Abstract A mining recovery method that utilizes the waste material from a mine to refill mined out areas. Particular suitability is in the oil shale mining field where spent oil shale is used to support the overburden. The method contemplates a long shield being placed in an underground opening and spent oil shale or other waste material conveyed underground from the surface and placed behind the shield under low pressure. Next, a conveyorcompressor, like an auger with a compressor cone, forces additional waste material at a high pressure into the previously placed material behind the long shield to form a high pressure inclusion for the support of the overburden. Before the expanding inclusion of high pressure waste material reaches the shield, a pressure sensing device includes a predetermined pressure level has been reached. This triggers the activation of low pressure conveyor-compressors to disengage the shield from its adjacent waste material wall and move it forward toward the mining face. The combined reaction of low pressure material along with the continued reaction of the high pressure compressor is used for this forward motion. Once disengaged and advanced the proper distance, the process is repeated to form another line of high pressure supporting inclusions behind the shield that overlaps the first line of inclusions. A series of these lines of high pressure inclusions can be used to support the overburden on one cut level with different levels of supported cuts being possible.
A long shield mining method for filling in previously mined out areas comprising the steps of: conveying processed mined waste material to the mining area where a long shield is placed near a mine wall; forcing the material through the shield under pressure behind said shield to form a spent material wall until a predetermined high pressure is reached and an overburden supporting high pressure zone formed; detecting the amount of predetermined high pressure developed and the appropriate location of said zone; forcing additional waste material through said shield at a lower pressure after said predetermined high pressure is detected to enable disengagement of the shield from the spent material wall; and repeating the forcing step to develop a high pressure zone and the forcing disengagement step so as to create a different high pressure zone that overlaps with said first zone.
Claim 2
Dependent Claim
142 words
A long shield mining method for filling in previously mined out areas comprising the steps of: conveying processed mined waste material to the mining area where a long shield is placed near a mine wall; forcing the material through the shield under pressure behind said shield to form a spent material wall until a predetermined high pressure is reached and an overburden supporting high pressure zone formed; detecting the amount of predetermined high pressure developed and the appropriate location of said zone; forcing additional waste material through said shield at a lower pressure after said predetermined high pressure is detected to enable disengagement of the shield from the spent material wall; and repeating the forcing step to develop a high pressure zone and the forcing disengagement step so as to create a different high pressure zone that overlaps with said first zone.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein part of said conveying step takes place between the earth''s surface and an area adjacent said mining area.
Claim 4
Dependent Claim
29 words
The method of claim 1 wherein said predetermined high pressure is at least 500 pounds per square inch and said lower pressure at least 5 pounds per square inch.
Claim 5
Dependent Claim
20 words
The method of claim 1 including the additional step of lubricating said material before it is forced through said shield.
Claim 6
Dependent Claim
27 words
The method of claim 1 including the additional step of forcing the material between the shield and mine wall under low pressure before said high pressure step.
Claim 7
Dependent Claim
18 words
The method of claim 1 wherein said detecting step takes place simultaneously at a plurality of different locations.
Claim 8
Dependent Claim
28 words
The method of claim 1 including the additional step of anchoring said shield in an upright position as it is being disengaged generally horizontally from the mining wall.