To avert excessive sulfuric acid exhaustion in the classical leaching procedure and to avoid leaching of other undesirable impurities, proper alkaline leaching has been achieved for dolostone of Gabal Allouga, Southwestern Sinai, Egypt. The relevant factors for alkaline leaching of a technological sample assaying 1.2% Cu and 0.15% U were examined using a mixture of Na 2 CO 3 / (NH 4) HCO 3 solution upon two samples namely; roasted sample at 540°C and raw materials un-roasted. The leaching kinetic results showed that the leaching procedure of uranium and copper from dolostone is controlled by shrinking core kinetic model 1-2/3(X)−(1−X) 2/3 = k d t.
Three new cross-linked chitosan derivatives were yielded through intensification of chitosan with diverse types of bis-aldehydes. The prepared cross-linked chitosan was characterized by FTIR, 1H NMR, XRD, and TGA techniques. TGA indicated an improvement in thermal stability of the cross-linked chitosan compared with pure chitosan. Batch adsorption experiments showed that the three novel cross-linked chitosan bis-aldehyde derivatives possessed good adsorption capacity against U(VI) in the order of BFPA > BFB > BODB (adsorption capacity of the three adsorbents for U(VI) reaches 142, 124, and 114 mg/g respectively) and the adsorption isotherm and kinetic were well described by the Langmuir and the pseudo-second-order kinetic model, respectively. In addition, the prepared cross-linked chitosan bis-aldehyde derivatives were examined as U(VI) catcher from waste solutions.
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