A Study of Engineering Characteristics of Columbite Tailings

Of great importance is columbite as a source of niobium, which is a valuable alloy of steel needed for numerous applications. In order to obtain this element, columbite is mined and processed and this produces unwanted materials called columbite tailings. Due to environmental, economic, and social impact of tailing materials disposal, studies have been conducted on them but this is very rare for columbite tailings. In this paper, mechanical behaviour of columbite tailings was studied by considering index properties, chemical and fabric characteristics, mineralogy as well as conduction of series of oedometer tests. Similar to other tailings, columbite tailing is poorly-graded in nature. The fabric is dominated by continuous clusters from aggregation of particles. The fabric is isotropic and heterogeneous with few inter-particle and intra-cluster pores. Mineralogy is dominated by ashanite, cristobalite, ilmenite and quartz which confirms the chemical composition that was dominated by silica. It is observed that the compression curves of columbite tailings are parallel and no unique normal compression line is found. This indicates that columbite tailings exhibit a transitional mode of behaviour which makes it to be initial state dependent.