Abstract: DL pantolactone is made by(a) introducing isobutyraldehyde, formalin and sodium cyanide solution continuously at a predetermined rate into a circulation reactor, continuously circulating the said mixture in said reactor while cooling the circulating mass in a heat exchanger, thus continuously causing the heat generated in the reaction between the components of said mixture to be discharged in said heat exchanger and by continuously re-mixing the formed reaction product with the reaction components;(b) continuously passing part of the reaction product into an after-treatment reactor where the said reaction is completed without re-mixing so as to form formisobutyraldolcyanohydrin;(c) passing the latter product into a first reaction chamber, reacting therein the product with a continuously introduced non-oxidizing strong acid at an elevated temperature and pressure so as to hydrolyze the product, thus forming a solution of .alpha.,.gamma.-dihydroxy-.beta.,.beta.

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.