This procedure is different from the reported methods in the literature without any requirement of calcination
step at high temperature (e.
But Zn has low thermal stability that causes the destruction of crystalline structure during calcinations
In this work, the optimum catalyst with moderate solid acidity was obtained by adding promoters and manipulating calcination
On basis of fundamental investigations of physical processes in granulated carbon materials, structural transformations and change of thermodynamic characteristics of anthracite for the first time scientific concept of a single-stage electric calcination
of anthracite with application of an orifice plate was suggested, which ensured achievement of calcination
temperatures due to increase of current density with simultaneous reduction of specific consumption of electric energy.
, sintering or chemical conversion of the precursor into the desired ceramic at elevated temperature, with the removal of organic components from the precursor fibers (15).
The formation of a-TCP phase as the secondary phase only occurred at the lowest dopant concentration, 2 mol%, even it happened after calcinations
of 900[degrees]C and above.
The sintering technologies (Stefanescu, 2000); (Stefanescu & Sandru, 1999) are conditioned by the shaping regime, the calcinations
regime and the sintering regime:
The specific surface of the mixed alumina and zirconia support was varied by means of the calcination
temperature while the nickel loading has been examined as a function of the support specific surface and of the impregnation step conditions also; these are the concentration of the Ni nitrate in the impregnation aqueous solution and the duration of the impregnation.
In this research, several influencing parameters such as pH value and Fe/Ba molar ratio of the sol, plus thin layer calcinations
temperature, solvent type, basic agent of the sol were studied carefully.
The effect of calcinations
on powder properties was studied.
treatment (HAp) has a delaying effect on sintering at low temperature: at temperatures in the range 950 to 1000[degrees]C, grains are more rounded and coalscence is reduced, that agrees with values higher in respect to HAp-e and the possibility to identify a preceding mechanism of particle rearrangement; but, at higher temperature, decreasing the probability of grain growth, the densification can be improved.
During the calcination
process on the active surface of the moulding form it is created a network of fine cracks that give to the moulding form the required permeability for alloy casting.