Extraction of rare earth elements (REEs) from fly ash and bottom ash of SaskPower's Poplar River thermal power plants

SaskPower是一家省级国营公司，也是萨斯喀彻温省的主要电力供应商，其设施发电量超过3 214兆瓦，其中包括三个燃煤、七个水力发电、四个天然气和两个风力发电设施。其中，三个燃煤火力发电设施是：1）Estevan的边界坝发电站，2）Coronach附近的白杨河发电站，3）Estevan附近的Shand发电站。所有这些发电厂都使用褐煤，在锅炉中燃烧褐煤产生蒸汽，使发电机发电。然而，在燃烧煤炭的过程中，会产生大量的飞灰和底灰。SaskPower的商店都在泻湖里。这些灰含有有价值的金属，特别是稀土元素（REEs），REEs被广泛用于高科技行业，用于生产智能手机、电动/混合动力汽车、风力涡轮机、永磁体、导弹等。由于现有的泻湖容量即将耗尽，SaskPower现在希望在泻湖蓄水之前吸引大量的粉煤灰。SaskPower还计划回收和循环利用封存的粉煤灰，并生产一个稀土浓缩矿体，这可以为公司带来额外的收入，作为稀土的增值副产品。本研究拟采用湿法冶金技术，从粉煤灰和底灰中回收有价值的稀土元素。

SaskPower is a provincial Crown Corporation and is the principal electricity supplier in Saskatchewan.SaskPower generates more than 3,214 megawatts (MW) of electricity from its facilities, which include threecoal-fired, seven hydroelectric, four natural gas-fired and two wind powered facilities. Among them, three coalfired thermal electric generating facilities are: 1) Boundary Dam Power Station at Estevan, 2) Poplar RiverPower Station near Coronach, and 3) Shand Power Station near Estevan. All those power plants use brown coalcalled lignite, which is burnt to make steam in the boiler that runs the generator to produce electricity.However, during firing of the coal, huge amounts of fly and bottom ash are produced. SaskPower stores thatashin lagoons. This ash contains valuable metals, especially rare earth elements (REEs), and REEs are widely usedin the high tech industries to produce smartphones, electric/hybrid cars, wind mill turbines, permanent magnets,missiles, etc. Since the existing lagoon capacities are running out, SaskPower is now looking to attract areseller of the fly ash being produced prior to impoundment in the lagoons. SaskPower has also planned theremoval and recycling of the impounded fly ash and produce a REEs concentrated ore body, which couldgenerate extra revenue for the company as a value added by-product of REEs. In the proposed research, asustainable process will be developed to recover valuable rare earth elements from the fly ash and bottom ashusing hydrometallurgical techniques.