Abstract: A method of providing a mixture of lean and rich gas of a desired composition by means of a jet compressor system comprising two or more jet compressors comprising:(1) adjusting the jet compressor system being used to mix the lean and rich gas to provide a leaner gas mixture than the desired composition;(2) then adding a predetermined amount of rich gas to the leaner gas mixture to attempt to obtain the desired composition; and(3) varying the amount of rich gas added to the leaner gas in response to the measurement of gas properties in the jet compressor system to thereby more nearly obtain a gas of the desired composition. Preferably the lean gas comprises air, blast furnace gas, or BOF gas, and the rich gas comprises methane, natural gas, propane, or butane.

Abstract: A method of surface conditioning a stainless steel to remove oxides and imperfections therefrom whereby the steel is heated in a controlled atmosphere having an oxygen potential, (log P.sub.O.sbsb.2) between (-29,280/T) + 5.6 and (-27,840/T) + 8.1 where T is the absolute temperature in degrees Kelvin.

Abstract: A coating composition containing 75-95% MgO, 2-10% B.sub.2 O.sub.3 and 0-15% C, which is effective in retarding oxidation of ferrous metal articles, especially at temperatures in excess of 2150.degree.F. Additional protection is achieved when about 11-17% TiO.sub.2 is substituted for about the same amount of MgO. The composition is admixed with a suitable vehicle and is applied to the metal surface in the form of a dispersion, suspension or as a slurry.