Abstract: There is described an apparatus for making metal oxide particles which are substantially free of coarse tail from an oxidizing agent and a metal reactant in a flow reactor. The apparatus can be a concentric tubular flow reactor comprising a substantially funnel-shaped reactant contacting region located adjacent to a reaction zone which is able to direct a flow of a hot oxidizing agent towards a flow of the metal reactant to form a reaction stream which flows downstream into a reaction zone, whereby the hot oxidizing agent of the reaction stream is able to surround the flow of metal reactant sufficient to prevent the metal reactant from contacting the wall of the reactant contacting region and forming scale on the wall.

Abstract: There is described a process for preparing metal oxide particles which are substantially free of coarse tail from an oxidizing agent and a vaporous metal reactant in a flow reactor; comprising, (a) directing a flow of the metal reactant into a contacting region of the flow reactor; comprising (a) passing a flow of oxidizing agent through a high temperature zone of the flow reactor to form a flow of hot oxidizing agent and directing the flow of the hot oxidizing agent onto the contacting region of the flow reactor at a flow condition sufficient to form a reaction stream comprising a flow of hot oxidizing agent, a flow of metal reactant and a diffusive flow of the hot oxidizing agent and the metal reactant, the temperature of the hot oxidizing agent being at least sufficient to initiate oxidation of the metal reactant in the diffusive flow; (c) passing the reaction stream into a reaction zone of the flow reactor, while simultaneously introducing a flow of an upper cooling fluid substantially coaxially with the

Abstract: The present invention provides a method and apparatus for the controlled synthesis of nanoparticles using a high temperature process. The reactor chamber includes a high temperature gas heated by means such as a plasma torch, and a reaction chamber. The homogenizer includes a region between the reactant inlets and the plasma (the spacer zone) to ensure that feeds from the reactant inlets are downstream of the recirculation zone induced by the high temperature gas. It also includes a region downstream of the reactant inlets that provides a nearly I dimensional (varying only in the axial direction) flow and concentration profile in the reaction zone to produce nanoparticles with narrow size distribution.

Abstract: The present invention relates to a process for recovering chlorine from a feed stream containing metal chlorides using a tubular reactor wherein a hot oxygen containing gas has an initial velocity such that the resulting velocity of the bulk gas formed from mixing the oxygen containing gas with the metal chloride feed stream and a scrubs feed stream is sufficient to remove wall deposits as fast as such deposits are formed.

Abstract: One aspect of the invention is to provide a composition comprising a titanium dioxide particle having on the surface of said particle a substantially encapsulating layer comprising a pyrogenically-deposited metal oxide; said substantially encapsulating layer having on its surface at least one organic surface treatment material selected from an organo-silane, an organo-siloxane, a fluoro-silane, an organo-phosphonate, an organo-acid phosphate, an organo-pyrophosphate, an organo-polyphosphate, an organo-metaphosphate, an organo-phosphinate, an organo-sulfonic compound, a hydrocarbon-based carboxylic acid, an associated ester of a hydrocarbon-based carboxylic acid, a derivative of a hydrocarbon-based carboxylic acid, a hydrocarbon-based amide, a low molecular weight hydrocarbon wax, a low molecular weight polyolefin, a co-polymer of a low molecular weight polyolefin, a hydrocarbon-based polyol, a derivative of a hydrocarbon-based polyol, an alkanolamine, a derivative of an alkanolamine, an organic dispersing age