Quarrying and all other branches of surface mining rather than
diminishing in importance have become of more and more consequence
economically, industrially and particularly with the depletion of
high-grade deep-mined mineral reserves. Low-grade minerals require low
cost extraction and this in many cases necessitates very expensive
mechanized equipment with the cost of individual units running into
millions of pounds in the case of large- scale operations with high
productivity. There has been, and there still is, a tendency for the
smaller single quarries to be amalgamated into groups with large
financial resources and therefore with the ability to purchase these
expensive machines so necessary to make operations viable. This in turn
requires wider administrative and technical knowledge in executives of
these groups and as these often handle a wide range of products from
widely differing systems of working, this technical knowledge should
embrace the exploitation of many different types of deposits. There is,
at present, a great dearth throughout the world of such qualified
executives as is apparent from advertisements of vacancies in the
technical press. It would appear that these industries offer an
attractive career to the widely qualified and experienced technologist
in these fields. This book deals with methods of working in the surface
extractive indus- tries, quarry management and power supply-but does not
deal with related ancillary processes except where these affect
quarrying operations.
