Abstract: A settable fluid cementitious composition which is fluid for sufficient time to be suitable for use in a flexible container to provide support in a mine said composition comprises (i) Portland cement in an amount from at least about 8% preferably 10%, (ii) a water soluble silicate in an amount from at least about 2% and (iii) water in an amount to provide a water to solids weight ratio of at lest about 1.2:1 preferably at least abou5 1.5:1 and where the % are by weight based on the combined weights of (i), (ii) and (iii). The viscosity immediately after mixing the components together is sufficiently low that additional water can be incorporated. The composition may include (iv) a pozzolan in an amount from 2 to 35% by weight based on the combined weight of (i), (ii), (iii) and (iv).

Abstract: The invention comprises a roof bolt and nut in screw threaded engagement, said bolt comprising a shaft for insertion in a hole drilled in a mine roof and a threaded portion engaged by the nut whereby the bolt may be rotated. The nut is offset with respect to the longitudinal axis of the shaft of the bolt so that when the bolt is rotated by means of the nut, the bolt is caused to describe a circle of greater diameter than its own diameter, the amount of said offset being from about 0.015 to about 0.50 inches. Preferably the offset is from about 0.02 to about 0.25 inches. The nut may be releasably locked in screw threaded engagement with the bolt so that the bolt can be rotated by means of the nut and above a selected torque the nut will break out.

Abstract: A process for the treatment of an aqueous coal slurry obtained as tailings from a coal treatment plant and containing fine mineral particles comprises adding to the slurry at least 0.2% of a binder and an amount of dispersant effective to reduce the viscosity and facilitate settling of solids, the % being based on the combined weight of water and mineral solids and allowing the solids to settle. The binder is preferably a cementitious material such as a finely divided blast furnace slag and an activator for the binder such a hydrated lime or Portland cement is preferably also included. The dispersant may be a polyarcylate, polycarboxylate or lignosulphonate.

Abstract: A settable fluid cementitious composition which is fluid for sufficient time to be suitable for use in a flexible container to provide support in a mine said composition comprises (i) Portland cement in an amount from at least about 8% preferably 10% (ii) a water soluble silicate in an amount from at least about 2% and (iii) water in an amount to provide a water to solids weight ratio of at least about 1.2:1 preferably at least about 1.5:1 and where the % are by weight based on the combined weights of (i), (ii) and (iii). The viscosity immediately after mixing the components together is sufficiently low that additional water can be incorporated. The composition may include (iv) a pozzolan in an amount from 2 to 35% by weight based on the combined weight of (i), (ii), (iii) and (iv).

Abstract: The invention comprises a roof bolt and nut in screw threaded engagement, said bolt comprising a shaft for insertion in a hole drilled in a mine roof and a threaded portion engaged by the nut whereby the bolt may be rotated. The nut is offset with respect to the longitudinal axis of the shaft of the bolt so that when the bolt is rotated by means of the nut, the bolt is caused to describe a circle of greater diameter than its own diameter, the amount of said offset being from about 0.015 to about 0.50 inches. Preferably the offset is from about 0.02 to about 0.25 inches.

Abstract: A method and apparatus are provided for installing a mine support (pillar, or pillar and grout bag) in a mine. The following are practiced: Locating a form in the mine where it is desired to provide support, the form being composed of a plurality of engaging parts shaped to produce a pillar when filled with a settable material, and the parts being disengageable to permit subsequent removal. Filling the form with a settable cementitous material and allowing the material to set to produce a pillar in the mine which is cuttable with a coal shearer. And, removing the form. When there is a gap between the top of the pillar and the roof of the mine a bag of yieldable grout is inserted in the gap. After use the support may be removed by cutting through the pillar and the bag of yieldable material, and the form may be reused to make a second pillar.

Abstract: A hardened cement is prepared by mixing together two slurries, one comprising water and a cement component and the other comprising water, beta anhydrite and calcium oxide and or calcium hydroxide. According to the invention the cement component of the first slurry comprises ferrite and C.sub.12 A.sub.7 or A.sub.7 A--CX.sub.2 (where X is a halogen atom) and a reactive source of silica.

Abstract: An aerated cementitious composition is produced by feeding a mixture comprising cement and foaming agent to a mixing chamber open to atmosphere together with a feed of liquid. The ingredients are mixed and the wetted mixture pumped to a desired site, the capacity of pumping being greater than the feed rate of the ingredients into the mixing chamber such that air is drawn into the mixing chamber.

Abstract: A settable cementitious composition is produced by mixing a ground mineral composition containing the phase 4CaO.3Al.sub.2 O.sub.3.SO.sub.3, in the presence of water, with a source of alkali metal or alkaline earth metal under alkaline conditions. In the pump packing method of stowing cavities in underground mines, an aqueous slurry of the mineral composition is mixed with a second slurry containing calcium sulfate, lime and, preferably, bentonite, an alkali metal sulfate and a setting and/or hardening accelerator. The components may be provided initially as a dry mixture. A preferred mineral composition comprises at least 15% by weight of 4CaO.3Al.sub.2 O.sub.3.SO.sub.3, less than 1% by weight of free lime, less than 25% by weight of CaO.2Al.sub.2 O.sub.3 and not more than 10% by weight of 12CaO.7Al.sub.2 O.sub.3.

Abstract: An aerated cementitious composition is produced by feeding a mixture comprising cement and foaming agent to a mixing chamber open to atmosphere together with a feed of liquid. The ingredients are mixed and the wetted mixture pumped to a desired site, the capacity of pumping being greater than the feed rate of the ingredients into the mixing chamber such that air is drawn into the mixing chamber.

Abstract: An aerated cementitious composition is produced by feeding a mixture comprising cement and foaming agent to a mixing chamber open to atmosphere together with a feed of liquid. The ingredients are mixed and the wetted mixture pumped to a desired site, the capacity of pumping being greater than the feed rate of the ingredients into the mixing chamber such that air is drawn into the mixing chamber.

Abstract: A quick setting cementitious composition with good early strength characteristics contains, by volume, 1-30% of a cement mixture including Portland Cement, calcium aluminate and calcium sulphate, 0.001-5% of clay and water in excess of 65%. The composition is especially suited for filling cavities in underground mines, for the construction of roadside packs, and the various components of the composition can be separately pumped or otherwise conveyed to the cavity.

Abstract: An agent for accelerating hardening of cement for use in an underground mining installation employing concrete-like packs including run-of-mine coal. The agent comprises by weight one and a half parts triethanolamine, five parts sodium carbonate and one part potassium carbonate. Too rapid setting of quick setting cement is avoided by the agent because a slurry of cement in water is mixed with a slurry of agent and run-of-mine coal in bentonite in a mixer immediately before being added to a pack so that setting cement does not occur in pipes leading to the mixer.