Poster
Mountains graphic with white diamonds on itGeoscience and Exploration

Preliminary Beneficiation Study of Selwyn Basin Barite Ore

Theatre Lobby

Author(s)

H. Li (Presenting)
University of Alberta
Q. Liu
University of Alberta
G. Lambiv Dzemua
Northwest Territories Geological Survey

A preliminary test beneficiation of the Selwyn Basin barite ore from the Northwest Territories was carried out in the Department of Chemical and Materials Engineering, University of Alberta. The test was carried out on a composite sample from the Anita and Wise showings. The feed grade was 28.67% Ba (corresponding to 48.7% barite) and 42.59% SiO2, and the objective of the study was to produce a drilling fluid-grade barite concentrate with a specific gravity > 4.22. Both showings of barite are in the Canol Formation, a shale unit, with quartz and other silicates being the main gangue phases.

Mapping and historic intermittent exploration by government and private entities have documented the regional occurrence of barite mineralization throughout the Selwyn Basin. However, previous test processing by Baroid of Canada in the 1970s failed to produce a concentrate with satisfactory characteristics. In this study, we tested the susceptibility of the ore to grinding using the standard Bond Work Index as well as the ability to separate barite from the associated gangue using gravity and batch flotation. According to our results, the Selwyn ore is medium to hard, with a Bond Work Index of 14.65 kWh/t. At a predetermined optimal grind size of 82% passing 106 µm, we were unable to produce a clean barite concentrate by gravity separation alone because of the preferential overgrinding of barite over gangue phases.

A satisfactory concentrate grading 54.39% Ba (equivalent to 92.5% barite and 4.27% g/cm3 density) at 81.4% barite recovery was produced at a grind size of 84% passing 53 µm, through direct flotation using sodium carbonate as pH modifier, sodium silicate as quartz/silicate depressant, and sodium oleate as barite collector. The successful flowsheet involves one rougher flotation stage and two cleaner stages in an open circuit. Closing the circuit by circulating the cleaner tailings and the scavenger concentrate is expected to further improve barite recovery.