Status and new developments in field portable geochemical techniques and on-site technologies for mineral exploration

International audienceThere is an ongoing need to be innovative with the way we undertake mineral exploration. Recent technological advances that have enabled successful mineral exploration include on-site or portable instruments, on-site laboratory technologies, various core scanners, and technologies for fluid analysis. Portable or field technologies such as pXRF, pXRD, pNIR-SWIR, µRaman, and LIBS, aid in obtaining chemical and mineralogical information. Spectral gamma tools, a well-known technology, recently took advantage of improved ground and airborne (drone) instruments, to complement hyperspectral imagery. Novel, groundbreaking technology Lab-at-Rig®, was developed by CSIRO, Imdex and Olympus at the Deep Exploration Technologies CRC, and is currently being retrofitted to diamond drilling. Cuttings are separated from drilling fluids in a Solid Removal Unit (SRU), producing one meter composite mud which is sub-sampled, dried and analyzed by both X-ray Fluorescence (XRF) and X-ray Diffraction (XRD) sensors that deliver the chemistry and mineralogy of a sample, respectively. These data are automatically uploaded to a cloud-based storage platform and subjected to a range of statistical analyses with results returned to the geologist in a matter of seconds, allowing decisions to be made in near real time. At a mine site, core scanners become a useful tool to analyse meters of core as it is being drilled. Core scanners include hyperspectral and XRF systems, such as Corescan, HyLogger and Minalyzer, for example. Fluid analyses are not as common as analyses of solid materials, but there are advances in such technologies as ASV, polarography, and ion exchange electrodes aiming for analysis of commodity or environmentally important elements. With all available portable, field and on-site technologies it is now possible to collect data at the exploration site or while drilling. Certainly, field and on-site analyses cannot yet compete with laboratory analyses in terms of sensitivity, precision and accuracy due to compromises in sample preparation, instrument performance and work environment. However, field and on-site results must only achieve the level of confidence expected from the decision. Most mineral exploration decisions are based on flexible thinking rather than on a pre-set framework of investigations. One of the key benefits of real-time analyses, or short delay analyses (less than a day) is the possibility to adjust sampling plans, test hypotheses based on ongoing results, and make fast decisions on the exploration process-especially drilling and sampling. This is particularly important for remote locations, where sample logistics to the laboratory may become long and demanding

Field-portable X-Ray Spectrometry as Rapid Measurement Tool for Environmental Geochemical Investigations in Former Mining Areas: The Case of Kirki Mines (Greece)

International audienc

Geology, Genetic Processes And Their Consequences On Environmental Impacts At The Abandoned W Mine Of Enguialès, Aveyron, France

International audienc

Introduction: New developments in field portable geochemical techniques and site technologies and their place in mineral exploration.

International audienceThere is an ongoing need to be innovative with the way we undertake mineral exploration. Recent technological advances that have enabled successful mineral exploration include on-site or portable instruments, on-site laboratory technologies, various core scanners, and technologies for fluid analysis. Portable or field technologies such as pXRF, pXRD, pNIR-SWIR, µRaman, and LIBS, aid in obtaining chemical and mineralogical information. Spectral gamma tools, a well-known technology, recently took advantage of improved ground and airborne (drone) instruments, to complement hyperspectral imagery. Novel, groundbreaking technology Lab-at-Rig®, was developed by CSIRO, Imdex and Olympus at the Deep Exploration Technologies CRC, and is currently being retrofitted to diamond drilling. Cuttings are separated from drilling fluids in a Solid Removal Unit (SRU), producing one meter composite mud which is sub-sampled, dried and analyzed by both X-ray Fluorescence (XRF) and X-ray Diffraction (XRD) sensors that deliver the chemistry and mineralogy of a sample, respectively. These data are automatically uploaded to a cloud-based storage platform and subjected to a range of statistical analyses with results returned to the geologist in a matter of seconds, allowing decisions to be made in near real time. At a mine site, core scanners become a useful tool to analyse meters of core as it is being drilled. Core scanners include hyperspectral and XRF systems, such as Corescan, HyLogger and Minalyzer CS, for example. Fluid analyses are not as common as analyses of solid materials, but there are advances in such technologies as ASV, polarography, and ion exchange electrodes aiming for analysis of commodity or environmentally important elements. In this session we will introduce some techniques which appeared since 2007 or underwent major progress and discuss their benefits, challenges and pitfalls, why use them and what to expect from them. WHY USING FIELD TECHNIQUES, WHAT TO EXPECT FROM THEM Field portable technologies have seen rapid development over the past two decades, and especially in the last one. This is the result of recent technology advances that made on-site analysis possible and a credible alternative to laboratory work. We provide here a review of the main technologies involved. However, application of field technologies was slower in the more regulated exploration industry because there were quality compromises compared with conventional laboratory technologies, and therefore the same accuracy was not achievable initially. By offering analytical results on the spot, in almost real time, on-site technologies fit the increasing needs of exploration teams for fast information that provides decision making support during field work and drilling operations, and sample screening before laboratory requests. The gain in time and flexibility, even without any consideration of lower analytical costs, has a significant impact on the efficiency and cost-effectiveness of field operations, especially in remote areas. For instance, field analyses allow the selection of the most promising formations (Gałuszka et al., 2015, Zhang et al, 2017), stream or soil areas, and to focus immediately on potential targets. At a drill site, they help the geologists to identify target formations, to sample mineralised sections more precisely, and to stop drilling when necessary. Benefits are therefore expected for field costs and the length of operations. But the most important benefits are for exploration efficiency, and for improved chances to hit targets, due to continuous feedback of information. SOME TECHNIQUES WHICH APPEARED SINCE 2007 OR UNDERWENT MAJOR PROGRESS Analytical technologies designed for the laboratory are increasingly adapted for on-site use, in order to address mineral exploration needs for faster or more efficient decision making (Lemiere, 2015). This includes elemental and mineralogical solids analysis, water analysis, and other more integrated strategies. The scope of this presentation covers handheld instruments, able to operate in the field, and site portable instruments, able to operate at remote sites, with limited logistics. All should provide decision-making results within minutes or on the same day as sampling and analysis. The fast evolution of technology implies that many of them were far less advanced or even non-existent for Exploration'07

L'outil d'aide à la décision GeDSeT : évaluer les impacts et bénéfices de différentes options de gestion des sédiments

National audienceThe GeDSeT decision support tool: evaluating impacts and benefits of different options for sediment managemen

Followup procedure in time-domain F-statistic searches for continuous gravitational waves

Potentially interesting gravitational-wave candidates (outliers) from the blind all-sky searches have to be confirmed or rejected by studying their origin and precisely estimating their parameters. We present the design and first results for the followup procedure of the {\tt Polgraw} all-sky search pipeline: a coherent search for almost-monochromatic gravitational-wave signals in several-day long time segments using the $F$-statistic method followed by the coincidences between the candidate signals. Approximate parameters resulting in these two initial steps are improved in the final followup step, in which the signals from detectors are studied separately, together with the network combination of them, and the true parameters and signal-to-noise values are established.Comment: 4 pages, 4 figures, published in Proceedings of the Polish Astronomical Society, vol. 7, 37-40 (2018

The GeDSeT project: (constitution of a decision support tool (DST) for the management and material recovery of waterways sediments in Belgium and Northern France)

International audienceThe European InterReg IV GeDSeT project (2008-2013) is a contribution to a sustainable management of waterways sediments, in order to develop good practice for the development of regional fluvial transport, water resource protection and land resources preservation. The GeDSeT decision support tool (DST), one of the results of this project, carried out as a partnership between Ecole des Mines de Douai, ISSeP, CTP, INERIS and BRGM, members of the GIS-3SP cluster, aims to provide sediment management options with relevant quantitative data, in order to evaluate various scenarios taking into account cost and sustainability

National mineral waste databases as an information source for assessing material recovery potential from mine waste, tailings and metallurgical waste

We examined the national mine waste registries from seven European countries, created to fulfil the requirements of the “Mine Waste Directive” (2006/21/EC), for their potential use as an initial source of information for the valorisation of specific mine waste deposits for their resource recovery. A set of parameters for mine waste valorisation was defined and divided into three groups: the “basic”, the “metal-centric” and the “material-centric” group. The “basic” group of 19 parameters considers properties of the mine waste deposit, including the location, history, homogeneity and quantity, among others, while the other two groups relate to the two desired material recovery types. The “metal-centric” group of parameters contains the six parameters needed to preliminarily assess the potential to valorise mine waste for metal extraction, while the “material-centric” group contains the nine parameters needed to consider the use of mine waste for the production of different construction materials. National mine waste registries from Slovenia, France, Spain, Italy, UK, Hungary and Portugal were reviewed to determine whether they contain information about each of the parameters. In line with the objectives of the Mine Waste Directive, the national mine waste registries were developed to reduce or prevent environmental damage, and not to enable resource recovery from mine waste. The registries contain most of the information for the parameters in the “basic” group, less information for the parameters in the “metal-centric” group and almost no information to define the parameters in the “material-centric” group. The conclusion is that national mine waste registries could serve only as an initial source of information, and more detailed information must be obtained from other sources. This misses an opportunity to see these sites as a resource, and not only as a potential source of pollution, given the urgent need to find alternative stocks of metals within the EU (European Union)

The GeDSeT project: constitution of a decision support tool (DST) for the management and material recovery of waterways sediments in Belgium and Northern France

International audienceThe European InterReg IV GeDSeT project (2008-2011) is a contribution to a sustainable management of waterways sediments, in order to develop good practice in a perspective of water resource protection and of the development of regional fluvial transport. Waterways sediments are a major environmental issue in the Walloon region of Belgium - Northern France trans-boundary region for several reasons, all of them resulting from the dense habitat, industrial pattern and waterways network, and of a long industrial history. Sediments affect water resources quality, through pollution, and availability, through flooding. Sediment dredging allows the development of environmentally-friendly regional fluvial transport, but also generates important waste deposits. Therefore material recovery for reuse in buildings or infrastructure is a key issue, as it allows a reduction of waste and limits the need for natural resources for the same use. In order to address waterways sediments management in a global way, the GeDSeT project intends to capitalise know-how regarding the criteria to take into account for a sustainable management, and to include them in a decision support methodology applicable to the transboundary context. Such decision support aims at developing good practice in a perspective of water resource management and development of regional fluvial transport. Relevant criteria include: - criteria evaluating the physical and chemical characteristics of the sediments to be dredged, and their level of contamination, - costs of dredging operations and benefits with respect to improved waterways, - potential material value and costs of sediment treatment for material recovery versus costs of sediment deposit management. The decision support methodology will rely in part on previous BRGM and European experience in the development of an environmentally extended, physical, quasi-dynamic input-output model for waste management. Experience from other specific DSTs on sediments will be valorised with the project partners. Potential recovery of secondary resources from dredged sediment will be addressed through a review and economic evaluation of available technologies, technical and economical constraints, side effects on the uses of recovered products, and a global balance of the environmental costs and benefits. Social and employment impacts, as well as land use issues in this densely populated area will be fully acknowledged as primary decision-support criteria. The expected benefit of the project comprises also the transboundary comparison of specific situations and methods, issued from a different history.Le projet InterReg IV GeDSeT (2008-2011) est une contribution à une gestion globale durable des sédiments des voies d’eau, au développement du transport régional fluvial et de bonnes pratiques pour la protection des ressources en eau et de l’espace urbain.Les sédiments des voies d’eau sont un enjeu majeur en Europe, et particulièrement dans la région transfrontalière Belgique Wallonie – Nord de la France pour plusieurs raisons, toutes liées à la densité de l’habitat, du tissu industriel passé et présent, et du réseau de voies d’eau. Non seulement les sédiments affectent la navigabilité, mais aussi la qualité des ressources en eau, par la pollution, et la gestion des inondations. Le curage régulier des sédiments permet le développement d’un transport régional fluvial éco-favorable, mais génère d’importants volumes de déchets potentiels. La réutilisation des sédiments pour la construction ou les infrastructures est donc un enjeu clé, en combinant réduction des déchets et des besoins en ressources naturelles pour le même usage.Afin de prendre en compte la problématique des sédiments fluviaux dans sa globalité, le projet GeDSeT va capitaliser l’état de l’art sur les critères pertinents pour une gestion durable, et les incorporer dans une méthodologie d’aide à la décision applicable au contexte transfrontalier. Cette méthodologie vise à développer des bonnes pratiques en harmonie avec la gestion des ressources en eau, et le développement du transport fluvial régional

Polar polycyclic aromatic compounds (polar PACs) occurence and origin : issues and requirements for future investigations

International audiencePolar polycyclic aromatic compounds (polar PACs) are less known than PAHs, and neither monitored nor regulated anywhere, despite their potential harmfulness and greater mobility. They were rarely intentionally produced, and they occur mainly as PAH metabolites. They often occur at the same sites (gasworks, coke plants, wood treatment sites) as PAHs and other PACs but have been mostly overlooked. Other potential sites include wood tar production and oil refineries or storage affected by accidents. PAH remediation treatments, such as thermal desorption or chemical oxidation may have promoted the formation of oxy-PACs while applied, along with the mitigation of regulated PAHs. According to existing regulations, the site contamination level related to the sum of PAH was reduced, but the actual risk may have been increased. In order to identify potential risks, the monitoring of oxy-PACs is required. However, analytical capabilities are not developed, data on oxy-PACs are scarce and research is still needed. Available results from contaminated site databases and from our investigations suggest that polar PACs may constitute between 10 and 20% of total PACs in soil, and their occurrence in shallow groundwater is often overlooked at contaminated sites. Their potential impact on risk analysis is largely unknown and may be underestimated, as their transfer properties are by far less favourable than those of PAHs. Their monitoring would require analysis standards and commercially available analytical services before any regulatory approach is undertaken. This is most important for sustainable remediation of PAH-contaminated sites