Production scheduling for lime stone open pit mines with special emphasis on lime stone saturation factor to reduce environmental impacts of cement industry (Case study: Tehran cement factory)

Since cement industries are among the polluting industries, efforts should be made to reduce the environmental pollution of this industry by planning and optimizing its raw materials. With this approach, considering the close proximity of Tehran's cement plant to the capital, it was decided that with the optimization of the planning of production of mines, the supplier of raw materials of this plant with the aim of reducing the amount of waste and pollutants to improve the activities of the factory stepped up in this direction Optimization of extraction and adjustment of raw materials was used in research methods in operations, especially linear programming. The most important sources of raw material supplies to the Bibishahrbanoo, Mesgarabad, Lapehzanak and Chehelghez mines (as CaO, Fe2O3 and Al2O3 fractionation compensators in the form of iron ore and bauxite stones). Cement production is based on the setting of calcium saturation modulus, silica modulus and alumina modulus, among which the calcium saturation modulus is the most important factor in the composition of raw materials. In this plan, the issue of short-term production planning, the modulus adjustment, and the determination of the contribution of each resource in the supply of feed to the factory becomes a very attractive engineering problem, which requires the solution of this issue in terms of environmental and engineering indicators. Based on data gathered from geological maps and exploratory boreholes, as well as the analysis of surface samples of the studied areas, the set of mines was divided into 31 utilizable blocks. Then, by coding in the Lingo software environment, the extraction of blocks based on cement modulus was prioritized. The results of analyzes in production planning showed that the amount of calcium saturation modulus in the optimum setting is 82.12% and the minimum amount of elemental (MgO) is 2.69%, which is the result of the Tehran cement complex and causes the least amount of environmental pollution.