Process and equipment for recovering platinum and palladium from petroleum catalyst

Abstract

The invention discloses a process and equipment for recovering platinum and palladium from a petroleum catalyst, and relates to the field of metal material recovery, carbon-supported platinum group noble metals platinum and palladium are recovered by using the patent technology, firstly, fine grinding, hydrolysis and filtration are performed, then a reducing agent is adopted for reduction, then acidification and filtration are performed to remove base metals, and hydrochloric acid and nitric acid solutions are adopted for leaching and saltpeter removal, so that the platinum and palladium are recovered. The high-purity palladium powder is prepared from the solution subjected to platinum precipitation through ammonium chloride platinum precipitation, ammonium chloroplatinate hydrazine hydrate reduction, high-purity platinum powder and ammonia water palladium precipitation and hydrazine hydrate reduction, the purposes of saving energy and reducing the production cost are achieved, the ashing roasting furnace is adopted for static ashing, the technology process is simplified, the platinum group precious metal recovery rate is high, and the smelting cost is low. And the quality and purity of the platinum-palladium product are high, the metal recovery rate is high, and the smelting cost is low.

Description

Technical Field

[0001] The invention relates to the field of metal material recovery, in particular to a process and equipment for recovering platinum and palladium from a petroleum catalyst. Background Art

[0002] In addition to gold and silver, platinum group precious metals (platinum, palladium, rhodium, iridium, and ruthenium) are widely used in industry due to their excellent physical and chemical properties (such as high-temperature oxidation resistance and corrosion resistance), electrical properties (excellent conductivity, high-temperature thermoelectric properties and stable resistance temperature coefficient, etc.), high catalytic activity, strong coordination ability, etc. With the rapid development of economic construction, the consumption of platinum group metals is increasing, and more and more waste is generated. Therefore, waste containing precious metals has become a very important secondary resource. Doing a good job in the recycling of precious metal secondary resources can make up for the serious shortage of primary minerals and reduce excessive dependence on the international precious metal market. It is of great strategic significance.

[0003] When refining petroleum, platinum group metal catalysts such as platinum-carbon catalysts and palladium-carbon catalysts are needed. A large number of metal catalysts are discarded every year. The discarded platinum-palladium carbon carrier catalyst contains 0.1-10% platinum and palladium. The content of discarded catalysts is lower than that of fresh catalysts. Therefore, the discarded catalysts can be used to recover platinum and palladium.

[0004] The traditional recycling method uses a fire method to add a capture agent and a slag-forming agent to smelt and capture platinum and palladium, then quench the alloy containing precious metals with water, then acidify and leach to remove base metals, and dissolve the insoluble platinum and palladium in the acid leaching with "aqua regia", drive out the nitrate, replace with zinc wire, and precipitate platinum and palladium to obtain sponge platinum and sponge palladium respectively. The traditional process consumes 10%-15% of copper-nickel capture agents and about 25% of slag-forming agents, with high production costs, and leads to the loss of precious metals with the loss of base metals, and the recovery rate is low. Summary of the invention

[0005] The object of the present invention is to provide a process and equipment for recovering platinum and palladium from petroleum catalysts to solve the problems raised by the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: A process for recovering platinum and palladium from a petroleum catalyst comprises the following steps: 1) Mix the discarded carbon-supported platinum and palladium catalysts with the oxidant, stir them evenly and put them into an ashing calcination furnace for calcination. After the carrier carbon is completely ashed, grind it and hydrolyze it to remove the oxidant metal ions; 2) After the raw materials are hydrolyzed and filtered, they are put into the reactor, slurried at a solid-liquid ratio of 1:3, and the reducing agent is added. The amount of the ash material and the amount of the reducing agent added are 1:0.1-1. The temperature is controlled at 65°C and stirred for 5 hours; 3) After the reduction reaction is completed, the reactor is acidified by adding 6 mol / L sulfuric acid into the reactor and stirring for 5 hours at a controlled temperature of 75°C to remove base metal ions; 4) The filtered solution is placed in a titanium container, and 2 mol / L aqua regia is added at a solid-liquid ratio of 1:2.5 for leaching. The temperature is controlled at 75°C, stirred for 4 hours, and then the temperature is raised to 95°C to drive out nitrate for 3 hours; 5) After the acidification reaction is completed, the nitrate is driven out for 3 hours, and then 2 mol / L ammonium chloride is added to generate ammonium chloroplatinate precipitate and filter it. The filter residue is ammonium chloroplatinate; 6) Add ammonium chloroplatinate into a titanium barrel to form a solution at a liquid-to-solid ratio of 2:1, adjust the pH value to between 8-9, heat the temperature to about 80°C, slowly drip hydrazine hydrate for reduction, add while stirring, the black precipitate produced during the reduction process is sponge platinum, and observe that the solution turns into clear and transparent water, indicating that the reduction is complete, and then repeatedly wash the sponge platinum with deionized water to obtain high-purity platinum powder; 7) Add 2 mol / L ammonia water to the filtrate after platinum precipitation for complexation, control the temperature at 80°C and stir for 3 hours, slowly add hydrochloric acid for acidification and precipitation, filter after the reaction is complete, and recycle the filtrate. Put the filter residue into a reactor at room temperature, add hydrazine hydrate, and stir while adding until the precious liquid is completely reduced and precipitated to obtain palladium powder. The palladium powder is repeatedly washed with deionized water and dried to obtain high-purity palladium powder.

[0007] On the basis of the above technical solution, the present invention also provides the following optional technical solution: In an optional scheme: in step 1), the ratio of the waste carbon-supported platinum and palladium catalyst to the oxidant is 1:0.1, and the oxidant is one of potassium permanganate, manganese dioxide and potassium nitrate.

[0008] In an optional scheme: in step 2), the reducing agent is one of formic acid, sodium formate, hydrazine hydrate and formaldehyde.

[0009] In an optional scheme: in step 3), the added acid solution is one of sulfuric acid, hydrochloric acid and nitric acid.

[0010] A device for recovering platinum and palladium from petroleum catalysts comprises an ashing and roasting furnace, wherein an ashing grate and an ashing furnace tray are arranged inside the ashing and roasting furnace, an outer shell wall is arranged outside the ashing and roasting furnace, oxygen-enriched air inlet pipes are arranged on both sides of the outer shell wall, and an ashing furnace fume duct is arranged on the top of the ashing and roasting furnace.

[0011] In an optional solution: one end of the ash furnace flue gas duct is connected to an ash furnace dust hopper, and the ash furnace dust hopper is connected to a bag dust collector, the bag dust collector includes a bag dust collector shell and a filter bag, the filter bag is arranged inside the bag dust collector shell, and a plurality of pulse bag dust collector hoppers are arranged below the bag dust collector shell.

[0012] In an optional solution: the side wall of the bag dust collector shell is connected to an induced draft fan, the air outlet of the induced draft fan is connected to an absorption tower, a plurality of absorption tower mesh plates are arranged inside the absorption tower, and an absorption tower filler layer is arranged on the absorption tower mesh plates.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This patented technology is used to recycle platinum and palladium, a precious metal of the platinum group, on carbon, to achieve the goal of energy saving and reducing production costs. The static ashing technology using an ashing roasting furnace simplifies the process, increases the recovery rate of platinum group precious metals, and reduces smelting costs, thereby achieving the goal of improving the quality of platinum and palladium products and increasing the recovery rate of platinum and palladium. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A cross-sectional view of an apparatus for recovering platinum and palladium from petroleum catalysts.

[0015] Figure 2 This is a schematic diagram of the structure of the ashing and calcining furnace in the equipment for recovering platinum and palladium from petroleum catalysts.

[0016] Figure 3 The following is an operational flow chart for recovering platinum and palladium from petroleum catalysts.

[0017] Notes on figure numbers: 1-ashing and roasting furnace, 2-oxygen-enriched air inlet pipe, 3-ashing furnace grate, 4-ashing furnace tray, 5-ashing furnace smoke hood, 6-ashing furnace flue gas duct, 7-ashing furnace dust hopper, 8-pulse bag dust collector hopper, 9-bag dust collector shell, 10-filter bag, 11-induced draft fan, 12-absorption tower observation hole, 13-absorption tower mesh plate, 14-absorption tower packing layer, 15-absorption tower steam-water separator, 16-absorption tower exhaust hole pipe, 17-circulating water pool, 18-absorption tower, 19-shell wall. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0020] like Figure 1-3 As shown, a process for recovering platinum and palladium from a petroleum catalyst provided by an embodiment of the present invention comprises the following steps: 1) Add the waste carbon-supported platinum and palladium catalysts in the ratio of 1:0.1 to the oxidant. The oxidant can be potassium permanganate, manganese dioxide, potassium nitrate, etc. After stirring evenly, put them into the ashing calcination furnace and control the temperature at 550℃-600℃ for 2 hours in oxygen-enriched calcination. After the carrier carbon is completely ashed, grind and hydrolyze to remove the oxidant metal ions. The chemical reaction is: 2KMnO4+3C=K2MnO4+2CO2↑+2H2O↑ (1) 2) After hydrolysis and filtration, the mixture is slurried in a reactor at a solid-liquid ratio of 1:3 and then a reducing agent is added (the reducing agent can be formic acid, sodium formate, hydrazine hydrate, formaldehyde, etc.). The amount of reducing agent added is 1:0.1-1 according to the amount of ashed material. This technology uses formic acid reduction, controls the temperature at 65°C and stirs for 5 hours. The chemical reaction is: PtO+HCOOH=Pt+H2O+CO2↑ (2) PdO+HCOOH=Pd+H2O+CO2↑ (3) 3) After the reduction reaction is completed, the reactor is acidified. Sulfuric acid, hydrochloric acid, and nitric acid can be used. This patent uses sulfuric acid for leaching and filtration. 6 mol / L sulfuric acid is added to the reactor and stirred for 5 hours under the condition of controlling the temperature at 75°C to remove the base metal ions. The chemical reaction is: Fe+H2SO4+H2O2→FeSO4+2H2O (4) 2Al+3H2SO4+H2O2→Al2(SO4)3+3H2O (5) 4) The acid-insoluble platinum and palladium ions after filtration are leached with "aqua regia" in a titanium container. 2 mol / L aqua regia is added at a solid-liquid ratio of 1:2.5 for leaching. The temperature is controlled at 75℃ and stirred for 4 hours. Then the temperature is raised to 95℃ to drive out nitrate for 3 hours. The chemical reaction is: 3Pt+4HNO3+18HCl=3H2PtCl6+8H2O+4NO (6) 3Pd+4HNO3+18HCl=3H2PdCl6+8H2O+4NO (7) 5) After the acidification reaction is completed and the nitrate is driven out for 3 hours, 2 mol / L ammonium chloride is added to generate ammonium chloroplatinate precipitation and then filtered. The filter residue is ammonium chloroplatinate. Its chemical reaction is: H2PtCl6+2NH4Cl =(NH4)2[PtCl6]↓+2HCl (8) 6) Add ammonium chloroplatinate into a titanium barrel to form a solution at a liquid-to-solid ratio of 2:1, adjust the pH value to between 8-9, heat the temperature to about 80°C, slowly drip hydrazine hydrate for reduction, add while stirring, the black precipitate produced during the reduction process is sponge platinum, and observe that the solution turns into clear and transparent water, indicating that the reduction is complete, and then repeatedly wash the sponge platinum with deionized water to obtain high-purity platinum powder; 7) Add 2 mol / L ammonia water to the filtrate after platinum precipitation for complexation, control the temperature at 80°C and stir for 3 hours, slowly add hydrochloric acid for acidification and precipitation, filter after the reaction is complete, and recycle the filtrate. Put the filter residue into the reactor at room temperature and add the prepared hydrazine hydrate while stirring until the precious liquid is completely reduced and precipitated to obtain palladium powder. The palladium powder is repeatedly washed with deionized water and dried to obtain high-purity palladium powder.

[0021] In order to reduce the loss of dynamic blast roasting, the discarded catalyst is mixed with an appropriate amount of potassium permanganate as a strong oxidant (the oxidant can be potassium permanganate, manganese dioxide, potassium manganate, etc.) and a thin layer is placed in an ashing furnace. Oxygen-enriched air with an oxygen concentration of 28% and a micro-pressure of 200Pa is introduced into the furnace. The temperature is raised to 500℃-600℃ and roasted for 2 hours. After complete ashing, it is taken out. The area of ​​the ashing roasting furnace bed is 6 square meters, the oxygen-enriched concentration is 28%, the single furnace processing capacity is 0.4 tons / furnace, and the blast pressure is 200Pa micro-pressure.

[0022] A device for recovering platinum and palladium from petroleum catalysts comprises an ashing and roasting furnace 1, wherein an ashing and roasting furnace 1 is provided with an ashing grate 3 and an ashing and roasting furnace tray 4, wherein an outer shell wall 19 is provided outside the ashing and roasting furnace 1, oxygen-enriched air inlet pipes 2 are provided on both sides of the outer shell wall 19, an ashing and roasting furnace fume hood 5 and an ashing and roasting furnace fume duct 6 are provided on the top of the ashing and roasting furnace 1, a carbon-supported platinum and palladium catalyst and a strong oxidant are placed on the tray, oxygen enters from the oxygen-enriched air inlet pipes 2 on both sides, and tail gas generated by the reaction is discharged upward from the ashing and roasting furnace fume duct 6 for treatment.

[0023] like Figure 1 As shown, as a preferred embodiment of the present invention, one end of the ashing furnace flue gas duct 6 is connected to an ashing furnace dust collecting hopper 7, and the ashing furnace dust collecting hopper 7 is connected to a bag dust collector, and the bag dust collector includes a bag dust collector housing 9 and a filter bag 10, and the size of the filter bag is The filter bag 10 is arranged inside the bag dust collector shell 9, and a plurality of pulse bag dust collector ash hoppers 8 are arranged below the bag dust collector shell 9.

[0024] like Figure 1As shown, as a preferred embodiment of the present invention, the side wall of the bag dust collector housing 9 is connected to an induced draft fan 11, the air outlet of the induced draft fan 11 is connected to an absorption tower 18, a plurality of absorption tower mesh plates 13 are arranged inside the absorption tower 18, an absorption tower filler layer 14 is arranged on the absorption tower mesh plates 13, an absorption tower exhaust hole pipe 16 is arranged on the top of the absorption tower 18, a plurality of absorption tower observation windows 12 are arranged outside the absorption tower 18, and a circulating water pool 17 is arranged at the bottom of the absorption tower 18.

[0025] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A process for recovering platinum and palladium from petroleum catalysts, characterized in that: The steps include: 1) Mix the discarded carbon-supported platinum and palladium catalysts with the oxidant, stir them evenly and put them into an ashing calcination furnace for calcination. After the carrier carbon is completely ashed, grind it and hydrolyze it to remove the oxidant metal ions; 2) After the raw materials are hydrolyzed and filtered, they are put into the reactor, slurried at a solid-liquid ratio of 1:3, and the reducing agent is added. The amount of the ash material and the amount of the reducing agent added are 1:0.1-1. The temperature is controlled at 65°C and stirred for 5 hours; 3) After the reduction reaction is completed, the reactor is acidified by adding 6 mol / L sulfuric acid into the reactor and stirring for 5 hours at a controlled temperature of 75°C to remove base metal ions; 4) The filtered solution is placed in a titanium container, and 2 mol / L aqua regia is added at a solid-liquid ratio of 1:2.5 for leaching. The temperature is controlled at 75°C, stirred for 4 hours, and then the temperature is raised to 95°C to drive out nitrate for 3 hours; 5) After the acidification reaction is completed, the nitrate is driven out for 3 hours, and then 2 mol / L ammonium chloride is added to generate ammonium chloroplatinate precipitate and filter it. The filter residue is ammonium chloroplatinate; 6) Add ammonium chloroplatinate into a titanium barrel to form a solution at a liquid-to-solid ratio of 2:1, adjust the pH value to between 8-9, heat the temperature to about 80°C, slowly drip hydrazine hydrate for reduction, add while stirring, the black precipitate produced during the reduction process is sponge platinum, and observe that the solution turns into clear and transparent water, indicating that the reduction is complete, and then repeatedly wash the sponge platinum with deionized water to obtain high-purity platinum powder; 7) Add 2 mol / L ammonia water to the filtrate after platinum precipitation for complexation, control the temperature at 80°C and stir for 3 hours, slowly add hydrochloric acid for acidification and precipitation, filter after the reaction is complete, and recycle the filtrate. Put the filter residue into a reactor at room temperature, add hydrazine hydrate, and stir while adding until the precious liquid is completely reduced and precipitated to obtain palladium powder. The palladium powder is repeatedly washed with deionized water and dried to obtain high-purity palladium powder.

2. The process for recovering platinum and palladium from petroleum catalysts according to claim 1, characterized in that: In step 1), the ratio of the waste carbon-supported platinum and palladium catalyst to the oxidant is 1:0.1, and the oxidant is one of potassium permanganate, manganese dioxide and potassium nitrate.

3. The process for recovering platinum and palladium from petroleum catalysts according to claim 1, characterized in that: In step 2), the reducing agent is one of formic acid, sodium formate, hydrazine hydrate and formaldehyde.

4. The process for recovering platinum and palladium from petroleum catalysts according to claim 1, characterized in that: In step 3), the added acid is one of sulfuric acid, hydrochloric acid and nitric acid.

5. An apparatus for recovering platinum and palladium from petroleum catalysts using the process described in any one of claims 1 to 4, comprising an ashing and roasting furnace, characterized in that: The ashing and roasting furnace is provided with an ashing grate and an ashing furnace tray inside, the ashing and roasting furnace is provided with an outer shell wall outside, oxygen-enriched air inlet pipes are provided on both sides of the outer shell wall, and an ashing furnace fume duct is provided on the top of the ashing and roasting furnace.

6. The device for recovering platinum and palladium from petroleum catalysts according to claim 5, characterized in that: One end of the ash furnace flue gas duct is connected to an ash furnace dust hopper, and the ash furnace dust hopper is connected to a bag dust collector. The bag dust collector includes a bag dust collector shell and a filter bag. The filter bag is arranged inside the bag dust collector shell, and a plurality of pulse bag dust collector hoppers are arranged below the bag dust collector shell.

7. The device for recovering platinum and palladium from petroleum catalysts according to claim 6, characterized in that: The side wall of the bag dust collector shell is connected to an induced draft fan, the air outlet of the induced draft fan is connected to an absorption tower, a plurality of absorption tower mesh plates are arranged inside the absorption tower, and an absorption tower filler layer is arranged on the absorption tower mesh plates.

Images