Separation and Recovery of Uranium and REEs from Rock Sample from El Sela Area using Treated Waste Clay

Abstract

In this study a sample El Sela area has been characterized using XRD, XRF, and ICP–OES. The factors affecting the leaching of both uranium and REEs from El Sela ore material including type of acid and its concentration, the particle size of ore, additives, the effect of solid to liquid phase ratio, stirring speed, leaching time and temperature have studied as well. Treated clay (TC) and treated clay impregnated with different organic reagents such as N‒cetyl‒N,N,N‒trimethyl ammonium bromide (CTAB), m‒aminophenol (AITC), gallic acid (GITC), and ß‒naphthol (NITC) have used as adsorbent materials to adsorb both uranium and REEs ions from their aqueous solutions. The effect of pH value, contact time, dose of adsorbent, initial metal ion concentration, and temperature have studied to investigate adsorption efficiencies of uranium as well as REEs. The maximum uranium loading capacities on TC, GITC, and NITC are 37.2, 193.0, and 175.2 mg/g, respectively, while the REEs maximum loading capacities on TC, CITC, and AITC are 30.6, 186.8, and 171.32 mg/g, respectively. The adsorption process of uranium and REEs followed well the pseudo–second–order kinetic as well as Langmuir isotherm model. The adsorption of uranium and REEs ions on TC is non‒spontaneous, while the adsorption of uranium on acid GITC, and NITC adsorbents are spontaneous. Moreover, the adsorption of REEs ions on both CITC and AITC adsorbents are spontaneous. The adsorption process of uranium and REEs are exothermic for the all adsorbents. Furthermore, the negative value of ∆Sº indicates the feasibility of adsorption and the decreased randomness for all adsorbents. The optimum desorption conditions of loaded uranium and REEs on the adsorbents have been studied as well.