A New Method of Obtaining High Purity Nickel(II) Perrhenate from Waste

Abstract

The article presents a new method of producing anhydrous nickel(II) perrhenate of high purity, entirely from waste from the national Cu industry. This method consists mainly of the reaction of water-washed nickel(II) oxide (obtained by purification in a mixture of alcohols, and subsequent roasting of the Ni-containing sulfate semi-finished products (NSP) at 1200 °C) with perrhenic acid (obtained using the ion exchange method). After the dissolution of nickel(II) oxide in the acid (at a temperature in the range of 60–80 °C) and obtaining a pH of 5–8, the solution is sent to evaporate to dryness, also at a temperature not exceeding 80 °C. The obtained crude nickel(II) perrhenate is washed with methanol and subsequently dried at 160 °C to obtain its anhydrous form, with the following composition: 10.5% of Ni; 66.6% of Re; <5 ppm of Bi, As, Zn and Cu; <10 ppm Co, Mg, Fe, K, Pb, Na, Ca and Mo. Importantly, this composition allows for the use of the compound for the production of superalloys and catalysts. A patent application and a technological scheme were prepared for the developed method. It consists of seven technological operations, including six based on processes in the field of hydrometallurgy, and one in the field of pyrometallurgy (roasting).