SUBLEVEL CAVING

Domain	Definition
Mining	A. A stoping method in which relatively thin blocks of ore are caused to cave by successively undermining small panels. The ore deposit is developed by a series of sublevels spaced at vertical intervals of 18 to 25 ft or 30 ft (5.5 to 7.6 m or 9.1 m) and occasionally more. Usually only one or two sublevels are developed at a time, beginning at the top of the orebody. The sublevels are developed by connecting the raises with a longitudinal subdrift from which timbered slice drifts are driven right and left opposite the raises to the ore boundaries or to the limits of the block. Usually alternate drifts are driven first, and caving back from them is begun and continued while the intermediate slices are being driven. The caving is begun at the ends of the slices by blasting out cuts and retreating in the same manner toward the raises. The broken and caved ore formerly was shoveled into cars and trammed to the raises, but in recent years it is dragged to the raises by power scrapers. Successively lower sublevels are developed and caved back until the entire block has been mined. This method is intermediate between block caving and top slicing, since part of the ore is mined as in top slicing and part is caved. See also:top slicing combined with ore caving b. Similar to top slicing from which it is thought to have been developed. The general plan of operations is to mine every other slice by driving crosscuts (slice drifts) from 18 to 36 ft (5.5 to 11.0 m) apart. The ore between the crosscuts as well as that in the slice above is then mined, thus causing the overlying material to cave. The method is applicable to irregular and steeply dipping orebodies that cannot be worked by top slicing. The present tendency is to sink vertical shafts in the footwall rather than inclined shafts as formerly done. Also called subdrift cavin. (references)
Source: compiled by the editor from various references; see credits.

Anagrams: SUBLEVEL CAVING

Scrabble® Enable2K-Verified Anagrams
	Words within the letters "a-b-c-e-e-g-i-l-l-n-s-u-v-v"
	-4 letters: licensable, villenages.
	-5 letters: bevelling, bluelines, callusing, evangelic, sliceable, univalves, unlivable, valencies, vesiculae, villenage, vulcanise.
Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro.