Abstract: Method for the production of fused silica in which a particulate silica feedstock material is passed from a silica feed tube through or near a plasma arc coupling zone in which at least two plasma arcs of opposite polarity are coupled, thereby raising the temperature of the feedstock material and collecting the material as fused silica.

Abstract: A process for the treatment of a continuous or perturbated stream of liquid material, which process consists essentially of passing the said stream of liquid material through a plasma arc coupling zone in which at least two plasma arcs are coupled at the surface of the liquid stream in order to raise both the bulk temperature of the stream and the temperature of the outer surface of the stream of material, thereby to effect a treatment of the stream selected from thermal, chemical, and a mixture of thermal and chemical.

Abstract: A method of melting materials at power densities in excess of 25 KW/ft.sup.2 of area within the metal shell of a melting vessel which method consists essentially of continuously feeding the material to be melted to a plasma arc furnace which is equipped with at least two transferred arc plasma electrodes and with means to rotate at least the portion of the furnace containing the material to be melted, melting the said feedstock material using the at least two transferred arc plasma electrodes whilst rotating at least the rotatable portion of the furnace containing the material to be melted and continuously discharging the material which has been melted from the furnace.Apparatus for melting materials under power densities of greater than 25 KW/ft.sup.2 is also disclosed.

Abstract: Material for the production of hydraulic cements or for pozzolanic materials which develop cementatious characteristics after blending with an activator, is treated in an expanded precessive plasma in a plasma reactor of the type in which at least one plasma gun orbits about a vertical axis and is directed obliquely to said axis towards a counter electrode. The material preferably includes at least a proportion of a naturally occurring carbonaceous material of low calorific value, such as colliery spoil, oil shale or oil sand. In such case, as the material emerges from the plasma it is preferably contacted with air to effect combustion of the combustible material. The thermal energy thus released is recovered by suitable instrumentalities and is preferably converted to electrical energy to power the plasma reactor.

Abstract: Apparatus and method are described for preparing a narrow trace of physiological fluid on a substrate from a discrete fluid pool. The trace so produced is substantially identical to traces manually prepared in that they are characterized by distinct macroscopic and microscopic zones. Automatic trace staining apparatus also is provided.

Abstract: A plasma arc furnace in which an expanded plasma column is generated between at least one orbiting electrode moving in a substantially circular path and a stationary electrode. The orbiting electrode is directed towards the orbital axis so as to generate a plasma column having a portion of generally inverted conical shape in the vicinity of the orbiting electrode and feedstock is introduced into the upper end of the plasma column. The orbiting electrode may be directed across the orbital axis whereby the generated plasma column is in the form of two generally conical portions meeting at a common apex.