Title of Invention

"AN IMPROVED METHOD FOR CONTINUOUS EXTRACTION OF COAL /ORE FROM COAL SEAM MINERAL BED IN UNDERGROUND MINES"

Abstract The present invention relates to an improved method for continuous extraction of coal/ore from coal seam/mineral bed in underground mines. The method of the invention is particularly useful when a conventional longwall device is employed for extraction of coal from underground mines. The extraction method employed herein results in increased productivity of extraction of coal. The method is economic and ascertains maximum recover of ore from the reserve.
Full Text This invention relates to an improved method for continuous extraction of coal/ore from coal seam/mineral bed in underground mines. The improved method of the present invention is particularly useful when a conventional longwall device is employed for extraction of coal / ore from coal seam / mineral bed in underground mines.
For faster extraction and higher productivity longwall system is being used for winning of coal from underground mines. This longwall system also needs less manpower as the cutting and loading from the face is completely done by machine. Therefore, it is a safe system and highly productive. The conventional longwall device and panel layout is shown in Fig. 1 of the drawings accompanying this specification. The system of longwall generally consists of hydraulic operated self-advancing type powered support along with shearer and conveyors at the face. A bridge stage loader is used to load the coal from face to gate belt conveyor and then to outbye system.
The conventional longwall is used for extraction of a block of coal/ore of rectangular size generally (150m x 1000m - 1500m x 3.0m - 4.5m). The conventional longwall package as shown in Fig. 1 of the drawings has problem of mechanisation in gate roads. The operations are though fully mechanised at the face machines, the operations in the gate roads need manual labour involvement and therefore it is very difficult for automation in the whole system. The improved longwall package developed by us (patent no. Indian Patent application 288 / del / 93 - USA 5,368,369 Dated 24-11-94 and Europe (GB,DE,FR) 93108685.4 - Dated 28.05.93.) could solve the problem of manual operation in the gate roads. Almost all the operations are mechanised in the device without any introduction of extra motors in the system. Rather a heavy motor has been eliminated from the conventional package. This has also improved safety in the gate roads. This longwall package are till date being used for cutting a rectangular shaped panel and the whole mine is planned and developed as a rectangular tunnel circuit. The package of longwall is dismantled after completing the extraction of a rectangular block and then the equipment is transported to a new panel scheduled to be extracted beyond the barriers. The operations for dismantling and assembling take quite considerable

time. In India it takes 6 months to one year which is an idle period for longwall mining. As longwall system is the costliest package in underground mining, the loss for this intermediate period is too high and there is need and scope for improvement. Even the percentage of recovery of coal/ore is not satisfactory, as many barriers are to be left in between the panels, which remains unrecoverable. In India recovery of coal reserve by mechanised extraction varies from 45 to 60% as extraction is done using conventional, intermediate technology and also by longwall system. However, the intermittent assembling and dismantling of packages after each panel results in loss of productivity and become uneconomic. Therefore, there is a definite need for developing an improved method for continuous extraction of coal/ore from coal seam/mineral bed in underground mines.
The main objective of the present invention is to provide an improved method for continues extraction of coal from coal seam/mineral bed in underground mines, which obviates the drawbacks of presently known methods.
Another object of the present invention is to increase productivity of extraction of coal from underground mines.
Yet another object of the present invention is to provide an improved method for continues extraction of coal using a longwall package.
Still another object of this invention is to provide an economic method for maximum recovery of ore/coal from the reserves.
Fig.-l of the drawings accompanying this specification shows the layout/plan of earlier method of extraction with the help of longwall package. In this the ore/seam is mined by following cross tunnels perpendicular to each other. In Figures 2 & 3 of the drawings accompanying this specification, the schematic diagram of the improved layout of the present invention is shown. In figures 2 & 3 6 of the drawings it is shown that the coal seam/ore is mined by making two or more vertical pits upto the bottom of the central zone of
reserves known as the pit bottom, then by cutting tunnels radially outward from the pit bottom to the furthest periphery of mining reserve. Then making /developing the farthest peripheral circular tunnels in which coal is to be

mined. Thereafter, making a plurality of peripheral circular tunnels concentric towards the central pits. The pits are generally made in the central zone of the mining reserve, which are interconnected with the peripheral tunnels through radial tunnels. The cutting, loading and supporting equipment longwall packages are generally placed in-between two peripheral tunnels for extraction of the block of reserve starting with the outer most circular peripheral tunnels and working concentrically inwards towards the central pit bottom.
Accordingly, the present invention provides an improved method for continuous extraction of coal/ore from coal seam /mineral bed in underground mines, which comprises:
(i) making by conventional methods at least one downward shaft/pit (1) and at least one upcast shaft/pit (17) reaching upto the bottom of the central zone of a mineable reserve;
(ii) making by conventional methods one or more interconnecting tunnels (19) in between the said downcast and upcast shafts/pits in such a manner so as to form short support pillars (18);
(iii) cutting one or more radially outward tunnels (2) from the said central zone capable of allowing transport of coal extracting equipment upto the outermost periphery of the mineable reserve;
(iv) cutting a plurality of circular concentric pair of peripheral tunnels (3 & 4.3; 7.3 & 4.2; 7.2 &4.1; 7.1) in such a manner so as to form circular barrier pillars (5.4,5.3,5.1) and mineable blocks of reserve (6.3,6.2,6.1) to be extracted;
(v) cutting a plurality of radially interconnecting tunnels (16,11);
(vi) transporting by known means one or more coal extracting equipment (8) through the said shafts/pits (1,17), and radially outward tunnel
(2);
(vii) assembling the said equipment at the outermost block of mineable reserve (6.1);
(viii) extracting the outermost circular block of mineable reserve (6.1) in such a manner so as to leave at the end position (20) a safety barrier pillar (21);

(ix) transporting the said assembled coal extracting equipment through a radial tunnel to the next inner circular block (6.2) of mineable reserve;
(x) Extracting the said circular block of mineable reserve (6.2);
(xi) repeating steps (ix) and (x) till the innermost mineable reserve is extracted;
(xii) dismantling and transporting by known means the coal extracting equipment (8) through the said radial tunnel (2) and shafts/pits (1,17).
In an embodiment of the present invention the mineable reserves are coal seam/mineral bed in an underground mines.
In another embodiment of the present invention the conventional methods used for making/cutting shafts/pits and tunnels are such as drilling and blasting, cutting by machines.
In yet another embodiment of the present invention the coal extracting equipment used are such as cutting machines like continuous miner, road header, dint header, loading machines, conveyors, powered supports, longwall packages.
In still another embodiment of the present invention means such as fans/blowers are provided to enable flow of fresh air (14,15) for ventilation in the working zone.
In another embodiment of the present invention means such as conveyor belt (12,13) are provided for transporting the extracted reserves from the cutting face to the central pit bottom.
The main advantages of the present invention:
1. It is a process for utilisation of longwall package continuously and
effectively.
2. It is a process for higher recovery of coal/ore reserve from underground
mines.
3. It is a safe method with minimum utilisation of manpower.
4. It is a time saving method with maximum economic benefit resulting in
higher productivity.

5. This process provides the possibilities for complete mechanisation and automation in the system of winning coal/ore.


We claim:
1. An improved method for continuous extraction of coal/ore from coal seam /mineral bed in underground mines, which comprises:
(i) making by conventional methods at least one downward shaft/pit (1) and at least one upcast shaft/pit (17) reaching upto the bottom of the central zone of a mineable reserve;
(ii) making by conventional methods one or more interconnecting tunnels (19) in between the said downcast and upcast shafts/pits in such a manner so as to form short support pillars (18);
(iii) cutting one or more radially outward tunnels (2) from the said central zone capable of allowing transport of coal extracting equipment upto the outermost periphery of the mineable reserve;
(iv) cutting a plurality of circular concentric pair of peripheral tunnels (3 & 4.3; 7.3 & 4.2; 7.2 &4.1; 7.1) in such a manner so as to form circular barrier pillars (5.4,5.3,5.1) and mineable blocks of reserve (6.3,6.2,6.1) to be extracted;
(v) cutting a plurality of radially interconnecting tunnels (16,11);
(vi) transporting by known means one or more coal extracting equipment (8) through the said shafts/pits (1,17), and radially outward tunnel
(2);
(vii) assembling the said equipment at the outermost block of mineable reserve (6.1);
(viii) extracting the outermost circular block of mineable reserve (6.1) in such a manner so as to leave at the end position (20) a safety barrier pillar (21);
(ix) transporting the said assembled coal extracting equipment through a radial tunnel to the next inner circular block (6.2) of mineable reserve;
(x) Extracting the said circular block of mineable reserve (6.2);
(xi) repeating steps (ix) and (x) till the innermost mineable reserve is extracted;
(xii) dismantling and transporting by known means the coal extracting equipment (8) through the said radial tunnel (2) and shafts/pits (1,17).
2. An improved method as claimed in claim 1 wherein the mineable
reserves are coal seams/mineral bed in underground mines.
3. An improved method as claimed in claims 1 & 2 wherein the
conventional methods used for making/cutting shafts/pits and tunnels are such
as drilling and blasting, cutting by machines.
4. An improved method as claimed in claims 1 to 3 wherein the coal
extracting equipment used are such as cutting machines like continues miner,
road header, dint header, loading machines, conveyors, powered supports,
longwall packages.
5. An improved method as claimed in claims 1 to 4 wherein means such
as fans/blower are provided to enable flow of fresh air (14,15) for ventilation in
the working zone.
6. An improved method as claimed in claims 1 to 5 wherein means such
as conveyor belt (12,13) are provided for transporting the extracted reserves
from the cutting face to the central pit bottom.
7. An improved method for continuous extraction of coal/ore from coal
seam /mineral bed in underground mines, substantially as herein described
with reference to figures 2 and 3 of the drawings accompanying this
specification.

Documents:

270-del-2000-abstract.pdf

270-del-2000-claims.pdf

270-del-2000-correspondence--po.pdf

270-del-2000-correspondence-others.pdf

270-del-2000-description (complete).pdf

270-del-2000-drawings.pdf

270-del-2000-form-1.pdf

270-del-2000-form-19.pdf

270-del-2000-form-2.pdf

270-del-2000-form-3.pdf


Patent Number 221201
Indian Patent Application Number 00270/DEL/2000
PG Journal Number 31/2008
Publication Date 01-Aug-2008
Grant Date 19-Jun-2008
Date of Filing 16-Mar-2000
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI-110 001, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 SIBNATH MAITY CENTRAL MINING RESEARCH INSTITUTE, DHANBAD, BIHAR-826001, INDIA
2 KLOFTA, THOMAS JAMES 10404 HOPEWELL HILLS, DRIVE, CINCINNATI, OHIO, 45249, USA
3 BROWN, PAMELA JEAN 7939 STABLEGATE LANE, MAINEVILLE, OHIO, 45039, USA
PCT International Classification Number E21C 035/20
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA