Abstract: Chemical waste is burned in oxygen using an electric plasma flame to heat a stream of gas which contains at least 70% by weight oxygen. Liquid waste in fine droplet form is introduced into the gas stream via a two-fluid atomizer using a carrier gas also preferably oxygen. The total amount of oxygen present is at least 30% more than required for complete combustion of the liquid waste. The reaction mixture is maintained at a temperature of at least 1450.degree. C. for a time of at least 2 milliseconds prior to cooling rapidly of the reaction products to a temperature below 300.degree. C.

Abstract: This relates to electric arc discharge apparatus including at least two pair of electrodes and a single power source which comprises a multi-phase transformer, arc stabilization means and two or more rectifier bridges. Each rectifier bridge provides a pair of electrical power outputs to supply power to a respective pair of electrodes.The invention enables the multi arc system to be employed using a single power source and is of particular use in heating gas to be used in the oxidation of titanium tetrachloride for the production of titanium dioxide pigments.