Nawshad Haque

Assessing rare earth element mineral deposit types and links to environmental impacts

Abstract Rare earth elements (REEs) have a crucial role in modern environmental and medical technologies, leading to a continuously growing demand for these elements. The relatively modest scale of the global REE mining sector means that the REE mineral deposit type knowledge base is small compared to more well-known styles of mineralisation. In this paper, we present a new classification scheme for differing REE mineral deposit types, outline the geological processes that cause REE enrichments, define characteristic grades and tonnages, and provide information on the environmental impact associated with REE mining, extraction and processing. Although current global REE supply is dominated by production from carbonatites, REEs are in fact found in a wide variety of deposits, including magmatic alkaline complex- and rhyolite-hosted REE mineralisation, REE-enriched iron oxide-copper–gold deposits, and REEs within heavy mineral sands, amongst others. Critically, REE mineralogy is linked to environmental risks during mining and refining, especially aspects such as radioactive U–Th, the use of harmful chemicals during processing and greenhouse gas emissions; future REE supply therefore needs to consider and address these environmental risks.

Application of a life cycle assessment to compare environmental performance in coal mine tailings management

This study compares coal mine tailings management strategies using life cycle assessment (LCA) and land-use area metrics methods. Hybrid methods (the Australian indicator set and the ReCiPe method) were used to assess the environmental impacts of tailings management strategies. Several strategies were considered: belt filter press (OPT 1), tailings paste (OPT 2), thickened tailings (OPT 3), and variations of OPT 1 using combinations of technology improvement and renewable energy sources (OPT 1A-D). Electrical energy was found to contribute more than 90% of the environmental impacts. The magnitude of land-use impacts associated with OPT 3 (thickened tailings) were 2.3 and 1.55 times higher than OPT 1 (tailings cake) and OPT 2 (tailings paste) respectively, while OPT 1B (tailings belt filter press with technology improvement and solar energy) and 1D (tailings belt press filter with technology improvement and wind energy) had the lowest ratio of environmental impact to land-use. Further analysis of an economic cost model and reuse opportunities is required to aid decision making on sustainable tailings management and industrial symbiosis.

Multistage leaching of metals from spent lithium ion battery waste using electrochemically generated acidic lixiviant

Lithium ion battery (LIB) waste contains significant valuable resources that could be recovered and reused to manufacture new products. This study aimed to develop an alternative process for extracting metals from LIB waste using acidic solutions generated by electrolysis for leaching. Results showed that solutions generated by electrolysis of 0.5 M NaCl at 8 V with graphite or mixed metal oxide (MMO) electrodes were weakly acidic and leach yields obtained under single stage (batch) leaching were poor (<10%). This was due to the highly acid-consuming nature of the battery waste. Multistage leaching with the graphite electrolyte solution improved leach yields overall, but the electrodes corroded over time. Though yields obtained with both electrolyte leach solutions were low when compared to the 4 M HCl control, there still remains potential to optimise the conditions for the generation of the acidic anolyte solution and the solubilisation of valuable metals from the LIB waste. A preliminary value proposition indicated that the process has the potential to be economically feasible if leach yields can be improved, especially based on the value of recoverable cobalt and lithium.

Life Cycle Assessment of Rare Earth Production from Monazite

The environmental life cycle impacts of conceptual rare earth production processes were assessed. An average greenhouse gas emission of 65.4 kg CO2e/kg was estimated for the 15 rare earths produced from monazite, ranging from 21.3 kg CO2e/kg for europium to 197.9 kg CO2e/kg for yttrium. The average water consumption of rare earth production was 11,170 kg/kg ranging from 3,803 kg/kg for samarium and gadolinium to 29,902 kg/kg for yttrium. The average gross energy requirement for production was 917 MJ/kg, ranging from 311 MJ/kg for samarium and gadolinium to 3,401 MJ/kg for yttrium. Given the low concentration of HREE in monazite, the high impacts across all categories for yttrium and other HREE are not necessarily representative of HREE sourced from all rare earth resources. Further studies into other rare earth mineral resources (e.g. bastnasite and xenotime) are recommended to improve the overall understanding of environmental impacts from rare earth production.

Issues and Challenges in Life Cycle Assessment in the Minerals and Metals Sector: A Chance to Improve Raw Materials Efficiency

A critical review was conducted on existing literature concerning life cycle assessment (LCA) and its application to the minerals and metals sector. This extensive literature search uncovers many of the issues that require immediate attention from the scientific community involved with LCA. The methodological drawbacks, mainly problems with inconsistencies in LCA results for the same situation under different assumptions and issues related to data quality, are considered to be the current shortcomings of LCA. In the minerals and metals sector, it is important to increase the objectivity of LCA by way of estimating and reporting those uncertainties; for example, whether land use has to be considered in detail or at a rough level. In regard to abiotic resource characterisation, the weight and time scales to be considered become a very critical issue of judgement. How the temporal and spatial dimensions should be incorporated into LCA is one of the biggest challenges ahead for those who are concerned. Addressing these issues will enable LCA to be used as a policy tool in environmental decision making. There has been enormous unresolved debate with respect to land use impacts, abiotic resource depletion, allocation procedure open-loop recycling and spatial and temporal dimensions. An example case has been presented for Australian iron ore using SimaPro software based on published inventory data to demonstrate that uniformity is required. Discussions aimed at bringing consensus amongst all the stakeholders involved in LCA (i.e. industry, academia, consulting organisations and government) have been presented. In addition, a commentary of different points of view on these issues has been provided. This review brings into perspective some of those contentious issues that are widely debated by many researchers. Finally, the authors conclude with their views on the prospects of LCA for future research endeavours.

Current Status and Future Direction of Low-Emission Integrated Steelmaking Process

In 2006 the Australian steel industry and CSIRO initiated an R&D program to reduce the industry’s net greenhouse emission by at least 50%. Given that most of the CO2 emissions in steel production occur during the reduction of iron ore to hot metal through use of coal and coke, a key focus of this program has been to substitute these with renewable carbon (charcoal) sourced from sustainable sources such as plantations of biomass species. Another key component of the program has been to recover the waste heat from molten slags and produce a by-product that could be substituted for Portland cement.

Characterisation of titanium-rich heavy mineral concentrates from the Brahmaputra River basin, Bangladesh

Abstract The Brahmaputra River of Bangladesh is a potential source of significant amounts of heavy mineral (HM) sand concentrates. This study provides the first ever reported characterisation data for a bulk titanium-rich HM sand sample sourced from the river system. The prepared concentrate contained ∼10–15 wt-% HMs with the remaining 85–90 wt-% of the sample comprising silicate and aluminosilicates. Modal analysis for the Fe- and Ti-rich components indicated that the HM concentrate contained 4·7% primary ilmenite, 4·4% Fe-oxide (magnetite), 0·91% titanomagnetite, 0·94% titanite and 0·08% rutile. Quantitative analysis of the ilmenite component showed the TiO2 content of the ilmenite was within the range 40–52 wt-%TiO2 (average ∼48 wt-%TiO2) with major impurities including MnO (1·83 wt-%) and MgO (0·20 wt-%) and minor impurities being Al2O3 (0·02 wt-%), Cr2O3 (0·03 wt-%), SiO2 (0·08 wt-%) and V2O5 (0·08 wt-%). Based on the composition of ilmenite and current specifications regarding ilmenite compositional purity, the most likely method for processing would be via the sulphate route.

Contributions of Prof. Tim Langrish in Drying Technology Research

It is my immense pleasure to write this brief report on the contributions of Prof. Tim Langrish in the field of drying research. Currently Prof. Langrish is the Head of the School of Chemical and Biomolecular Engineering at The University of Sydney, Australia. Prof. Langrish was born in Christchurch, New Zealand and obtained his chemical engineering undergraduate degree from the University of Canterbury. He later completed his D.Phil. (Engineering Science) from Balliol College, University of Oxford in 1989. He was a post-doctoral fellow at Harwell Lab, Oxford, U.K. and later at the University of Canterbury, New Zealand. At Canterbury, he worked very closely with Prof. Roger Keey as a collaborator throughout his career. Prof. Keey is one of the pioneers in establishing drying technology as a distinct area of chemical engineering discipline. Although I have not closely worked with Prof. Keey, I met him on brief occasions when he visited Sydney and through collaboration work with Prof. Langrish. I found Prof. Keey had qualities that an ideal devoted academic and scientist should have. I need to go back to this root because I find many of these qualities in Prof. Langrish Prof. Keey had a significant influence on his career. After working with Prof. Keey, Prof. Langrish started his teaching career as a lecturer and subsequently became a professor at the University of Sydney. Most of the members of this group once led by Prof. Keey including Prof. Langrish have made a significant contribution in the field of drying technology. According to Web of Science, 117 articles have been published by Professor Langrish in the drying field. Of these, there are 105 journal articles and 11 conference presentations. The highest number, 17 articles, were published in 2008, followed by 10 articles in 2007. The majority of these works were undertaken since he has been at the University of Sydney, Australia, and were funded by highly competitive Australian Research Council (ARC) grants. These papers were written with 92 different coauthors. The highest cited article by Prof. Langrish was co-authored by Dr. Tobias Kockel in Chemical Engineering Journal on ‘‘The assessment of a characteristic drying curve for milk powder for use in CFD.’’ His highest cited article in Drying Technology was coauthored with Dr. David Southwell on ‘‘Observations of flow patterns in a spray dryer.’’ The list of co-authors demonstrates Prof. Langrish’s many collaborations with a number of universities, institutes, organizations, companies and industry associations. Prof. Langrish has co-authors from CSIRO, NZFRI, the New South Wales Government’s Forests Agency in Australia, Pasminco Smelting, Ltd., and several leading Australian universities. Prof. Langrish has also received support and sponsorship from the engineering company Boral, Ltd.; the food companies Lang Technologies and Bonlac Foods, Ltd.; Australian government and industry R&D corporations, such as the Dairy Research and Development Corporation, the Australian Forest and Wood Products R&D Corporation, and the New Zealand government’s Foundation for Research, Science and Technology; and the solar kiln manufacturing company, Australian Choice Timber Supplies, Ltd. Drying Technology, 30: 900–901, 2012 Copyright # 2012 Taylor & Francis Group, LLC ISSN: 0737-3937 print=1532-2300 online DOI: 10.1080/07373937.2012.675860

Evaluation of Variation in the Life Cycle Based Environmental Impacts for Copper Concentrate Production

This study reported life cycle assessment (LCA) of six copper mines in Australia, Papua New Guinea and Portugal. Inventory data was sourced from published papers, sustainability reports by mining companies, independent technical reports and previous CSIRO studies. SimaPro software and various databases were used to evaluate life cycle based environmental impacts. The impact indicators were: global warming potential (GWP), acidification potential, water footprint, ecotoxicity potential, ozone depletion potential and human toxicity potential (carcinogenic and non-carcinogenic), abiotic resource depletion potential (minerals and fossil fuels), particulate matter and ionizing radiation. Generally, open pit mines were found to have a GWP of approximately 1.0 t CO2-eq/t Cu concentrate while underground mines had approximately 1.3 to 1.8 t CO2-eq/t Cu concentrate. Environmental impacts varied between mines considerably due to several factors, most notably: ore grade, mining method, flowsheets and ore mineralogy. Energy consumption and sources were significant contributors to most impact categories.

Heavy mineral resource potential of Tista river sands, Northern Bangladesh

ABSTRACT Surface and borehole sampling along a ∼80 km section of the lower Tista river, northwestern Bangladesh, indicated that the river sands offer significant potential as a heavy mineral (HM) resource. Characterisation of sediments from the surface to 15 m depth showed that the sand-sized component was dominated by quartz, feldspar, mica, lithic fragments, amphibole and pyroxene group minerals. The most common particle size was between +125–500 μm with 84 wt-% of all material reporting to this size range. Laterally spaced sampling indicated slight grain size coarsening upstream. Heavy liquid separation studies revealed that HMs such as amphiboles, micas, garnets, aluminosilicate (Al2SiO5) phases, ilmenite and zircon made up ∼10.99% (on average). The percentage of valuable HMs (ilmenite, rutile, zircon, monazite, garnet) was 2.47% (average). Detailed borehole sampling and resource mapping of a large, mid-channel sand bar showed that placer-style HM accumulations occur upstream and along the margins of the bar.