Backfilling in mines
AssigneeFosroc International Limited
InventorRoderick M. Smart
Life of this patent
Estimating the term…
Abstract
A void in a mine is backfilled by a backfill slurry comprising water, an inert filler, e.g. mine tailings, and a binder, e.g. cement, lime or slag, to which a gelling agent, e.g. sodium silicate, is added just before placement.
Claims14
A method of forming an infill in an underground void, the method comprising forming a backfill slurry comprising about 15 to 55% by weight of water, a substantially inert filler and 0.5 and 15% of a binder, the weight ratio of the substantially inert filler to the binder ranging from about 7.5:1 to 30:1, the method further comprising transporting the slurry to the void and placing the slurry therein, and adding an inorganic gelling agent therefor while or just before the slurry is placed, the quantity of gelling agent added being from about 0.3 to about 8% by weight relative to the weight of the slurry thereby to cause the slurry to set to form a set material infill containing substantially all the water of the slurry.
A method according to claim 2, wherein the gelling agent is present in a concentration of from about 0.5% to about 2% by weight, relative to the weight of the slurry.
A method of infilling an underground void in a mine or tunnel, the method comprising making a backfill slurry comprising water in a proportion of from about 15% to about 50% by weight of the slurry, a hydraulically settable binder in a weight proportion from about 0.5% to about 15% of the slurry, the balance comprising a substantially inert filler selected from the group comprising mine tailings, other mine waste, slimes, rockfill, aggregate, coal, sands and mixtures of any of these, the weight ratio of the substantially inert filler to the binder ranging from about 7.5:1 to 30:1, the method further comprising transporting the slurry in a transport pipe to the void and discharging the slurry therefrom into the void, and adding a gelling agent to the slurry while or just before the slurry exists from the pipe, the gelling agent being added in a proportion of from about 0.3 to about 8% of the slurry to cause the slurry to set to form a substantially homogeneous infill containing substantially all the content of water from the slurry.
Dependencies are inferred from the claim text.