Papers by Keyword: Hydrothermal Decomposition

Abstract: The aegirine-augite syenite potash ore, taken from Changling, Luonan in Shannxi province, were hydrothermally decomposed over the temperature ranges of 533 K to 563 K using calcium hydroxide as additive. The dissolution ratio of the K2O at different reaction temperature and time was determined. Analysis of the experimental results revealed that the dissolution rate of potash ore satisfies the chemical reaction controlled kinetic equation. The rate constant of hydrothermal reaction at different temperatures was obtained. The activation energy was calculated using the Arrhenius equation. The hydrothermal decomposition mechanism of microcline was proposed.

Abstract: We prepared nanometer-sized nickel oxide by hydrothermal decomposition. In this work, NiSO₄•6H₂O and Na₂CO₃ were used as raw materials to prepare the precursors. Nanometer-sized nickel oxide was obtained after calcining the precursors. The temperature of the calcination process affects the morphology and size of the nanometer-sized nickel oxide. The precursors and products were analyzed by TG, XRD and SEM. Sheet nanometer-sized nickel oxide was obtained and characterized by its high purity, smooth surface, regular hexagon shape, average size of 500 nm and 30-60 nm thickness. The results indicate that the NiO particles become open pore structures at a calcination temperature above 500 °C

Abstract: In this paper, Cu nano-powder was used to reduce CuO nano-powder by hydrogen reduction process, which was prepared by hydrothermal decomposition method taken CuSO4•5H2O and NaOH as raw materials. The reaction conditions of CuO nano-stick were that concentration of CuSO4 liquor was 0.1mol•L-1, concentration of NaOH liquor was 5mol•L-1, dropping speed was 50ml•min-1, pH value of reacting terminal was 12, stirring speed was 1200 r•min-1, reacting temperature was 60°C, reacting time was 30min. The CuO stick longness was 200nm, diameter was 30nm. The reaction conditions of CuO nano-boll were that dropping speed was 50ml•min-1, pH value of reacting terminal was 7, stirring speed 100 r•min-1, reacting temperature was 80°C, reacting time 30min. The diameter of CuO nano-ball was 50~100 nm. The Cu powder was prepared with materials CuO tick by hydrogen reduction in closed circular system. The higher the temperature, the reaction speed is faster. Hydrogen reduction time was 400s in reacting temperature 240°C. The Cu powder’ size was less than 100nm.