Abstract: A process is disclosed for the separation of 4-androsten-3,17-dione/1,4-androstadien-3,17-dione mixtures, which are produced, e.g., upon microbiological sterol-side chain decomposition, through conversion of said mixture into a mixture of 17.beta.-cyano-17.alpha.-hydroxy-4-androsten-3-one/17.beta.-cyano-17.alpha .-hydroxy-1,4-androstadien-3-one, from which the difficultly soluble 17.beta.-cyano-17.alpha.-hydroxy-4-androsten-3-one is separated in crystalline form through filtration, and the 17.beta.-cyano-17.alpha.-hydroxy-1,4-androstadiene remaining in the mother liquor is re-split, directly or after extraction with organic solvent, by treatment in alkaline medium, into 1,4-androstadien-3,17-dione, and isolated as such. The separation of the products follows in high yields, and in sufficient purity for further working-up in the synthesis of androstane and pregnane derivatives, as well as estratrienes.

Abstract: An apparatus for making DL-pantolactone in a continuous process comprises the following parts and setup:A circulation heater and a circulation reactor, means for introducing the components into the reactor, a heat-exchanger forming part of the circulation reactor, a longitudinal aftertreatment reactor and a final longitudinal reactor comprising dual reaction chambers with means for applying heat and pressure in the first chamber and maintaining the reaction product in the second chamber at such heat and pressure. The apparatus may also include a chamber for forming a premix of some of the components with a subsequent cooling device prior to the introduction into the circulation reactor. It may furthermore include a stripping column and pulsation column for recovering the final product from the solution.

Abstract: The method comprises preheating a cyanide solution to be detoxified by passing the cyanide solution through a heat exchanger and initiating a detoxifying hydrolysis of the cyanide solution by subjecting the cyanide solution to a temperature shock raising the temperature of the cyanide solution to between about 200.degree. and 250.degree. C and passing the cyanide solution through a tubular reactor at a pressure of between about 40 and 140 atm.