Uranium uptake from acidic solutions using synthetic titanium and magnesium based adsorbents

Uranium uptake from acidic solutions is comprised practically in this study into three main steps namely; adsorbent synthesis, uranium uptake procedure, and desorption step. In this respect, two uranium adsorbents were synthesized from mineral processing of ilmenite and talc. Titanium phosphate adsorbent (TP) was deposited from titanium sulfate solution obtained from ilmenite sands processing. On the other hand, magnesium silicate adsorbent (MS) is prepared by sodium metasilicate neutralization of the acidic magnesium bearing waste solution resulted from talc whitening process. Structurally and chemically the two adsorbents were investigated by XRD, IR and SEM-EDX analyses. The studied factors affecting the uranium uptake onto TP and MS adsorbents were uranium concentration (10-1000 ppm), acidic pH range (1-6), contact time, shaking time and solid to liquid ratio. The uranium analysis was determined spectrophotometrically using arsenazo(III) dye where SEM-EDX analysis confirmed the uranium uptake by adsorbents. The optimum conditions obtained were applied to uranium bearing, highly mineralized granite samples (5200 ppm U) and black shale (40 ppm U). The uranium uptake was more than 98% for the mineralized granite samples and more than 97% for shale. The loaded uranium was recycled by using 0.5 and 1M HNO3 in case of TP and MS with percentage recovery of 96 and 98% respectively.