Fine particle flotation: Niobium minerals

这项研究计划针对矿物加工和关键和战略金属供应方面的两个重要挑战。它们是：1)铌回收和2)细颗粒浮选。铌是一种重要的合金金属，主要存在于高级结构钢中。第二大应用是高温合金，例如在飞机发动机部件中，铌提供的高热阻至关重要。鉴于铌的供应风险和经济重要性，它已被欧盟列为高度关键材料之一。主要的铌开采业务是巴西的两个矿山（Catalão和arax<e:1>）和魁北克（加拿大）的Niobec矿床。与许多采矿作业的情况一样，有价值的矿物常常以“泥”的形式流失到尾矿流中。这些泥含有超过2.5%（占铌总质量的15%）的含铌矿物，以焦绿石和柱长石的形式存在。因此，能够从这些泥中回收铌矿物将对加工厂的经济效益和这种战略金属的可用性产生重大的有益影响。矿物加工在很大程度上取决于粒度，每一种分离技术都有一个最佳粒度范围，超出这个范围，效率会急剧下降。浮选是从废物中分离有价值矿物的最常用方法；其目的是通过改变矿物（有价值的和废弃的）的表面化学性质和浮选船的操作参数，选择性地将特定矿物的颗粒附着在气泡上。本项目将研究采用柱浮选和絮凝浮选相结合的浮选技术选择性回收铌矿物的方法。该项目的总体目标是更好地了解这两种浮选技术，并利用这些知识对含有战略金属铌的矿物进行案例研究。该项目得到了Niobec（总部位于魁北克）的支持，Niobec是领先的铌生产商之一，也是巴西以外最大的铌生产商。

This research proposal is targeted at two important challenges in mineral processing, and the supply of critical and strategic metals. These are: 1) niobium recovery and 2) fine particle flotation.Niobium is a vital alloying metal, with the majority found in high-grade structural steel. The second largest application is superalloys, such as in components for aircraft engines where the high thermal resistance provided by the niobium is vital. Niobium has been included as one of the highly critical materials by the European Union, based upon the supply risk and economic importance. The main niobium mining operations are two mines in Brazil (Catalão and Araxá), and the Niobec deposit in Quebec (Canada). As is the case in many mining operations, valuable minerals are often lost to the tailings stream in the form of "slimes". These slimes contain more than 2.5 % (leading to 15 % of the total mass of niobium) niobium-bearing minerals, in the form of pyrochlore and columbite. As such, being able to recover the niobium minerals from these slimes will have a significant beneficial impact on the economic performance of a processing plant, and on the availability of this strategic metal.Mineral processing is very much dependent upon particle size, with each separation technique having an optimum particle size range outside of which efficiency decreases dramatically. Flotation is the most common method of separating valuable minerals from waste; the aim of which is to selectively attach particles of a particular mineral to air bubbles by changing the surface chemistry of the minerals (valuable and waste) and the operating parameters of the flotation vessel. This project will investigate methods of selectively recovering niobium minerals using a combination of flotation techniques, namely column flotation and floc-flotation.The overall aim of this project is to better understand the two flotation techniques, and to utilise this knowledge on a case study of minerals containing the strategic metal niobium. This project is supported by Niobec (based in Quebec), which is one of the leading producers of niobium, and the largest outside of Brazil.