Voorbeelden van hard rock

• Mining hard rock instead of coal also greatly increases the risk of machine damage.

• Chapter 6 covers 'hard rock' techniques with emphasis on thin sections, but like nearly all others it is too concise to help with applications to ceramics, a non-trivial subject.

• In most heavy metal and hard rock, this ambiguity was not played up to a large degree, with the modality usually being firmly established through context.

• This tension appeared even before 1881, however, beginning in 1874 when most of the upper layers of earth had been sifted through, and now, lying beneath, was hard rock.

• Three principal types of formation are under consideration—hard rock, clay and salt.

• Others are found in hard rock and have to be worked by mining methods that are relatively high cost.

• There is a future for hard rock mining in my county.

• Radiation-induced lung cancers have been reported in uranium and hard rock miners for a long time.