Method for preparing soluble rhodium compound

Abstract

The invention provides a method for preparing a soluble rhodium compound. The method comprises the following steps: S1, roasting; s2, washing; s3, dissolving; s4, removing barium ions; s5, precipitating; s6, dissolving; and S7, preparing an electroplating rhodium solution. The invention provides a method for preparing a soluble rhodium compound, the soluble rhodium compound is prepared by adopting a barium peroxide roasting method, and the prepared soluble rhodium compound does not limit component preparation of an electroplating rhodium solution and can be used for preparation and production of the soluble rhodium compound in the fields of chemical engineering, metallurgy, precision electronics and the like. The preparation method overcomes the defects of the original preparation method, improves the process stability, has the advantages of easiness in process control, low toxicity and environmental pollution to human bodies, low safety production risk and hidden danger and easiness in implementation, and reduces the toxicity and environmental pollution to human bodies and completely eradicates the safety production risk and hidden danger while improving the stability of the electroplating rhodium solution.

Description

Technical Field

[0001] The invention relates to the field of preparation of rhodium electroplating solutions for various nickel-based alloy materials, and in particular to a method for preparing a soluble rhodium compound. Background Art

[0002] The rhodium plating has a smooth and bright appearance, excellent chemical stability, high corrosion resistance, ablation resistance and oxidation resistance. It will not oxidize below 500°C, and the color can remain unchanged for a long time. It has high conductivity and low contact resistance. The hardness of rhodium is extremely high (HV 400~HV 800), close to that of chromium, so it is particularly wear-resistant.

[0003] Rhodium plating is widely used in aerospace, chemical, metallurgy, automobile, electronics and other fields. It is mainly used to improve the contact reliability of sliding electrical contact elements (such as contact sheets, reeds, slip rings and conductive rings, etc.) to improve their conductivity and wear resistance, reduce friction torque, and improve contact reliability. It can also be used to improve the contact reliability of electrical contact elements, to prevent oxidation and burning of contact reeds during the on-off process, to prevent discoloration of silver contacts and corrosion of parts. In order to obtain rhodium plating, compared with vacuum coating, etc., aqueous solution electroplating is the most economical method. However, the rhodium electroplating solution is sensitive to various impurities, and it is necessary to prepare a high-purity soluble rhodium compound-rhodium sulfate.

[0004] At present, there are two main methods for preparing soluble rhodium compounds: chlorination method and sodium bisulfate melting method. The chlorination method is to first mix rhodium powder and sodium chloride, load them into a chlorination furnace, introduce chlorine gas, and generate soluble sodium chlororhodate at a certain pressure and temperature for a certain period of time. The sodium bisulfate melting method is to first mix rhodium powder and sodium bisulfate, sinter and melt them at nearly 600°C, but both methods have major problems: (1) the preparation process is unstable and difficult to control; (2) the chlorination method requires the introduction of a large amount of toxic chlorine gas and the reaction under high temperature and high pressure. The sodium bisulfate melting method will produce a large amount of toxic gas sulfur dioxide during the reaction process. Chlorine and sulfur dioxide gases will cause harm to the operator and environmental pollution. At the same time, high temperature and high pressure have a large safety risk.

[0005] Therefore, it is necessary to provide a method for preparing a soluble rhodium compound to solve the above-mentioned technical problems. Summary of the invention

[0006] The invention provides a method for preparing a soluble rhodium compound, which solves the problems that the preparation process of the soluble rhodium compound is unstable, difficult to control, harmful to the operator's body and environmental pollution, and has great hidden safety risks due to high temperature and high pressure.

[0007] In order to solve the above technical problems, the present invention provides a method for preparing a soluble rhodium compound, comprising the following steps:

[0008] S1: calcination; weigh pure rhodium powder with an analytical balance, grind it in a glass mortar, and grind it with a mortar. Mix 1 / 5 of barium peroxide with the rhodium powder, pour the mixture into the mortar and grind it again, spread a layer of barium peroxide loosely on the bottom of the porcelain crucible, pour the mixture of rhodium powder, and then evenly cover the mixture with a layer of barium peroxide. Put the crucible into a muffle furnace, heat it to 850℃, keep it warm for 5h, cool it down to below 100℃ and take it out of the furnace. The sintered product should be uniform gray-black. Gently tap the sintered product to remove it from the crucible. The reaction formula is: 2Rh+3BaO2Rh2O3+3BaO;

[0009] S2: Washing: grind the sintered material carefully in a mortar and pour it into a beaker, wash it with 60℃ pure water for 6 times, and discard the supernatant;

[0010] S3: dissolving; the remaining precipitate is heated slightly, not overheated, and concentrated hydrochloric acid is added after cooling, and heated on a hot plate to dissolve to form a dark red rhodium chloride solution: Rh2O3+6HCl=2RhCl3+3H2O; BaO+2HCl=BaCl2+H2O; the red rhodium chloride solution is poured into a separate beaker, and the remaining sinter is treated with concentrated hydrochloric acid, and this is repeated until the solution no longer appears red, and the rhodium chloride solution is filtered;

[0011] S4: Remove barium ions; evaporate the rhodium chloride solution on a hot plate until it is almost dry, then dilute it with pure water to 0.5-1.5L, filter it, heat the filtrate to boil, add 1:3 hot sulfuric acid to the solution drop by drop with stirring until there is no white barium sulfate precipitate, boil the solution again, let it stand to fully precipitate barium ions, filter the solution and wash the precipitate until no red color appears, and discard the precipitated barium sulfate: BaCl2+H2SO4=BaSO4↓+2HCl;

[0012] S5: precipitation; dilute the rhodium trichloride solution with pure water, heat to about 60°C, add 40% potassium hydroxide solution drop by drop under strong stirring until the pH of the solution reaches 7-7.5, the color changes from red to bright yellow, the rhodium hydroxide should be loose snow flakes, and the cleaning performance is good, discard the upper solution: RhCl3+3KOH=Rh(OH)3↓+3KCl; after the solution is clarified, wash the rhodium hydroxide repeatedly with 80°C hot pure water 10 times until there is no white precipitate in the washing solution after checking with silver nitrate;

[0013] S6: dissolving; the rhodium hydroxide precipitate is adjusted into a paste with pure water, and then concentrated sulfuric acid is added drop by drop to the rhodium hydroxide prepared by any of the above methods, and vigorously stirred until the rhodium hydroxide is completely dissolved; to accelerate the dissolution, it can be heated appropriately, diluted to 1L with pure water, and the content of rhodium and sulfuric acid is chemically analyzed to obtain refined rhodium sulfate and filter: 2Rh(OH)3+3H2SO4=Rh2(SO4)3+6H2O;

[0014] S7: preparing rhodium plating solution; preparing rhodium plating solution according to the total amount of rhodium in the concentrated solution, first adding 2 / 3 volume of pure water to the plating tank, adding the above-mentioned rhodium sulfate concentrated solution while stirring, adding other dissolved components, adding pure water to the working liquid level, stirring fully, and trial plating under specified working conditions.

[0015] Preferably, when weighing the barium peroxide, 25 g of barium peroxide is calculated per gram of rhodium.

[0016] Preferably, the amount of concentrated hydrochloric acid added after cooling is 50-100 mL per gram of rhodium.

[0017] A method for preparing a soluble rhodium compound, wherein a stirring device is required during the stirring process of concentrated sulfuric acid in step S6 of the method for preparing a soluble rhodium compound, and the stirring device includes a stirring cup;

[0018] A splash-proof cover, the splash-proof cover is arranged on the top of the outer surface of the stirring cup, a motor box is fixedly installed in the middle of the top of the splash-proof cover, a control switch is fixedly installed on the outer surface of the motor box, a servo motor is fixedly installed inside the motor box, and a stirring device is fixedly connected to the bottom end of the output shaft of the servo motor, and the stirring device includes a rotating plate, a first gear block, a stirring rod and a stirring plate;

[0019] A cleaning device is threadedly engaged with the outer surface of the stirring device, and the cleaning device comprises a rotating ring block, a second tooth block, a sliding column, a limiting sliding block, a connecting plate and a scraper.

[0020] Preferably, a groove is provided in the middle of the bottom of the splash-proof cover, and a threaded layer is provided on the inner cavity wall surface of the groove.

[0021] Preferably, an annular sliding groove is provided in the middle of the top of the inner cavity wall of the groove, and the top of the annular sliding groove is connected to the limited position cavity.

[0022] Preferably, the stirring rod is fixedly connected to the bottom end of the output shaft of the servo motor, the rotating plate is fixedly connected to the top of the outer surface of the stirring rod, a plurality of the first tooth blocks are equidistantly fixedly connected to the outer surface of the rotating plate, and the stirring plate is fixedly installed on the outer surface of the stirring rod.

[0023] Preferably, the limiting slider is arranged inside the limiting cavity, the sliding column is slidably installed inside the annular sliding groove, the rotating ring block is fixedly installed on one end of the sliding column, a plurality of the second tooth blocks are equidistantly fixedly installed on the surface of the inner cavity wall of the rotating ring block, the connecting plate is fixedly installed on one side of the bottom of the rotating ring block, and the two scrapers are respectively fixedly installed on both sides of the outer surface of the connecting plate.

[0024] Preferably, opening holes are formed all around the outer surface of the mixing cup, movable grooves are connected to both sides of the inner cavity wall of the opening holes, a sliding rod is fixedly installed inside the movable groove, a spring is sleeved on one side of the outer surface of the sliding rod, an extrusion block is sleeved on the other side of the outer surface of the sliding rod, a connecting block is fixedly connected to one side of the extrusion block, and a clamping block is fixedly connected to one side of the connecting block.

[0025] Preferably, the inner cavity wall of the groove is provided with clamping holes all around.

[0026] Compared with the related art, the method for preparing a soluble rhodium compound provided by the present invention has the following beneficial effects:

[0027] The invention provides a method for preparing a soluble rhodium compound. The soluble rhodium compound is prepared by adopting a barium peroxide roasting method. The prepared soluble rhodium compound is not limited in the preparation of the components of an electroplating rhodium solution and can be used for the preparation and production of the soluble rhodium compound in the fields of chemical industry, metallurgy, precision electronics, etc. The defects of the original preparation method are solved, the process stability is improved, the process control is easy, the toxicity to human body and the environmental pollution are small, the hidden danger of safety production risk is small, and the implementation is easy. While improving the stability of the electroplating rhodium solution, the toxicity to human body and the environmental pollution are reduced, and the hidden danger of safety production risk is eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a process flow of a first embodiment of a method for preparing a soluble rhodium compound provided by the present invention;

[0029] Figure 2 A schematic structural diagram of a second embodiment of a method for preparing a soluble rhodium compound provided by the present invention;

[0030] Figure 3 for Figure 2 The schematic diagram of the splash cover structure shown;

[0031] Figure 4 for Figure 3 The schematic diagram of the stirring device structure shown;

[0032] Figure 5 for Figure 4 An enlarged schematic diagram of point A is shown;

[0033] Figure 6 for Figure 3 The schematic diagram of the cleaning device structure shown;

[0034] Figure 7 A schematic structural diagram of a third embodiment of a method for preparing a soluble rhodium compound provided by the present invention;

[0035] Figure 8 for Figure 7 A schematic side view of the splash cover shown;

[0036] Fig. 9 for Figure 7 A schematic cross-sectional view of a blender cup is shown;

[0037] Fig.10 for Fig. 9 An enlarged schematic diagram of point B is shown.

[0038] Numbers in the figure: 1. stirring cup, 2. splash-proof cover, 3. motor box, 4. control switch, 5. connecting line, 6. stirring device, 61. rotating plate, 62. first tooth block, 63. stirring rod, 64. stirring plate, 7. cleaning device, 71. rotating ring block, 72. second tooth block, 73. sliding column, 74. limiting slider, 75. connecting plate, 76. scraper, 8. groove, 9. threaded layer, 10. annular slide groove, 11. limiting cavity, 12. clamping hole, 13. hole, 14. movable groove, 15. sliding rod, 16. spring, 17. extrusion block, 18. connecting block, 19. clamping block. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0040] Please refer to Figure 1 ,in, Figure 1 A process flow diagram of the first embodiment of a method for preparing a soluble rhodium compound provided by the present invention. A method for preparing a soluble rhodium compound, comprising the following steps: S1: roasting; weighing pure rhodium powder with an analytical balance, fully grinding it in a glass mortar, and grinding it with a mortar, taking 1 / 5 of barium peroxide and mixing it with the rhodium powder, and pouring the mixture into the mortar and grinding it again, loosely spreading a layer of barium peroxide on the bottom of a porcelain crucible, pouring the mixture of rhodium powder, and then evenly covering the mixture with a layer of barium peroxide, placing the crucible in a muffle furnace, heating it to 850°C with the furnace, keeping it warm for 5 hours, cooling it to below 100°C with the furnace, and taking it out of the furnace. The sintered product should be uniform gray-black, and gently tapping the sintered product to remove it from the crucible. The reaction formula is: 2Rh+3BaO2Rh2O3+3BaO;

[0041] S2: Washing: grind the sintered material carefully in a mortar and pour it into a beaker, wash it with 60℃ pure water for 6 times, and discard the supernatant;

[0042] S3: dissolving; the remaining precipitate is heated slightly, not overheated, and concentrated hydrochloric acid is added after cooling, and heated on a hot plate to dissolve to form a dark red rhodium chloride solution: Rh2O3+6HCl=2RhCl3+3H2O; BaO+2HCl=BaCl2+H2O; the red rhodium chloride solution is poured into a separate beaker, and the remaining sinter is treated with concentrated hydrochloric acid, and this is repeated until the solution no longer appears red, and the rhodium chloride solution is filtered;

[0043] S4: Remove barium ions; evaporate the rhodium chloride solution on a hot plate until it is almost dry, then dilute it with pure water to 0.5-1.5L, filter it, heat the filtrate to boil, add 1:3 hot sulfuric acid to the solution drop by drop with stirring until there is no white barium sulfate precipitate, boil the solution again, let it stand to fully precipitate barium ions, filter the solution and wash the precipitate until no red color appears, and discard the precipitated barium sulfate: BaCl2+H2SO4=BaSO4↓+2HCl;

[0044] S5: precipitation; dilute the rhodium trichloride solution with pure water, heat to about 60°C, add 40% potassium hydroxide solution drop by drop under strong stirring until the pH of the solution reaches 7-7.5, the color changes from red to bright yellow, the rhodium hydroxide should be loose snow flakes, and the cleaning performance is good, discard the upper solution: RhCl3+3KOH=Rh(OH)3↓+3KCl; after the solution is clarified, wash the rhodium hydroxide repeatedly with 80°C hot pure water 10 times until there is no white precipitate in the washing solution after checking with silver nitrate;

[0045] S6: dissolving; the rhodium hydroxide precipitate is adjusted into a paste with pure water, and then concentrated sulfuric acid is added drop by drop to the rhodium hydroxide prepared by any of the above methods, and vigorously stirred until the rhodium hydroxide is completely dissolved; to accelerate the dissolution, it can be heated appropriately, diluted to 1L with pure water, and the content of rhodium and sulfuric acid is chemically analyzed to obtain refined rhodium sulfate and filter: 2Rh(OH)3+3H2SO4=Rh2(SO4)3+6H2O;

[0046] S7: preparing rhodium plating solution; preparing rhodium plating solution according to the total amount of rhodium in the concentrated solution, first adding 2 / 3 volume of pure water to the plating tank, adding the above-mentioned rhodium sulfate concentrated solution while stirring, adding other dissolved components, adding pure water to the working liquid level, stirring fully, and trial plating under specified working conditions.

[0047] When weighing the barium peroxide, 25 g of barium peroxide is calculated per gram of rhodium.

[0048] After cooling, the amount of concentrated hydrochloric acid added is 50-100 mL per gram of rhodium.

[0049] The working principle of a method for preparing a soluble rhodium compound provided by the present invention is as follows:

[0050] When working, first roast: weigh pure rhodium powder with an analytical balance, and grind it thoroughly in a glass mortar, weigh barium peroxide (calculated at 25g of barium peroxide per gram of rhodium), and grind it in a mortar, take 1 / 5 of the barium peroxide and mix it with the rhodium powder, and pour the mixture into the mortar and grind it again to mix well.

[0051] Loosely spread a layer of barium peroxide on the bottom of the porcelain crucible, pour in the mixture of rhodium powder, and then evenly cover the mixture with a layer of barium peroxide. Put the crucible into a muffle furnace, heat it up to 850℃, keep it warm for 5 hours, cool it down to below 100℃ and take it out of the furnace. The sintered material should be uniform gray-black. Gently tap the sintered material to remove it from the crucible. The reaction formula is:

[0052] 2Rh+3BaO2Rh2O3+3BaO

[0053] Washing: grind the sintered material carefully in a mortar and pour it into a beaker, wash it with 60℃ pure water for 5 to 6 times, and discard the supernatant;

[0054] Dissolution: Heat the remaining precipitate slightly, but not overheating. After cooling, add concentrated hydrochloric acid (about 50-100 mL per gram of rhodium) and heat on a hot plate to dissolve to form a deep red rhodium trichloride solution:

[0055] Rh2O3+6HCl=2RhCl3+3H2O

[0056] BaO+2HCl=BaCl2+H2O

[0057] Pour the red rhodium trichloride solution into a separate beaker, and continue to treat the remaining sintered material with concentrated hydrochloric acid. Repeat this process until the solution no longer appears red, and filter the rhodium trichloride solution.

[0058] Removal of barium ions: Evaporate the rhodium chloride solution on a hot plate until it is almost dry, then dilute it with pure water to (0.5-1.5) L, filter it, heat the filtrate to boil, add 1:3 hot sulfuric acid to the solution drop by drop while stirring until there is no white barium sulfate precipitate, boil the solution again, and let it stand for (12-24) hours to fully precipitate the barium ions. Filter the solution and wash the precipitate until it no longer appears red, and discard the precipitated barium sulfate.

[0059] BaCl2+H2SO4=BaSO4↓+2HCl

[0060] Precipitation: dilute the rhodium chloride solution with pure water to about (1-1.5) L, heat to about 60°C, add 40% potassium hydroxide solution (weight percentage) drop by drop under strong stirring until the solution pH reaches 7-7.5, the color changes from red to bright yellow, the rhodium hydroxide should be loose snow flakes with good cleaning performance, and discard the upper solution.

[0061] RhCl3+3KOH=Rh(OH)3↓+3KCl

[0062] After the solution is clarified, wash the rhodium hydroxide repeatedly with (60-80)°C hot pure water for 8-10 times until there is no white precipitate in the washing solution when checked with silver nitrate.

[0063] Dissolution: Mix the rhodium hydroxide precipitate with pure water to make a paste, then add concentrated sulfuric acid drop by drop into the rhodium hydroxide prepared by any of the above methods, and stir vigorously until the rhodium hydroxide is completely dissolved. To accelerate the dissolution, it can be heated appropriately and diluted to (1-1.5) L with pure water. Chemically analyze the content of rhodium and sulfuric acid, and obtain refined rhodium sulfate and filter it.

[0064] 2Rh(OH)3+3H2SO4=Rh2(SO4)3+6H2O

[0065] Prepare the bath solution: prepare the rhodium plating solution according to the total amount of rhodium in the above concentrated solution, first add 2 / 3 volume of pure water to the plating tank, add the above rhodium sulfate concentrated solution while stirring, add other dissolved ingredients, add pure water to the working liquid level, stir thoroughly, and try plating under the specified working conditions.

[0066] Compared with the related art, the method for preparing a soluble rhodium compound provided by the present invention has the following beneficial effects:

[0067] The invention provides a method for preparing a soluble rhodium compound. The soluble rhodium compound is prepared by adopting a barium peroxide roasting method. The prepared soluble rhodium compound is not limited in the preparation of the components of an electroplating rhodium solution and can be used for the preparation and production of the soluble rhodium compound in the fields of chemical industry, metallurgy, precision electronics, etc. The defects of the original preparation method are solved, the process stability is improved, the process control is easy, the toxicity to human body and the environmental pollution are small, the hidden danger of safety production risk is small, and the implementation is easy. While improving the stability of the electroplating rhodium solution, the toxicity to human body and the environmental pollution are reduced, and the hidden danger of safety production risk is eliminated.

[0068] Second embodiment

[0069] Please refer to Figure 2-Figure 6Based on the method for preparing a soluble rhodium compound provided in the first embodiment of the present application, the second embodiment of the present application proposes another method for preparing a soluble rhodium compound. The second embodiment is only a preferred method of the first embodiment, and the implementation of the second embodiment will not affect the independent implementation of the first embodiment.

[0070] Specifically, the method for preparing a soluble rhodium compound provided in the second embodiment of the present application is different in that, in a method for preparing a soluble rhodium compound, a stirring device is required during the stirring process of concentrated sulfuric acid in step S6 of the method for preparing a soluble rhodium compound, and the stirring device includes a stirring cup 1;

[0071] A splash-proof cover 2, the splash-proof cover 2 is arranged on the top of the outer surface of the stirring cup 1, a motor box 3 is fixedly installed in the middle of the top of the splash-proof cover 2, a control switch 4 is fixedly installed on the outer surface of the motor box 3, a servo motor is fixedly installed inside the motor box 3, and a stirring device 6 is fixedly connected to the bottom end of the output shaft of the servo motor, and the stirring device 6 includes a rotating plate 61, a first tooth block 62, a stirring rod 63 and a stirring plate 64;

[0072] The cleaning device 7 is threadedly engaged with the outer surface of the stirring device 6 , and the cleaning device 7 includes a rotating ring block 71 , a second tooth block 72 , a sliding column 73 , a limiting sliding block 74 , a connecting plate 75 and a scraper 76 .

[0073] A slot 8 is provided in the middle of the bottom of the splash-proof cover 2 , and a thread layer 9 is provided on the inner wall surface of the slot 8 .

[0074] An annular sliding groove 10 is provided in the middle of the top of the inner cavity wall of the groove 8 , and the top of the annular sliding groove 10 is connected to the limited position cavity 11 .

[0075] The stirring rod 63 is fixedly connected to the bottom end of the output shaft of the servo motor, the rotating plate 61 is fixedly connected to the top of the outer surface of the stirring rod 63, a plurality of the first tooth blocks 62 are fixedly connected to the outer surface of the rotating plate 61 at equal intervals, and the stirring plate 64 is fixedly installed on the outer surface of the stirring rod 63.

[0076] The limiting slider 74 is arranged inside the limiting cavity 11, the sliding column 73 is slidably installed inside the annular slide groove 10, the rotating ring block 71 is fixedly installed on one end of the sliding column 73, and multiple second tooth blocks 72 are equidistantly fixedly installed on the surface of the inner cavity wall of the rotating ring block 71, the connecting plate 75 is fixedly installed on one side of the bottom of the rotating ring block 71, and the two scrapers 76 are respectively fixedly installed on both sides of the outer surface of the connecting plate 75.

[0077] The working principle of a method for preparing a soluble rhodium compound provided by the present invention is as follows:

[0078] During operation, the splash-proof cover 2 is first threadedly engaged on the top of the stirring cup 1 through the threaded layer 9, and the output shaft of the servo motor rotates to drive the stirring rod 63 to rotate, and the stirring rod 63 drives the stirring plate 64 and the rotating plate 61 to rotate, and the rotating plate 61 rotates to drive the first tooth block 62 to engage with the second tooth block 72 to rotate, and the second tooth block 72 drives the rotating ring block 71 to rotate, and the rotating ring block 71 drives the scraper 76 to scrape the residual solution on the inner wall surface of the stirring cup 1 and mix it with the solution in the cup.

[0079] Compared with the related art, the method for preparing a soluble rhodium compound provided by the present invention has the following beneficial effects:

[0080] The invention provides a method for preparing a soluble rhodium compound. A splash-proof cover 2 is threadedly engaged on the top of a stirring cup 1 through a threaded layer 9. The output shaft of a servo motor rotates to drive a stirring device 6 and a cleaning device 7 to rotate. The stirring device 6 imitates the effect of a glass rod stirring a solution inside a beaker to achieve an effect of fully stirring the solution. The device is small in size and easy to carry, and is suitable for use in stirring solutions in experiments. The splash-proof cover 2 prevents the solution from splashing out due to stirring, thereby protecting the health of experimenters. The stirring device 6 rotates to drive the cleaning device 7 to rotate on the inner wall surface of the stirring cup 1, cleans the solution splashed on the inner wall surface of the stirring cup 1, and improves the mixing effect of the solution.

[0081] Third embodiment

[0082] Please refer to Figure 7-10 Based on the method for preparing a soluble rhodium compound provided in the first embodiment of the present application, the third embodiment of the present application proposes another method for preparing a soluble rhodium compound. The third embodiment is only a preferred method of the first embodiment, and the implementation of the third embodiment will not affect the independent implementation of the first embodiment.

[0083] Specifically, the difference of the method for preparing a soluble rhodium compound provided in the third embodiment of the present application is that, in a method for preparing a soluble rhodium compound, opening holes 13 are opened all around the outer surface of the stirring cup 1, and both sides of the inner cavity wall of the opening hole 13 are connected to movable grooves 14, and a slide rod 15 is fixedly installed inside the movable groove 14, and a spring 16 is sleeved on one side of the outer surface of the slide rod 15, and an extrusion block 17 is sleeved on the other side of the outer surface of the slide rod 15, and a connecting block 18 is fixedly connected to one side of the extrusion block 17, and a clamping block 19 is fixedly connected to one side of the connecting block 18.

[0084] The inner wall of the slot 8 is provided with clamping holes 12 around it.

[0085] The working principle of a method for preparing a soluble rhodium compound provided by the present invention is as follows:

[0086] During operation, the user first buckles the splash-proof cover 2 onto the top of the outer surface of the mixing cup 1 through the slot 8, and squeezes the block 19 on the inner wall of the slot 8. The block 19 drives the connecting block 18 and the squeezing block 17 to move. The squeezing block 17 slides along the slide rod 15 and squeezes the spring 16, and the block 19 is embedded in the hole 13.

[0087] When the splash-proof cover 2 is completely embedded in the outer surface of the mixing cup 1 , the clamping hole 12 is connected to the opening hole 13 , the restoring elastic force of the spring 16 pushes the extrusion block 17 to move, and the extrusion block 17 drives the connecting block 18 and the clamping block 19 to move, and the clamping block 19 is embedded in the inside of the clamping hole 12 .

[0088] When the splash-proof cover 2 needs to be removed, the user can pull the splash-proof cover 2 upwards with force.

[0089] Compared with the related art, the method for preparing a soluble rhodium compound provided by the present invention has the following beneficial effects:

[0090] The present invention provides a method for preparing a soluble rhodium compound. The restoring elastic force of a spring 16 pushes a card block 19 to be embedded into a card hole 12 in a slot 8 of a splash-proof cover 2, so that a user can quickly install and remove the splash-proof cover 2 from the surface of a stirring cup 1. The device has a simple structure and strong practicality. The cover body and the cup body can be quickly installed and removed, thereby improving the convenience of stirring the solution.

[0091] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a soluble rhodium compound, characterized in that, The following steps are involved: S1: calcination; weigh pure rhodium powder with an analytical balance, grind it in a glass mortar, and grind it with a mortar. Mix 1 / 5 of barium peroxide with the rhodium powder, pour the mixture into the mortar and grind it again, spread a layer of barium peroxide loosely on the bottom of the porcelain crucible, pour the mixture of rhodium powder, and then evenly cover the mixture with a layer of barium peroxide. Put the crucible into a muffle furnace, heat it to 850℃, keep it warm for 5h, cool it down to below 100℃ and take it out of the furnace. The sintered product should be uniform gray-black. Gently tap the sintered product to remove it from the crucible. The reaction formula is: 2Rh+3BaO2Rh2O3+3BaO; S2: washing; The sintered material was carefully crushed in a mortar and poured into a beaker, washed with 60°C pure water for 6 times, and the supernatant was discarded; S3: dissolving; the remaining precipitate is heated slightly, not overheated, and concentrated hydrochloric acid is added after cooling, and heated on a hot plate to dissolve to form a dark red rhodium chloride solution: Rh2O3+6HCl=2RhCl3+3H2O; BaO+2HCl=BaCl2+H2O; the red rhodium chloride solution is poured into a separate beaker, and the remaining sinter is treated with concentrated hydrochloric acid, and this is repeated until the solution no longer appears red, and the rhodium chloride solution is filtered; S4: remove barium ions; Evaporate the rhodium chloride solution on a hot plate until it is almost dry, then dilute it with pure water to 0.5-1.5L, filter it, heat the filtrate to boil, add 1:3 hot sulfuric acid drop by drop to the solution under stirring until there is no white barium sulfate precipitate, boil the solution again, let it stand to fully precipitate barium ions, filter the solution and wash the precipitate until no red color appears, and discard the precipitated barium sulfate: BaCl2+H2SO4=BaSO4↓+2HCl; S5: precipitation; dilute the rhodium trichloride solution with pure water, heat to about 60°C, add 40% potassium hydroxide solution drop by drop under strong stirring until the pH of the solution reaches 7-7.5, the color changes from red to bright yellow, the rhodium hydroxide should be loose snow flakes, and the cleaning performance is good, discard the upper solution: RhCl3+3KOH=Rh(OH)3↓+3KCl; after the solution is clarified, wash the rhodium hydroxide repeatedly with 80°C hot pure water 10 times until there is no white precipitate in the washing solution after checking with silver nitrate; S6: dissolving; the rhodium hydroxide precipitate is adjusted into a paste with pure water, and then concentrated sulfuric acid is added drop by drop to the rhodium hydroxide prepared by any of the above methods, and vigorously stirred until the rhodium hydroxide is completely dissolved; to accelerate the dissolution, it can be heated appropriately, diluted to 1L with pure water, and the content of rhodium and sulfuric acid is chemically analyzed to obtain refined rhodium sulfate and filter: 2Rh(OH)3+3H2SO4=Rh2(SO4)3+6H2O; S7: preparing rhodium plating solution; preparing rhodium plating solution according to the total amount of rhodium in the concentrated solution, first adding 2 / 3 volume of pure water to the plating tank, adding the above-mentioned rhodium sulfate concentrated solution while stirring, adding other dissolved components, adding pure water to the working liquid level, stirring fully, and trial plating under specified working conditions.

2. A method for preparing a soluble rhodium compound according to claim 1, characterized in that: When weighing the barium peroxide, 25 g of barium peroxide is calculated per gram of rhodium.

3. A method for preparing a soluble rhodium compound according to claim 1, characterized in that: After cooling, the amount of concentrated hydrochloric acid added is 50-100 mL per gram of rhodium.

4. A method for preparing a soluble rhodium compound according to claim 1, characterized in that: In step S6 of the method for preparing a soluble rhodium compound, a stirring device is required during the stirring of concentrated sulfuric acid, and the stirring device includes a stirring cup; A splash-proof cover, the splash-proof cover is arranged on the top of the outer surface of the stirring cup, a motor box is fixedly installed in the middle of the top of the splash-proof cover, a control switch is fixedly installed on the outer surface of the motor box, a servo motor is fixedly installed inside the motor box, and a stirring device is fixedly connected to the bottom end of the output shaft of the servo motor, and the stirring device includes a rotating plate, a first gear block, a stirring rod and a stirring plate; A cleaning device is threadedly engaged with the outer surface of the stirring device, and the cleaning device comprises a rotating ring block, a second tooth block, a sliding column, a limiting sliding block, a connecting plate and a scraper.

5. A method for preparing a soluble rhodium compound according to claim 4, characterized in that: A slot is provided in the middle of the bottom of the splash-proof cover, and a thread layer is provided on the inner cavity wall surface of the slot.

6. A method for preparing a soluble rhodium compound according to claim 5, characterized in that: An annular sliding groove is provided in the middle of the top of the inner cavity wall of the groove, and the top of the annular sliding groove is connected to the limited position cavity.

7. A method for preparing a soluble rhodium compound according to claim 4, characterized in that: The stirring rod is fixedly connected to the bottom end of the output shaft of the servo motor, the rotating plate is fixedly connected to the top of the outer surface of the stirring rod, a plurality of the first tooth blocks are fixedly connected to the outer surface of the rotating plate at equal intervals, and the stirring plate is fixedly installed on the outer surface of the stirring rod.

8. A method for preparing a soluble rhodium compound according to claim 6, characterized in that: The limiting slider is arranged inside the limiting cavity, the sliding column is slidably installed inside the annular sliding groove, the rotating ring block is fixedly installed on one end of the sliding column, a plurality of the second tooth blocks are equidistantly fixedly installed on the surface of the inner cavity wall of the rotating ring block, the connecting plate is fixedly installed on one side of the bottom of the rotating ring block, and the two scrapers are respectively fixedly installed on both sides of the outer surface of the connecting plate.

9. A method for preparing a soluble rhodium compound according to claim 1, characterized in that: The outer surface of the mixing cup is provided with opening holes all around, and both sides of the inner cavity wall of the opening hole are connected with movable grooves, a sliding rod is fixedly installed inside the movable groove, a spring is sleeved on one side of the outer surface of the sliding rod, and an extrusion block is sleeved on the other side of the outer surface of the sliding rod, one side of the extrusion block is fixedly connected to a connecting block, and one side of the connecting block is fixedly connected to a clamping block.

10. A method for preparing a soluble rhodium compound according to claim 5, characterized in that: The inner cavity wall of the groove is provided with clamping holes all around.

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