Pit limit design has,up to date,focused mainly on maximization of economic profit alone,with environmental and social issues largely ignored.This paper focuses on incorporating both environmental and social issues in ...Pit limit design has,up to date,focused mainly on maximization of economic profit alone,with environmental and social issues largely ignored.This paper focuses on incorporating both environmental and social issues in the pit limit design process and provides an approach to pit limit optimization that is in compliance with sustainable development.The case study demonstrates that ecological costs have a substantial down-sizing effect and social benefits have a substantial up-sizing effect on the optimal pit limit.When the ecological costs are factored in,the optimal pit limit is 37.5%smaller than the economically optimal pit limit.However,when the social benefits are factored in,the optimal pit limit is 48.3%larger than the economically optimal one.The overall optimal pit limit,with the economic profit,ecological costs and social benefits simultaneously considered,is a result of balancing conflicting goals of maximizing economic profit,minimizing ecological cost,and maximizing social benefit.展开更多
An integral connection exists among the mine production planning, the mined material destination, and the ultimate pit limit （UPL） in the mining engineering economy. This relation is reinforced by real information a...An integral connection exists among the mine production planning, the mined material destination, and the ultimate pit limit （UPL） in the mining engineering economy. This relation is reinforced by real information and the benefits it engenders in the mining economy. Hence, it is important to create optimizing algorithms to reduce the errors of economic calculations. In this work, a logical mathematical algorithm that considers the important designing parameters and the mining economy is proposed. This algorithm creates an optimizing repetitive process among different designing constituents and directs them into the maximum amount of the mine economical parameters. This process will produce the highest amount of ores and the highest degree of safety. The modeling produces a new relation between the concept of the cutoff grade, mine designing, and mine planning, and it provides the maximum benefit by calculating the destination of the ores. The proposed algorithm is evaluated in a real case study. The results show that the net present value of the mine production is increased by 3% compared to previous methods of production design and UPL.展开更多
The space effects of oval-shaped furrow pit slopes were analyzed by the elastic mechanics principle.The interaction of limit equilibrium slope angle,friction coefficient,cohesion and horizontal radius of oval-shaped f...The space effects of oval-shaped furrow pit slopes were analyzed by the elastic mechanics principle.The interaction of limit equilibrium slope angle,friction coefficient,cohesion and horizontal radius of oval-shaped furrow pits has been derived.The oval trumpet-like rock mass is homogeneous and elastic while only loaded by its dead weight.The interaction indicates that the deeper an oval-shaped furrow pit is excavated,the greater the limit equilibrium slope angle.Both the theory base for reducing stripping waste rock in an oval-shaped furrow pit and the basic way to determine the configuration of a stable slope were developed from the mentioned interaction.The theory includes the preceding principles of stability analysis of slopes.Compared with the configuration determined by traditional theory of slope stability,a great quantity of stripping waste rock can be reduced by that determined in this paper under stable conditions.展开更多
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(Nos.52074061,51974060,U1903216)Northeastern University Doctoral Basal Research Fund,China(No.N2001006).
文摘Pit limit design has,up to date,focused mainly on maximization of economic profit alone,with environmental and social issues largely ignored.This paper focuses on incorporating both environmental and social issues in the pit limit design process and provides an approach to pit limit optimization that is in compliance with sustainable development.The case study demonstrates that ecological costs have a substantial down-sizing effect and social benefits have a substantial up-sizing effect on the optimal pit limit.When the ecological costs are factored in,the optimal pit limit is 37.5%smaller than the economically optimal pit limit.However,when the social benefits are factored in,the optimal pit limit is 48.3%larger than the economically optimal one.The overall optimal pit limit,with the economic profit,ecological costs and social benefits simultaneously considered,is a result of balancing conflicting goals of maximizing economic profit,minimizing ecological cost,and maximizing social benefit.
文摘An integral connection exists among the mine production planning, the mined material destination, and the ultimate pit limit （UPL） in the mining engineering economy. This relation is reinforced by real information and the benefits it engenders in the mining economy. Hence, it is important to create optimizing algorithms to reduce the errors of economic calculations. In this work, a logical mathematical algorithm that considers the important designing parameters and the mining economy is proposed. This algorithm creates an optimizing repetitive process among different designing constituents and directs them into the maximum amount of the mine economical parameters. This process will produce the highest amount of ores and the highest degree of safety. The modeling produces a new relation between the concept of the cutoff grade, mine designing, and mine planning, and it provides the maximum benefit by calculating the destination of the ores. The proposed algorithm is evaluated in a real case study. The results show that the net present value of the mine production is increased by 3% compared to previous methods of production design and UPL.
文摘The space effects of oval-shaped furrow pit slopes were analyzed by the elastic mechanics principle.The interaction of limit equilibrium slope angle,friction coefficient,cohesion and horizontal radius of oval-shaped furrow pits has been derived.The oval trumpet-like rock mass is homogeneous and elastic while only loaded by its dead weight.The interaction indicates that the deeper an oval-shaped furrow pit is excavated,the greater the limit equilibrium slope angle.Both the theory base for reducing stripping waste rock in an oval-shaped furrow pit and the basic way to determine the configuration of a stable slope were developed from the mentioned interaction.The theory includes the preceding principles of stability analysis of slopes.Compared with the configuration determined by traditional theory of slope stability,a great quantity of stripping waste rock can be reduced by that determined in this paper under stable conditions.
