摘要:
A process is disclosed for the leaching of gold and silver from ores and ore concentrates through intimate contact of the ore or ore concentrate with an aqueous leach solution containing cyanide. The leach solution has a pH of 8 to 13. The leaching process takes place in the presence of an oxygen-releasing peroxo compound. The separation of the formed cyano complexes of gold and silver takes place in a known manner. During leaching, at least one peroxoborate compound is present, in an effective quantity, as the peroxo compound. The peroxoborate is preferably a sodium or calcium peroxoborate. Compared to previously known leaching techniques in the presence of hydrogen peroxide or calcium peroxide, the leaching process according to the present invention provides a higher and/or faster precious metal yield and/or minimizes the consumption of cyanide and/or oxidizing agent.
摘要:
Novel .alpha.-haloethylcarbamyl halides and a process for their manufacture by reacting vinyl isocyanate with a hydrogen halide.The .alpha.-haloethylcarbamyl halides, especially .alpha.-chloroethylcarbamyl chloride, prepared by the process of the invention, are valuable starting materials for the manufacture of surface-coating raw materials, textile coatings, dyes, drugs and crop protection agents.
摘要:
New N-fluoromethyl-carbamic acid fluorides and a new process for their manufacture by reacting N-halomethyl-carbamic acid halides with metal fluorides. The products are starting materials for the manufacture of drugs, dyes, pesticides, plastics, plastics auxiliaries and textile auxiliaries.
摘要:
New and valuable N-cycloalkyl-, N-alkenyl- or alkynyl-substituted carbothiolates having a good herbicidal action, herbicides containing these compounds, a process for controlling the growth of unwanted plants with these compounds, and a process for producing these compounds.
摘要:
New and valuable pesticide on the basis of an active ingredient from the group of organophosphorus compounds or chlorinated hydrocarbons, and additionally containing a thiol carbamate.
摘要:
Halogenated tertiary alkyl isocyanates and a process for their preparation by reacting a tertiary alkyl isocyanate with halogen, sulfuryl chloride and/or sulfuryl bromide.The halogenated tertiary alkyl isocyanates prepared by the process of the invention are valuable starting materials for the preparation of pest control agents, fatliquoring agents, drugs, flameproofing agents, lubricating oils, synthetic resins and slip agents.
摘要:
1-Monohalogenated isocyanates, and a process for the preparation of mixtures of 1-monohalogenated isocyanates and 1,2-unsaturated isocyanates by reacting 1-monohalogenated carbamic acid halides or isocyanates with a halogen-free isocyanate or diisocyanate or by reacting 1,2-unsaturated isocyanates with a carbamic acid halide or a bis-carbamic acid halide.The 1,2-unsaturated isocyanates and 1-monohalogenated isocyanates prepared according to the invention are valuable starting materials for the preparation of pest control agents, dyes, drugs, water-repellent textile finishes, detergents, plastics, bleaches and adhesives.
摘要:
Aroylureas of the formula ##STR1## where A denotes a phenyl, thienyl or pyridyl-3 radical which is mono- or polysubstituted by halogen, linear or branched alkyl of 1 to 4 carbon atoms, or linear or branched alkoxy of 1 to 4 carbon atoms, R denotes linear or branched alkyl of 1 to 4 carbon atoms or linear or branched alkoxy of 1 to 4 carbon atoms, and n denotes one of the integers 0,1 and 2, which have an insecticidal and acarididal action, and a process for combating insects and mites with these active ingredients.
摘要:
A process for the preparation of 2,2-dimethyl-4-cyano-butyraldoxime N-methyl-carbamate wherein 2,2-dimethyl-4-cyano-butyraldoxime is reacted with an at least equimolar amount of methylcarbamic acid chloride in the form of a concentrated solution of at least 8 moles thereof per liter of inert organic solvent, in the presence of from 1.05 to 2 moles of a tertiary aliphatic amine per mole of 2,2-dimethyl-4-cyano-butyraldoxime, at from 0.degree. to 30.degree. C.
摘要:
A process for the preparation of substituted fluorobenzenes which contain a nitro group or a cyano group and may or may not contain an aliphatic radical or an additional halogen atom, wherein the corresponding substituted chlorobenzene is reacted with potassium fluoride in the presence of a crown ether and a solvent at from 150.degree. to 230.degree. C.