Flash melting

Connolly H. C., Jr., Jones B. D., and Hewins R. H. (1998) The flash melting of chondrules an experimental investigation into the melting history and physical nature of chondrule precursors. Geochim. Cosmochim. Acta 62, 2725-2735. 

Hewins R. H. and Connolly H. C., Jr. (1996) Peak temperatures of flash-melted chondrules. In Chondrules and the Proto-planetary Disk (eds. R. H. Hewins, R. H. Jones, and E. R. D. Scott). Cambridge University Press, Cambridge, pp. 197-204. 

Perhaps the best current way to view the disk of debris from which the Earth accreted was as an environment of vigorous mixing. Volatile-depleted material that had witnessed very high temperatures at an early stage (CAIs) mixed with material that had been flash melted (chondrules) a few milhon years later. Then presolar grains that had escaped these processes rained into the... 

The basic structures of the DFC burner and the FLASH melting burner are shown in figure 1. The FLASH melting burner has the structure in which the outlet of the powdered material is placed annularly. The structure makes the high dispersibility of supplied powder in the flame. 

Figure 1 Schematic of conventional FLASH melting burner and DFC burner...

We designed the DFC burner based on the FLASH melting burner to improve the heat transfer to the particles in the flame and the heat transfer to the surface of the molten glass. The DFC burner has the structure in which the outlet of the powdered material is also placed annularly and placed between outlets of the fuel. The new structure causes the flow of raw material caught between inside flame and outside flame. Because the flames heat the raw material immediately after the injection, the residence time of the particles in the flame is extended. Therefore, the raw material is heated high effectively during its fall. 

The experimental conditions are shown in table 4. Table 5 shows the results of experiment. The melting efficiency of the FLASH melting burner is 43 %. One of the DFC burner is 54%. The temperature of the melt using DFC burner is over 1410 °C. We confirmed that the DFC burner is relatively efficient as compared with the FLASH melting burners. The dso of glass cullet is about 300 pm. 

FLASH melting Bench-scale Pilot-scale burner DFC burner DFC burner... 

The high-grade matte from the converter process or the flash melting process contains sulfur and some amounts of copper, cobalt and iron and, in addition, traces of noble metals. Refined nickel is produced by a variety of methods and is delivered as nickel cathodes or nickel powder. The latter are produced partly by carbonyl processes, partly by hydrogen reduction in conjunction with pressure leaching processes. In the latter, matte is leached under pressure with acid or ammonia, and nickel is recovered as a powder by reduction with hydrogen under pressure. 

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