The Settlement Properties of Fine Multi-metals Tailings Modified by Flocculants in Shizhuyuan Mine of China
9th International Symposium on Mining with Backfill
Shizhuyuan Mine in Hunan Province is the biggest multi-metals deposit containing tungsten, molybdenum, bismuth and fluorite in China. The mine planed to employ total tailings as filling materials in order to dispose of mill tailings and make up for the shortage of backfill materials. But the slurry of multi-metals tailings contained a lot of residual chemicals such some dispersants as soluble glass, which caused that the fine particles of tailings kept in a suspended state for a long time. For this reason, the tailings dewatering became very difficult. The settlement properties of tailings modified by flocculants were investigated in the mine, with the aims being to screen for the most effective flocculants and the optimum dosage rates for the tailings sedimentation. The settlement rate was used as the indicator of effective tailings sedimentation. Calcareousness and three polyacrylamides F1, F2 and F3 were chosen for settlement property evaluation. The results show that sole calcareousness or any polyacrylamide has no apparent effect on sedimentation for the fine multi-metals tailings slurry. Remarkable benefit for sedimentation can be obtained from together addition of calcareousness and polyacrylamides, and addition of polyacrylamide F2 together with calcareousness is the most effective. The optimum dosage rate of F2 and calcareousness is 50g/t and 3kg/t respectively. The density of tailings slurry has effect on sedimentation at the early settlement stage,and the lower the density, the quicker the settlement.
tailings dewatering, Tailings backfill, Flocculant, settlement property