Catalysts are conventional used in the petroleum distillation and petrochemical industry. Catalysts are an indispensable part of the industry and are widely used. Used catalysts, whose function ends, are discarded as solid waste. Although it is called waste, it is not appropriate to call used catalysts completely waste. Because it contains metals that can be recovered in high concentrations, which must be recovered.
There are different types of used catalysts and generally contain many precious metals. For instance, spent hydrodesulphurization (HDS) catalysts, one of the most used catalysts, account nearly one-third of the entire worldwide catalyst utilization. HDS catalysts contain high rate Mo elements. Therefore, it constitutes an important secondary source of Mo in the world. In addition to molybdenum, in used catalysts; also available in V, W, Co, Ni, Ru, Zn, Cu, Fe, Al, Ag, Au, Rh, Pt and Pd metals.
The amount of used catalyst produced in one year worldwide is approximately 150,000-170,000 tons. Considering the metals it contains, the non-recycling of used catalysts creates a serious loss. The recovery of precious metals is also very important economically and ecologically. Recycling is necessary both to reduce the demand for increasing primary ore resources and to provide financial gain. Proses Makina Company has an important place in recycling these wastes into a valuable resource with its recycling systems.
The price of precious metals in spent catalysts, even in the past five years, has increased significantly, showing how much the recovery has been gaining day by day. For instance, the price of Palladium, which was 658.45 EURO / Ounce in 2015, has become approximately 3 times more valuable today as 2019.37 EURO / Ounce. Here, the economic importance of recycling is clearly seen.