The internationalisation of the Australian mineral industry in the 1990s

Overseas mineral exploration and mining investment by Australian companies increased dramatically from the early 1990s until 1997. In the wake of the Asian economic crisis and lower commodity prices it declined somewhat in 1998 and 1999. Reflecting their international competitiveness, Australian resource companies were actively involved in projects in about eighty nations in 1999. This study assesses the extent of growth in exploration and mining operations, the distribution between large and small companies and the changing regional focus which has been occurring. It also reflects on some of the key influences on this development. These include a strong domestic finance sector, supporting mining services provision, technological competitiveness, a growing attractiveness of offshore locations and increasing structural impediments at home.     

Stabilization of thioarsenates in iron-rich waters

In recent years, thioarsenates have been shown to be important arsenic species in sulfidic, low-iron waters. Here, we show for the first time that thioarsenates also occur in iron-rich ground waters, and that all methods previously used to preserve arsenic speciation (acidification, flash-freezing, or EDTA addition) fail to preserve thioarsenates in such matrices. Laboratory studies were conducted to identify the best approach for stabilizing thioarsenates by combination and modification of the previously-applied methods. Since acidification was shown to induce conversions between thioarsenates and precipitation of arsenic-sulfide minerals, we first conducted a detailed study of thioarsenate preservation by flash-freezing. In pure water, thioarsenates were stable for 21 d when the samples were flash-frozen and cryo-stored with a minimal and anoxic headspace. Increasing headspace volume and oxygen presence in the headspace were detrimental to thioarsenate stability during cryo-storage. Addition of NaOH (0.1 M) or EtOH (1% V/V) counteracted these effects and stabilized thioarsenates during cryo-storage. Addition of Fe(II) to thioarsenate solutions caused immediate changes in arsenic speciation and a loss of total arsenic from solution during cryo-storage. Both effects were largely eliminated by addition of a neutral EDTA-solution, and thioarsenates were significantly stabilized during cryo-storage by this procedure. Neutralization of EDTA was required to prevent alteration of thioarsenate speciation through pH change. With the modified method (anoxic cryo-preservation by flash-freezing with minimal headspace after addition of neutralized EDTA-solution), the fractions of mono- and dithioarsenate, the two thioarsenates observed in the iron-rich ground waters, remained stable over a cryo-storage period of 11 d. Further modifications are needed for the higher SH-substituted thioarsenates (tri- and tetrathioarsenate), which were not encountered in the studied iron-rich ground waters.     

Investigation of the usage of centrifuging waste of mineral wool melt (CMWW), contaminated with phenol and formaldehyde,in manufacturing of ceramic products

Large amounts of centrifuging waste of mineral wool melt (CMWW) are created during the production of mineral wool. CMWW is technogenic aluminum silicate raw material, formed from the particles of undefibred melt (60–70%) and mineral wool fibers (30–40%). 0.3–0.6% of organic binder with phenol and formaldehyde in its composition exists in this material. Objective of the research is to investigate the possibility to use CMWW as an additive for the production of ceramic products, by neutralising phenol and formaldehyde existing in CMWW. Formation masses were prepared by incorporating 10%, 20% and 30% of CMWW additive and burned at various temperatures. It was identified that the amount of 10–30% of CMWW additive influences the following physical and mechanical properties of the ceramic body: lowers drying and firing shrinkage, density, increases compressive strength and water absorption. Investigations carried out show that CMWW waste can be used for the production of ceramic products of various purposes.     

Comparison of alkaline industrial wastes for aqueous mineral carbon sequestration through a parallel reactivity study

Thirty-one alkaline industrial wastes from a wide range of industrial processes were acquired and screened for application in an aqueous carbon sequestration process. The wastes were evaluated for their potential to leach polyvalent cations and base species. Following mixing with a simple sodium bicarbonate solution, chemistries of the aqueous and solid phases were analyzed. Experimental results indicated that the most reactive materials were capable of sequestering between 77% and 93% of the available carbon under experimental conditions in four hours. These materials – cement kiln dust, spray dryer absorber ash, and circulating dry scrubber ash – are thus good candidates for detailed, process-oriented studies. Chemical equilibrium modeling indicated that amorphous calcium carbonate is likely responsible for the observed sequestration. High variability and low reactive fractions render many other materials less attractive for further pursuit without considering preprocessing or activation techniques.     

Anaerobic treatment of sulfate-rich wastewater in an anaerobic sequential batch reactor (AnSBR) using butanol as the carbon source

Biological sulfate reduction was studied in a laboratory-scale anaerobic sequential batch reactor (14 L) containing mineral coal for biomass attachment. The reactor was fed industrial wastewater with increasingly high sulfate concentrations to establish its application limits. Special attention was paid to the use of butanol in the sulfate reduction that originated from melamine resin production. This product was used as the main organic amendment to support the biological process. The reactor was operated for 65 cycles (48 h each) at sulfate loading rates ranging from 2.2 to 23.8 g SO(4)(2-)/cycle, which corresponds to sulfate concentrations of 0.25, 0.5, 1.0, 2.0 and 3.0 g SO(4)(2-) L(-1). The sulfate removal efficiency reached 99% at concentrations of 0.25, 0.5 and 1.0 g SO(4)(2-) L(-1). At higher sulfate concentrations (2.0 and 3.0 g SO(4)(2-) L(-1)), the sulfate conversion remained in the range of 71-95%. The results demonstrate the potential applicability of butanol as the carbon source for the biological treatment of sulfate in an anaerobic batch reactor.     

战略环评中环境合理性综合论证要点分析——以矿产资源总体规划环评为例

对矿产资源总体规划环评中的环境影响识别与预测评价以及资源环境承载力影响评价进行了简述,提出了矿产资源总体规划环评中环境合理性综合论证要点。其结论可为国内开展矿产资源总体规划环评提供技术参考,对于其他针对空间规划的环境影响评价也具有较强的借鉴意义。     

Soil burdens of persistent organic pollutants - Their levels, fate and risk. Part II. Are there any trends in PCDD/F levels in mountain soils?

Good quality data apt for an assessment of temporal trends of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) in soils are difficult to obtain since there is a general lack of information on their residues in soils. Variability of soil profiles, non-homogeneity of samples, and often also inconsistency of applied sampling procedures further complicate this problem. To assess spatial and temporal trends of contamination, three soil sampling campaigns have been performed over the period of 12 years at the mountain forest sites in the Czech Republic. Relation between the air, needle and soil contaminations was addressed in addition to time-related variability of soil. It has been confirmed that soil is a good matrix for evaluation of spatial distribution of persistent organic pollutants (POPs) but difficult for establishment of temporal trends. A slow rate of the soil-forming processes and their site-specificity was generally the major source of uncertainties.     

A natural analogue for CO2 mineral sequestration in Miocene basalt in the Kuanhsi-Chutung area, Northwestern Taiwan

In general, CO₂ sequestration by carbonation is estimated by laboratory experimentation and geochemical simulation. In this study, however, estimation is based on a natural analogue study of the Miocene basalt in the Kuanhsi-Chutung area, Northwestern Taiwan. This region has great potential in terms of geological and geochemical environments for CO₂ sequestration. Outcropping Miocene basalt in the study area shows extensive serpentinization and carbonation. The carbon stable isotopes of carbonates lie on the depleted side of the Lohmann meteoric calcite line, which demonstrates that the carbonates most probably precipitate directly from meteoric fluid, and water–rock interaction is less involved in the carbonation process. Oxygen stable isotope examinations also show much depleted ratios, representative of product formation under low temperatures (∼50–90 °C). This translates to a depth of 1–2 km, which is a practical depth for a CO₂ sequestration reservoir. According to petrographic observation and electron microprobe analysis, the diopside grains in the basalt are resistant to serpentinization and carbonation; therefore, the fluid causing alteration is likely enriched with calcium and there must be additional sources of calcium for carbon mineralization. These derived geochemical properties of the fluid support the late Miocene sandstone and enclosed basalts as having high potential for being a CO₂ sequestration reservoir. Moreover, the existing geochemical environments allow for mineralogical assemblages of ultramafic xenoliths, indicating that forsterite, orthopyroxene and feldspar minerals are readily replaced by carbonates. Based on the mineral transformation in xenoliths, the capacity of CO₂ mineral sequestration of the Miocene basalt is semi-quantitatively estimated at 94.15 kg CO₂ chemically trapped per 1 m³ basalt. With this value, total CO₂ sequestration capacity can be evaluated by a geophysical survey of the amount of viable Miocene basalt at the potential sites. Such a survey is required in the near future.     

A perspective on community and state interests in small-scale mining in India including the role of women

To achieve 8% growth of the Indian economy, the industrial sector must grow at 10% rate. The vision statements of various core sectors of the country show that the mining sector will have to expand greatly. India is among the top ten mineral producing nations in the world and the Indian mining industry indicates almost the full range of extractive mineral products. Small-scale mining is quite prevalent in India. Such mines constitute about 90% of total number of mines, 42% of the total non-fuel minerals and metals, 5% of the fuel minerals. Some 3,000 small-scale mines account for a work force of about 0.5 million people. Yet this sector is a neglected sector in Indian economy and still considered as an unorganized sector. This article examines the community and state interests in small-scale mining and the contribution of small-scale mines to employment, national mineral production, practices, and Indian policy on small-scale mining. It identifies drawbacks in the existing Government policy and discusses a possible role for the Government to upgrade the sector. This paper highlights the impacts of mining on women community, the socioeconomic characteristics of women as miners and on the productive roles that women play in mining. It also discusses how the pursuit of sustainable livelihoods, poverty alleviation, indigenous peoples right and gender equity in artesianal and small-scale mining be more effective when these communities are disadvantaged or neglected by government policies. The respective roles of the indigenous people and migrant workers in the social organization of ASM sectors in different parts of the country are discussed. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.     

论矿产资源开发与环境保护

矿产资源开发带来巨大经济效益，但也破坏了生态环境，引发了严重的地质灾害。本文讨论了资源开发和环境对社会发展的影响，提出了具体建议和方案。