High-purity limestone in the UAE

High-purity limestone in the UAE Clive Mitchell, Industrial Minerals Specialist, British Geological Survey, Nottingham, UK Email: cjmi@bgs.ac.uk High-purity limestone can be defined as carbonate rock that contains greater than 97% calcium carbonate (CaCO3). Limestone is thought to have the largest number of commercial uses of all industrial minerals; including as construction material, mineral fillers (paper, paint, plastic, rubber and pharmaceuticals), adhesives, abrasives, fertilisers and soil conditioners, the production of cement, lime and calcium chemicals. Exploration for high-purity limestone involves a detailed examination of known deposits as defined by existing geological information. National geological surveys are usually responsible for reconnaissance-scale mineral resource assessments which have a national or regional focus. BGS reconnaissance surveys of limestone make use of a classification scheme, whereby their ‘purity’ is based on the calcium carbonate content (CaCO3) as follows: very-high purity (>98.5%), high purity (97-98.5%), medium-purity (93.5-97%), low-purity (85-93.5%) and impure (<85%). In addition, the magnesia (MgO), silica (SiO2) and iron oxide (Fe2O3) are also used as quality criteria. Laboratory evaluation of limestone includes chemical and mineralogical analysis, and physical property testing. The evaluation is informed by the needs of industry and relies on the availability of technical data sheets and specifications. A reconnaissance survey was carried out in the UAE (2009-10) to identify high-purity limestone. Large resources were identified in the northern Emirates that have the potential to be used for high value industrial uses such as mineral fillers, ceramics, glass, food, pharmaceuticals, calcium chemical and lime production. Further to this initial survey, a more detailed assessment of the high-purity limestone resources of the northern Emirates will be carried out over the next 2 years. The development of these resources has the potential to make a substantial contribution to the economic diversification of the UAE.