Technical processes

Initially the spent catalyst is subjected to processes such as separation, sieving, breaking, etc., in order to facilitate thermal and hydrometallurgical treatment. Subsequently the material is thermally treated in a fluidized-bed kiln, and/or rotating tubular kiln, depending on the type of material. The combustible part of the waste, containing hydrocarbons and sulfur compounds, is treated in the fluid-bed process. Gases are primarily cleaned in a cyclone and dust collecting filter, and the sulfur oxide compounds of the flue gas are treated with magnesium hydroxide, in a series of scrubbing towers, and converted to magnesium sulfate, which is refined to a quality suitable for use as an agricultural fertilizer product. This unique desulphurization process is so effective that it yields efficiency which is usually 20 times greater than is required. The rotary kiln is a perfect means of treating metal-containing waste by drying or calcination. After dust collection in a separate cyclone and filter system, the gases are either condensed or passed through the previously mentioned gas cleaning system. The treated material can be reused as a raw material or returned to the customer.

The intermediate metal products will be worked up through a new well-developed hydrometallurgical process into pure metal oxide and concentrates. These materials will be refined according to international standard specifications. Our finished products, such as molybdenum oxides, molybdenum concentrates, vanadates, cobalt oxides and nickel products, meet, or even exceed, the international standards of such product classifications. Lately, we have developed a further step in which we transfer our already finished products, such as high grade ferro/molybdenum, ferro/vanadium and ferro/nickel products, back into non-ferrous metal products based on customer classifications, in all different shapes and forms (fines, granules, and blocks), by an ingenious pyrometallurgical melting process.

The Moxba-Metrex technology, originally set up in co-operation with some of the Netherlands largest and most reputable research institutes such as TNO, ECN and KEMA, is unique. We have increasingly been able to include more complicated waste products and metallic residues from every branch of industry in our recycling system, so it is not only spent metal catalyst we are processing. In past years more and more innovative projects have been successfully implemented by recycling routes that have never been used before. Our modern, well equipped laboratory, together with the Moxba-Metrex R&D department, is the key to this success.