| 发明名称 |
METHOD OF MINING POTASH ORES AND THE LIKE |
| 摘要 |
<p>In the mining of potash ore or the like, the step of extracting ore in a split chevron pattern in which at least one wing passageway is advanced ahead of and on each side of a central entry before said central entry is advanced.</p> |
| 申请公布号 |
CA1079757(A) |
申请公布日期 |
1980.06.17 |
| 申请号 |
CA19770291266 |
申请日期 |
1977.11.18 |
| 申请人 |
APM OPERATORS LTD. |
发明人 |
CAIRNS, JOHN D.;PHILLIPS, GORDON D. |
| 分类号 |
E21C41/16;(IPC1-7):21C41/08 |
主分类号 |
E21C41/16 |
| 代理机构 |
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代理人 |
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| 主权项 |
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| 地址 |
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