CN108678744A - A kind of mining methods of the tilted manganese ore layer of mobile shield support digging ore body - Google Patents
A kind of mining methods of the tilted manganese ore layer of mobile shield support digging ore body Download PDFInfo
- Publication number
- CN108678744A CN108678744A CN201810437656.8A CN201810437656A CN108678744A CN 108678744 A CN108678744 A CN 108678744A CN 201810437656 A CN201810437656 A CN 201810437656A CN 108678744 A CN108678744 A CN 108678744A
- Authority
- CN
- China
- Prior art keywords
- ore
- digging
- manganese
- manganese ore
- lane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910052748 manganese Inorganic materials 0.000 title claims abstract description 58
- 239000011572 manganese Substances 0.000 title claims abstract description 58
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 title claims abstract description 57
- 238000005065 mining Methods 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000004519 manufacturing process Methods 0.000 claims abstract description 35
- 239000002360 explosive Substances 0.000 claims description 12
- 239000011435 rock Substances 0.000 claims description 10
- 229910000831 Steel Inorganic materials 0.000 claims description 8
- 239000010959 steel Substances 0.000 claims description 8
- 238000002485 combustion reaction Methods 0.000 claims description 3
- 239000004567 concrete Substances 0.000 claims description 3
- 239000000839 emulsion Substances 0.000 claims description 3
- 238000000605 extraction Methods 0.000 claims description 3
- 239000011378 shotcrete Substances 0.000 claims description 3
- 239000000463 material Substances 0.000 claims 1
- 239000002023 wood Substances 0.000 claims 1
- 239000002994 raw material Substances 0.000 abstract description 3
- 230000000694 effects Effects 0.000 abstract description 2
- 238000009412 basement excavation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001727 in vivo Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 201000010041 presbyopia Diseases 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 230000005641 tunneling Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/22—Methods of underground mining; Layouts therefor for ores, e.g. mining placers
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Remote Sensing (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
The present invention relates to a kind of mining methods of the mobile tilted manganese ore layer of shield support digging ore body, air return lane and transportation roadway and the back production lane communicated therewith, the arrangement shielding frame body in back production lane are tunneled including reconnoitring ore body, in ore body, working space, mobile shielding frame body are formed in cover frame body, so that working space is moved along stope, manganese ore in mining work space, it is made to be sent out by transportation roadway；Technical solution using the present invention, it only needs to tunnel air return lane, transportation roadway and back production lane, simplify mining technique, save the tunnelling activity duration, improve efficiency, make fresh air that can constantly pass through in air return lane or transportation roadway inflow back production lane, it ensure that the operating environment and job safety in back production lane, the mining operations to inclined manganese ore layer are allow to keep continuously mining operations, improve mining efficiency, shielding frame body may be reused, and save supporting operation raw material.
Description
Technical field
The invention belongs to mining technique field more particularly to a kind of tilted manganese ore layers of mobile shield support digging ore body
Mining methods.
Background technology
In the prior art, for the exploitation of manganese ore layer generally use openstope method, caved stopes, shrinkage stoping,
The mining methods such as the method for mining by the way of filling, wherein openstope method are most widely used, it refers to relying primarily on and enclosing in exploitation process
The stability of rock itself or a small amount of ore pillar, artificial pillar support the mining methods in goaf.It is right when using openstope method
Ore body surrounding rock stability is more demanding, still, if manganese ore layer is with respect to the horizontal plane heeling condition in ore body, since ore body encloses
Rock stability is poor, is susceptible to top plate collapse accident, and there are larger security risks, meanwhile, resource recovery is low, drivage ratio
Height affects mining firm's production efficiency.
Invention content
In order to solve the above technical problems, the present invention provides a kind of mobile tilted manganese ore layers of shield support digging ore body
Mining methods.
The present invention is achieved by the following technical programs.
The present invention provides a kind of mining methods of the tilted manganese ore layer of mobile shield support digging ore body, includes mainly following
Step：
Step 1：Reconnoitre ore body：Finding somewhere on geographical location has the geologic body of extraction value as ore body, the mine
There is the manganese ore layer being inclined relative to horizontal, the manganese ore layer to be relatively distant from the one end on ground as ore bed upper end, institute in vivo
It states manganese ore layer and is connected to each other subaerial one end as ore bed lower end；
Step 2：On ore body outer surface corresponding to the ore bed upper end described in step 1, into ore body digging tunnel to be formed back
Air way, on ore body outer surface corresponding to the ore bed lower end described in step 1, into ore body digging tunnel to form transportation roadway；
Step 3：The direction digging extended along manganese ore layer described in step 1 goes out a back production lane, the both ends in the back production lane
It is connected to respectively with air return lane, transportation roadway described in step 2, back production lane inner bottom wall is as stope；
Step 4：Prepare more shield supports, by all shield supports along under ore bed upper end to ore bed described in step 1
The direction at end is layed in back production lane roof, on side wall side by side, wherein passes through item between any adjacent two shield support
Shape timber, which links together, forms shielding frame body, reuses hydraulic prop and group shielding frame body is abutted against the back production lane
Roof, on side wall, reuse a plurality of steel wire rope and be connected to all shield supports of the same wall surface in the back production lane
Together, so that the stope is surrounded respectively with two groups of shielding frame bodies and form working space；
Step 5：In the working space described in step 4, to the stope below digging manganese ore, make the manganese ore
It is carried out outside ore body by the transportation roadway；
Step 6：After the completion of manganese ore digging in working space, make to screen frame body along described in step 1 described in step 4
A distance of equal length integrated therewith is moved in the direction of ore bed upper end to ore bed lower end, make the stope respectively with
Shielding frame body after movement, which surrounds, forms new working space；
Step 7：Step 5 is repeated to step 6, make the working space along the stope from ore bed upper end to
Ore bed lower end is moved, and the manganese ore that digging obtains in all working space is carried out by the transportation roadway outside ore body.
Described in step 5 in working space, to the stope below digging manganese ore it is further comprising the steps of：
Step 1：Drag conveyor is installed in transportation roadway；
Step 2：It is terminal by starting point, the ore bed upper end of the ore bed lower end, faces upward along the actual mining
The direction of extension is bored on the stope using rock drill and attacks several borehole holes；
Step 3：Load appropriate explosive and detonator respectively into borehole hole described in step 2, and simultaneously by all detonator leads
After row link together, combustion wire is put, all detonators and explosive is ignited, manganese ore in the stope is blasted；
Step 4：Enameled trough is laid with by ore bed lower end to ore bed upper end along the direction that the stope extends, is made
Manganese ore is blasted described in step 3 carry over enameled trough and slid to transportation roadway, then be delivered to by drag conveyor described in step 1
Outside the ore body.
Borehole hole depth described in step 2 is 3 meters to 5 meters.
Borehole hole described in step 2 is arranged as at least two rows of, adjacent two artillery salvo along the direction that the stope extends
It is 0.8 meter to 1 meter that spacing is arranged between eyelet.
Explosive described in step 3 is two level rock emulsion explosive.
It screens frame body to be welded to connect by the shield support described in step 4 and forms " bow " glyph shape.
Shield support described in step 4 is made using No. 11 I-beam for mine.
The air return lane and transportation roadway respectively prop up it using laying anchor net, gunite concrete, hydraulic prop
Shield.
It includes at least 15 to 30 shield supports that frame body is screened described in step 4.
The beneficial effects of the present invention are：Technical solution using the present invention, it is a plurality of without being tunneled to inclined manganese ore layer
Digging tunnel, and only need to tunnel air return lane, transportation roadway and back production lane, tunnelling rate is considerably reduced, is simplified
Mining technique saves the tunnelling activity duration, improves efficiency；Due to two of back production lane ends respectively with return
Air way, transportation roadway connection make fresh air that can constantly pass through in air return lane or transportation roadway inflow back production lane, ensure that back production lane
Operating environment, it is mobile screen frame body by way of supporting carried out to back production lane, the effective protection people of digging operation personnel
Body safety, allows the mining operations to inclined manganese ore layer to keep continuously mining operations, improves mining efficiency, cover
Retaining frame body may be reused, and save supporting operation raw material.
Description of the drawings
Fig. 1 is present invention process flow chart；
Fig. 2 be air return lane of the present invention, transportation roadway, back production lane arrangement schematic diagram.
In figure：1- air return lanes, 2- transportation roadways, 3- manganese ore layers, 4- shielding frame bodies, 5- country rocks, 8- drag conveyors, 9- are advanced
Supporting.
Specific implementation mode
Be described further below technical scheme of the present invention, but claimed range be not limited to it is described.
As shown in Figure 1 and Figure 2, the present invention provides a kind of mining side of the tilted manganese ore layer of mobile shield support digging ore body
Method includes the following steps：
Step 1：Reconnoitre ore body：Finding somewhere on geographical location has the geologic body of extraction value as ore body, in ore body
With the manganese ore layer being inclined relative to horizontal, manganese ore layer is relatively distant from the one end on ground as ore bed upper end, and manganese ore layer is opposite
Subaerial one end is as ore bed lower end；
Step 2：On the ore body outer surface corresponding to step 1 ore bed upper end, into ore body digging tunnel to form air return lane,
On the ore body outer surface corresponding to step 1 ore bed lower end, into ore body digging tunnel to form transportation roadway；Air return lane and transportation roadway
Supporting is carried out to it using laying anchor net, gunite concrete, hydraulic prop respectively.
Step 3：The direction digging extended along step 1 manganese ore layer goes out a back production lane, the both ends in back production lane respectively with step
Rapid two air return lane, transportation roadway connection, back production lane inner bottom wall is as stope；
Step 4：Prepare more shield supports, by all shield supports along step 1 ore bed upper end to ore bed lower end
Direction is layed in back production lane roof, on side wall side by side, is wherein connected by bar shaped timber between any adjacent two shield support
Be connected together composition shielding frame body, reuses hydraulic prop and group shielding frame body is abutted against the roof in back production lane, side wall
On, reuse a plurality of steel wire rope by back production lane all shield supports of same wall surface link together, make actual mining
Face surrounds with two groups of shielding frame bodies form working space respectively；Further, steel wire rope is preferably 4, and shielding frame body is by screening
Holder is welded to connect to form " bow " glyph shape.Further, three interior angles of " bow " font shielding frame body are respectively set to
125 °, 135 °, 145 ° are advisable, between each shield support junction use steel plate reinforcement, while on shield support bore attack it is more
Group bolt hole will screen frame body to link together for fixing steel wire rope by steel wire rope.
Shield support is made using No. 11 I-beam for mine.It includes at least 15 to 30 shield supports to screen frame body.Engineering is real
In border, in mobile shielding frame body, it is only necessary to it removes and screens frame body close to the shield support of ore bed upper end side 5 to 10, it will
It is layed in shielding frame body close to ore bed lower end side, reuses monomer hydraulic bracket and steel wire rope is formed new cover frame
Body, it should be noted that when using this method, to ensure construction safety, the shielding that need not be removed in cover frame body
The minimum number of holder should be maintained within 10 to 20.
Step 5：In step 4 working space, to stope below digging manganese ore, make manganese ore by transportation roadway transport
It sends out outside ore body；
Step 6：After the completion of manganese ore digging in working space, make shielding frame body along ore bed upper end to ore bed lower end
A distance of equal length integrated therewith is moved in direction, so that stope is surrounded respectively with the shielding frame body after movement and is formed
New working space；
Step 7：Step 5 is repeated to step 6, makes working space along stope from ore bed upper end to ore bed lower end
Mobile, the manganese ore that digging obtains in all working space is carried out by transportation roadway outside ore body.
Technical solution using the present invention without tunneling a plurality of digging tunnel to inclined manganese ore layer, and only needs to tunnel
Air return lane, transportation roadway and back production lane, considerably reduce tunnelling rate, simplify mining technique, save lane
The road excavation operation time, improve efficiency；Since two ends in back production lane are connected to air return lane, transportation roadway respectively, make new
Fresh air can constantly pass through air return lane or transportation roadway flows into back production lane, ensure that the operating environment in back production lane, passes through movement
The mode of frame body is screened to carry out supporting to back production lane, the effective protection personal safety of digging operation personnel makes to inclined manganese
The mining operations of ore bed can keep continuously mining operations, improve mining efficiency, and shielding frame body may be reused,
Save supporting operation raw material.
Further, in working space, to stope below digging manganese ore it is further comprising the steps of：
Step 1：Drag conveyor is installed in transportation roadway；
Step 2：It is terminal by starting point, ore bed upper end of ore bed lower end, the direction upwardly extended along stope makes
It is bored on stope with rock drill and attacks several borehole holes；Further, the side that borehole hole extends along stope
At least two rows of to being arranged as, row's spacing is 0.8 meter to 1 meter between adjacent two rows borehole hole.Borehole hole depth is 3 meters to 5 meters.Into
One step, borehole hole can also be arranged according to five presbyopia fusiforms, and spacing is 0.6 meter to 0.8 meter between two borehole holes of arbitrary neighborhood.
Step 3：It loads appropriate explosive and detonator respectively into borehole hole, and all detonator leads is connected to one side by side
After rising, combustion wire is put, all detonators and explosive is ignited, manganese ore in stope is blasted；Further, the preferred two level of explosive
Rock emulsion explosive.
Step 4：Enameled trough is laid with by ore bed lower end to ore bed upper end along the direction that stope extends, makes to be fried
Go out manganese ore and carry over enameled trough to slide to transportation roadway, then is delivered to outside ore body by drag conveyor.
Claims (9)
1. a kind of mining methods of the tilted manganese ore layer of mobile shield support digging ore body, it is characterised in that：Include the following steps：
Step 1：Reconnoitre ore body：Finding somewhere on geographical location has the geologic body of extraction value as ore body, in the ore body
With the manganese ore layer being inclined relative to horizontal, the manganese ore layer is relatively distant from the one end on ground as ore bed upper end, the manganese
Ore bed is connected to each other subaerial one end as ore bed lower end；
Step 2：On ore body outer surface corresponding to the ore bed upper end described in step 1, into ore body digging tunnel to form air return lane,
On ore body outer surface corresponding to the ore bed lower end described in step 1, into ore body digging tunnel to form transportation roadway；
Step 3：The direction digging extended along manganese ore layer described in step 1 goes out a back production lane, the both ends difference in the back production lane
It is connected to air return lane, transportation roadway described in step 2, back production lane inner bottom wall is as stope；
Step 4：Prepare more shield supports, by all shield supports along ore bed upper end described in step 1 to ore bed lower end
Direction is layed in back production lane roof, on side wall side by side, passes through bar shaped wood wherein between any adjacent two shield support
Material, which links together, forms shielding frame body, reuses the top that group shielding frame body is abutted against the back production lane by hydraulic prop
On wall, side wall, reuses a plurality of steel wire rope and all shield supports of the same wall surface in the back production lane links together,
So that the stope is surrounded respectively with two groups of shielding frame bodies and forms working space；
Step 5：In the working space described in step 4, to the stope below digging manganese ore, so that the manganese ore is passed through
The transportation roadway is carried out outside ore body；
Step 6：After the completion of manganese ore digging in working space, make to screen frame body along ore bed described in step 1 described in step 4
A distance of equal length integrated therewith is moved in the direction of upper end to ore bed lower end, make the stope respectively with movement
Shielding frame body afterwards surrounds and forms new working space；
Step 7：Step 5 is repeated to step 6, makes the working space along the stope from ore bed upper end to ore bed
Lower end is moved, and the manganese ore that digging obtains in all working space is carried out by the transportation roadway outside ore body.
2. the mining methods of the tilted manganese ore layer of mobile shield support digging ore body as described in claim 1, it is characterised in that：
Described in step 5 in working space, to the stope below digging manganese ore it is further comprising the steps of：
Step 1：Drag conveyor is installed in transportation roadway；
Step 2：It is terminal by starting point, the ore bed upper end of the ore bed lower end, is upwardly extended along the stope
Direction, bored on the stope using rock drill and attack several borehole holes；
Step 3：It loads appropriate explosive and detonator respectively into borehole hole described in step 2, and all detonator leads is connected side by side
After being connected together, combustion wire is put, all detonators and explosive is ignited, manganese ore in the stope is blasted；
Step 4：Enameled trough is laid with by ore bed lower end to ore bed upper end along the direction that the stope extends, makes step
3 it is described blasted manganese ore and carry over enameled trough slide to transportation roadway, then be delivered to by drag conveyor described in step 1 described
Outside ore body.
3. the mining methods of the tilted manganese ore layer of mobile shield support digging ore body as claimed in claim 2, it is characterised in that：
Borehole hole depth described in step 2 is 3 meters to 5 meters.
4. the mining methods of the tilted manganese ore layer of mobile shield support digging ore body as claimed in claim 2, it is characterised in that：
Borehole hole described in step 2 be arranged as along the direction that the stope extends it is at least two rows of, between adjacent two rows borehole hole
It is 0.8 meter to 1 meter to arrange spacing.
5. the mining methods of the tilted manganese ore layer of mobile shield support digging ore body as claimed in claim 2, it is characterised in that：
Explosive described in step 3 is two level rock emulsion explosive.
6. the mining methods of the tilted manganese ore layer of mobile shield support digging ore body as described in claim 1, it is characterised in that：
It screens frame body to be welded to connect by the shield support described in step 4 and forms " bow " glyph shape.
7. the mining methods of the tilted manganese ore layer of mobile shield support digging ore body as described in claim 1, it is characterised in that：
Shield support described in step 4 is made using No. 11 I-beam for mine.
8. the mining methods of the tilted manganese ore layer of mobile shield support digging ore body as described in claim 1, it is characterised in that：
The air return lane and transportation roadway carry out supporting using laying anchor net, gunite concrete, hydraulic prop to it respectively.
9. the mining methods of the tilted manganese ore layer of mobile shield support digging ore body as described in claim 1, it is characterised in that：
It includes at least 15 to 30 shield supports that frame body is screened described in step 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810437656.8A CN108678744B (en) | 2018-05-09 | 2018-05-09 | Mining method for excavating inclined manganese ore layer in ore body by using movable shield support |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810437656.8A CN108678744B (en) | 2018-05-09 | 2018-05-09 | Mining method for excavating inclined manganese ore layer in ore body by using movable shield support |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108678744A true CN108678744A (en) | 2018-10-19 |
| CN108678744B CN108678744B (en) | 2020-09-01 |
Family
ID=63805954
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810437656.8A Expired - Fee Related CN108678744B (en) | 2018-05-09 | 2018-05-09 | Mining method for excavating inclined manganese ore layer in ore body by using movable shield support |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108678744B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1657745A (en) * | 2005-03-03 | 2005-08-24 | 开滦（集团）有限责任公司 | Coal-minin method of high-dipping thick seam |
| CN101469612A (en) * | 2007-12-26 | 2009-07-01 | 孙世超 | Mining method for segmented metallic ore |
| CN103775085A (en) * | 2012-10-25 | 2014-05-07 | 泰安市华硕能源科技有限公司 | Flexible shield support excavation integrated supporting coal-pillar-free mining method of steep medium-thickness coal seam |
| AU2014200978A1 (en) * | 2013-03-01 | 2014-09-18 | Poseidon Nickel Limited | Underground Mining Method |
-
2018
- 2018-05-09 CN CN201810437656.8A patent/CN108678744B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1657745A (en) * | 2005-03-03 | 2005-08-24 | 开滦（集团）有限责任公司 | Coal-minin method of high-dipping thick seam |
| CN101469612A (en) * | 2007-12-26 | 2009-07-01 | 孙世超 | Mining method for segmented metallic ore |
| CN103775085A (en) * | 2012-10-25 | 2014-05-07 | 泰安市华硕能源科技有限公司 | Flexible shield support excavation integrated supporting coal-pillar-free mining method of steep medium-thickness coal seam |
| AU2014200978A1 (en) * | 2013-03-01 | 2014-09-18 | Poseidon Nickel Limited | Underground Mining Method |
Non-Patent Citations (1)
| Title |
|---|
| 钟义旆: "《金属矿床开采》", 31 May 1990 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108678744B (en) | 2020-09-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108661643B (en) | It a kind of coal working face end adopts return channel and cuts top release shield lane method | |
| CN102518438B (en) | Roof regeneration medium-length hole ore blast backfill mining method | |
| CN101105129B (en) | Mining environment reconstructed continuous mining afterwards filling mining method | |
| CN103527200B (en) | Bottom-column-free sectional Rhombic room afterwards filling mining method | |
| CN102844522B (en) | underground mining | |
| CN103410515B (en) | It is a kind of that three-soft seam is reciprocating combines mining method without coal column | |
| CN105971606B (en) | A kind of thick sandstone coal wall recovery method | |
| CN105041314A (en) | Method for united mining of deep subsequent stoping chamber and layered stoping jamb | |
| CN104632220B (en) | Mining method with adjustable and controllable structure size of gentle dip medium-thickness ore body strip column reconstructed stope | |
| CN102168579A (en) | Rib-pillar-free continuous sublevel filling method for mining preparation in medium-thickness slope crushed ore body vein | |
| CN1982649A (en) | Mining method | |
| CN105909247A (en) | Non-pillar sublevel mining cemented filling mining method | |
| CN113738367B (en) | Sublevel caving downward filling mining method for complex broken and steeply inclined thin vein | |
| CN102720498A (en) | Gob-side entry retaining mining process for coal face | |
| CN109026005B (en) | Comprehensive mechanized ore-breaking layered caving mining method | |
| CN108266189A (en) | A kind of lane top Tunnelling Along Goaf goaf isolation method | |
| CN104453900A (en) | Filling mining method of near-horizontal ore body | |
| CN105673014A (en) | Method for controlling rock burst of hard roof jump mining working face | |
| CN114592909A (en) | Downward layered access filling mining method for extremely-broken thick and large ore body | |
| CN104265294A (en) | Coal pillar-free mining technology for blasting mining face of steeply dipping seam | |
| CN109779652A (en) | A kind of expansion of coal-mine soft-rock tailentry is repaired and method for protecting support | |
| CN108952725B (en) | Low dilution mining method suitable for gentle dip thin ore body | |
| CN110219650B (en) | Deep hole subsequent filling mining method in environment reconstruction stage | |
| CN110118085A (en) | A kind of compound advanced secondary tunneling method in two lane of top working face of large mining depth high working face | |
| CN1195149C (en) | Roof bolt protection and sectioned empty field method for phosphorate rock mining |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200901 |