Electrochemical Dissolution Process of Tungsten Carbide in Low Temperature Molten Salt System

Tungsten was extracted from LiCl-KCl-Li2WO4 molten salt with tungsten carbide as soluble anode, and its electrochemical dissolution was studied. Although the fused salt electrochemical method has the advantages of short process and easy operation of the equipment, there are some problems in the current electrolysis process, such as higher electrolysis temperature, high energy consumption and complex composition of the products, in order to reduce the electrolysis temperature and energy consumption, tungsten was extracted by LiCl-KCl-Li2WO4 molten salt system at 400-600°C. In addition, compared with the blank salt electrolysis, the addition of Li2WO4 as the active material makes the reaction more likely to occur, and improves the dissolution efficiency and the current efficiency. Through a series of electrochemical tests, it is proved that adding Li2WO4 decreases the charge transfer resistance, speeds up the reaction and studies the oxidation-reduction process of tungsten ion in tungstate, it is proved that the redox process is a reversible process controlled by diffusion. Clusters of spherical tungsten powders were prepared at 500℃ by changing the experimental parameters to obtain the optimal conditions.

Physical and Electrical Studies of High Molecular Weight Poly (Methyl Methacrylate) Based Solid Polymer Electrolytes

In this work, the film contained a mixture of PMMA, salt, and plasticizers are studied. PMMA as a host polymer, ammonium trifluoromethane sulphonate or ammonium triflate (NH4CF3SO3) as a doping salt and ethylene carbonate (EC) as a plasticizer is used in this present study. PMMA salt complexes system and plasticized PMMA salt complexes system are prepared by solution cast technique at room temperature. FTIR is used to study the interaction between polymer and salt, and between polymer–salt and plasticizer. The carbonyl group C=O asymmetric stretching mode observed at 1721 cm-1 is broadened and shifted to lower wavenumber when ammonium triflate was added into PMMA. The broadening, shifting and reduction in wavenumbers of FTIR spectra show that the complexation has occurred between the polymer and salt. EIS is performed to measure the electrical conductivity of the polymer–salt system prepared at ambient temperature. The electrical conductivity of film containing 1.0 g of PMMA–35 wt% NH4CF3SO3–16 wt% EC exhibit the highest electrical conductivity with the value of 2.461 x 10-4 S/cm2. XRD is carried out to study the pattern of pure PMMA, PMMA–NH4CF3SO3 and PMMA–NH4CF3SO3–EC. The XRD analysis shows the addition of plasticizer to the polymer–salt system increase the amorphousness of the polymer electrolytes hence increases in conductivity.