Tantalum and niobium ore dressing investigations at CANMET

Tantalum and niobium have become important metals with a variety of metallurgical uses. They are in short supply on a world basis and as demand is certain to increase, it is in Canada's interest to search for and develop additional resources. The purpose of the present report is to encourage this. It describes the properties, uses and resources, both domestic and global, and gives production and consumption statistics for both metals. Tantalum is being mined in Canada only in low-grade pegmatite ores containing less than 0.2% Ta205 at Bernie Lake, Manitoba, and is recovered by gravity concentration followed by flotation of sulphide minerals from the tantalum concentrate when a larger than normal amount of these minerals occur in the concentrate. The tantalum concentrate produced has 50% Ta2 05 grade with 65 to 75% tantalum recovery depending on the degree of dissemination of the tantalum-bearing minerals (tantalite or wodginite,microlite and tapiolite) in the ore. The other known deposits have so far not been thoroughly explored. As for niobium, present production is by flotation from carboniatite ores containing 0.76% Nb2O5 at St-Honoré, Québec. A deposit grading 0.5% Nb2O5 was worked at Oka, Québec between 1961 and 1976, where extensive reserves of a lower grade still exist on the original and neighbouring properties and production may resume depending on economic conditions. Another major deposit where the grade is 0.52% Nb2 05 awaits development near Moosonee, Ontario, but improved processes with recoveries greater than 70% as at present will likely be required before new plants are built. Information on the mineralogy of the ores and their amenability to beneficiation is intended to facilitate the evaluation of potential resources and direct future ore dressing investigations to achieve better recovery at lower cost. The report has two appendices consisting of brief reviews of ore dressing investigations related to the mineralogy and concentration of Canadian ores conducted at CANMET; it also covers research on foreign niobium ores considered to be of interest in treating domestic ores. The summaries consist of brief descriptions of the mineralogy and analyses of the ore samples tested, state the purpose of each investigation, the methods of concentration, results obtained, and conclusions. They also offer recommendations for future action.