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There is fragmentary knowledge of iron ore sources exploited in the past for many regions including the Southern Levant. This missing information has the potential to shed light on political, economic, craft-production, and trading patterns of past societies. This paper presents the results of smelting experiments performed in graphite crucibles and a muffle furnace, using 14 iron ore samples from the Southern Levant, in an attempt to determine their suitability for smelting using ancient techniques. A range of analytical techniques, including optical and electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, and portable X-ray fluorescence were used to comparatively investigate the mineralogy and composition of the precursor iron ores and their smelting products: Iron bloom and slag. Several parameters attesting to the ability of a given ore to be successfully reduced and consolidated into a solid metal mass were quantified. The generated results highlight the significance of a &lsquo ; correct balance&rsquo ; between iron oxides and other major elements in the smelting system in order to form fluid slag and a well-consolidated bloom. These data contribute to the understanding of factors, potentially influencing choices of iron ore exploitation by past human societies in the Southern Levant.

"In response to a request from the Pan American Health Organization (PAHO), an investigation was begun into possible exposures to heavy metals and sulfur-dioxide (7446095) at Empresa Metalurigica Vinto (SIC-3339), a large tin smelter near Oruro, Bolivia. Fifteen workers were selected for exposure monitoring. Of the 15, 14 had exposures greater than the NIOSH Recommended Exposure Limit or the OSHA Permissible Exposure Level to arsenic; 11 had hazardous exposures to cadmium (7440439), and eight had hazardous exposures to sulfur-dioxide. Surfaces throughout the facility were highly contaminated with heavy metals. Fifteen workers participated in biological monitoring studies. The median value for urinary arsenic (7440382) (UA) was 78 micrograms per gram creatinine. Nine of the 15 workers had UA levels exceeding the American Conference of Governmental Industrial Hygienists Biological Exposure Index. The median blood lead (7439921) level was 19 micrograms per deciliter. The authors conclude that a significant health hazard from exposures to heavy metals and sulfur-dioxide exists for some of the employees at this location. The authors recommend that measures be taken to control the hazards, including further study of exposure, implementing engineering controls, improving hygiene facilities, implementing medical surveillance programs, and improving respiratory protection programs. (A Spanish language version of this publication is available. See NTIS-PB95-261061). =" - NIOSHTIC-2 ; Shipping list no.: 95-0164-P. ; "January 1995"--P. [1]. ; NIOSH investigators: Aaron Sussell, Mitchell Singal. ; Also available via the World Wide Web. ; Includes bibliographical references (p. 26-28).

Flash sintering (FS) is of great interest today, as it allows the production of high-density ceramics in seconds at lower temperatures than conventional sintering. In this study, the effects of conventional sintering at 1250°C for 4 h and FS at various electric fields (12.5, 25, 50 and 75 V/mm) on copper smelting slag (CSS), which is a multiphase material system, are investigated. The results show that FS occurs at substantially lower temperatures with much shorter times than conventional sintering, in conjunction with improved density and hardness values for CSS. The optimum condition for better densification is observed for the sample applied the 25 V/mm electric field in 554 s, and the maximum power density of about 76.49 mW/mm3. On the other hand, the shortest FS duration is achieved with the sample applied 75 V/mm in 114 s. Flash sintering at lower temperatures also stabilizedthe magnetite-hematite the phase transition, which arouses at higher temperatures. Overall, FS has made a huge contribution to reducing sintering time and temperature while providing better microstructure integrity and mechanical properties in multiphase materials systems.