Crystallization of Antimonite (Sb2S3)
In this article we shall consider the crystallization of antimonite, Sb2S3, under hydrothermal conditions in aqueous solutions of chlorides and Na2S. We studied the crystallization of Sb2S3 in ordinary autoclaves with floating titanium linings having knife-edge bearings. As solvent we used aqueous solutions of NH4C1, NH4Br, and Na2S in concentrations between 2 and 12 wt.%. The solvent was poured into the lining with an autoclave occupation factor of 0.7. The experiments were carried out at 300 and 400°C; the temperature drop was kept constant at 20°C. The duration of the experiments was times so as to leave some unspent mixture in the lining after the experiments had ended. The residue of incompletely-reacted material indicated that the process had been interrupted while material was still being supplied to the growi crystal. The rate of crystal growth could therefore be determined by dividing the thickness of the layer by the time of the experiment, which was kept constant at six days. The rate of growth of the (001) face was determined by dividing the length of the crystal by the time of the experiment. The rate of growth in a direction perpendicular to the needle axis, or in the  direction, was determined by dividing the width of the face by the time of the experiment. In each experiment we selected 100 crystals and measured them under binoculars. The results of the measurements were analyzed statistically, using the equations of  (Table 1).
KeywordsHydrothermal Condition Solvent Concentration Chloride Complex Kinetic Coefficient Absolute Growth Rate
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