Abstract: A method for burning a fuel, containing chemically bound nitrogen, in a two-stage, rich-lean combustion process, including; introducing the fuel and at least one stream of primary air into a primary combustion region at a fuel-air ratio above the stoichiometric ratio and in a manner to intimately mix the fuel and air and establish a stabilized flame adjacent the upstream end of the primary combustion region, maintaining the flame in the primary combustion region for a period of time sufficient to produce a combustion product mixture containing less than a predetermined amount of NO.sub.x pollutants and abruptly terminating the primary combustion region while introducing at least one stream of secondary air into the secondary region in an amount sufficient to reduce the overall fuel-air ratio below the stoichiometric ratio and in a manner to prevent backflow of the secondary air into the primary combustion region.

Abstract: Water soluble thickened acid compositions suitable for matrix or fracture acidizing are provided comprising water, an acid, and a water thickening amount of a copolymer of a N-vinyl lactam and an unsaturated amide. This composition can contain in addition a crosslinking agent to give a gelled acid composition. In a preferred embodiment, a lactam-containing copolymer is made in a diluent containing dissolved electrolytes. These compositions are particularly useful in acid or matrix fracturing in subterranean formations exhibiting a hostile environment, as exemplified by high temperatures and/or high concentration of multivalent metal cations.

Abstract: Polychromium compounds such as octakis(.mu.-trimethylsilylmethyl) tetrachromium(II) as well as a process to make these new compounds are disclosed. The compounds are useful in the production of, e.g., dual valence chromium catalysts useful in the production of linear low density polyethylene.

Abstract: Olefin polymerization catalysts are described which are based on solid inorganic oxides (such as silica) and polychromium complexes (such as octakis(.mu.-trimethylsilylmethyl) tetrachromium(II)). Linear low density ethylene homopolymers with specific short chain branching as well as polymerization processes to make these polymers using the specific catalyst described are also disclosed.

Abstract: Fines are reduced in refractory materials by mixing the refractory material with an acid composition in a liquid polar organic compound and thereafter working the mixture until a decrease in volume occurs. The resulting product can be shaped and subjected to conventional finishing treatments. The resulting product exhibits reduced fines and thus is an improved material for use as a catalyst support. The resulting catalyst is of particular utility in the production of film grade ethylene polymer.

Abstract: A well-working fluid such as a drilling mud containing a mixture of sulfonated asphalt and a causticized lignite. The use of the mixture gives a less expensive composition than would be the case with pure sulfonated asphalt and at the same time results in a higher quality fluid in that foaming is reduced and on balance the rheological properties are improved. The invention is of particular applicability in drilling muds using conventional ingredients such as clays and polymeric thickening agents such as CMC.

Abstract: Water-soluble polymers comprising an N-vinyl lactam are found to be useful in processes wherein the polymer is introduced into a subterranean wellbore.Polymers useful in the recovery of natural resources are prepared by polymerizing an N-vinyl lactam by free radical initiation, with polymerization conducted in an aqueous solution polymerization medium preferably containing a mixture of dissolved electrolytes, or in a polymerization medium consisting essentially of a tertiary alkanol. Copolymers of such N-vinyl lactams with unsaturated amides, and terpolymers prepared by polymerizing an N-vinyl lactam and an unsaturated amide with a selected termonomer compound are also useful when prepared by these methods.

Abstract: A catalyst support based on aluminum polyphosphate or polyphosphoric acid-impregnated alumina is provided by two alternative techniques. In the first embodiment, an aluminum polyphosphate composition is heated in a dry atmosphere and thereafter impregnated with a zerovalent chromium component under anhydrous conditions. The resulting catalyst is active for olefin polymerization. In the second embodiment, alumina is impregnated with a polyphosphoric acid composition. This resulting polyphosphoric acid impregnated alumina can be used as a support for zerovalent chromium or can be impregnated with a chromium component and oxidized to give an active hexavalent chromium species. The resulting catalysts are advantageous because of their unusual sensitivity to hydrogen thus allowing great leeway in molecular weight control.