Tantalum and Niobium Services

SGS MINERALS SERVICES – T3 SGS 056 09-2013

TANTALUM AND NIOBIUM

MINERALOGY & MINERAL IDENTIFICATION DEPORTMENT AND TEXTURE METALLURGY Owing to the extensive solid solution Deportment and textural associations between Ta, Nb and Fe, identification define liberation and locking Since 1982, the dramatic increase in of Ta and Nb minerals is critical to the characteristics that are crucial for demand for tantalum has been fueled at evaluation of mineral recovery and metallurgical processing. For instance, a rate of 10% per year by the electronics deposit economics. For example, the back-scattered electron image at right industry (Roskill Information Services). the sample to the right contains shows pyrochlore (white) locked with Characterized by a low natural abundance, intergrown plumbopyrochlore (ppc) gangue minerals, implying poor liberation few known deposits, sporadic supply and (Pb,U,Ca)Nb2O6(OH), pyrochlore (pc) and recovery, and suggesting the need for difficult metallurgy, tantalum is a high tech (Ca,Na)2(Nb,Ta) 2O6(OH,F) (red arrow), regrinding. metal of the future. ilmenorutile (Ti,Nb,Fe)3O6 (ilmr) and SGS Minerals Services has contributed quartz (qtz) gangue. CHEMICAL COMPOSITION to many tantalum projects over the Quantification of the chemical years and can bring an integrated suite composition assists in the elemental of services to either the exploration allocation among Ta and Nb species. It or developmental stages of Ta and Nb also assists in the metallurgical mass projects. balance calculations used to optimize recovery. Deleterious elements can MINERALOGICAL create environmental concerns or result INVESTIGATIONS in smelter penalties. In the case to the right, ferrotapiolite (bright white) (Fe,Mn) Early identification of the Ta or Nb (Ta,Nb)2O6 has a different trace element minerals in an ore as well as their 100 µm composition (SEM spectrum) from deportment, textural associations and pyrochlore and columbite, and can contain micro-chemical composition plays a Sn, U, Th and Pb. critical role in determining a deposit’s amenability to metallurgical processing. METALLURGICAL PROCESSING ilmr Mineralogical data provides the grain qtz size and textural parameters needed to establish and optimize a metallurgical pc flowsheet. Depending on the grain size, textural associations and accessory minerals present, a variety of different ppc separation strategies can be used to concentrate Ta and Nb minerals, 70 µm including grinding, conventional and centrifugal gravity separation, regular or high intensity magnetic separation and advanced flotation techniques. SGS MINERALS SERVICES – T3 SGS 056 2

GRINDING MAGNETIC SEPARATION FLOTATION Proper grinding parameters ensure Low and high intensity magnetic SGS Minerals Services’ metallurgical effective liberation. For Ta or Nb separation can separate Ta and group has developed new flotation processing, it is particularly important to Nb minerals of varying magnetic reagents that yield excellent primary minimize the production of fines. susceptibility during final up-grading. separations between Ta and Nb minerals Here tantalite is being separated from and gangue. The sample to the right is CONVENTIONAL AND CENTRIFUGAL quartz-calcite gangue using bench-scale a highly liberated Ta-Nb ore (pyrochlore, GRAVITY SEPARATION high intensity magnetic separation. columbite) (bright white) with a calcite- quartz gangue (dull grey), which Ta and Nb minerals are easily separated responded well to these reagents. from gangue due to their high specific Traditional flotation technology is also gravity. SGS Minerals Services has a wide used to remove or concentrate associated variety of bench and pilot scale gravity sulphide minerals. Reverse flotation separation equipment available for testing. procedures and regrinding circuits then are used to prepare final Ta or Nb concentrates. Make the right choices for the right reasons. Mineralogical scoping studies early in a project result in efficient metallurgical bench-scale and piloting later. Maximize the return on your investment.