Spent Catalyst Recycling Service

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The goal of Alfa Chemistry Catalysts is to provide a commercially competitive recycling program and emphasize environmentally sound management.

We have mature recycling technology that can recover valuable metals in spent catalysts, such as Pt, Pd, Au, Rh, Ru, Co, Al, Re, Ni and Cu. Many recovered metals are returned to the industry in the form of high-purity raw materials, thereby closing the circulation loop.

The choice of spent catalyst recycling method is based on a comprehensive decision on the composition, content, carrier type, value of recycled materials, recycling rate, enterprise equipment and technical capabilities, and recycling costs of the catalyst. Alfa Chemistry Catalysts can tailor a spent catalyst recycling program for you according to customer needs.

Spent Catalyst Recovery Technology

• Dry method

Generally, a heating furnace is used to heat and melt the spent catalyst together with the reducing agent and the flux, so that the metal component is reduced and melted into a metal or alloy to be recovered as an alloy or alloy raw material, and the carrier and the flux are formed into slag and discharged. Dry methods usually include oxidation roasting method, sublimation method and chloride volatilization method. Such as Co-Mo/Al2O3, Ni-Mo/Al2O3, Cu-Ni, Ni-Cr and other catalysts can be recovered by this method. However, the dry method consumes a lot of energy and may release gases such as SO during the melting and smelting process.

• Wet method

Use acid, alkali or other solvents to dissolve the main components of spent industrial catalysts. After purification, the filtrate can be separated to obtain hardly water-soluble sulfides or metal hydroxides. After drying, they can be further processed into final products as needed. Precious metal catalysts, hydrodesulfurization catalysts, copper-based and nickel-based spent catalysts are generally recovered by wet methods. When the spent catalyst is treated by wet method, if the carrier is dissolved together with the metal, the separation of the metal and the carrier will produce a large amount of waste liquid, which may cause secondary pollution.

• Dry-wet combination method

For platinum group metal catalysts with carbon as a carrier, due to the strong adsorption capacity of the carbon carrier, any direct leaching method is not ideal. However, the carrier of this type of catalyst is very easy to burn, so it adopts oxidative roasting (the roasting temperature is generally controlled at 450-650 °C) and then uses wet method to recover platinum group metals from the slag after decarburization. The dry-wet combination method effectively enriches the precious metals after the carrier is burned through roasting pretreatment, can improve the recovery rate, and has a short cycle and simple refining. Therefore, in actual production, the dry-wet combination method is a common method.

Spent Catalyst Recycling Cases

• Pt reforming spent catalyst

The Pt reforming catalyst is prepared by impregnating H2PtCl6 solution on alumina pellets and using alumina as a carrier. This catalyst will lose its activity due to carbon deposits during use. The method of leaching Pt with aqua regia and precipitation with ammonium chloride is mainly to dissolve and remove Al with sulfuric acid. Pt residue is leached with aqua regia after alkali roasting, and then ammonium chloride is used as a precipitant to crystallize and precipitate Pt in the solution in the form of (NH4)2PtCl6, and then refined into Pt powder.

• Pd spent catalyst

Pd-containing catalysts are mainly used for catalytic hydrogenation and dehydrogenation, catalytic oxidation, etc. in petrochemical industry. The recovery method is to pulverize the spent catalyst and then dissolve it with HCl, and use the difference in solubility of Pd and Cu in hydrochloric acid to reduce and precipitate Pd.