Underground mineral extraction
US4226475A · kind A · utility
Inventors
Key dates
| Filing date | Apr 19, 1978 |
| Grant date | Oct 7, 1980 |
| Priority date | — |
| Expiry date | Apr 19, 1998 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21C41/18
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for extracting an underground mineral such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the surface of the earth. The vehicle hydraulically drills pilot holes during its entrances into the seam, and then directs sideward jets at the seam during its withdrawal from each pilot hole to comminute the mineral surrounding the pilot hole and combine it with water into a slurry, so that the slurried mineral can flow down to a location where a pump raises the slurry to the surface. Droplets of liquid carbon dioxide or other suitable material may be added to the water prior to its exit from a jet nozzle on the vehicle, so that as the water pressure drops in movement through the nozzle the liquid carbon dioxide or other material explodes into a vapor to greatly increase the velocity of the water jet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.