Method for short-flow recovery of platinum group metal from waste catalysts

Abstract

The invention discloses a method for short-flow recovery of platinum group metal from waste catalysts. The method is determined on the basis of analyzing and researching states and contents of carriers and active components in the waste catalysts; in order to effectively separate the platinum group metal from the carriers, the method uses the characteristics of different acid dissolubility of aluminum trioxide with different crystal forms for controlling the roasting temperature to totally convert gamma-Al2O3 in the waste catalyst carriers to alpha-Al2O3 through two-step roasting, and uses dissolution of aqua regia for leaching out the platinum group metal; the leaching rate of aluminum oxide is lower than 0.2%; after leaching liquid is concentrated to catch acid, and the acidity is adjusted, hydrazine hydrate is used for selective reduction to obtain sponge platinum with a purity of higher than 99%; and the recovery rate of platinum is higher than 99%. The method saves a middle impurity removing link, effectively shortens the recovery flow of the platinum group metal in the waste catalysts, introduces no impurity metal in the whole process, and is high in purity of the sponge platinum and high in refining efficiency.

Description

technical field

[0001] The invention belongs to the technical field of precious metal secondary resource recovery, and in particular relates to a method for recovering platinum group metals from spent catalysts in a short process. Background technique

[0002] In the petrochemical industry, platinum metal catalysts are required for about 80% of chemical reactions. With the rapid development of the global petrochemical industry, the amount of corresponding catalysts is increasing day by day. However, after a period of use of the active component platinum group metals, which play a catalytic role, the catalysis may be caused by surface carbon or catalyst pore blockage, poisoning, and oxidation of active components. Loss of activity and scrapped. However, the amount of platinum group metals in the spent catalyst remains unchanged, and the content is much higher than that in minerals. Therefore, the platinum group metals with high economic value need to be recycled.

[0003] F...

Examples

Embodiment 1

[0017] Take 50g of spent catalyst (in which the platinum content is 1981g / t and the alumina is 76.2%). The waste catalyst was placed in a muffle furnace, calcined in two steps, and the temperature was controlled by program. The first step was kept at 700 ° C for 30 minutes, and the organic impurities were removed by burning. The second step was calcined at 1300 ° C for 30 minutes, and the γ- Al 2 O 3 Converted to α-Al 2 O 3 ; Cool to room temperature, place the calcined waste catalyst in a 500 mL beaker, add 200 mL of aqua regia with a mass concentration of 30% to dissolve the leached platinum, heat to 90 °C and stir for 1 h; after the reaction is complete, filter to obtain the leaching residue and the leaching solution, the leaching slag was used to recover alumina, the leaching solution was concentrated and acid-driven, the platinum content was 6.21g / L, the aluminum content was 0.0002g / L, the pH was adjusted to 7.0, and hydrazine hydrate was used for selective reduction, ...

Embodiment 2

[0019] Take 50g of spent catalyst (in which the platinum content is 1981g / t and the alumina is 76.2%). The waste catalyst was placed in a muffle furnace, calcined in two steps, and the temperature was controlled by program. The first step was kept at 800 °C for 30 minutes, and the organic impurities were removed by burning. The second step was calcined at 1300 °C for 35 minutes, and the γ- Al 2 O 3 Converted to α-Al 2 O 3 ; Cool to room temperature, place the calcined waste catalyst in a 500mL beaker, add 200ml of aqua regia with a mass concentration of 30% to dissolve the leached platinum, heat to 85 °C and stir for 1.5h; after the reaction is complete, filter to obtain the leaching The slag and leaching solution, the leaching slag was recovered alumina, the leaching solution was concentrated and acid-driven, the platinum content was 6.05g / L, the aluminum content was 0.0002g / L, the pH was adjusted to 7.0, and the hydrazine hydrate was selectively reduced to measure the alu...

Embodiment 3

[0021] Take 100g of spent catalyst (in which the platinum content is 1981g / t and the alumina is 76.2%). The waste catalyst was placed in a muffle furnace, calcined in two steps, and the temperature was controlled by program. The first step was kept at 750 °C for 30 minutes, and the organic impurities were removed by burning. The second step was calcined at 1300 °C for 40 minutes, and the γ- Al 2 O 3 Converted to α-Al 2 O 3 ; Cool to room temperature, place the calcined waste catalyst in a 1000mL beaker, add 400ml of aqua regia with a mass concentration of 30% to dissolve the leached platinum, heat to 80 °C and stir for 2h; after the reaction is complete, filter to obtain the leaching residue and the leaching solution, the leaching slag was used to recover alumina, the leaching solution was concentrated and the content of platinum was 6.50g / L, the content of aluminum was 0.0003g / L, the pH was adjusted to 8.0, and it was selectively reduced with hydrazine hydrate, and the con...

technical field

[0001] The invention belongs to the technical field of precious metal secondary resource recovery, and in particular relates to a method for recovering platinum group metals from spent catalysts in a short process. Background technique

[0002] In the petrochemical industry, platinum metal catalysts are required for about 80% of chemical reactions. With the rapid development of the global petrochemical industry, the amount of corresponding catalysts is increasing day by day. However, after a period of use of the active component platinum group metals, which play a catalytic role, the catalysis may be caused by surface carbon or catalyst pore blockage, poisoning, and oxidation of active components. Loss of activity and scrapped. However, the amount of platinum group metals in the spent catalyst remains unchanged, and the content is much higher than that in minerals. Therefore, the platinum group metals with high economic value need to be recycled.

[0003] F...

Examples

Embodiment 1

[0017] Take 50g of spent catalyst (in which the platinum content is 1981g / t and the alumina is 76.2%). The waste catalyst was placed in a muffle furnace, calcined in two steps, and the temperature was controlled by program. The first step was kept at 700 ° C for 30 minutes, and the organic impurities were removed by burning. The second step was calcined at 1300 ° C for 30 minutes, and the γ- Al 2 O 3 Converted to α-Al 2 O 3 ; Cool to room temperature, place the calcined waste catalyst in a 500 mL beaker, add 200 mL of aqua regia with a mass concentration of 30% to dissolve the leached platinum, heat to 90 °C and stir for 1 h; after the reaction is complete, filter to obtain the leaching residue and the leaching solution, the leaching slag was used to recover alumina, the leaching solution was concentrated and acid-driven, the platinum content was 6.21g / L, the aluminum content was 0.0002g / L, the pH was adjusted to 7.0, and hydrazine hydrate was used for selective reduction, ...

Embodiment 2

[0019] Take 50g of spent catalyst (in which the platinum content is 1981g / t and the alumina is 76.2%). The waste catalyst was placed in a muffle furnace, calcined in two steps, and the temperature was controlled by program. The first step was kept at 800 °C for 30 minutes, and the organic impurities were removed by burning. The second step was calcined at 1300 °C for 35 minutes, and the γ- Al 2 O 3 Converted to α-Al 2 O 3 ; Cool to room temperature, place the calcined waste catalyst in a 500mL beaker, add 200ml of aqua regia with a mass concentration of 30% to dissolve the leached platinum, heat to 85 °C and stir for 1.5h; after the reaction is complete, filter to obtain the leaching The slag and leaching solution, the leaching slag was recovered alumina, the leaching solution was concentrated and acid-driven, the platinum content was 6.05g / L, the aluminum content was 0.0002g / L, the pH was adjusted to 7.0, and the hydrazine hydrate was selectively reduced to measure the alu...

Embodiment 3

[0021] Take 100g of spent catalyst (in which the platinum content is 1981g / t and the alumina is 76.2%). The waste catalyst was placed in a muffle furnace, calcined in two steps, and the temperature was controlled by program. The first step was kept at 750 °C for 30 minutes, and the organic impurities were removed by burning. The second step was calcined at 1300 °C for 40 minutes, and the γ- Al 2 O 3 Converted to α-Al 2 O 3 ; Cool to room temperature, place the calcined waste catalyst in a 1000mL beaker, add 400ml of aqua regia with a mass concentration of 30% to dissolve the leached platinum, heat to 80 °C and stir for 2h; after the reaction is complete, filter to obtain the leaching residue and the leaching solution, the leaching slag was used to recover alumina, the leaching solution was concentrated and the content of platinum was 6.50g / L, the content of aluminum was 0.0003g / L, the pH was adjusted to 8.0, and it was selectively reduced with hydrazine hydrate, and the con...

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