Real-time measurement of rock weight during loading and hauling operations

The article discusses an automated control system for underground mining of copper-nickel ores and the weight control system as a part of this system. The main functions of the weight control system are described, as well as the requirements towards this system, the principle of applying the proposed algorithms and the results of implementing this system at an existing mining operation. The experience of measuring the rock mass during loading and hauling operations is described in terms of operational management and control of actual quantitative and qualitative parameters of ore flow in the multistage process of the ore grade stabilization in underground mining. The obtained results help to solve the challenge of controlling the LHD bucket load while ensuring the required parameters and operating conditions for the following application scenarios: (1) control of the transported rock mass for each haul cycle with the accuracy of ±6%; (2) control of the transported rock mass by a particular LHD per shift with the accuracy not worse than 1% for 60 haul cycles per shift; (3) for the operations with high moisture content of the transported load, it is possible to account for the stuck material for each haul cycle; (4) no special requirements to the weighing process; (5) minimization of the operating costs for calibration and maintenance; (6) high reliability due to minimum amount of hardware; (7) no degradation of the method when using readings of the hydraulic system; (8) unification of the system. The accuracy and reliability of the data obtained gradually increases during the operation when the test measurements are made about once a month. The disadvantages include: (1) impossibility to use the metrological level for measurements; (2) dependence on the technical condition of the onboard hydraulic system; (3) partial dependence on the LHD mileage. A conclusion is made that the process of ore grade stabilization should be multistage, and the measurement of the rock mass during the loading and hauling operations is one of the mandatory methods for implementation of the geometallurgical tasks.