Regeneration method for a process waste containing sulfur and phosphorus.

摘要

The present invention is related to a method for treatment of a process waste containing sulfur and phosphorus and/or compounds thereof. The waste is preferably a by-product from the synthesis of alkylthiophene compounds. The method is characterized by the following steps: (a) adding sulfur to the process waste to produce a mixture, (b) evaporating the mixture of step (a) at a temperature of 500 - 700 DEG C to separate it into a gaseous product and a solid evaporation residue, (c) condensing the gaseous product of step (b) to recover a purified phosphorus pentasulfide and furnishes phosphorus pentasulfide of sufficiently high purity for recycling in said synthesis process, as well as an evaporation residue suited for use as a raw material for fertilizers. In the treatment method according to the invention, the process waste is subjected to vacuum evaporation in a combination heating/evaporation reactor at 500 - 700 DEG C and under a partial vacuum of 0.01 - 0.2 atm or is evaporated at atmospheric pressure in the presence of an inert gas. The evaporating phosphorus pentasulfide is condensed, and when desired, pulverized. The usable, phosphorus- and potassium-containing evaporation residue is removed from the reactor and cooled for further use.