Joint Reduction of NiO/WO3 Pair and NiWO4 by Mg + C Combined Reducer at High Heating Rates

Functional features of Ni-W composite materials combined with successful performance enabled a breakthrough in their broad application. To disclose the formation pathway at extreme conditions combustion synthesis NiO-WO3-Mg-C and NiWO4-Mg-C systems for optimization procedure, process was modeled under programmed linear heating by thermal analysis methods. The reduction kinetics tungsten nickel oxides mixture tungstate Mg + C reducer non-isothermal studied high rates (100–1200 °C min−1) high-speed temperature scanner techniques. It shown that when moving from low to rates, mechanism both magnesiothermic magnesio-carbothermic reductions initial mixtures changes; is, transition solid-solid scheme solid-liquid is observed. strong influence rate on degree kinetic parameters study affirmed. simultaneous utilization magnesium carbon as reducers allowed lowering starting maximum temperatures processes, evidenced synergetic effect reducer. effective values activation energy (Ea) reactions proceeding NiO WO3 4Mg, 2.5Mg 1.5C, NiWO4 4Mg 2Mg 2C were estimated Kissinger isoconversional method 146 ± 10, 141 216 15 148 kJ mol−1, respectively.