A computerized model for truck dispatching in open pit mines.

摘要

In an effort to improve shovel-truck haulage system efficiency and productivity and reduce costs, truck dispatching in open pit mines has received a lot of attention since the late 1970's. Various dispatching systems have been proposed, developed and are commercially being used to various degrees of success. Though claims have been made about the ability of a reasonable number of dispatching systems to increase production of shovel-truck haulage systems, similar claims have not been made about the success of such dispatching systems to maintain ore quality within prescribed upper and lower limits.; In this study a three stage truck dispatching model which minimizes truck travel time, maximizes production and maintains ore quality within prescribed upper and lower limits is formulated, developed and validated.; In the first stage, a vehicle routing program based on the shortest route problem was developed to select the best routes between sources and destinations, in both directions. A non-preemptive goal programming model, which introduces the concept of a centralized target quality value, was used in the second stage to maximize production and minimize deviation of optimal ore quality values from targets. In the third stage--the real time dispatching stage, a transportation model was used to assign trucks to needy shovels, based on the criteria of minimizing the deviation of route cumulative tonnage ratios from the mean and minimizing waiting time of shovels and trucks.; Simulation with a real open pit mine data showed a significant production increase by the dispatching model over a fixed dispatching model. In addition, the dispatching model has the capability of maintaining ore quality within prescribed upper and lower limits, thereby eliminating stockpiling or rehandling.