Preparation of ultrafine alumina powders by plasma evaporation

Effect of quenching conditions on particle formation and growth in thermal plasma synthesis of fine powders

“…*3a2nGda-(a*)3n(t'a*) dt J (18) The initial condition for the above equation is t=0, Vr =0 (19) Once the amount of species C in the vapor phase and the condensed phase has been calculated, the concentrations of the reactants A and B can be determined by a straightforward material balance governed by the stoichiometry of the reaction in Eq. (1). The differential equations (13), (15), and (18) can be solved with the corresponding initial conditions.…”

Preparation of α-Fe2O3 submicro-flowers by a hydrothermal approach and their electrochemical performance in lithium-ion batteries

“…Among the various methods for the preparation of oxide powders, such as the sol-gel process [1], solid-state transformation [2], chemical vapour deposition [3], physical vapour deposition [4], spray pyrolysis [5], microwave-induced hydrolysis [6], and emulsion [7] and hydrothermal processes [8], the hydrothermal technique occupies a unique place, owing to its advantages over conventional technologies. Various crystalline powders with high purity, phase homogeneity, controlled morphology, narrow particle size distribution, little or no macroscopic agglomeration, and excellent reproducibility can be produced by this technique, due to a combination of simple equipment with easy sintering and less time consumption than in other methods [9,10].…”

Thermal plasma production of fumed silica: The effect of quench conditions on thickening and thixotropic ability

“…(3) The feasibility of fumed silica production using thermal plasmas has been demonstrated by various workers over the past two decades. Everest et al (1971) reported the production of ultrafine silica powders with specific surface areas ranging from 92-160 m2/g. Evaluation of the thickening *Author to whom correspondance may be addressed.…”