Forming refractory masses

Claim 1

A process of forming a refractory mass on a surface of a substrate at a high deposition rate and with less risk of combustion within a feed line of apparatus employed, which refractory mass has a low porosity thereby rendering it compact and more durable, and contains substantially no noncombusted oxidizable material therein, the process comprising: a. admixing a mixture of oxidizable particles and refractory particles with a stream of carrier gas, which carrier gas may contain oxygen but is not substantially all oxygen; b. feeding the mixture and the carrier gas along a feed line towards a lance outlet; c. introducing oxygen gas into the feed line at at least one location therealong downstream of step a and at least about 1 m from the lance outlet; d. mixing the oxygen gas with the stream of carrier gas and the mixture of oxidizable particles and refractory particles to form a combustible mixture which is completely mixed during the flow towards the lance outlet and before reaching the lance outlet; and e. spraying the combustible mixture from the lance outlet and against the surface of the substrate, and combusting substantially all of the oxidizable particles to generate sufficient heat to soften or melt at least the surfaces of the refractory particles and form the refractory mass, which refractory mass thereby has substantially no noncombusted oxidizable particles therein.