Passive Leached Waste Metal Remediation

废弃的金属矿曾经是英国经济和就业的重要贡献者，但却留下了问题遗留，造成了许多河流和溪流的污染。在使用时，矿井被抽水以保持地下工作干燥，然而在废弃后，水泵被拆除，慢慢地矿井充满了水。与金属矿石反应后，水形成了富含溶解金属的酸性溶液，这些溶液现在已经到达地球表面，仅在威尔士就与200多公里的河流混合在一起，全英国有453个水体违反了铅、锌和镉等金属的法律。许多处理矿井水污染的方法在英国高地的偏远地区是具有挑战性的，因为那里有许多矿井。在过去的两年中，我们开发并扩大了低碳，低成本的无源过滤系统工艺（被动浸出废金属，PLWM），使用的材料来自海藻，具有优异的金属捕获性能。我们已经在长达3个月的试验中证明，我们可以捕获几乎所有的金属污染。PLWM的主要优点是金属去除效率高，几分钟内即可完成。这意味着PLWM不需要截留大量的水，以便有时间进行处理，也不需要进行广泛而昂贵的土木工程，并将视觉影响和土地需求降至最低。与其他金属矿山处理方法相比，PLWM还有其他几个优点，包括：运行重力给料过滤器的能源需求非常低，金属捕获效率非常高，可持续且接近碳中性的主过滤材料，维护需求低。在这个项目中，PLWM将扩大到10,000 L的规模，并在威尔士的Cwmystwyth金属矿山连续运行一年，为随后的商业化提供关键的性能数据。此外，之前的试验确定了改善锌捕获所需的修改，因此，将在项目中向PLWM引入综合化学剂量。最后，综合过滤材料回收将进行大规模试验，生产含有捕获金属的酸性液体，用于场外金属回收，为金属供应和减少废物提供循环经济途径。

Once important contributors to the UK economy and employment, abandoned metal mines have created a problematic legacy, causing pollution in many of our rivers and streams. When in use, the mines were pumped to keep the underground workings dry, however after abandonment the pumps were removed and slowly the mines filled with water. Reacting with metal ore, the water formed acid solutions, rich in dissolved metal, which has now found its way to the surface of the Earth and mixed with over 200km of rivers in Wales alone, with 453 water bodies breaching legislation throughout the UK for metals including lead, zinc and cadmium. Many methods for treating mine water pollution are challenging to deploy in remote areas of upland Britain where many of the mines are.Over the last 2 years, we have developed and scaled-up a low carbon, low cost passive filter system process (passive leached waste metals, PLWM) using a material derived from seaweed, which has excellent metal capture properties. We have demonstrated in trials of up to 3 months duration that we can capture nearly all the metal pollution.The main advantage of PLWM is the high efficiency of metal removal, within minutes. This means PLWM does not need to hold back large volumes of water to allow time for the treatment to work and extensive, and expensive, civil engineering works are not required and visual impact and land requirements minimised. PLWM has several other advantages over alternative methods for metal mine treatment, including: very low energy demands to run the gravity fed filters, very efficient metal capture, a sustainable and near carbon neutral main filter material and low maintenance needs.In this project, PLWM will be both scaled up to 10,000 L scale and run continuously for a year at Cwmystwyth metal mine in Wales providing critical performance data for subsequent commercialisation. In addition the previous trial identified modifications needed to improve zinc capture and, therefore, integrated chemical dosing will be introduced to PLWM in the project. Finally, integrated filter material recycling will be trialled at scale, producing an acid liquor containing the captured metals for offsite metal recovery, providing a circular economy route to metal supply and waste reduction.