Pyrometallurgical slags from three Cu-Co smelters (Nkana, Mufulira, Chambishi) in the Copperbelt Province, Zambia, were studied from mineralogical and chemical points of view. The slags were enriched in metals and metalloids, mainly Cu (up to 35 wt.%), Co (up to 2.4 wt.%) and As (up to 3650 ppm). The following primary phases were observed in slags: Ca-Fe silicates (clinopyroxene, olivine) and leucite, oxides (spinel-series phases), ubiquitous silicate glass and sulphide/metallic droplets of various sizes. The presence of glass and skeletal/dendritic crystal shapes indicated rapid cooling of the slag melt. Copper and cobalt were found in low concentrations in the majority of silicates (olivine, clinopyroxene) and oxides, substituting for Fe in their structures (up to 7.15 wt.% CoO in olivine, 4.11 wt.% CuO in spinel). Similarly, up to 0.91 wt.% CoO and 6.90 wt.% CuO were observed in the interstitial glass. Nevertheless, the main carriers of these metals in the slags studied were Cu sulphides (digenite, chalcocite, bornite, chalcopyrite), Co-Fe sulphides (cobaltpentlandite), Co-bearing intermetallic phases ((Fe,Co)2As) and alloys. Weathering features corresponding to the presence of secondary metal-bearing phases, such as malachite (Cu2(CO3)(OH)2), brochantite (Cu4SO4(OH)6) and sphaerocobaltite (CoCO3), were observed on the slag surfaces. They indicate that the slags studied are reactive on contact with water/atmosphere and that their environmental stability and release of potentially harmful metals and metalloids must be evaluated further.

Slag dumps occur at several historical smelting sites in north Queensland, Australia. The microcrystalline slags contain primary slag phases, relict flux, ore and furnace materials and secondary weathering related minerals. Common primary slag phases are glass, Zn-rich fayalite (± Zn-rich kirschsteinite) and Zn-rich hedenbergite. Other minor minerals include wollastonite, Zn-rich melilite, Zn-rich iscorite (Fe7SiO10), magnetite as well as a number of sulphides (pyrrhotite, galena, bornite, sphalerite, wurtzite), metallic phases (Ag, Cu, Pb, Sb), alloys (Cu3Sn), and unknown metal compounds. The slag materials contain wt.% concentrations of Zn and elevated levels of Ag, As, Cd, Cu, Ni, Pb, Sb and W. Glass, hedenbergite and fayalite/kirschsteinite are the main repositories of Zn, whereas much of the Cu and Pb is hosted by glass, sulphides, Cu3Sn alloys, metallic Cu and Pb, and unknown CuSb, AsSnPb and FeAsCu compounds. The slags are undergoing contemporaneous reaction with air and rainwater. The weathering results in the release of metals and metalloids from primary slag phases, particularly from glass, and the partial immobilization of these metals in secondary soluble and insoluble minerals in the slag heaps. Zinc exhibits pronounced chemical mobility and reports together with elevated Ca and sulphate into surface seepages (up to 10.2 mg l−1 Zn at pH 6.97). The slag dumps represent long-term sources of metal pollutants, particularly of Zn, to local ground and surface waters.

Toxic trace elements present an environmental hazard in the vicinity of mining and smelting activities. However, the processes of transfer of these elements to groundwater and to plants are not always clear. Tharsis mine, in the Iberian pyrite belt (SW Spain), has been exploited since 2500 BC, with extensive smelting taking place from the 1850s until the 1920s. Sixty four soil (mainly topsoils) and vegetation samples were collected in February 2001 and analysed by ICP-AES for 23 elements. Concentrations are 6—6300 mg kg-1 As and 14—24800 mg kg-1 Pb in soils, and 0.20—9 mg kg-1 As and 2—195 mg kg-1 Pb in vegetation. Trace element concentrations decrease rapidly away from the mine, with As and Pb concentrations in the range 6—1850 mg kg—1 (median 22 mg kg—1) and 14—31 mg kg—1 (median 43 mg kg—1), respectively, 1 km away from the mine. These concentrations are low when compared to other well-studied mining and smelting areas (e.g. 600 mg kg—1 As at 8 km from Yellowknife smelter, Canada; >100 mg kg—1 Pb over 270 km2 around the Pb-Zn Port Pirie smelter, South Australia; mean of 1419 mg kg—1 Pb around Aberystwyth smelter, Wales, UK). The high metal content of the vegetation and the low soil pH (mean pH 4.93) indicate the potential for trace element mobility which could explain the relatively low concentration of metals in Tharsis topsoils and cause threats to plans to redevelop the Tharsis area as an orange plantation.

In this reconnaissance study, skeletal materials from people, dating from ∼1500 B.P., who lived by or worked at the ancient copper mines and furnaces of the Wadi Faynan in southern Jordan, were analysed using atomic absorption spectrophotometry (AAS) to determine the intensities of accumulation of copper and lead in their bones. Many of the bones analysed contained concentrations of these metals which are comparable to those of modern individuals who are heavily exposed to metals through contemporary industrial processes.

Patterns of partitioning throughout the skeleton of a number of individuals were also studied. These AAS data suggest that within the human organism there may be some ability to influence the patterns of accumulation of copper within the skeleton. The humerus was frequently found to contain more copper than other bones studied. Within the humerus itself, the medial epicondyle frequently contained the highest concentrations, which may indicate a significant degree of organization or control of the process. These metal concentration data together with their toxicological consequences suggest that the health of the ancient human populations must have been adversely affected by exposure during life to copper in the environment. They also point to the need for further detailed studies of metal partitioning within the bones of the human skeleton.

The scientific investigation involves the examination of copper alloy nails dated back tothe Roman Age. The artifacts were retrieved from a shipwreck discovered offshore Elbaisland (Italy). Further carbon dating measurements indicated the origin between 140 and300 AD. This work includes a brief overview of the ship’s routes and fortunes in order togive some context to the metallographic investigations. The experimental procedureinvolves the use of both Optical and Scanning Electron Microscopy (OM and SEM) coupledwith EDS and EBSD probes. The attention has been focused on the metallurgical features ofthe nails with the intent of casting some light on the metalwork processes of the RomanAge. The scientific trials revealed a “brazed” joint, which allowed to learn more aboutthe applications of this technique during this historical period. In addition, thetextural analysis yielded a strong work-hardening, evidence of an intense cold shapingprocedure in use by the Roman blacksmiths.