Longwall mining of thick underground mineral seams
US4030752A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 8, 1976 |
| Grant date | Jun 21, 1977 |
| Priority date | — |
| Expiry date | Mar 8, 1996 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21C41/18
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In the mining of a thick underground mineral seam, parallel submain entries are developed at the top of the seam or at an upper level where a competent roof exists. Spaced apart parallel sets of panel entries are driven at right angles to these submain entries along a downwardly sloping path to the bottom of the seam. The entries are continued coincident with the bottom of the seam to any desired point at which their extremities are connected with bleeder entries so as to define a series of longwall panels. These panels are mined in retreat under the protection of advancing roof support structures so as to induce caving of overlying strata. After mining a series of panels in sequence in this manner, auxiliary sets of parallel development entries are driven in a downwardly sloping path beneath and substantially coextensive with the submains to enable recovery of a substantial percentage of the mineral beneath said submains by again longwalling in retreat at right angles to the first mining direction with sublevel caving.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.