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

萨斯克电力公司是一家省级皇家公司，是萨斯喀彻温省的主要电力供应商。SaskPower的电力设施发电量超过3214兆瓦（MW），其中包括3座燃煤电厂、7座水力发电厂、4座天然气发电厂和2座风力发电厂。其中，3个燃煤火力发电设施分别是：1)埃斯特万边界坝电站，2)科罗纳奇附近的白杨河电站，3)埃斯特万附近的山德电站。所有这些发电厂都使用褐煤，这种褐煤在锅炉中燃烧产生蒸汽，从而驱动发电机发电。然而，在煤的燃烧过程中，产生了大量的飞灰和底灰。SaskPower将其储存在泻湖中。这种灰烬含有有价值的金属，尤其是稀土元素（ree），稀土元素被广泛用于高科技行业，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现在正在寻找在泻湖蓄水前生产的粉煤灰的卖家。SaskPower还计划清除和回收被扣押的飞灰，生产稀土精矿，作为稀土的增值副产品，这可能为公司带来额外收入。在本文的研究中，将开发利用湿法冶金技术从粉煤灰和底灰中回收有价稀土元素的可持续工艺。

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.