Thermal characterization of glasses from Fe–Sb–S–I system

Abstract

Thermal characterization of glasses from the Fe x [(Sb 2 S 3 ) 0.75 (SbSI) 0.25 )] 100-x system, for x = 0, 0.01, 0.1, 0.5, 0.8, 2, 3 and 5 at.%, in the temperature range from 300 to 770 K, was done. The DSC recordings, obtained at different heating rates, revealed three processes: glass transition, crystallization of the corresponding crystalline phases and melting of formed crystalline phases. The glass transition process was characterized with two parameters: onset glass transition temperature T g and apparent activation energy of glass transition E g . Also, the effect of increasing the content of iron in the glass composition on the T g value was determined. The complex crystallization process corresponds to the crystallization of at least two crystalline phases: SbSI and Sb 2 S 3 . Due to the considerable overlapping of the exothermic peaks, crystallization kinetics was done for Sb 2 S 3 crystalline phase in the compositions with 0.01 and 0.5 at.% of iron. Analysis was carried out by using the Johnson-Mehl-Avrami theoretical model under non-isothermal conditions. The apparent activation energy of crystal growth E c and the value of the Avrami index n were determined. The value of Avrami index n was determined by using the Matusita-Sakka theory. It has been shown that volumetric nucleation and three-dimensional growth occur. The shape of endothermic peaks on curves, which appear behind the crystallization processes, indicated the simultaneously progress of a multiple processes. It has been found that in addition to the melting of the SbSI phase, the process of thermal decomposition of the glass also begins at given temperatures.

Microstructure and wear resistance of Ti6Al4V surfaces processed by pulsed laser

“…Those discrepancies in the prediction of martensitic layer thickness and volume fractions might be due to the reaction-rate constant K and Avrami index n used in the phase composition calculations as well as the rough estimation of β phase transition during both heating and cooling. K and n depend on the temperature, material components and the mechanism of transformation [50][51][52]. K and n in the current studies are in a temperature range of 1023 to 1223 K. However, in the experiment, the temperature range is up to 3000 K. Besides, super heating and cooling conditions are also known to cause significant changes in transformation parameters and mechanisms [53,54].…”

Recovery of Sb and Fe from Sb-bearing Slags through a Reduction Roasting Process with Low Density Polyethylene

“…The volatilization rates, α and β, for antimony and lead respectively, were calculated through Eqs. (1) and (2). .…”

“…The Sb has a variety of industrial application, especially for manufacture of flame retardant, sliding bearing and welding flux. [1][2][3] Due to the depletion of antimony primary ore resource, recovery of it from secondary resources has gained attention, such as from Sb-bearing slags, As-Sb dust and Sb alloy scraps. [4][5][6] The corresponding processing methods existed mainly consists of pyrometallurgical and hydrometallurgical processes, and the separation of Sb from As and/or Pb compounds is the key problem.…”