Coordination of the operation of four quarries to optimize limestone blending.

Rapid expansion of the cement industry, development of new technology and the economic situation have resulted in expansion and construction of high capacity cement plants. This requires large quantities of cement-grade lime- stone, either from a single quarry or from several quarries at different locations. It is difficult to produce blended limestone from quarries at different locations because of the challenges presented by different geological formations, different grades of material in the different quarries, etc. Any change in raw mix with respect to limestone quality or quantity, will have an impact on long-term strategic resource planning due to the quantities of different grades from the different quarries. The authors have attempted to provide a long-term strategic plan for optimization of quarry planning and production scheduling for four limestone quarries some distance apart. The limestone deposit involves varying thicknesses of argillaceous limestone interspersed with highly siliceous limestone, with underlying shale in some of the quarries. Quarry production schedules for the blended limestone have been prepared for all the four quarries with the help of Multimine Scheduler software to achieve an optimum economical extraction sequence with minimum quality variation and an effective optimum on site/multi-site blending scheme. An Optimal Extraction Sequence (OES) for model quarries has been generated to create a workable quarrying plan that takes account of the effects of quarrying constraints to produce practical quarry designs and achievable quarrying schedules. As a result, it has been possible to achieve the raw (run-of-mine) limestone grade with a specified CaO and SiO2 content and a target annual production rate with enhanced quarry life. [ABSTRACT FROM AUTHOR]