The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 20, 1982
Filed:
Feb. 13, 1980
Karoly Barsi, Tatabanya, HU;
Laszlo Dorombozi, Tatabanya, HU;
Istvan Forisek, Tatabanya, HU;
Gyula Kuburczik, Tatabanya, HU;
Gyorgy Stuber, Tatabanya, HU;
Tatabanyai Szenbanyak, Tatabanya, HU;
Abstract
In mining a heavy coal seam that must be excavated in several benches, the excavation of the uppermost bench is accompanied by the introduction of a cementitious slurry into the resulting stope for consolidating the waste rock present therein, preparatorily to the excavation of the next-lower bench, and proceeding in like manner with the second bench if a third one is to follow. The cementitious slurry comprises burnt or slaked lime, and/or portland cement, suspended in water in a quantity of about 10 to 60% by weight and preferably together with a small percentage of chlorides of one or more alkali or alkaline-earth metals, to which ceramic aggregates at large specific surface such as mineral ashes, slag, sand or dolomite powder may be added in a quantity of up to about 30% of the weight of the water. The slurry, on being admitted to the stope in an amount of at least 10% of the volume thereof, causes the waste rock to swell and to form a solid layer of up to approximately a meter in thickness which allows the next-lower bench to be excavated after only about a month's delay.