This invention relates to an entirely new technology of completely recovering
chromium and
vanadium from
vanadium-
chromium miscible liquid. The main procedures include: first a primary-secondary compound amine extracting agent contacts the
vanadium-
chromium miscible liquid by means of countercurrent contact and extract, so as to extract most of vanadium and a small amount of chromium into a organic phase while most of chromium stays into a aqueous phase; and a reduction reaction is conducted with pH of acid adjustable faffinate (aqueous phase) and a certain amount of a
reducing agent; the
sodium hydroxide is used for adjusting pH value of the solution and filter, and finally the product is hydrous
chromium oxide; at that time, the lye is used as a stripping agent; the vanadium is stripped from the vanadium-rich organic phase into water in the manner of countercurrent contact; and the vanadium is separated from the solution witthe method of
ammonium precipitation and in the form of
ammonium metavanadate; and finally the supernatant clear solution of the one is processed with deposited vanadium with a high-efficient
distillation technology, and the strong aqua
ammonia is left in the
tower top and deamidization solution is left in the
tower bottom until the extraction process is reached. The invention uses the primary-secondary compound amine as the extracting agent, extracts and separates vanadium and chromium selectively at a low temperature. The invention not only has a simple process flow, but also is low-cost, quite applicable in large-scale industrial production. In addition, the invention also provides high-purity
ammonium metavanadate and 16 percentage strong aqua
ammonia, and makes sure the vanadium and chromium can be completely recovered through re-use of the solution.