracted to the bottom end of the spring, gathered and then dripped. The driving member is connected to the top end of the spring, and the driving member stretches or relaxes the spring to change the pitch of the spring. The pitch of the spring is negatively correlated with the adsorption force of the spring on the droplets.

[0022] A visual mechanism, arranged on the side of the reaction bottle, for obtaining the color in the reaction bottle;

[0023] A control system controls the amount of stretching of the spring by the driving member according to the color obtained by the visual mechanism, thereby controlling the particle size of the droplets output by the second pipeline. Further, the spring is a tower spring. Further, the spring is provided with elastic rods at intervals along its winding direction, and the elastic rods are arranged obliquely upward. Further, when the spring is compressed, the elastic rods are elastically deformed and then laid on the inner ring of the spring, and when the spring is stretched, the elastic rods are elastically deformed and then swung toward the outer ring of the spring, thereby separating the droplets output by the second pipeline.

[0024] Therefore, the present invention provides the following effects and / or advantages:

[0025] The present application uses the characteristics of sodium gold sulfite crystals being easily soluble in water and insoluble in anhydrous ethanol solvents to precipitate sodium gold sulfite crystals in a solution through an ethanol solvent, and mainly involves steps such as gold treatment, aqua regia dissolution, sodium hydroxide solution preparation, chloroauric acid pH adjustment, anhydrous sodium sulfite solution preparation, complexation reaction, alcohol extraction, baking of sodium gold sulfite crystals, dissolution with water, and filtration. This preparation method can effectively wash and remove chloride ions, so that the chloride ion content of the sodium gold sulfite solution is less than 30ppm, and the chloride ions are left in the precipitation solution, and the crystals are then used to prepare the sodium gold sulfite solution, thereby achieving the purpose of separating chloride ions. After washing with ethanol, the chloride ion content in the final product is less than 30ppm.

[0026] The process of the present application adopts aqua regia to dissolve gold to obtain chloroauric acid, which is then directly reacted with anhydrous sodium sulfite for complexation reaction. The liquid-liquid reaction rate is fast, and ethanol can be used to reverse the solution to precipitate sodium gold sulfite, with a precipitation rate of more than 99%. The produced sodium gold sulfite can be filtered and washed quickly, and the preparation only takes 1 day, which reduces a lot of production time.

[0027] The process provided in this application clarifies the process reaction mechanism, optimizes the process parameters, and obtains the best operating process.

[0028] In the present application, chloroauric acid is stored in a first containing bottle and inputted into a reaction bottle filled with sodium sulfite for reaction to generate sodium gold sulfite. During the reaction, sodium hydroxide stored in a second containing bottle is dripped into the reaction bottle to adjust the pH value in the reaction bottle. A droplet size adjustment mechanism is combined to adjust the particle size of the output sodium hydroxide droplets, so that sodium hydroxide droplets of corresponding particle size can be accurately output for adjusting the pH value in the reaction bottle.

[0029] The present application stretches the spring through a driving member, thereby changing the pitch of the spring, and the pitch is used to adjust the contact amount of the spring with the droplet, and is used to adjust the adsorption force of the spring on the droplet, thereby changing the particle size of the droplet.

[0030] The present application provides an elastic rod on the spring, and the elastic rod can be rebounded from the inner circle of the spring to the outer circle of the spring after the spring is stretched. Through this action, the droplets adsorbed on the bottom end of the spring can be detached, thereby obtaining droplets with smaller particle size.

[0031] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0032] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flowchart of an embodiment of the present invention.

[0034] Figure 2 It is a schematic structural diagram of an embodiment of the present invention.

[0035] Figure 3 It is a schematic diagram of the structure of the droplet size adjustment mechanism.

[0036] Figure 4 Schematic diagram of the state where a droplet is adsorbed on the droplet size adjustment mechanism.

[0037] Figure 5 It is a schematic diagram of the state in which the elastic rod is arranged on the inner circle of the spring.

[0038] Figure 6 It is a schematic diagram of the state in which the elastic rod is swung toward the outer ring of the spring.

[0039] Description of reference numerals:

[0040] Reaction bottle 1, stirring member 2, first receiving bottle 3, first pump body 4, first pipeline 5, second receiving bottle 6, second pump body 7, second pipeline 8, movable sleeve 801, droplet size adjustment mechanism 9, spring 901, driving member 902, elastic rod 903. DETAILED DESCRIPTION

[0041] In order to facilitate understanding by those skilled in the art, the structure of the present invention is further described in detail with reference to the embodiments in conjunction with the accompanying drawings:

[0042] refer to Figure 1 , a method for preparing a sodium gold sulfite solution, comprising the following steps:

[0043] S1, preparing chloroauric acid;

[0044] S2. Slowly drop the prepared chloroauric acid into the sodium sulfite solution. When the solution turns light yellow, temporarily stop dropping the chloroauric acid, adjust the pH, and continue to drop the chloroauric acid after the solution turns colorless and transparent, until the chloroauric acid is completely added, to obtain a crude sodium gold sulfite solution;

[0045] S3, adding ethanol to the crude sodium gold sulfite solution, precipitating a crystalline product with an anti-solvent, and washing the crystalline product with ethanol for multiple times after solid-liquid separation to obtain sodium gold sulfite crystals;

[0046] S4, dissolving the obtained sodium gold sulfite crystals in a sodium sulfite solution to prepare a sodium gold sulfite solution, thereby obtaining a sodium gold sulfite solution.

[0047] Furthermore, in step S2, the pH is adjusted to 7.5-9.

[0048] Furthermore, in step S1, chloroauric acid is prepared by dissolving gold in aqua regia.

[0049] Furthermore, in step S3, after obtaining the sodium gold sulfite crystals, the crystals are left to stand to allow the ethanol to evaporate.

[0050] Example 1

[0051] Aqua regia is used as a dissolving liquid, gold hydroxide is generated by dissolving, and after filtering, it is complexed with sodium sulfite and filtered to obtain a sodium gold sulfite solution. The specific process steps include:

[0052] (1) Prepare raw materials: prepare pure gold with a purity of more than 99.9%; sodium sulfite with a purity of more than 99.9%; sodium hydroxide with a purity of more than 99.9%.

[0053] (2) Preparation of gold foil: Pure gold is cut into thin slices to prepare gold foil.

[0054] (3) Preparation of chloroauric acid: Place gold foil in a nitric acid + hydrochloric acid solution, heat to 80 degrees, turn on the stirring paddle, set the speed to 300 rpm, and allow the gold foil to be completely dissolved. Then, use a peristaltic pump to add sodium hydroxide, set the peristaltic pump speed to 250, and control the pH of the chloroauric acid solution to 4-5.

[0055] (4) Preparation of sodium sulfite solution: Dissolve sodium sulfite in water to prepare a sodium sulfite solution with a concentration of 0.32 mol / L.

[0056] (5) Preparation of sodium gold sulfite solution: The sodium sulfite solution in the reaction kettle is heated to 50 degrees, maintained at this temperature, the stirring blade is turned on, the speed is set to 300 rpm, and chloroauric acid is added to the sodium sulfite solution to allow the chloroauric acid to completely react with the sodium sulfite to generate a crude sodium gold sulfite solution. The pH of the sodium gold sulfite solution is controlled at 8-9.

[0057] (6) Preparation of gold sodium sulfite solution crystals: Add alcohol to the gold sodium sulfite solution, with the volume ratio of alcohol: gold sodium sulfite solution = 3:1, and extract the gold sodium sulfite crystals.

[0058] (7) Volatilizing alcohol: The sodium gold sulfite crystals extracted with alcohol are washed and filtered twice with alcohol. After filtering, they are transferred to a tray for drying.

[0059] (8) Prepare sodium gold sulfite solution: add pure water (water:gold 4:1) into the reaction kettle, pour the dried sodium gold sulfite crystals into the reaction kettle to dissolve, add anhydrous sodium sulfite (anhydrous sodium sulfite 1:1 gold) after dissolution, add dilute sulfuric acid to adjust the pH to 8.5-9 after dissolution, and transfer to a bucket for filtration.

[0060] Example 2

[0061] Aqua regia is used as a dissolving liquid, gold hydroxide is generated by dissolving, and after filtering, it is complexed with sodium sulfite and filtered to obtain a sodium gold sulfite solution. The specific process steps include:

[0062] (1) Prepare raw materials: prepare pure gold with a purity of more than 99.9%; sodium sulfite with a purity of more than 99.9%; sodium hydroxide with a purity of more than 99.9%.

[0063] (2) Preparation of gold foil: Pure gold is cut into thin slices to prepare gold foil.

[0064] (3) Preparation of chloroauric acid: Place gold foil in a nitric acid + hydrochloric acid solution, heat to 92 degrees, turn on the stirring paddle, set the speed to 100 rpm, and allow the gold foil to be completely dissolved. Then, use a peristaltic pump to add sodium hydroxide, set the peristaltic pump speed to 200, and control the pH of the chloroauric acid solution to 4-5.

[0065] (4) Preparation of sodium sulfite solution: Dissolve sodium sulfite in water to prepare a sodium sulfite solution with a concentration of 0.32 mol / L.

[0066] (5) Preparation of sodium gold sulfite solution: The sodium sulfite solution in the reaction kettle is heated to 62 degrees, maintained at this temperature, the stirring blade is turned on, the speed is set to 100 rpm, and chloroauric acid is added to the sodium sulfite solution to allow the chloroauric acid to completely react with the sodium sulfite to generate a sodium gold sulfite solution. The pH of the sodium gold sulfite solution is controlled at 8-9.

[0067] (6) Preparation of gold sodium sulfite solution crystals: Add alcohol to the gold sodium sulfite solution, with the volume ratio of alcohol: gold sodium sulfite solution = 4:1, and extract the gold sodium sulfite crystals.

[0068] (7) Volatilizing alcohol: The sodium gold sulfite crystals extracted with alcohol are washed and filtered twice with alcohol. After filtering, they are transferred to a tray for drying.

[0069] (8) Prepare sodium gold sulfite solution: add pure water (water:gold 4:1) into the reaction kettle, pour the dried sodium gold sulfite crystals into the reaction kettle to dissolve, add anhydrous sodium sulfite (anhydrous sodium sulfite 1:1 gold) after dissolution, add dilute sulfuric acid to adjust the pH to 8.5-9 after dissolution, and transfer to a bucket for filtration.

[0070] Example 3

[0071] Aqua regia is used as a dissolving liquid, gold hydroxide is generated by dissolving, and after filtering, it is complexed with sodium sulfite and filtered to obtain a sodium gold sulfite solution. The specific process steps include:

[0072] (1) Prepare raw materials: prepare pure gold with a purity of more than 99.9%; sodium sulfite with a purity of more than 99.9%; sodium hydroxide with a purity of more than 99.9%.

[0073] (2) Preparation of gold foil: Pure gold is cut into thin slices to prepare gold foil.

[0074] (3) Preparation of chloroauric acid: Place gold foil in a nitric acid + hydrochloric acid solution, heat to 92 degrees, turn on the stirring paddle, set the speed to 100 rpm, and allow the gold foil to be completely dissolved. Then, use a peristaltic pump to add sodium hydroxide, set the peristaltic pump speed to 200, and control the pH of the chloroauric acid solution to 4-5.

[0075] (4) Preparation of sodium sulfite solution: Dissolve sodium sulfite in water to prepare a sodium sulfite solution with a concentration of 0.32 mol / L.

[0076] (5) Preparation of sodium gold sulfite solution: The sodium sulfite solution in the reaction kettle is heated to 50 degrees, maintained at this temperature, the stirring blade is turned on, the speed is set to 100 rpm, and chloroauric acid is added to the sodium sulfite solution to allow the chloroauric acid to completely react with the sodium sulfite to generate a sodium gold sulfite solution. The pH of the sodium gold sulfite solution is controlled at 8-9.

[0077] (6) Preparation of gold sodium sulfite solution crystals: Add alcohol to the gold sodium sulfite solution, with the volume ratio of alcohol: gold sodium sulfite solution = 4:1, and extract the gold sodium sulfite crystals.

[0078] (7) Volatilizing alcohol: The sodium gold sulfite crystals extracted with alcohol are washed and filtered twice with alcohol. After filtering, they are transferred to a tray for drying.

[0079] (8) Prepare sodium gold sulfite solution: add pure water in a molar ratio of 5:1 water to gold into the reactor, pour the dried sodium gold sulfite crystals into the reactor to dissolve, add anhydrous sodium sulfite in a molar ratio of 2:1 anhydrous sodium sulfite to gold after dissolution, add dilute sulfuric acid to adjust the pH to 8.5-9 after dissolution, and transfer to a bucket for filtration.

[0080] The gold sodium sulfite of Example 1 has a primary yield of 88% and a chloride ion of 80 ppm; the gold sodium sulfite of Example 2 has a primary yield of 95% and a chloride ion of 30 ppm; the gold sodium sulfite of Example 3 has a primary yield of 92% and a chloride ion of 50 ppm; the gold sodium sulfite of the prior art solution has a primary yield of 96% and a chloride ion of 20 ppm. It can be seen that the solution provided by Example 3 is the best.

[0081] Example 4

[0082] Step S2 is based on a preparation device for a sodium gold sulfite solution, comprising: Figure 2-3 ,

[0083] A reaction bottle 1 is provided with a stirring member 2, and the reaction bottle 1 is used to store sodium sulfite;

[0084] a first receiving bottle 3 and a first pump body 4, wherein the first receiving bottle 3 is used to store chloroauric acid, and the first pump body 4 outputs chloroauric acid to the reaction bottle through a first pipeline 5;

[0085] a second receiving bottle 6 and a second pump body 7, wherein the second receiving bottle 6 is used to store sodium hydroxide, and the second pump body 7 outputs sodium hydroxide to the reaction bottle 1 through a second pipe 8;

[0086] In this embodiment, the first containing bottle 3, the first pump body 4, the second containing bottle 6 and the second pump body 7 can all be directly adopted from the prior art, which will not be elaborated here. In order to improve the flow control of the pump body, the first pump body 4 and the second pump body 7 can adopt micro pumps.

[0087] The droplet size adjustment mechanism 9 includes a spring 901 and a driving member 902. The bottom end of the spring 901 is fixedly connected to the liquid outlet end of the second pipe 8. The end of the spring 901 extends to the lower side of the liquid outlet end of the second pipe 8. After the liquid is discharged from the second pipe 8, the droplets are attracted to the bottom end of the spring 901, gathered and then dripped. The driving member 902 is connected to the top end of the spring 901. The driving member 902 stretches or relaxes the spring 901 to change the pitch of the spring 901. The pitch of the spring 901 is negatively correlated with the adsorption force of the spring 901 on the droplets.

[0088] The droplet size adjustment mechanism 9 is one of the core improvements of the present application. Since the sodium hydroxide solution is viscous and the viscosity is related to the concentration of sodium hydroxide, the sodium hydroxide is more easily attracted and adsorbed on the surrounding objects, and has the characteristics of being able to gather into droplets of different sizes according to the concentration, external attraction, etc.

[0089] In this embodiment, the bottom end of the spring 901 extends to the lower side of the liquid outlet end of the second pipe 8, so that after the sodium hydroxide is output from the second pipe 8, it will be pulled by the end of the spring 901 and adsorbed to the bottom end of the spring 901 and gathered into droplets. When the second pipe 8 continues to output the sodium hydroxide solution, the droplets gathered at the bottom of the spring 901 become larger and larger. When the weight of the liquid exceeds the adsorption force of the sodium hydroxide solution at the bottom of the spring 901, the droplets fall off and drip into the reaction bottle 1.

[0090] Specifically, Figure 4As shown, the top of the droplet will be adsorbed to the bottom of the spring 901. When the stretching amount of the spring 901 increases, the pitch D of the spring 901 increases. At this time, the coils of the spring 901 are farther from each other. After the droplet is pulled by the end of the spring 901, the adsorption capacity of the bottom of the spring 901 to the droplet is reduced, and the droplet convergence capacity is also reduced accordingly, so that the particle size of the droplet is smaller when it drips from the bottom of the spring 901. On the contrary, when the stretching amount of the spring 901 decreases, the pitch D of the spring 901 decreases. At this time, the coils of the spring 901 are closer to each other. After the droplet is pulled by the end of the spring 901, the bottom of the spring 901 is more likely to adsorb the droplet, and the droplet convergence capacity is also increased accordingly, so that the particle size of the droplet is larger when it drips from the bottom of the spring 901. Through this structural feature, the pitch of the spring 901 of the spring 901 when the second pump body 7 outputs the droplet can be controlled to control the particle size of the droplet when it drips.

[0091] A visual mechanism (not shown) is disposed on the side of the reaction bottle 1 and is used to obtain the color inside the reaction bottle 1; the visual mechanism may be a camera.

[0092] The control system controls the stretching amount of the spring 901 by the driving member 902 according to the color obtained by the visual mechanism, thereby controlling the particle size of the droplets output by the second pipeline 8.

[0093] In the process that chloroauric acid is slowly added dropwise to transparent sodium sulfite solution, when the pH value of the solution in reaction flask 1 is not about 8, the yield of sodium sulfite gold decreases, and at this time, chloroauric acid is not completely reacted, and the residual chloroauric acid will make the reaction flask 1 present a faint yellow color (chloroauric acid itself is faint yellow, a strong acid). The pH value in reaction flask 1 can be known by the color in reaction flask 1. When the yellow in reaction flask 1 is darker, it indicates that the pH value of the solution in reaction flask 1 decreases more, and more sodium hydroxide needs to be added. However, in the prior art, the pH value is generally adjusted by directly dropping sodium hydroxide. Generally speaking, the volume of a drop of liquid is about 0.05 milliliters, and the amount of sodium hydroxide added dropwise to reaction flask 1 each time is fixed, and it is difficult to accurately adjust the pH value in reaction flask 1.

[0094] By controlling the particle size of the sodium hydroxide droplets when they fall, the pH of the liquid in the reaction bottle 1 is controlled. Preferably, the pH value of the liquid in the reaction bottle 1 is controlled at about 8, so that the best yield of sodium gold sulfite can be obtained. Therefore, when chloroauric acid is slowly output through the first pump body 4, the volume of the sodium hydroxide solution to be added can be inferred according to the depth of the color in the reaction bottle 1, and then the volume of the sodium hydroxide droplets output from the second pipeline 8 is adjusted according to the droplet particle size adjustment mechanism 9, so as to quantitatively add the volume of the sodium hydroxide solution and accurately adjust the pH value in the reaction bottle 1.

[0095] Furthermore, the second pipe 8 is sleeved with a movable sleeve 801 , and the movable sleeve 801 is movably arranged up and down along the second pipe 8 , and the top end of the spring 901 is connected to the bottom surface of the movable sleeve 801 .

[0096] In this embodiment, the movable sleeve 801 can help the spring 901 to achieve better upward and downward stretching.

[0097] Furthermore, the liquid outlet end of the second pipe 8 is narrowed.

[0098] Furthermore, the spring 901 is a tower spring.

[0099] In this embodiment, the liquid outlet end of the second pipe 8 is narrowed, so that the slowly output sodium hydroxide solution can fall in the shape of water drops. The bottom of the tower spring is narrowed, so that it can better surround the liquid outlet end of the second pipe 8, and the bottom diameter of the tower spring is small, which can better attract and adsorb the sodium hydroxide droplets.

[0100] Furthermore, the spring 901 is provided with elastic rods 903 at intervals along the winding direction thereof, and the elastic rods 903 are arranged obliquely upward.

[0101] Furthermore, when the spring 901 is compressed, the elastic rod 903 is elastically deformed and mounted on the inner circle of the spring 901. When the spring 901 is stretched, the elastic rod 903 is elastically deformed and swung toward the outer circle of the spring 901 to separate the droplets output by the second pipe 8.

[0102] In this embodiment, the elastic rod 903 can increase the contact area between the spring 901 and the droplet, thereby improving the adsorption capacity of the bottom end of the spring 901 to the droplet; on the other hand, the elastic rod 903 can be a rubber material support with a certain bending elasticity. When the spring 901 is compressed, the elastic rod 903 is elastically deformed and placed on the inner circle of the spring 901. Figure 5 At this time, the elastic rod 903 and the spring 901 absorb the droplets together. When the spring 901 is further stretched, the pitch of the spring 901 increases. At this time, the elastic rod 903 is elastically deformed and swung toward the outer ring of the spring 901, as shown in FIG. Figure 6 As shown, under this structure, the droplets adsorbed on the bottom of the spring 901 can be thrown off to make them detach better.

[0103] A preparation process of a sodium gold sulfite solution is further provided, and the preparation process of the sodium gold sulfite solution comprises the following steps:

[0104] The chloroauric acid is slowly output to the sodium sulfite in the reaction bottle 1 through the first pump body 4;

[0105] Detecting the color of the reaction bottle 1 by the visual mechanism;

[0106] Control the driving member 902 to adjust the stretching amount of the spring 901 according to the color of the reaction bottle 1;

[0107] Sodium hydroxide droplets of corresponding droplet particle size are outputted through the second pump body 7 , so that the sodium hydroxide droplets fall off to the sodium sulfite in the reaction bottle 1 .

[0108] Further, detecting the color of the reaction bottle by the visual mechanism includes: detecting the yellow color of the reaction bottle by the visual mechanism and outputting a yellow depth value;

[0109] Controlling the driving member 902 to adjust the stretching amount of the spring 901 according to the color of the reaction bottle includes: controlling the driving member 902 to adjust the stretching amount of the spring 901 according to the yellow depth value, and the stretching amount is negatively correlated with the yellow depth value.

[0110] Further, after the second pump body outputs the sodium hydroxide droplets of the corresponding droplet particle size, before the sodium hydroxide droplets fall off to the sodium sulfite in the reaction bottle, the method comprises:

[0111] The spring 901 is further stretched by the driving member 902 , so that the elastic rod 903 swings toward the outer ring of the spring 901 .

[0112] The principle of this embodiment can refer to the principle of a preparation device for sodium gold sulfite solution.

[0113] By using the equipment provided in this embodiment and combining it with the preparation method provided in Example 3, the primary yield of sodium gold sulfite is about 95% and the chloride ion concentration is less than 30 ppm.

[0114] It should be noted that in the claims, any reference signs placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claim. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0115] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0116] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0117] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

Claims

1. A method for preparing a sodium gold sulfite solution, characterized in that: The following steps are involved: S1, preparing chloroauric acid; S2. Slowly drop the prepared chloroauric acid into the sodium sulfite solution. When the solution turns light yellow, temporarily stop dropping the chloroauric acid, adjust the pH, and continue to drop the chloroauric acid after the solution turns colorless and transparent, until the chloroauric acid is completely added, to obtain a crude sodium gold sulfite solution; S3, adding ethanol to the crude sodium gold sulfite solution, precipitating a crystalline product with an anti-solvent, and washing the crystalline product with ethanol for multiple times after solid-liquid separation to obtain sodium gold sulfite crystals; S4, dissolving the obtained sodium gold sulfite crystals in a sodium sulfite solution to prepare a sodium gold sulfite solution, thereby obtaining a sodium gold sulfite solution.

2. The method for preparing a sodium gold sulfite solution according to claim 1, wherein: In step S2, the pH is adjusted to 7.5-9.

3. The method for preparing a sodium gold sulfite solution according to claim 1, wherein: In step S1, chloroauric acid is prepared by dissolving gold in aqua regia.

4. The method for preparing a sodium gold sulfite solution according to claim 1, wherein: In step S3, after obtaining the sodium gold sulfite crystals, the mixture is allowed to stand to allow the ethanol to evaporate.

5. The method for preparing a sodium gold sulfite solution according to claim 1, wherein: Step S2 is based on a preparation device, and the preparation device includes: A reaction bottle (1) is provided with a stirring element (2), and the reaction bottle (1) is used to store sodium sulfite; A first receiving bottle (3) and a first pump body (4), wherein the first receiving bottle (3) is used to store chloroauric acid, and the first pump body (4) outputs chloroauric acid to the reaction bottle (1) through a first pipeline (5); a second containing bottle (6) and a second pump body (7), wherein the second containing bottle (6) is used to store sodium hydroxide, and the second pump body (7) outputs sodium hydroxide to the reaction bottle (1) through a second pipeline (8); A droplet size adjustment mechanism (9), comprising a spring (901) and a driving member (902), wherein the bottom end of the spring (901) is fixedly connected to the liquid outlet end of the second pipe (8), the end of the spring (901) extends to the lower side of the liquid outlet end of the second pipe (8), after the liquid is discharged from the second pipe (8), the droplets are attracted to the bottom end of the spring (901) to gather and then drip, the driving member (902) is connected to the top end of the spring (901), the driving member (902) stretches or relaxes the spring (901) to change the pitch of the spring (901), and the pitch of the spring (901) is negatively correlated with the adsorption force of the spring (901) on the droplets; A visual mechanism, arranged on the side of the reaction bottle (1), for obtaining the color inside the reaction bottle (1); A control system controls the amount of stretching of the spring (901) by the driving member (902) according to the color obtained by the visual mechanism, thereby controlling the particle size of the droplets output by the second pipe (8).

6. The method for preparing a sodium gold sulfite solution according to claim 5, wherein: The spring (901) is a tower spring.

7. The method for preparing a sodium gold sulfite solution according to claim 6, wherein: The spring (901) is provided with elastic rods (903) at intervals along the winding direction thereof, and the elastic rods (903) are arranged obliquely upward.

8. The method for preparing a sodium gold sulfite solution according to claim 7, wherein: When the spring (901) is compressed, the elastic rod (903) is elastically deformed and then mounted on the inner ring of the spring (901); when the spring (901) is stretched, the elastic rod (903) is elastically deformed and then swung toward the outer ring of the spring (901), thereby separating the liquid droplets output by the second pipe (8).

Images