Method for separating and recovering platinum and ruthenium from ruthenium evaporation residues

Abstract

The invention discloses a method for separating and recovering platinum and ruthenium from ruthenium evaporation residues, and belongs to the technical field of metal recovery. According to the method for separating and recovering platinum and ruthenium from the ruthenium evaporation residues, the crushed and sieved ruthenium evaporation residues and the specific type of ingredients are mixed and placed, then the mixture is melted in the inert environment and then washed with water, the washed solid is dissolved with aqua regia and then subjected to solid-liquid separation, the platinum-containing leachate with the high platinum content and the low ruthenium content can be obtained, and platinum is effectively recovered; separating and enriching the ruthenium-containing filter residue, and then carrying out alkali fusion or chlorination ruthenium evaporation to recover ruthenium; and platinum and ruthenium can be effectively separated and recovered from the ruthenium evaporation residues. Moreover, the method provided by the invention is simple to operate, relatively short in process flow, capable of effectively improving the separation and recovery efficiency and beneficial to practical application.

Description

Technical Field

[0001] The invention belongs to the technical field of metal recovery, and in particular relates to a method for separating and recovering platinum and ruthenium from ruthenium distillation residue. Background Art

[0002] Ruthenium distillation residue is a solid waste generated by the metallurgical industry. It has a complex composition and still contains a certain amount of precious metals such as ruthenium, platinum, palladium, and rhodium. Recycling and reusing these non-renewable resources can not only save resources but also reduce pollution to the environment.

[0003] Pure wet recovery has problems such as low leaching rate of platinum group metals and poor recovery effect. Therefore, the current effective method for recovering platinum group metals from ruthenium distillation residues is mainly pyrometallurgical enrichment, among which pyrometallurgical enrichment mainly adopts plasma smelting method and pyrometallurgical capture method. The disadvantages of plasma smelting method are complex equipment, cumbersome control process, troublesome operation, and difficulty in handling some slags, and the recovery rate of precious metals is low. Pyrometallurgical capture method mainly includes metal collector method and matte collector method. Metal collectors mainly include lead, copper, iron, etc., and matte collectors mainly include copper matte (matte), nickel matte and iron matte, etc. These matte collectors are difficult to apply due to their limited use and source. Patent CN116555581A discloses that ruthenium distillation residue, cobalt sulfate collector, reducing agent, slag-forming agent and flux are mixed and ground in a certain proportion; although the limitation of the types of matte collectors is reduced to a certain extent, the problems of high collection temperature, complicated and numerous ingredients, large amount of insoluble slag, high pressure of subsequent treatment and the like cannot be avoided. In addition, the addition of cobalt sulfate in an amount of 2-5 times the weight ratio of the ruthenium distillation residue will cause problems such as dissolution of cobalt sulfate and difficulty in filtering and separation. Summary of the invention

[0004] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and to provide a method for separating and recovering platinum and ruthenium from ruthenium distillation residue, which has a short process flow, is convenient to operate, has a good separation effect and a high recovery rate.

[0005] To achieve the above object, the present invention provides a method for separating and recovering platinum ruthenium from ruthenium distillation residue, the method comprising the following steps:

[0006] (1) mixing the crushed and sieved ruthenium distillation residue and the ingredients and melting them in an inert environment to obtain a molten material;

[0007] (2) washing the melted material with water, separating the solid from the liquid after the washing, collecting the solid and dissolving it with aqua regia, and then separating the solid from the liquid to obtain a platinum-containing leachate and a ruthenium-containing filter residue;

[0008] (3) sorting the ruthenium-containing filter residue to obtain ruthenium-containing enriched residue, and then subjecting the ruthenium-containing enriched residue to alkaline melting or chlorination distillation of ruthenium to recover ruthenium;

[0009] The ingredients include sodium peroxide and at least one of sodium hydroxide and potassium hydroxide.

[0010] In the method for separating and recovering platinum and ruthenium from ruthenium distillation residue provided by the present invention, the crushed and screened ruthenium distillation residue and a specific type of ingredients are mixed and placed, melted and washed in an inert environment, and the washed solid is dissolved in aqua regia and then separated into solid and liquid, so that a platinum-containing leaching solution with high platinum content and low ruthenium content can be obtained, and platinum can be effectively recovered; then, the ruthenium-containing filter residue is sorted and enriched, and then alkali-melted, and then washed with water to obtain a ruthenium-containing enriched liquid and residue, and the ruthenium-containing enriched liquid is subjected to chlorination distillation of ruthenium to recover ruthenium; platinum and ruthenium can be effectively separated and recovered from the ruthenium distillation residue. In addition, the method provided by the present invention is simple to operate, has a short process flow, can effectively improve the separation and recovery efficiency, and is conducive to practical application.

[0011] As a preferred embodiment of the method of the present invention, the ingredients also include sodium carbonate.

[0012] The present invention has found that mixing the crushed and screened ruthenium distillation residue with a specific type of ingredients and then melting them in an inert environment can effectively improve the subsequent platinum leaching rate and reduce the ruthenium leaching rate, thereby effectively separating platinum and ruthenium; and the selection of the ingredients of the present invention will not increase the amount of slag after treatment, that is, the subsequent process of separating ruthenium is also relatively simple, and the introduced salt substances are all water-soluble salts, which are easy to remove. Further introducing sodium carbonate into the ingredients can better improve the activation effect, effectively separate platinum and ruthenium, and also improve the recovery rate of platinum and ruthenium.

[0013] As a preferred embodiment of the method of the present invention, based on the mass of the crushed and sieved ruthenium distillation residue, the mass percentage of sodium peroxide is 50-200%, the mass percentage of sodium carbonate is 150-400%, and the mass percentage of the sum of the masses of sodium hydroxide and potassium hydroxide is 50-200%.

[0014] Preferably, based on the mass of the crushed and sieved ruthenium distillation residue, the mass percentage of sodium peroxide is 100-150%, the mass percentage of sodium carbonate is 150-300%, and the mass percentage of the sum of the masses of sodium hydroxide and potassium hydroxide is 100-150%.

[0015] The present invention has found that the mass percentage of the substances in the ingredients compared to the crushed and screened ruthenium distillation residue will affect the subsequent platinum-ruthenium separation effect to a certain extent, and will also have a certain impact on the recovery rate of platinum-ruthenium, and will also affect the separation efficiency; when the mass percentage of the components in the ingredients is further selected to be within the above range, the separation effect is better and the recovery yield is higher.

[0016] As a preferred embodiment of the method of the present invention, the mixing and placing in step (1) is as follows: part of the sodium hydroxide and / or potassium hydroxide is laid on the bottom to form a bottom layer of ingredients; then the crushed and sieved ruthenium distillation residue and sodium peroxide, sodium carbonate and another part of the sodium hydroxide and / or potassium hydroxide are mixed evenly and placed on the bottom layer of ingredients to form a mixed material layer; finally, the remaining part of the sodium hydroxide and / or potassium hydroxide is placed on the mixed material layer.

[0017] Preferably, based on the mass of sodium hydroxide and / or potassium hydroxide, the mass percentage of part of the sodium hydroxide and / or potassium hydroxide is 40-45%, and the mass percentage of the other part of the sodium hydroxide and / or potassium hydroxide is 28-30%.

[0018] The present invention has been found that the use of a specific mixing and placement method can avoid direct contact between the mixed material layer and the crucible used in melting, and can make the reaction between the materials more complete, ensuring a better melting effect of the materials, thereby improving the separation efficiency and recovery rate of platinum and ruthenium.

[0019] As a preferred embodiment of the method of the present invention, in the step (1), the melting process is: heating to 340-360°C at a heating rate of ≤7°C / min, then keeping warm for 30-60min, then continuing to heat to 640-660°C at a heating rate of ≤7°C / min, then keeping warm for 60-180min, and then cooling to 20-30°C.

[0020] Preferably, in step (1), the melting process is: heating to 350°C at a heating rate of 5-7°C / min, then keeping warm for 30-60min, then heating to 650°C at a heating rate of 5-7°C / min, then keeping warm for 60-180min, and then cooling to 20-30°C.

[0021] The present invention has found that the heating rate, holding time and holding temperature during the melting process will affect the platinum leaching rate, thereby affecting the platinum-ruthenium separation effect. When the parameters of the melting process are further selected within the range given by the present invention, the obtained platinum-ruthenium separation effect is better. Specifically, the obtained platinum-containing leachate has a higher platinum content and a lower ruthenium content.

[0022] As a preferred embodiment of the method of the present invention, in step (1), the inert environment is a nitrogen or rare gas environment.

[0023] As a preferred embodiment of the method of the present invention, in step (2), water washing is performed until the conductivity of the washing liquid is ≤100 μS / cm.

[0024] The present invention has been found that the water washing process can clean up the by-product salts introduced during the melting process. By selecting the water washing process until the conductivity of the washing liquid is ≤100μS / cm, it can ensure that the impurity ions are cleaned up to avoid affecting the subsequent processes and products, thereby improving the recovery rate of platinum ruthenium.

[0025] Preferably, ultrasonic treatment is performed during the water washing process, and the frequency of the ultrasound is 25-50kHz and the power is 180-300w.

[0026] The present invention has found that the introduction of ultrasound during water washing can provide sufficient energy to help materials to be stirred and mixed, so that the materials are fully dissolved, thereby improving the cleaning and dissolving effects.

[0027] As a preferred embodiment of the method of the present invention, in the step (2), the mass ratio of the solid to the aqua regia is 1:(6-8).

[0028] The present invention has been found that by using aqua regia to dissolve the solid after preliminary treatment, a platinum-containing leaching solution with high platinum content and low ruthenium content can be effectively obtained, especially when the mass ratio of the solid and aqua regia is further selected to be within the above range, the platinum-ruthenium separation effect obtained is better.

[0029] Preferably, the aqua regia comprises hydrochloric acid, nitric acid and pure water in a volume ratio of 3:1:3.

[0030] Preferably, the temperature of the aqua regia is 80-90°C.

[0031] Preferably, the leaching time is 2-3 hours.

[0032] More preferably, stirring is used during the leaching process, and the rotation speed is adjusted to stir up the bottom residue to facilitate the reaction.

[0033] As a preferred embodiment of the method of the present invention, the method of obtaining platinum powder from the platinum-containing leaching solution can be carried out by a conventional method.

[0034] The conventional method comprises the following steps: treating the platinum-containing leaching solution to remove nitrate, then concentrating it to a platinum concentration of 30-80 g / L, adding ammonium chloride to precipitate the platinum, then filtering, collecting the filter residue and washing it with a saturated ammonium chloride solution to obtain ammonium chloroplatinate, and finally reducing the ammonium chloroplatinate with hydrazine hydrate to obtain platinum powder.

[0035] As a preferred embodiment of the method of the present invention, in the step (3), the sorting is performed using a tapered flow trough with a tapered ratio of 1:(10-15), a flow trough length of 1000-1200 mm, a feed concentration of 60-65%, and a feed slope of 15-17°.

[0036] The present invention has found that the ruthenium content in the ruthenium-containing residue obtained by solid-liquid separation after melting aqua regia is low and is not suitable for direct alkaline fusion or chlorination distillation of ruthenium treatment; however, ruthenium can be effectively enriched after sorting within the sorting parameter range given by the present invention, which is beneficial to the subsequent further recovery of ruthenium and improves the recovery rate of ruthenium.

[0037] As a preferred embodiment of the method of the present invention, in the step (3), when the ruthenium content in the ruthenium-enriched slag is 50-80%, alkali melting is performed to recover ruthenium;

[0038] In the step (3), when the ruthenium content in the ruthenium-enriched slag is greater than 80%, chlorination distillation of ruthenium is performed to recover ruthenium.

[0039] The present invention has found that by selecting different methods for recovering ruthenium according to the ruthenium content range obtained by testing after sorting, ruthenium can be recovered more effectively and the recovery rate of ruthenium can be improved.

[0040] As a preferred embodiment of the method of the present invention, the alkali fusion comprises the following steps: placing a mixture of ruthenium-enriched slag and sodium peroxide on a solid layer of sodium hydroxide and / or potassium hydroxide, then spreading sodium hydroxide and / or potassium hydroxide on the mixture, then heating to melt, cooling after the heating and melting, and obtaining a molten material; then adding water to the molten material for ultrasonic treatment, separating the solid and the liquid after the ultrasonic treatment, obtaining a ruthenium-enriched liquid and a solid residue, detecting the ruthenium content of the solid residue to determine the amount of ruthenium and returning it for screening or discarding it, and subjecting the ruthenium-enriched liquid to chlorination and ruthenium distillation treatment.

[0041] Preferably, the mass ratio of ruthenium-enriched slag to sodium peroxide is 1:(2-4).

[0042] Preferably, the thickness of the solid layer is 0.8-1.2 cm.

[0043] Preferably, the heating and melting process is: heating to 680-720°C at a heating rate of 5-7°C / min, keeping the temperature for 30-60 minutes, and then cooling to 20-30°C.

[0044] Preferably, the ultrasonic treatment has a power of 180w-300w and a time of 0.25-0.5h.

[0045] As a preferred embodiment of the method of the present invention, the chlorination and distillation of ruthenium includes the following steps: controlling the solution potential between 640-1000mV, continuously adding 20% ​​sodium hydroxide aqueous solution during the process, controlling the solution pH between 6-8, continuously introducing chlorine gas during the process, volatilizing ruthenium as tetroxide, absorbing ruthenium tetroxide with hydrochloric acid solution, and producing pure ruthenium powder by conventional refining method.

[0046] Preferably, the solution comprises a ruthenium-enriched solution obtained after solid-liquid separation in an alkali fusion treatment.

[0047] The present invention has been found that by controlling the potential and pH value of the solution in the above-mentioned range during the chlorination distillation of ruthenium, it is possible to avoid the leaching of other precious metals while ensuring that ruthenium is efficiently distilled, that is, it is possible to improve the recovery rate of ruthenium and the purity of the recovered ruthenium.

[0048] Preferably, the conventional refining method includes: concentrating the absorption liquid to 30 g / L, using ammonium chloride to precipitate ruthenium, then filtering and washing with a saturated ammonium chloride solution and drying, and finally reducing it to high-purity ruthenium powder using hydrogen.

[0049] As a preferred embodiment of the method of the present invention, in the step (1), an acid leaching step is also included before the crushed and sieved ruthenium distillation residue is mixed with the ingredients.

[0050] The present invention has found that if the ruthenium distillation residue contains platinum-containing insoluble materials, it can be firstly subjected to acid leaching treatment to remove the base metal.

[0051] Preferably, the acid leaching treatment is carried out using hydrochloric acid, the mass percentage of the hydrochloric acid is 15-20%, and the amount of the hydrochloric acid used is 1-1.2 times the total mass of the base metals in the ruthenium distillation residue.

[0052] Preferably, the acid leaching treatment is carried out at a temperature of 20-40°C and for a time of 15 min-60 min.

[0053] As a preferred embodiment of the method of the present invention, the crushing and screening includes multi-stage crushing and screening; wherein, the crushing can be performed using an air flow crusher; and the screening includes sequentially passing through 200 mesh, 300 mesh, and 500 mesh sieves.

[0054] The present invention has found that the use of an air flow crusher for crushing and multi-stage screening not only achieves a good crushing effect on the obtained material, but also makes the particle size after crushing finer and more evenly distributed. Moreover, the principle of air flow crushing is to use high-pressure gas to make the material collide, without introducing other impurities.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] In the method for separating and recovering platinum and ruthenium from ruthenium distillation residue provided by the present invention, the crushed and screened ruthenium distillation residue and a specific type of ingredients are mixed and placed, melted and washed in an inert environment, and the washed solid is dissolved in aqua regia and then separated into solid and liquid, so that a platinum-containing leaching solution with high platinum content and low ruthenium content can be obtained, and platinum can be effectively recovered; then, the ruthenium-containing filter residue is sorted and enriched, and then alkali fusion or chlorination ruthenium distillation is performed to recover ruthenium; platinum and ruthenium can be effectively separated and recovered from the ruthenium distillation residue. In addition, the method provided by the present invention is simple to operate, has a short process flow, can effectively improve the separation and recovery efficiency, and is conducive to practical application. DETAILED DESCRIPTION

[0057] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0058] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0059] The ruthenium evaporation residues used in the embodiments of the present invention and the comparative examples are from the same batch of materials. After testing, the ruthenium evaporation residues include the following elements in percentage by mass: 6.76% ruthenium, 0.53% platinum, 12.48% aluminum, 2.33% chromium, and other elements.

[0060] Example 1

[0061] The embodiment of the present invention provides a method for separating and recovering platinum ruthenium from ruthenium distillation residue, the method comprising the following steps:

[0062] (1) crushing the ruthenium distillation residue using a jet crusher, and then passing it through 200-mesh, 300-mesh and 500-mesh sieves in sequence, collecting the sieved material to obtain the crushed and sieved ruthenium distillation residue;

[0063] (2) placing the crushed and sieved ruthenium distillation residue in a 20 wt % hydrochloric acid solution at 25° C. for acid leaching for 20 min, separating the solid from the liquid after the treatment, collecting the solid and drying it to obtain the ruthenium distillation residue after acid leaching;

[0064] (3) taking a portion of sodium hydroxide (accounting for 40% of the total mass of sodium hydroxide) and placing it at the bottom of the nickel crucible to form a bottom layer of ingredients, then mixing the ruthenium distillation residue after acid leaching, sodium peroxide, sodium carbonate and another portion of sodium hydroxide (accounting for 30% of the total mass of sodium hydroxide) and placing them on the bottom layer of ingredients to form a mixed material layer, and finally placing the remaining portion of sodium hydroxide on the mixed material layer; then placing the crucible in a vacuum tube furnace, using nitrogen to remove air, maintaining nitrogen flow, starting to heat at a rate of 7°C / min, to 350°C and keeping the temperature for 60min, continuing to heat to 650°C, keeping the temperature for 180min, and stopping heating, cooling to room temperature and stopping nitrogen flow to obtain a molten material;

[0065] Wherein, based on the mass of the ruthenium distillation residue after acid leaching, the mass percentage of sodium hydroxide is 100%, the mass percentage of sodium carbonate is 300%, and the mass percentage of sodium peroxide is 100%;

[0066] (4) The melted material is taken out, desalted with pure water, and cleaned with an ultrasonic cleaning rod at a frequency of 40 kHz and a power of 180 w. The cleaning is repeated several times until the conductivity of the aqueous solution after cleaning is less than 100 μS / cm. The cleaning and solid-liquid separation are completed, and the solid is collected. The solid is leached with 7 times the mass of 80°C aqua regia (hydrochloric acid: nitric acid: pure water = 3:1:3, volume ratio). The solid is stirred during the leaching process. After leaching for 2.5 hours, the solid-liquid separation is performed to obtain a platinum-containing leachate and a ruthenium-containing filter residue;

[0067] The platinum-containing leachate is treated to remove nitrate, then concentrated to a platinum concentration of 55 g / L, and ammonium chloride is added to precipitate the platinum, followed by filtration, the filter residue is collected and washed with a saturated ammonium chloride solution to obtain ammonium chloroplatinate, and finally the ammonium chloroplatinate is reduced with hydrazine hydrate to obtain platinum powder;

[0068] (5) using a tapered flow trough to sort the ruthenium-containing filter residue, wherein the tapered ratio is 1:12, the flow trough length is 1000 mm, the feed concentration is 60%, the feed slope is 15°, and after sorting, a ruthenium-containing enriched slag is obtained;

[0069] (6) placing a mixture of ruthenium-enriched slag and sodium peroxide (the mass ratio of ruthenium-enriched slag to sodium peroxide is 1:3) on a sodium hydroxide solid layer (the thickness of the solid layer is 1 cm) and then covering it with sodium hydroxide (the thickness is 1 cm); then placing the crucible in a vacuum tube furnace, using nitrogen to expel the air, maintaining nitrogen flow, and starting to heat at a rate of 7°C / min, stopping heating after keeping the temperature at 700°C for 45 minutes, and stopping nitrogen flow after cooling to room temperature to obtain a molten material; then adding the molten material to water for ultrasonic treatment (ultrasonic power of 200w, time of 0.4h), and separating the solid and liquid after the ultrasonic treatment to obtain a ruthenium-enriched liquid and a solid residue;

[0070] (7) Chlorination distillation of ruthenium from the ruthenium-enriched liquid is performed, specifically, the potential of the ruthenium-enriched liquid is controlled between 640-1000 mV, 20% sodium hydroxide aqueous solution is continuously added during the process, the pH value of the solution is controlled between 6-8, chlorine gas is continuously introduced during the process, ruthenium is volatilized as tetroxide, ruthenium tetroxide is absorbed by hydrochloric acid solution, the absorption liquid is concentrated to 30 g / L, ammonium chloride is used to precipitate ruthenium, then filtered and washed with saturated ammonium chloride solution and dried, and finally reduced to high-purity ruthenium powder using hydrogen.

[0071] Example 2

[0072] The embodiment of the present invention provides a method for separating and recovering platinum and ruthenium from ruthenium distillation residue. The difference between the method and embodiment 1 lies in step (3). Step (3) of the present embodiment is:

[0073] Taking part of sodium hydroxide (accounting for 40% of the total mass of sodium hydroxide) and placing it at the bottom of the nickel crucible to form a batch bottom layer, then mixing the ruthenium distillation residue after acid leaching, sodium peroxide, sodium carbonate and another part of sodium hydroxide (accounting for 30% of the total mass of sodium hydroxide) evenly and placing them on the batch bottom layer to form a mixed material layer, and finally placing the remaining part of sodium hydroxide on the mixed material layer; then putting the crucible into a vacuum tube furnace, using nitrogen to remove air, maintaining nitrogen flow, starting to heat at a rate of 5°C / min, to 350°C and keeping the temperature for 60min, continuing to heat to 650°C, keeping the temperature for 180min and then stopping heating, cooling to room temperature and stopping nitrogen flow to obtain a molten material;

[0074] Wherein, based on the mass of the ruthenium distillation residue after acid leaching, the mass percentage of sodium hydroxide is 150%, the mass percentage of sodium carbonate is 150%, and the mass percentage of sodium peroxide is 150%.

[0075] Example 3

[0076] The embodiment of the present invention provides a method for separating and recovering platinum and ruthenium from ruthenium distillation residue. The difference between the method and embodiment 1 is that in step (3), the temperature is initially increased at a rate of 2°C / min, and is kept at 350°C for 60 min. The temperature is then increased to 650°C, and the heating is stopped after being kept for 180 min. After cooling to room temperature, the nitrogen flow is stopped to obtain a molten material.

[0077] Example 4

[0078] The embodiment of the present invention provides a method for separating and recovering platinum and ruthenium from ruthenium distillation residue. The difference between the method and embodiment 1 is that in step (3), the temperature is initially increased at a rate of 10°C / min, and the temperature is kept at 350°C for 60 minutes. The temperature is then increased to 650°C, and the heating is stopped after being kept for 180 minutes. After cooling to room temperature, the nitrogen flow is stopped to obtain a molten material.

[0079] Example 5

[0080] The embodiment of the present invention provides a method for separating and recovering platinum ruthenium from ruthenium distillation residue. The difference between the method and Example 1 is that in step (3), based on the mass of the ruthenium distillation residue after acid leaching, the mass percentage of sodium hydroxide is 200%, the mass percentage of sodium carbonate is 400%, and the mass percentage of sodium peroxide is 50%.

[0081] Example 6

[0082] The embodiment of the present invention provides a method for separating and recovering platinum ruthenium from ruthenium distillation residue. The difference between the method and Example 1 is that in step (3), based on the mass of the ruthenium distillation residue after acid leaching, the mass percentage of sodium hydroxide is 50%, the mass percentage of sodium carbonate is 400%, and the mass percentage of sodium peroxide is 200%.

[0083] Example 7

[0084] The embodiment of the present invention provides a method for separating and recovering platinum ruthenium from ruthenium distillation residue. The difference between the method and embodiment 1 is that sodium carbonate is not added in step (3).

[0085] Comparative Example 1

[0086] The comparative example of the present invention provides a method for separating and recovering platinum ruthenium from ruthenium distillation residue, the method differs from Example 1 in that sodium peroxide is not added in step (3).

[0087] Comparative Example 2

[0088] The comparative example of the present invention provides a method for separating and recovering platinum and ruthenium from ruthenium distillation residue. The difference between the method and Example 1 is that sodium hydroxide is not added in step (3).

[0089] Comparative Example 3

[0090] The comparative example of the present invention provides a method for separating and recovering platinum and ruthenium from ruthenium distillation residue. The difference between the method and Example 1 is that the melting in step (3) is carried out in an air environment.

[0091] Effect example

[0092] The effect example of the present invention records the platinum leaching rate and ruthenium leaching rate in the platinum-containing leaching solution obtained in the method for separating and recovering platinum and ruthenium in Examples 1-7 and Comparative Examples 1-3, the platinum content and ruthenium content in the ruthenium-containing filter residue, and calculates the recovery rate of the platinum and ruthenium finally recovered;

[0093] Among them, the testing and calculation methods of platinum leaching rate and ruthenium leaching rate in the leaching solution are: inductively coupled plasma emission spectrometer; the calculation method is: platinum leaching rate = platinum content in platinum-containing leaching solution after dissolution with aqua regia / platinum content in raw materials * 100%; ruthenium leaching rate = ruthenium content in platinum-containing leaching solution / ruthenium content in raw materials * 100%;

[0094] The test and calculation methods of platinum content and ruthenium content in ruthenium-containing filter residue are as follows: Inductively coupled plasma emission spectrometer, platinum content = platinum content in ruthenium-containing filter residue / platinum content in raw material * 100%; ruthenium content = ruthenium content in ruthenium-containing filter residue / ruthenium content in raw material * 100%;

[0095] The calculation method of the recovery rate of platinum and ruthenium is: direct recovery rate = mass of (platinum / ruthenium) recovered by reduction / content of (platinum / ruthenium) in the raw material*100%;

[0096] The obtained results are shown in Table 1;

[0097] Table 1

[0098]

[0099]

[0100] As can be seen from Table 1, when the method for separating and recovering platinum and ruthenium from ruthenium distillation residue provided by the present invention is adopted, the separation of platinum and ruthenium can be effectively achieved, and the recovery rate of platinum and ruthenium obtained is relatively high; specifically, the platinum leaching rate in the obtained platinum-containing leaching solution is above 90.24%, and the ruthenium leaching rate is below 5.47%; the ruthenium content in the ruthenium-containing residue is above 7.34%, and the platinum content is below 7.8%; the final platinum recovery rate is above 87.24%, and the ruthenium recovery rate is above 80.75%;

[0101] It can be seen from Example 1 and Comparative Examples 1-2 that when the ingredients of the present invention are not added during the melting process, the separation of platinum and ruthenium cannot be effectively achieved; it can be seen from Example 1 and Comparative Example 3 that when the melting is carried out in an air environment, the purpose of separation and recovery of the present invention cannot be achieved.

[0102] Finally, it should be noted that the above embodiments are intended to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for separating and recovering platinum and ruthenium from ruthenium distillation residue, characterized in that: The method comprises the following steps: (1) mixing the crushed and sieved ruthenium distillation residue and the ingredients and melting them in an inert environment to obtain a molten material; (2) washing the melted material with water, separating the solid from the liquid after the washing, collecting the solid and dissolving it with aqua regia, and then separating the solid from the liquid to obtain a platinum-containing leachate and a ruthenium-containing filter residue; (3) sorting the ruthenium-containing filter residue to obtain ruthenium-containing enriched residue, and then subjecting the ruthenium-containing enriched residue to alkaline melting or chlorination distillation of ruthenium to recover ruthenium; The ingredients include sodium peroxide and at least one of sodium hydroxide and potassium hydroxide.

2. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 1, characterized in that: The ingredients also include sodium carbonate.

3. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 2, characterized in that: Calculated by the mass of the crushed and sieved ruthenium distillation residue, the mass percentage of sodium peroxide is 50-200%, the mass percentage of sodium carbonate is 150-400%, and the mass percentage of the sum of the masses of sodium hydroxide and potassium hydroxide is 50-200%.

4. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 2, characterized in that: The mixing and placing in step (1) is as follows: part of the sodium hydroxide and / or potassium hydroxide is laid on the bottom to form a bottom ingredient layer; then the crushed and sieved ruthenium distillation residue, sodium carbonate and sodium peroxide and another part of the sodium hydroxide and / or potassium hydroxide are mixed evenly and placed on the bottom ingredient layer to form a mixed material layer; finally, the remaining part of the sodium hydroxide and / or potassium hydroxide is placed on the mixed material layer.

5. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 1, characterized in that: In the step (1), the melting process is as follows: heating to 340-360°C at a heating rate of ≤7°C / min, then keeping warm for 30-60min, then heating to 640-660°C at a heating rate of ≤7°C / min, then keeping warm for 60-180min, and then cooling to 20-30°C.

6. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 1, characterized in that: In the step (2), the water washing is performed until the conductivity of the washing liquid is ≤100 μS / cm.

7. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 1, characterized in that: In the step (2), the mass ratio of the solid to the aqua regia is 1:(6-8).

8. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 1, characterized in that: In the step (3), the sorting is performed using a tapered flow trough, the tapered ratio is 1:(10-15), the flow trough length is 1000-1200 mm, the feed concentration is 60-65%, and the feed slope is 15-17°.

9. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 1, characterized in that: In the step (3), when the ruthenium content in the ruthenium-enriched slag is 50-80%, alkali melting is performed to recover ruthenium; In the step (3), when the ruthenium content in the ruthenium-enriched slag is greater than 80%, chlorination distillation of ruthenium is performed to recover ruthenium.

10. The method for separating and recovering platinum and ruthenium from ruthenium distillation residue according to claim 1, characterized in that: In the step (1), an acid leaching step is also included before the crushed and sieved ruthenium distillation residue is mixed with the ingredients.

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