Hydrothermal Oxidation of Si3N4 Powder

INFLUENCE OF Si-POWDER CHARACTERISTICS ON THE PORE STRUCTURE OF Si-POWDER COMPACTS AND OF REACTION-BONDED Si3N4

In order to achieve a homogeneous starting material for the production of dense Si3N4 by post-sintering of RBSN, the morphological and chemical characteristics of the Si-starting powders as well as the pore structure of the Si-powder compacts have to be optimized. In this context, the influence of the grain size distribution on the micropore size distribution of the Sipowder compacts was determ...

Synthesis of Hydroxyapatite Bio-Ceramic Powder by Hydrothermal Method

Hydroxyapatite bio-ceramic powder was synthesized using waste eggshells as calcium source by a straight forward thermal method. The process is carried out at high temperature. Different calcium phosphate phases were obtained just by changing the thermal treatment. HAp is the only apatite present in the reaction products, along with minute fractions of other calcium compounds. The final product ...

Hydrothermal Oxidation of Fecal Sludge: Experimental Investigations and Kinetic Modeling

Hydrothermal oxidation (HTO) provides an efficient technique to completely destroy wet organic wastes. In this study, HTO was applied to treat fecal sludge at well-defined experimental conditions. Four different kinetic models were adjusted to the obtained data. Among others, a distributed activation energy model (DAEM) was applied. A total of 33 experiments were carried out in an unstirred bat...

Supercritical water oxidation of recalcitrant compounds under a hydrothermal flame

Supercritical water oxidation (SCWO) is able to completely mineralize every kind of waste in residence times lower than one minute. Supercritical water oxidation in presence of hydrothermal flames can reduce residence times to the order of milliseconds. The most recalcitrant compounds in terms of difficulty to oxidation for the supercritical water oxidation are acetic acid and ammonia. The obje...

The oxidation state of hydrothermal systems on early Enceladus