Method for producing homogeneous mixtures of rhenium(VII) salts

Abstract

The subject of the application is a method for producing mixtures of rhenates(VII) of selected metals, i.e. copper and / or nickel and / or cobalt, which is characterized in that nickel(II) oxide with a grain size ranging from 10 to 50 nm and / or cobalt(II) oxide is added to rhenic(VII) acid with a rhenium concentration of ≥50 g / dm3, neutralization is carried out at a temperature of 75°C - 85°C until a pH of 0.7 - 1.5 is obtained, the undissolved residue is filtered and washed cyclically using 0.005 - 0.020 dm3 of isopropyl alcohol for each 1 g, and the undissolved residue is returned to the neutralization of a new portion of rhenic(VII) acid in such an amount that the mass of the undissolved residue does not exceed 75%, while the filtrate resulting from the filtration of the undissolved residue is added copper(II) oxide is added successively until a pH of 3.8 - 4.3 is obtained, neutralization is carried out at a temperature of 75°C - 85°C for another minimum of 60 minutes,the undissolved copper residue is filtered and washed cyclically using 0.005 - 0.020 dm3 of isopropyl alcohol for each 1 g of undissolved copper residue, the undissolved copper residue after washing with isopropyl alcohol is returned to the neutralization of rhenic acid (VII) after its prior neutralization with nickel (II) oxide and / or cobalt (II) in such an amount that the mass of the undissolved copper residue does not exceed 50%, while the filtrate resulting from the filtration of the undissolved copper residue is sent for evaporation to dryness, the evaporation is carried out at a temperature not exceeding 85°C, the precipitate thus formed is sent for drying, first at a temperature of ≥150°C for 3 - 6 h, and then at a temperature of ≥190°C for 6 - 12 h, until a constant, homogeneous, non-hygroscopic mass is obtained mixtures of rhenates(VII), containing in total ≥10% of copper and / or nickel and / or cobalt,