Feasibility of Removing Transition Metals from Liquid Propellant Solutions byCathodic Reduction

摘要

Electrochemical and some nonelectrochemical techniques were experimentallyevaluated for removing trace quantities of iron and copper from hydroxyl ammonium nitrate solutions. A high mass transfer packed bed electrochemical reactor was designed and built for removing the trace metals by cathodic plating. Several bed materials were evaluated including lead and amalgamated copper. Electrode potential and solution pH were the operating variables studied. Although cathodic plating of copper worked quite well with removal efficiency of 93%, iron was not so efficiently removed. It was determined that lead was unsuitable as a substrate, but amalgamated copper (and perhaps graphite) are still candidate substrate materials. Both electrochemical and nonelectrochemical techniques for removing metal ions as a hydroxide precipitate were investigated. Some success appeared to be achieved using alumina as a coagulation agent at a pH of 3.1. These results have yet to be reproduced. This report presents the details of the experiments of this research. Keywords: Liquid propellants, Cathodic reduction, HAN, Iron, Hydroxylammonium nitrate, Copper, Electrolysis, Transition metals. (JS)