Abstract: A fuel cell energy generating system which includes a reformate generating device that contains a hydrocarbon reforming reactor and produces a high-hydrogen reformate, has a fuel cell arrangement to which reformate generated by the reformate generating device can be fed on the inlet side by way of a reformate supply line, having at least one reformate-quality-indicating sensor arranged in the reformate flow path, and having a control unit. A valve is provided in the reformate supply line which can be controlled by the control unit such that it releases or interrupts the feeding of the reformate supplied by the reformate generating device into the fuel cell arrangement as a function of the output signal of the at least one reformate-quality-indicating sensor.

Abstract: A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe.sub.3 O.sub.4. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe.sub.2 O.sub.3. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater.

Abstract: An apparatus for desilvering silver-containing solutions comprises an electrolytic cell (10) having an anode (20), a cathode (30) and a reference electrode (45) positioned adjacent the cathode (30), and electrical power supply control means (41) for controlling the supply of electrical power to the anode (20) and the cathode (30). The power supply control means (41) includes means (60) for adjusting the cathode potential and control means (70) linked to said adjustment means (60) to reduce the cathode potential, at least periodically, as the desilvering process continues. The process leads to better silver adhesion on the cathode occurs, while maintaining good desilvering levels in the solution, and cathode poisoning is minimised.

Abstract: Process for the production of pure tungsten and/or molybdenum solutions from sources, such as alkaline decomposition solutions, which are contaminated with tantalum, niobium, titanium, aluminium, tin, arsenic, phosphorus and/or silicon, by application of a three stage purification process of pH reduction, anion exchange and membrane electrolysis.