Fine particle flotation: Niobium minerals

点击翻译按钮获取中文摘要

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.