In the boundary of open-pit, characteristic division of mine can be treated as working grid, working grid and mine boundary grid are the basic grid.

在矿界内把露天矿区的特征分区看作一个工作网格，工作网格结合矿界就构成了矿区的基本网格。

youdao

The effect of casting blast could influence working performance of dragline and cost of production in open-pit.

在露天矿抛掷爆破中，爆破效果的优劣影响到拉斗铲作业效率及露天矿生产成本。

youdao

Encina said Codelco is working to convert one of its biggest mines, Chuquicamata, from open pit to underground.

FORBES: Continuous Mining To Help Chile Extend Mine Life, Save Money