An evaluation of steel scrap as a reducing agent in the galvanic stripping of iron from D2EHPA

A new process to remove iron from metallurgical process streams using solvent extraction techniques has been developed. The unique aspect of the process is the use of solid metal reductants directly in the organic phase, such as D2EHPA, as a means of selectively separating the undesired metal cation impurities. The process, called galvanic stripping, has been demonstrated on both beaker and bench scale continuous levels. Previous research focussed on using zinc or iron powders as the reducing agents. A recent study evaluated the use of steel scrap as a possible alternative that might enhance the process economics and product purity. A TBP modifier to the D2EHPA was also tested to determine the effect on process efficiency. The operating variables chosen for the study included reductant surface area, reaction time, diluents and ferric ion concentration in the organic. Once the pertinent parameters were identified by feasibility tests, an experimental design with statistical analysis was utilized to optimize overall process efficiency and iron removal.