Selection of Elements at the Dissolution of Heat Resistant Nickel Alloys in Mineral Acid Solutions

Abstract

Thermodynamic modeling of the interaction of a heat-resistant nickel alloy containing refractory rare metals with hydrochloric, sulfuric and nitric acids with a temperature change in the range of 20-100 ∘ C and a concentration of 50 to 150 g / dm3 at a pressure of 1 atm was carried out. The thermodynamic assessment data were confirmed in experiments on the anodic dissolution of the alloy in sulfate solutions. According to the results of x-ray phase analysis of the sludge, it was revealed that tungsten in the form of a solid solution in nickel passes to this product. Also, tantalum and niobium pass into the slurry in the form of oxides. Mostly, Re, Co, Cr passed into the electrolyte solution. The results of the study can serve as a scientific basis for the development of promising technologies for processing metal waste from heat-resistant alloys. Keywords: thermodynamic modeling, heat resistant nickel alloy, rare elements, mineral acids, dissolution