Optimization Research On System Mining Of Karst Accumulated Bauxite Deposit

Pingguo bauxite is the karst accumulated bauxite which is exploited firstly in the world. The ore is widely distributed with large reserves and tremendous economic value. The quality of the ore grade changes greatly, the aluminum-silicon ratio is distributed from3.92to33.93. Guangxi Branch of Aluminum Corporation of China uses the pure Bayer process for the alumina production. The bauxite with Al-Si ratio below7is not suitable for the alumina production. In order to ensure the sustainable use of bauxite resources, the exploitation of karst accumulated bauxite should be systematically and reach the global optimization.On the basis of the concept of sustainable use of resources, the paper used scientific method of systems engineering, gray system theory, multi-objective decision-making and logistics planning theory, to make the research on karst accumulated bauxite production process systems modeling and optimization. Firstly, karst accumulation bauxite resources and mining conditions were analyzed systematically. Secondly the gray analytic hierarchy process was used to select the major mining process, while the gray fuzzy comprehensive decision-making model was used to choose the stripping equipment suitable for the exploitation process. Thirdly, the0-1integer programming model with gray parameter was constructed. In the model, the site selection and the ore blending were combined. The best site of accumulated bauxite as well as long-term production planning program were got by the advanced operations optimization software FICO MP-Xpress. Finally, on the basis of long-term planning, the accumulated bauxite blending system combined with stope and yard was analyzed. By the gray goal programming theory, the stope and yard ore blending mathematical model for the accumulate bauxite were constructed. The model could guarantee the comprehensive utilization of bauxite resources and provide the stable supply of ore grade alumina in long term. The main research results were as follows:(1) After the exploration and geological survey of the ore body of Pingguo Taiping south, the occurrence condition, regional geological, geological features and hydrogeology condition of the ore deposit were studied, reserves and industrial index were got. The ore supply ability and quality are researched. The resource conditions, mining conditions, and external construction conditions were analyzed. The result shows that the accumulated bauxite in mine design has high economic value and it can meet the production requirements.(2) Considering the main characteristics of karst accumulated bauxite, the AHP-GRAM evaluation model for mining technology selection of karst accumulated bauxite was proposed. Firstly, the main influential factors of mining method selection were analyzed. Secondly, by using the system engineering, grey system theory and scientific decision-making method, the mining method and mining process were optimized to meet the needs of the project. And then, the open pit boundary of the accumulated bauxite was analyzed and the boundary parameters were studied. Finally, the production scale and service life of the mining area were determined.(3) The deposit geological characteristics, geology and hydrological characteristics, the existing mining machinery equipment, the mining methods, and the ore quality requirements of alumina plant were analyzed. Combining with the related physical and mechanical properties of the ore-body and surrounding rock medium, reference to the similar mining technical conditions at home and abroad, on the basis of the mining equipment selection principles for accumulated bauxite, the systematic science method such as grey system theory, fuzzy mathematics theory, and operational research were used comprehensively to establish the grey fuzzy comprehensive decision model for the mining equipments for accumulated bauxite. The model could select the main technical equipments for the mining area.(4) The site selection problem of karst accumulated bauxite is actually a mining logistics optimization problem. It is comprehensive optimization problem on site selection, transportation, production and alumina plant process need. The mining process system is actually a typical gray system. By introducing the method of gray planning system, the optimization model on site selection and ore blending with gray parameters was built. After the optimization calculation by advanced operations research software FICO Xpress-MP, the best site and the long-term planning of bauxite mining were got. The model ensures the economy of mine development and stable persistence of ore supply.(5) The united technology system on stope and yard ore blending of karst accumulated bauxite was proposed. The paper made the analysis on the planning efficiency of stope ore blending and buffer-regulating efficiency of yard ore blending under the combined effects mode. By taking advantage of FICO Xpress-MP, the gray multi-objective programming model for stope ore blending and mathematical model for yard ore blending were built. The study makes the karst accumulated bauxite ore blending problem turn systematism and modeling.