摘要:
A process for recovering palladium, rhodium and ruthenium from aqueous solutions deriving from the treatment of nuclear fuels and containing also iron and nickel, by reducing carbonylation with carbon monoxide at a pressure up to 1 atmosphere in a nitric acid solution at a pH of between 2 and 4 and at a temperature of between room and 100.degree. C. and reaction times of from 6 to 100 hours.
摘要:
There is disclosed a process for the preparation of thiocarbamates having the following general formula: ##STR1## wherein: R represents alkyl C.sub.1 -C.sub.4 optionally substituted with one or more halogen atoms, alkenyl C.sub.2 -C.sub.4 optionally substituted with one or more halogen atoms, phenyl optionally substituted with one or more halogen atoms, benzyl optionally substituted with one or more halogen atoms on the phenyl ring;R.sup.1 and R.sup.2, equal or different from one another, represent alkyl C.sub.1 -C.sub.4 or cycloalkyl;consisting in reacting organic dithiocarbonates with organic carbamoyl halides, in the presence of an aqueous solution of an inorganic base and a phase transfer catalyst, at a temperature of 10.degree. to 50.degree. C. for time periods of 5 to 10 hours.The thiocarbamates obtained are used as herbicides, fungicides, etc., and in general in various fields of "fine chemicals".
摘要:
Process for the practically total precipitation of precious metals from solutions which contain them, according to which said solutions are treated with carbon monoxide in the presence of a quantity of water or a primary or secondary alcohol at least equal in weight to the total quantity of precious metal present.
摘要:
Process for separating and recovering rhodium and/or iridium from the other precious metals (Pd, Pt, Ru, Os, Au, Ag), according to which a solution containing the precious metals in any form is treated for a time between 15 minutes and 10 hours with carbon monoxide in the presence of a quantity of water or primary or secondary alcohols at least equal in weight to the total quantity of precious metals present, the crystalline precipitate which forms, and which contains all the noble metals except Rh and Ir in a state of high purity is separated and the Rh and/or Ir are recovered practically totally from the solution.