Environmental Engineering Reference
In-Depth Information
Figure 19.5.
Particle size distributions of coal, iron ore and bauxite washery tailings (a) without and (b)
with dispersant added.
strength rock (and even low strength rock) tailings will have in-place void ratio of 0.6 to
0.9 for sand sized particles and 0.7 to 1.3 for slimes. The exceptions are phosphatic clays,
bauxite (alumina) and oil sands and slimes.
It will be noted that the dry densities are very much lower than the specific gravity (or
dry density) of the parent rock. In many mining operations a very small percentage of the
ore is removed as mineral in the milling process and it would not be unusual for the tail-
ings volume to be 150% to 200% of the original volume of the mined ore.
