Integrated exploration of clay deposits: Some changes of strategy

Clay deposits often occur associated with deposits of ores and hydrocarbons. Because exploration projects strictly follow only one target, useful information on associated rocks is lost and valuable by-products remain unrecovered. Modem mineral policy and exploration strategy suggest integrated exploration during which all potential raw materials in the prospection area are registered and evaluated. A tough timing of exploitation often impairs selective mining and storage of valuable by-products. Regarding clays, certain modification of exploration procedures are necessary and simplification of sampling and analytical strategy is required. Integrated exploration leads to an integral extraction of all raw materials which occur in the prospected area. It also respects the geotechnical and ecological conditions of other deposits. All aspects of field exploration, subsequent laboratory examination (analyses and technological testing) and economic assessment should be balanced and scheduled in a logical sequence. Such a new strategy has to respect distinct quality requirements of different users and manufactured products. However, particular specifications of clay raw materials are nowadays too complex and not always justified. Therefore they should be unified and simplified in the near future. Civil engineering exploration, soils exploration and environmental care call for other parameters of clays. These differ from those required by ceramics and other industries. Information on basic mineral, chemical and textural properties, thorough examination of physical and chemical properties and long term behaviour of clays are of primary importance.