Method for preparing ammonium chlororuthenate from waste liquid containing ruthenium and platinum and application of ammonium chlororuthenate

Abstract

The invention belongs to the technical field of precious metal secondary resource recycling, and discloses a method for preparing ammonium chlororuthenate from ruthenium-platinum-containing waste liquid and application, and the method comprises the following steps: (1) converting the ruthenium-platinum-containing waste liquid into ruthenium hydroxide hydrate, (2) filtering and separating the ruthenium hydroxide hydrate solution, (3) synthesizing ammonium chlororuthenate crystals, and (4) carrying out suction filtration and drying on ammonium chlororuthenate. Through the steps, ruthenium is separated from the waste liquid containing ruthenium and platinum, and ammonium chlororuthenate is prepared. According to the method, ruthenium is separated from the waste liquid containing ruthenium and platinum and prepared into ammonium chlororuthenate, the method is environmentally friendly and high in process integration, secondary precious metal resources are utilized, the production cost is reduced, pollutant emission is reduced, and meanwhile resource recovery and utilization are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of precious metal secondary resource recycling, in particular to a method for preparing ammonium chlororuthenate from ruthenium-platinum-containing waste liquid and its application. Background Art

[0002] Ammonium chlororuthenate, with the chemical formula (NH4)2RuCl6, is a brown crystalline powder that absorbs moisture easily and deliquesces in the air. It is soluble in water and alcohol, and is also soluble in acetone. Its molecular weight is 349.86. Ammonium chlororuthenate is a brown crystalline powder. Ammonium chlororuthenate is mainly used for scientific research or industrial applications. Ammonium chlororuthenate is widely used in catalytic reactions in the petrochemical, pharmaceutical and other industries. It is also used in fuel cells and electrocatalytic reactions. It can also be used as a reference reagent for the determination of ruthenium content by spectrophotometry.

[0003] At present, the preparation method of ammonium chlororuthenate is mainly prepared by using ruthenium chloride and ammonia. This method produces a large amount of irritating gas during the synthesis process, so a special waste system is required for subsequent related treatment, the preparation is cumbersome, and the production cost is increased. At the same time, the raw materials in this preparation method are expensive, the reaction requirements are strict, which is not conducive to implementation and brings great inconvenience to production.

[0004] Therefore, a new preparation method of ammonium chlororuthenate is urgently needed. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method and application for preparing ammonium chlororuthenate from ruthenium-platinum-containing waste liquid.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A method for preparing ammonium chlororuthenate from ruthenium-platinum waste liquid comprises the following steps:

[0008] ⑴ Take ruthenium-containing platinum waste liquid, the mass concentration of ruthenium in the waste liquid is not less than 5%, too low has no recovery value, add 36% mass concentration of hydrochloric acid and 30% mass concentration of hydrogen peroxide solution to the ruthenium-containing platinum waste liquid, then add pure water to make up the solution volume, heat and boil for 10 to 20 minutes, add 30% mass concentration of sodium hydroxide solution during stirring and boil for 30 to 60 minutes, add water at any time to maintain the solution volume, cool, and generate a black precipitate of hydrated ruthenium hydroxide;

[0009] (2) Filtering the generated ruthenium hydroxide and separating it from the mother liquor, washing the ruthenium hydroxide filter cake with a 5% sodium hydroxide aqueous solution for 3 to 4 times, and then washing it with pure water for 3 to 4 times, and drying the filter cake to obtain hydrated ruthenium hydroxide;

[0010] ⑶ Take hydrated ruthenium hydroxide, add 36% hydrochloric acid and 30% hydrogen peroxide solution, heat and boil for 10 to 20 minutes, keep the solution temperature at 90 to 100°C, add 45% ammonium chloride aqueous solution to the solution under stirring, the 45% ammonium chloride aqueous solution should be heated to 90 to 100°C in advance, and stir and cool to room temperature to generate a large amount of dark brown ammonium chlororuthenate crystals;

[0011] (4) Filter out the generated ammonium chlororuthenate by suction, wash the crystals with 95% ethanol by volume for 3 to 4 times, and then dry them at 80 to 90° C. to obtain ammonium chlororuthenate.

[0012] Furthermore, in step (1), 200-400 mL of 36% hydrochloric acid and 30-50 mL of 30% hydrogen peroxide solution are added to every 0.5 liter of ruthenium-platinum waste liquid, and 800-1600 mL of 30% sodium hydroxide solution is added to every 0.5 liter of ruthenium-platinum waste liquid.

[0013] Furthermore, in step (1), the total volume after adding 36% hydrochloric acid, 30% hydrogen peroxide solution and pure water to every 0.5 liter of ruthenium-platinum waste liquid is 4 liters.

[0014] Furthermore, in step (3), 800-1200 mL of 36% hydrochloric acid and 200-400 mL of 30% hydrogen peroxide solution are added to every 200 g of hydrated ruthenium hydroxide solution, and 1000-1500 g of 45% ammonium chloride aqueous solution is added to every 200 g of hydrated ruthenium hydroxide solution.

[0015] Application of the method as described above in the preparation of ammonium chlororuthenate.

[0016] The advantages and positive effects achieved by the present invention are:

[0017] 1. The method of the present invention separates ruthenium from ruthenium-platinum-containing waste liquid and prepares ammonium chlororuthenate. The method of the present invention is environmentally friendly and has high process integration. The present invention utilizes secondary precious metal resources, reduces production costs, reduces pollutant emissions, and realizes resource recovery and utilization.

[0018] 2. The present invention provides a new method for preparing ammonium chlororuthenate from ruthenium-platinum waste liquid. The method of the present invention can reduce environmental pollution and production costs, improve production efficiency, and achieve resource recycling.

[0019] 3. Due to the shortage of precious metal resources at home and abroad in recent years, blind mining of mineral resources has reduced mineral resources, but the demand is rising every year, causing the price of precious metals to soar. Therefore, the market for recycling waste precious metal products is relatively active. Therefore, the present invention will also have a wide range of market applications in the future. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the embodiments. The following embodiments are descriptive rather than restrictive, and the protection scope of the present invention cannot be limited by the following embodiments.

[0021] The various experimental operations involved in the specific embodiments are all routine techniques in the art. For parts not specially annotated in this document, ordinary technicians in the art can implement them by referring to various commonly used reference books, scientific and technological literature or related instructions, manuals, etc. before the filing date of this invention.

[0022] A method for preparing ammonium chlororuthenate from ruthenium-platinum waste liquid comprises the following steps:

[0023] ⑴ Take ruthenium-containing platinum waste liquid, the mass concentration of ruthenium in the waste liquid is not less than 5%, too low has no recovery value, add 36% mass concentration of hydrochloric acid and 30% mass concentration of hydrogen peroxide solution to the ruthenium-containing platinum waste liquid, then add pure water to make up the solution volume, heat and boil for 10 to 20 minutes, add 30% mass concentration of sodium hydroxide solution during stirring and boil for 30 to 60 minutes, add water at any time to maintain the solution volume, cool, and generate a black precipitate of hydrated ruthenium hydroxide;

[0024] (2) Filtering the generated ruthenium hydroxide and separating it from the mother liquor, washing the ruthenium hydroxide filter cake with a 5% sodium hydroxide aqueous solution for 3 to 4 times, and then washing it with pure water for 3 to 4 times, and drying the filter cake to obtain hydrated ruthenium hydroxide;

[0025] ⑶ Take hydrated ruthenium hydroxide, add 36% hydrochloric acid and 30% hydrogen peroxide solution, heat and boil for 10 to 20 minutes, keep the solution temperature at 90 to 100°C, add 45% ammonium chloride aqueous solution to the solution under stirring, the 45% ammonium chloride aqueous solution should be heated to 90 to 100°C in advance, and stir and cool to room temperature to generate a large amount of dark brown ammonium chlororuthenate crystals;

[0026] (4) Filter out the generated ammonium chlororuthenate by suction, wash the crystals with 95% ethanol by volume for 3 to 4 times, and then dry them at 80 to 90° C. to obtain ammonium chlororuthenate.

[0027] Preferably, in step (1), 200-400 mL of 36% hydrochloric acid and 30-50 mL of 30% hydrogen peroxide solution are added to every 0.5 liter of ruthenium-platinum waste liquid, and 800-1600 mL of 30% sodium hydroxide solution is added to every 0.5 liter of ruthenium-platinum waste liquid.

[0028] Preferably, in step (1), the total volume after adding 36% hydrochloric acid, 30% hydrogen peroxide solution and pure water to every 0.5 liter of ruthenium-platinum waste liquid is 4 liters.

[0029] Preferably, in step (3), 800-1200 mL of 36% hydrochloric acid and 200-400 mL of 30% hydrogen peroxide solution are added to every 200 g of hydrated ruthenium hydroxide solution, and 1000-1500 g of 45% ammonium chloride aqueous solution is added to every 200 g of hydrated ruthenium hydroxide solution.

[0030] Application of the method as described above in the preparation of ammonium chlororuthenate.

[0031] Specifically, the relevant preparation and detection are as follows:

[0032] Example 1

[0033] A method for preparing ammonium chlororuthenate from ruthenium-platinum waste liquid comprises the following steps:

[0034] ⑴ Add 300 mL of 36% hydrochloric acid and 40 mL of 30% hydrogen peroxide solution to 500 mL of ruthenium-platinum waste liquid, add pure water to make the solution volume 4 liters, heat and boil for 20 minutes, add 800 mL of 30% sodium hydroxide solution during stirring and boil for 40 minutes, add water at any time to maintain the solution volume, cool, and generate a black precipitate of hydrated ruthenium hydroxide;

[0035] The ruthenium-platinum chloride waste liquid is produced in the process of producing aerospace industry catalysts. In the past, due to the low ruthenium content in the waste liquid and the low price of metallic ruthenium, it was treated as waste liquid and not recycled. In recent years, due to the instability of precious metal market resources and prices, the price of ruthenium has soared. The user adjusted the waste liquid production process and recycled the waste liquid. The relevant indicators in the waste liquid before and after the improvement are shown in Table 2.

[0036] Table 2 Related indicators of new and old processes for ruthenium platinum chloride wastewater

[0037]

[0038]

[0039] The above percentages represent mass percentages.

[0040] (2) Filter the generated ruthenium hydroxide and separate it from the mother liquor. Wash the ruthenium hydroxide filter cake three times with a 5% sodium hydroxide aqueous solution and then wash it three times with pure water. Blot dry the filter cake to obtain hydrated ruthenium hydroxide.

[0041] ⑶ Take 200 grams of hydrated ruthenium hydroxide, add 800 mL of 36% hydrochloric acid and 200 mL of 30% hydrogen peroxide solution, heat and boil for 20 minutes, keep the solution temperature at 90°C, add 1000 grams of 45% ammonium chloride aqueous solution to the solution under stirring, the 45% ammonium chloride aqueous solution is heated to 90°C in advance, stirred for 10 minutes, and cooled to room temperature to generate a large amount of dark brown ammonium chlororuthenate crystals;

[0042] (4) Filter out the generated ammonium chlororuthenate, wash the crystals three times with 95% ethanol by volume, and then dry at 90°C to obtain the finished product.

[0043] Using the same method, for the same batch of ruthenium platinum chloride waste liquid, the sodium hydroxide solution containing 30% by mass concentration was added in step (1) of Example 1 and boiled for 20 minutes (i.e., Example 2) and 60 minutes (i.e., Example 3) and other conditions were the same.

[0044] The comparison table of test results is shown in Table 3.

[0045] Table 3

[0046]

[0047] Table 3 shows that adding 30% sodium hydroxide and boiling for 40 minutes is the best solution for recovering ammonium chlororuthenate from waste liquid.

[0048] Using the same method, the same batch of platinum ruthenium chloride waste liquid was subjected to the same test under the same conditions except that the 30% sodium hydroxide solution by mass in step (1) of Example 1 was replaced by a 20% sodium hydroxide solution by mass (ie, Example 4).

[0049] The comparison table of test results is shown in Table 4.

[0050] Table 4

[0051] Example Quantity of Platinum Ruthenium Chloride Wastewater Ruthenium content of original waste liquid % Sodium hydroxide mass concentration% Ammonium chlororuthenate quantity G 1 500ML 11 30 5 4 500ML 11 20 1.5

[0052] Table 4 shows that adding sodium hydroxide at a mass concentration of 30% is the best solution for recovering ammonium chlororuthenate from waste liquid.

[0053] At the same time, by comparing Examples 1 to 4, it can be seen that the addition of a 30% sodium hydroxide solution in step (1) in the method of the present invention and boiling for 40 minutes has a synergistic effect with the 30% sodium hydroxide solution in step (1), and the two can significantly synergistically improve the relevant properties of the prepared ammonium chloroplatinate.

[0054] Although the embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for preparing ammonium chlororuthenate from ruthenium-containing platinum waste liquid, characterized in that: The steps include: ⑴ Take ruthenium-containing platinum waste liquid, the mass concentration of ruthenium in the waste liquid is not less than 5%, add 36% mass concentration hydrochloric acid and 30% mass concentration hydrogen peroxide solution to the ruthenium-containing platinum waste liquid, then add pure water to make up the solution volume, heat and boil for 10 to 20 minutes, add 30% mass concentration sodium hydroxide solution during stirring and boil for 30 to 60 minutes, add water at any time to maintain the solution volume, cool, and generate a black precipitate of hydrated ruthenium hydroxide; (2) Filtering the generated ruthenium hydroxide and separating it from the mother liquor, washing the ruthenium hydroxide filter cake with a 5% sodium hydroxide aqueous solution for 3 to 4 times, and then washing it with pure water for 3 to 4 times, and drying the filter cake to obtain hydrated ruthenium hydroxide; ⑶ Take hydrated ruthenium hydroxide, add 36% hydrochloric acid and 30% hydrogen peroxide solution, heat and boil for 10 to 20 minutes, keep the solution temperature at 90 to 100°C, add 45% ammonium chloride aqueous solution to the solution under stirring, the 45% ammonium chloride aqueous solution should be heated to 90 to 100°C in advance, and stir and cool to room temperature to generate dark brown ammonium chlororuthenate crystals; (4) Filter out the generated ammonium chlororuthenate, wash the crystals with 95% ethanol by volume for 3 to 4 times, and then dry them at 80 to 90°C to obtain ammonium chlororuthenate.

2. The method according to claim 1, characterized in that: In step (1), 200-400 mL of 36% hydrochloric acid and 30-50 mL of 30% hydrogen peroxide solution are added to every 0.5 liter of ruthenium-platinum waste liquid, and 800-1600 mL of 30% sodium hydroxide solution is added to every 0.5 liter of ruthenium-platinum waste liquid.

3. The method according to claim 1, characterized in that: In step (1), the total volume after adding 36% hydrochloric acid, 30% hydrogen peroxide solution and pure water to every 0.5 liter of ruthenium-platinum waste liquid is 4 liters.

4. The method according to any one of claims 11 to 3, characterized in that: In step (3), 800-1200 mL of 36% hydrochloric acid and 200-400 mL of 30% hydrogen peroxide solution are added to every 200 g of hydrated ruthenium hydroxide solution, and 1000-1500 g of 45% ammonium chloride aqueous solution is added to every 200 g of hydrated ruthenium hydroxide solution.

5. Application of the method according to any one of claims 1 to 4 in the preparation of ammonium chlororuthenate.

Images