1 kW imaging furnace with in situ measurement of surface temperature

Abstract

This article describes the development and characterization of a 1kW imaging furnace that allows to investigate materials such as sulfides at ultrahigh temperatures under controlled atmosphere. Peak flux densities up to (15.37±0.66)×106Wm−2 corresponding to a maximum stagnation temperature of 3090K can be reached in the center of the heating zone of 3mm diameter (full width at half height). Individual sample holders can be mounted on a generic sample stage that is aligned in three axes. Together they define an experiment. Experiments can thus be easily interchanged without requiring any realignment. The use of a specific sample holder is reported where the sample rests on a water-cooled tip to avoid contamination by crucible material and where a protective glass dome can be mounted to allow the study of samples releasing condensable or corrosive gases. With the dome in place the peak flux density decreases to a value of (13.59±0.45)×106Wm−2 (Tstag=2980K). The surface temperature of the sample and the average irradiance can be measured simultaneously by the pyrometric method flash assisted multiwavelength pyrometry. The irradiance on the sample and, thus, the temperature reached can be controlled by adjusting the position of the sample. This is effected by a computer controlled fork lift with a resolution of 0.05mm.

Thermal decomposition of copper concentrates under concentrated radiation — Mechanistic aspects of the separation of copper from iron sulfide phases

“…In series 2, samples were initially irradiated for 45 s and then repeatedly ground, pressed and irradiated for periods of 5 s. At the end of each exposure the furnace was switched off and the sample left to cool. Within about 2 s the temperature drops exponentially from 1913 K to about 1000 K (Guesdon et al, 2006a).…”

“…Procedures 2 and 3 give the conditions for tempering in the all-liquid state (2) and partly solid state (3). Temperatures above the focal plane were experimentally determined (Guesdon et al, 2006a). After each thermal treatment the sample was ground, pressed and heated again.…”

Biomass gasification under high solar heat flux: Experiments on thermally thick samples

“…The aim of the device is to expose thermally thick beech wood samples to radiative heat flux above 1 MW/m 2 (1000 suns). In order to achieve such high heat flux, an artificial sun was used [28][29][30][31]. Two main parameters were varied during this study: initial moisture content and fiber orientation.…”

Solar extraction of copper: on application of concentrated sunlight in extractive metallurgy

“…Studies on the decomposition of copper concentrates were initiated by reacting pressed copper concentrate samples (,100 mg) in an imaging furnace. [7][8][9] Phase analysis of the solidified residues showed the formation of copper and iron sulphide. So far, none of the experiments provided evidence for a significant loss of copper owing to evaporation as it is predicted by chemical equilibrium calculations with thermochemical data for ideal phases.…”