Abstract：
The new technologies used in the green transition towards carbon-free societies typically demand extensive use of metals. This leads to a heavily growing need for exploration and extraction of ore deposits. Exploration can be facilitated by measuring metal concentrations in ground and surface waters carrying trace concentrations of metals leached from nearby deposits. Currently, measuring metal concentrations in water is slow and expensive and it cannot be done on-site, which hinders the discovery of new ore deposits. To address this challenge, we have developed a method to collect and concentrate the dissolved metals in a solid filter and measure the metal concentrations directly from the filter with a portable X-ray fluorescence spectrometer. The permeable filter is made of mesoporous silicon modified with bisphosphonates. Two types of adsorbing materials for the filters were prepared based on scalable production methods: i) regenerative etching of metallurgical grade silicon powder, and ii) magnesiothermic reduction of silica from barley husks. Empirical calibrations were prepared in a concentration range of 10-200 μg/L for Mn, Co, Ni, Cu, Zn, and Pb using water samples prepared by spiking well water with standard metal solutions. Both filter types were tested for their ability to adsorb metals from the real water samples taken from drill holes. The developed system was able to detect metal concentrations down to 12 μg/L (ppb) showing its potential for on-site measurements of dissolved metals in water samples, which could be feasible in the discovery of new mineral deposits. This innovation enables smart sampling during exploration and provides real-time information on metal concentrations in water.
摘要：
在向无碳社会的绿色过渡中使用的新技术通常需要广泛使用金属。这导致对矿床勘探和开采的需求急剧增长。通过测量从附近沉积物中浸出的痕量金属浓度的地下水和地表水中的金属浓度，可以促进勘探。目前,测量水中金属浓度缓慢且昂贵，无法在现场完成，这阻碍了新矿床的发现。为了应对这一挑战，我们已经开发了一种方法来收集和浓缩固体过滤器中溶解的金属，并测量金属浓度直接从过滤器与便携式X射线荧光光谱仪。可渗透的过滤器由用双膦酸盐改性的中孔硅制成。基于可扩展的生产方法，制备了两种用于过滤器的吸附材料：i）冶金级硅粉的再生蚀刻，和ii）从大麦壳中镁热还原二氧化硅。在10-200μg/L的浓度范围内制备Mn的经验校准，Co,Ni,Cu,Zn,和铅使用通过用标准金属溶液加标井水制备的水样。测试了两种过滤器类型从钻孔采集的真实水样中吸附金属的能力。开发的系统能够检测到低至12μg/L（ppb）的金属浓度，表明其在现场测量水样中溶解金属的潜力。这在发现新的矿床中是可行的。这项创新实现了在勘探过程中进行智能采样，并提供了有关水中金属浓度的实时信息。
