Chemomechanical Effects in Hard Rock Drilling.

摘要

A study was made of the environment-sensitive pendulum hardness and laboratory scale rotary diamond drilling behavior of granite and its component phases,quartz and feldspar. It has been found that,by controlling the chemistry of their environment,it is possible to predictably vary the hardness and increase the rates of drilling of these materials. For example,relative to values obtained in water,environment-induced increases of some 20% in the hardness of quartz and microcline have been produced which,in turn,are primarily responsible for more than thirteen-fold increases in the rate of drilling of quartz and three-fold increases for microcline and granite. These observations of enhanced drilling efficiency associated with hardness increases should be contrasted with previous reports of the beneficial value of 'hardness reducers'. It has been found also that at this scale the drilling behavior of granite is largely determined by the chemomechanical behavior of the harder quartz phase,rather than by pre-existing flaws or other microstructural features.