Abstract: A mixture of cyanide complexes with certain Group VIII metals and other metals is passed in contact with solid subdivided cross-linked polyvinylpyrrolidone whereby the Group VIII metals--platinum, palladium, rhodium and iridium--are preferentially retained on the cross-linked polyvinylpyrrolidone. The retained metals are recovered by ashing or chemical treatment of the cross-linked polyvinylpyrrolidone.

Abstract: A high pH solution containing a silica material and an inorganic fluoride salt which hydrolyzes to form hydrofluoric acid are introduced into a subterranean zone where the pH is reduced by the acid whereby the silica material forms a gel and plugs the subterranean zone. The pH at which gelling occurs can be increased by adding a soluble inorganic salt to the solution.

Abstract: Trimethylbenzene is selectively prepared by contacting a C.sub.1 to C.sub.4 alkane with magnesium under reaction conditions to produce a reaction product. The reaction product thus produced, is contacted with water or a lower alcohol to promote a protonolysis reaction. The reaction mixture or a fraction thereof from the protonolysis reaction is contacted with a metal containing Y zeolite catalyst under reaction conditions to produce trimethylbenzene.

Abstract: A process for converting sulfide ion present in a solution to innocuous, water soluble sulfur species is provided. The process basically includes the steps of contacting the sulfide ion with an oxidizing agent to oxidize it to the water soluble sulfur species and admixing a surface active agent with the solution in an amount sufficient to inhibit precipitation of elemental sulfur and to promote subsequent oxidation. To enhance the formation of the water soluble sulfur species and to speed up the reaction, the oxidation reaction is conducted under alkaline conditions.

Abstract: High permeability zones in subterranean formations are reduced in permeability by the gelation of water soluble polymers of polyalkylenimines, polyalkylenepolyamines and mixtures thereof in such formations with cross-linking agents containing difunctional groups which are capable of cross-linking with said polymers.

Abstract: High permeability zones in subterranean formations are reduced in permeability by the gelation of water soluble polymers of polyalkylenimines, polyalkylenepolyamines and mixtures thereof is such formations with nonionic polymers which are hydrolyzable to anionic polymers which are capable of cross-linking with and gelling said water soluble polymers.

Abstract: High permeability zones in a subterranean formation are reduced in permeability by the time-delayed gelation of water soluble polymers in such formation with alkoxy amine esters of boric acid which slowly hydrolyze. Boric acid resulting from the hydrolysis converts to the borate ion which crosslinks the polymers to form gels.

Abstract: Processes and oxidizing agents for oxidizing sulfide ion found in sour water to innocuous, soluble sulfur species are provided. The processes basically comprise contacting the sour water with a nitrogen halogenated triazine or a nitrogen halogenated derivative thereof for a period of time sufficient to convert the sulfide ion to sulfate ion. The processes are particularly useful for removing sulfide ion from oil field produced waters, particularly waters associated with secondary recovery or enhanced oil recovery operations.