Surface mining operations extract a large quantity of waste material,which is generally disposed into a dump area.This waste can cause a series of environmental problems ranging from landscape deterioration to acidic ...Surface mining operations extract a large quantity of waste material,which is generally disposed into a dump area.This waste can cause a series of environmental problems ranging from landscape deterioration to acidic water generation and water pollution.Therefore,mine waste management is a significant task in mining operations.As known,in strip mining,the overburden is not transported to waste dumps but disposed directly into adjacent strip which was mined out.This concept can be adapted for mine planning of relatively horizontal deposits through a mixed integer programming(MIP)model.The main idea behind this work is that,in one pit,production voids created in early year of mining are used for waste landfilling in late years of production.In other words,in addition to external dumping,a landfilling option within the same pit is proposed for mine design optimization.The problem is formulated as maximization of the net present value(NPV)of the mining project under the constraints of access,landfill waste handling,mining and processing capacities.A case study using a data set was carried out to see the performance of the proposed approach.The findings showed that this approach could be used in waste management incorporating a landfilling option into mine planning.As a result,material handling costs decrease,and environmental compliance increases due to less external waste quantity.展开更多
Solid wastes derived from metallurgical industries pose a significant threat to environment. The utilization and disposal of these solid wastes are the major concern in the world. Semi-coke generated in coal-based dir...Solid wastes derived from metallurgical industries pose a significant threat to environment. The utilization and disposal of these solid wastes are the major concern in the world. Semi-coke generated in coal-based direct reduction process of iron ore is a by-product and its suitable utilization is not available so far. In order to handle it properly, the characteristics of this by-product were comprehensively investigated. A series of analysis methods were used to demonstrate its mineral compositions, petrography and physico-chemical properties. The results reveal that the semi-coke has poor washability. The fixed carbon content of semi-coke reaches 76.11% and the gross calorific value is 28.10 MJ/kg, both of which are similar to those of traditional sinter coke breeze. Also, semi-coke ash possesses lower content of SiO2, Al2O3, S and higher content of CaO and MgO, which could improve the strength of sinter ore when partially substituting for coke breeze in sintering. Semi-coke features well-development porous structure and higher reaction activity, which predicts that the sintering speed could be elevated to some extent when employing it as a partial replacement of coke breeze, so the studies further suggest that the potential adverse effect of the high reactivity on sintering process could be weakened by adequately coarsening the semi-coke's particle size.展开更多
文摘Surface mining operations extract a large quantity of waste material,which is generally disposed into a dump area.This waste can cause a series of environmental problems ranging from landscape deterioration to acidic water generation and water pollution.Therefore,mine waste management is a significant task in mining operations.As known,in strip mining,the overburden is not transported to waste dumps but disposed directly into adjacent strip which was mined out.This concept can be adapted for mine planning of relatively horizontal deposits through a mixed integer programming(MIP)model.The main idea behind this work is that,in one pit,production voids created in early year of mining are used for waste landfilling in late years of production.In other words,in addition to external dumping,a landfilling option within the same pit is proposed for mine design optimization.The problem is formulated as maximization of the net present value(NPV)of the mining project under the constraints of access,landfill waste handling,mining and processing capacities.A case study using a data set was carried out to see the performance of the proposed approach.The findings showed that this approach could be used in waste management incorporating a landfilling option into mine planning.As a result,material handling costs decrease,and environmental compliance increases due to less external waste quantity.
基金Project(2011GH561685)supported by the China Torch Program
文摘Solid wastes derived from metallurgical industries pose a significant threat to environment. The utilization and disposal of these solid wastes are the major concern in the world. Semi-coke generated in coal-based direct reduction process of iron ore is a by-product and its suitable utilization is not available so far. In order to handle it properly, the characteristics of this by-product were comprehensively investigated. A series of analysis methods were used to demonstrate its mineral compositions, petrography and physico-chemical properties. The results reveal that the semi-coke has poor washability. The fixed carbon content of semi-coke reaches 76.11% and the gross calorific value is 28.10 MJ/kg, both of which are similar to those of traditional sinter coke breeze. Also, semi-coke ash possesses lower content of SiO2, Al2O3, S and higher content of CaO and MgO, which could improve the strength of sinter ore when partially substituting for coke breeze in sintering. Semi-coke features well-development porous structure and higher reaction activity, which predicts that the sintering speed could be elevated to some extent when employing it as a partial replacement of coke breeze, so the studies further suggest that the potential adverse effect of the high reactivity on sintering process could be weakened by adequately coarsening the semi-coke's particle size.
