Ion exchange chelating resins

The content of the ores around the world has been gradually decreasing, which results in an ever-lower concentration of metals of interest and higher levels of contaminants. This is verified in the hydrometallurgical processing of nickel laterite ore, in which the iron content is higher than that of the main elements of interest – nickel, copper, and cobalt. The untapped reserves contain iron content 8 times greater than nickel, 130 times higher than copper, and 250 times higher than cobalt. However, this becomes even more critical when considering that cobalt does not have its own ore, and its achievement is totally dependent on the extraction of nickel and copper.

For this reason, it is important the use of selective separation techniques to obtain high purity products. Among them, there are the ion exchange chelating resins. These resins have an order of selectivity, depending on their functional group, then can selectively separate the metals. Also, it is possible to use to concentrate elements presented in trace concentrations, as is the case with rare earth metals. Comparing this technique with others, the chelating resins have advantages: easy operation, cost of resins, non-flammable, reuse, and continuous operation.

So, it is possible to separate copper, nickel, and cobalt from the liquor generated in nickel laterite leaching using chelating resins in a continuous process, obtaining different concentrate solutions of these metals. Moreover, the main contaminants are present in trace concentrations.

The main equipment used for the execution of this project are X-ray fluorescence by dispersive energy (EDXRF), scanning electron microscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), cation and anion chromatography, and analyzer voltammetry (VA).