Thermodynamic Simulation of Simultaneous Extraction of Metals During Waste Processing Industry

The depletion of ores, a rise in the cost of their extraction, enrichment and processing led in the last 10‒15 years to a sharp rise in prices for tungsten products. Therefore, the processing began to involve technogenic waste ‒ dumps of enrichment factories and metallurgical industries, which previously did not represent the commercial interest on this case, we present the information on the results of the thermodynamic modeling of tungsten and bismuth chloride distillation in the processing of industrial waste using NaCl as a chlorinating agent. To calculate thermodynamic models for the associated extraction of tungsten and bismuth from industrial wastes, the ASTRA-4 software complex was used which created on basis of the maximum entropy of all possible reactions occurring during the retrieval of refractory metals from waste. Thus, the calculations carried out and experimental studies of the main provisions of thermodynamic calculation have shown the possibility of using NaCl salts for bismuth chlorination. At the same time, the maximum degree of sublimation of bismuth not be lower than 98% and can be achieved even at a temperature of 1200 K and a pressure of 0.01–0.1 MPa. At the same time, NaCl is not an effective chlorinating agent for retrieving of tungsten during high-temperature processing of industrial wastes.

One-Pot Synthesis of Bi/Fe3O4 and Its Catalytic Performances for 4-Nitrophenol Reduction

<p>A novel approach was successfully developed for the catalyst Bi-deposited Fe₃O₄ magnetic nanoparticles, which was used in the degradation of 4-nitrophenol (4-NP). The Bi/Fe₃O₄ composite was prepared via a one-pot process from ferrous sulfate and bismuth chloride using hydrazine hydrate as a reducing agent. The catalyst was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. In the composite pure Fe₃O₄ particles were synthesized and bismuth particles were well dispersed. The catalytic performances were investigated for the reduction of 4-NP with sodium borohydride. The catalyst has higher activity when Bi/Fe molar ratio is 1:4 in the composite and the rate constant k is about 0.611 min^-1. The catalyst has good reusability which can be used 10 cycles without obvious deactivation. Furthermore, the catalyst can be easily separated by an external magnetic field. Copyright © 2017 BCREC GROUP. All rights reserved</p><p><em>Received: 11^st August 2016; Revised: 20^th December 2016; Accepted: 21^st December 2016</em></p><p><strong>How to Cite:</strong> Cai, K.Y., Liu, Y.S., Xu, Y., Zhou, H., Zhang, L., Cui., Y. (2017). One-Pot Synthesis of Bi/Fe₃O₄ and Its Catalytic Performances for 4-Nitrophenol Reduction.<em> Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 12 (1): 89-95 (doi:10.9767/bcrec.12.1.621.89-95)</p><p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.12.1.621.89-95</p><p> </p>