Some fossils are useful as clues in the search for oil, coal and valuable mineral deposit.

有些化石还可作为有用的线索用于寻找石油 、 煤以及有价值的矿床.

Floatation column is a high efficiency separation equipment recovering valuable mineral fines.

浮选柱是回收细颗粒有价矿物的高效分选设备.