Over 80% of spent industrial catalysts from oil refineries contain precious metals that must be recovered due to their high market and technical value. Facilities typically choose between thermal roasting of supports in special tubular furnaces and chemical dissolution of active components in concentrated acid reagents. Each of these technological approaches has its own operational requirements and limitations. Thermal treatment focuses on the rapid burning off of organic impurities, while the chemical method ensures maximum recovery of platinum, palladium, or rhenium without significant destruction of the aluminosilicate base. The choice of a specific processing path determines the financial costs of the industrial facility. The environmental impact of both options also varies significantly during large-scale implementation.
Hydrometallurgical recovery of platinum and palladium
The hydrometallurgical method involves leaching metals using mixtures of mineral acids. This method is used for processing fine powders and spherical aluminum oxide supports. During the reaction, stable soluble complexes of ammonium chloroplatinate or chloropalladate are formed, which are subsequently reduced to pure metals using hydrazine. The technology shows high efficiency in purifying reforming catalysts of the KR-108 and KR-110 grades. Titanium-lined chemical reactors ensure the equipment's resistance to aggressive environments during prolonged contact with acids at 90 °C.
Pyrometallurgical process at 1200 °C
In electric arc furnaces, pyrometallurgical treatment is based on high-temperature melting of the spent material together with fluxes and collector metals. The main advantage of this complex approach is the ability to simultaneously process large batches of heterogeneous raw materials without prior fine grinding. However, the method requires significant energy consumption. The high melting temperature leads to rapid wear of the furnace lining and requires additional costs for gas cleaning equipment to capture dust.
Classification according to codes 16 08 01* and 16 08 02*
Due to their high toxicity, spent petrochemical catalysts belong to the category of hazardous industrial waste. The National List of Wastes classifies these materials into several main categories. For example, spent industrial wastes containing gold, platinum, palladium, rhodium, or rhenium are marked with the code 16 08 01*. If the mixture contains other transition metals, the code 16 08 02* is applied. Is it safe to store such substances? Prolonged accumulation of these materials in open areas leads to the leaching of toxic nickel and cobalt compounds into groundwater.
Technical composition of aluminosilicate supports
Typically, a standard spent catalyst contains up to 95% of active aluminum oxide Al2O3, which acts as a porous support. The concentration of platinum or palladium in such systems rarely exceeds 1%, but this is sufficient for the profitable recovery of the components. Contaminants include sulfur and silicon compounds, as well as residues of heavy oil fractions. Before starting chemical leaching, all raw materials are mandatorily analyzed for iron and arsenic content using an X-ray fluorescence spectrometer.
Application practice in the petrochemical sector
In catalytic reforming and diesel fuel hydrotreating units, the described processes occur constantly. The company UtilVtorProm ensures the safe collection and temporary storage of such hazardous waste.
Transfer of waste under code 16 08 01* for processing
The direct transfer of spent catalysts to specialized organizations allows industrial enterprises to completely avoid fines provided they have properly executed documentation. Licensed activity minimizes legal risks. An official contract ensures the rapid receipt of acceptance certificates and complete environmental reporting for regulatory authorities of the State Ecological Inspectorate. Transportation is carried out by special sealed vehicles that have all official permits for the safe transportation of hazardous substances of the corresponding class. All waste operations undergo strict accounting in state registers. Timely processing of raw materials allows valuable metals to be returned to the country's industrial circulation. The company UtilVtorProm provides services for the collection, transportation, storage, and environmentally safe management of industrial waste of this type.