Adsorption extraction of nickel (II) from industrial aqueous solutions

Abstract

A scheme for the primary unit of a technological means for the adsorption extraction of nickel from industrial solutions resulting from the processing of oxidised nickel ores is presented. The solutions comprise an aqueous extract of complex compounds of transition metals from an ore having an initial nickel content of 1-2 %. The traditional stepwise treatment of the solutions is oriented towards sequential precipitation of metals by ammonia water in the form of hydroxides, involving their decantation and filtration, etc., which significantly complicates the process of obtaining the target metal. The adsorption process significantly increases the economic efficiency of the extraction process for this valuable metal. In terms of their properties, carbon sorbents are chemically resistant, able to endure the harsh conditions of high temperature exposure and treatments based on strongly acidic and strongly alkaline solutions. Moreover, such sorbents have a developed porous structure, a significant specific surface area and high mechanical strength. The process of nickel extraction using carbon adsorbents from solutions in a weakly alkaline environment at elevated temperatures is described. The scheme of the nickel (II) ion extraction by adsorption unit is based on the use of a fluidised bed whose operational parameters are calculated directly by studying the sorption of nickel ions. The adsorption extraction of nickel (II) ions facilitates the complete selective separation and derivation of the metal following desorption of a saturated solution making the process suitable for direct electrolytic metal production.