Shovel Operation Research Articles

Sustainable open pit mining through GHG-conscious short-term production scheduling

ABSTRACT The mining industry is a notable contributor to global greenhouse gas (GHG) emissions, posing challenges to achieving the Paris Agreement’s goal of capping emissions at 30 Gt CO2-equivalent annually by 2030. This paper introduces a novel Mixed Integer Linear Programming (MILP) model tailored for short-term open-pit mine planning that integrates environmental considerations, particularly GHG emissions, alongside economic objectives. The model handles complex operational challenges including block sequencing, multiple transport destinations, and stockpile management. Additionally, it provides the opportunity to examine the adoption of In-Pit Crushing and Conveying (IPCC) systems as the main transport method, an innovative approach aimed at reducing emissions from haulage – which accounts for over 35% of GHG emissions in open-pit mining. Applied to a case study in an iron ore mine, the model not only considers the environmental benefits of IPCC systems compared to traditional truck and shovel (TS) operations but also highlights significant reductions in haulage costs and carbon tax liabilities. The findings demonstrate that fixed IPCC (FIPCC) systems, in particular, offer substantial decreases in GHG emissions, presenting a compelling case for their broader adoption in the industry.

Experimental study of dual-cycle thermal management system for engineering radiator

With the increasing demand for heat dissipation of engineering vehicles, a dual-cycle cooling system is introduced in this paper to prevent the adverse effects of engineering vehicles’ equipment when operating at the overheating temperature. The performance of the new system is analyzed through tests, and the results show that the dual-cycle cooling system can meet the thermal balance requirements of the engineering vehicle during the shovel operation. Compared with the traditional cooling system, the new cooling system improved performance in terms of volume, engine energy consumption and working oil efficiency. The oil consumption of a wheel loader using the dual-cycle cooling system is reduced by 1% per hour, and the temperature of its transmission oil and hydraulic oil is reduced by more than 10 °C. The new cooling system has bright future in energy saving and emission reduction of engineering vehicles.

An efficient method for modeling and evaluating the bench terrain of open-pit mines

In order to quantitatively analyze the roughness of the bench floor during open-pit mine blasting, this study proposes a real-time measuring method for the three-dimensional terrain of the bench floor during the excavation process. Real-time monitoring is conducted at the boundary and discrete internal points of the workbench floor during electric shovel operation, utilizing real-time kinematic global navigation satellite system (RTK-GNSS) positioning technology. An improved convex hull algorithm is introduced to automatically extract the optimal boundary of discrete point clouds based on their spatial distribution characteristics. This study establishes a digital elevation model (DEM) using five interpolation algorithms for 3D terrain visualization simulation. Through cross-validation, a comparative analysis of the DEM accuracy, the simulation results of the ordinary kriging interpolation algorithm were found to be optimized. The optimized interpolation algorithm is applied to simulate the 3D terrain in the Dexing open-pit copper mine, and the relevant terrain parameters were calculated. This dataset can serve as a precise foundation for the real-time path planning of elevation blasting design and ground leveling operations.

仿生金蝉花生挖掘铲的研究与分析

In order to reduce the high resistance problem during peanut digging shovel operation and improve the soil loosening effect, a bionic peanut digging shovel was designed according to the streamlined profile of the head of the golden cicada, and the range of values of the digging operation parameters was analyzed. A discrete element model was developed to verify that the operational resistance of the bionic excavation shovel is lower than that of the flat shovel. The reliability of the simulation test was confirmed by conducting a resistance test on the excavation shovel through a soil trench test. A three-factor, three-water orthogonal combination test was designed to determine the optimal operating parameters of the excavation shovel: the bevel angle of the shovel blade was 55°, the digging depth was 130 mm, and the width of the shovel face was 309 mm. The paper can provide a reference for designing and optimizing peanut-digging shovels.

3-D modeling and monitoring system on intelligent film-lifting shovel based on BECKHOFF

Film shovel is the key device for mechanized operation of residual film recovery, in which the depth of soil breakage of the shovel is related to the degree of damage to the plastic film and the recovery efficiency of the residual film. However, the current mode of operation requires experience and visual inspection, which often leads to low level of mechanization and inefficient operation. The topic is to improve the existing residual film recovery device, focusing on the three-dimensional modeling and monitoring system of intelligent film lifting shovel. By optimizing the three-dimensional structure of the intelligent film-lifting shovel and kinematics simulation analysis based on Adams software, the design inclination angle of the loosening shovel is 60∘, and the breaking depth of the safe operation is 20–50 mm. Then through the use of Ethernet interface based on EtherCAT bus and the real-time bidirectional communication between BECKHOFF CX2030 controller and module and HMI, the on-line data transmission in the process of intelligent film shovel operation is realized. Field test results verify that the intelligent film-lifting shovel is feasible in the intelligent operation and recovery efficiency of the residual film recovery operation, which can greatly improve the efficiency of the whole machine operation.

Optimization design and experimental analysis of bionic viscosity reduction of chisel type energy saving subsoiling shovel

In order to solve the problems of adhesion to soil and high resistance in traditional subsoiling shovel operation, a bionic energy-saving subsoiling shovel with bionic viscosity reducing and resistance reducing chisel is designed based on the polygon geometry structure of pangolin scales. In this paper, the bionic modeling analysis of chisel type energy-saving subsoiling shovel is carried out by using 3D modeling software. According to the simulation analysis data, we optimize the key structural parameters, and try to produce the bionic energy-saving deep scarifier with reducing viscosity and resistance. In order to study the performance of the chisel type energy-saving subsoiling shovel, L9 (34) orthogonal test was carried out in the field with the number of bionic surfaces, coating materials and forward speed as the experimental factors, and the adhesion soil amount and traction resistance as the test indexes. The results show that the order of influence of each factor on the index is the number of subsoiling shovel bionic surface, coating material and advancing speed; the optimal horizontal combination is that the number of bionic surfaces of subsoiling shovel is 10, the coating material is UHMWPE, and the advancing speed is 6km/h.

Performance Analysis of Log Extraction by a Small Shovel Operation in Steep Forests of South Korea

In South Korea, logs for low-value products, such as pulpwood and fuelwood, are primarily extracted from harvest sites and transported to roadside or landing areas using small shovels. Previous studies on log extraction, however, have focused on cable yarding operations with the goal of improving productivity on steep slopes and inaccessible sites, leaving small-shovel operations relatively unexamined. Therefore, the main objectives were to determine small-shovel extraction productivity and costs and to evaluate the impact of related variables on productivity. In addition, we developed a model to estimate productivity under various site conditions. The study took place in 30 case study areas; each area has trees with stems at a diameter at breast height ranging from 18 to 32 cm and a steep slope (greater than 15%). The areas ranged from 241 to 1129 trees per hectare, with conifer, deciduous, and mixed stands. Small-shovel drives ranged from 36 to 72 m per extraction cycle from stump to landing. The results indicated that the mean extraction productivity of small-shovel operations ranged between 2.44 to 9.85 m3 per scheduled machine hour (including all delays). At the forest level, the estimated average stump-to-forest road log production costs were US $4.37 to 17.66/m3. Small-shovel productivity was significantly correlated with stem size (diameter at breast height and tree volume) and total travelled distance (TTD). However, a Pearson’s correlation analysis indicated that stand density and slope did not have a significant effect on productivity. Our findings provide insights into how stem size and TTD influence small shovel performance and the predictive ability of productivity. Further, this information may be a valuable asset to forest planners and managers.

Capacity-based performance measurements for loading equipment in open pit mines

The purpose of this study is to develop an integrated framework for capacity analysis to address the influence of systematic hazardous factors on the haulage fleet nominal capacity. The proposed model was made to capture unexpected risks for mining equipment based upon data-driven method considering different scenarios. Probabilistic risk assessment (PRA) was employed to quantify the loss of production capacity by focusing on severity of failure incidents and maintainability measurements. Discrete-event simulation was configured to characterize the nominal capacity for mining operation. Accordingly, the system capacity was analyzed through the comparison of nominal and actual capacity. A case study was completed to validate the research methodology. The past operation and maintenance field data were collected for shovel operation. The discrete-event simulation was developed to estimate the rate of shovel nominal capacity. Then, the effects of undesirable scenarios were assessed by developing the PRA approach. The research results provide significant insights into how to enhance the production capacity in mines. The analyst gets a well judgment for the crucial elements dealing with high risk levels. A holistic maintenance plan can be developed to mitigate and control the losses.

Mining shovel energy efficiency and its relationship with the explosive fracture of rocks

Production cycles are correlated with the processes of drilling and blasting in rocks. It is shown that energy efficiencies of explosive fracture and shovel operation are interconnected with the face advance velocity. Modeling results on operation per one run of rope power shovels with different bucket capacities are presented. The found approximate relation for the determination of energy efficiency of excavation is based on the interconnection of explosive fracture of rocks, geometry of face and dynamics shoveling.

A multiple objective transportation problem approach to dynamic truck dispatching in surface mines

In surface mining operations, fleet management systems seek to make optimal decisions to handle material in two steps: path production optimization and real-time truck dispatching. This paper develops a multiple objective transportation model for real-time truck dispatching. The model addresses two major drawbacks of former models. The proposed model dispatches the trucks to destinations trying to simultaneously minimize shovel idle times, truck wait times, and deviations from the path production requirements established by the production optimization stage. To evaluate the performance of the proposed model, we developed a benchmark model based on the backbone of the most widely used fleet management system in the mining industry (Modular Mining DISPATCH). Afterward, we built a discrete event simulation model of the truck and shovel operation using an iron ore mine case study, implemented both of the dispatching models, and compared the results. The implementation of the models suggests that the multiple objective model developed in this paper is able to meet the production requirements of the operation using a fleet at 85% of the size of the deterministically calculated desired fleet. In addition, the model is able to meet the full capacity of the processing plants with a fleet of 30% less trucks than the desired fleet.

Development of a goal programming model for optimization of truck allocation in open pit mines

Truck and shovel operations comprise approximately 60% of the total operating costs in open pit mines. In order to increase productivity and reduce the cost of mining operations, it is essential to manage the equipment used with high efficiency. In this work, the chance-constrained goal programing (CCGP) model presented by Michalakopoulos and Panagiotou is developed to determine an optimal truck allocation plan in open pit mines and reduce the waiting times of trucks and shovels. The developed goal programming (GP) model is established considering four desired goals: “maximizing shovel production”, “minimizing deviations in head grade”, “minimizing deviations in tonnage feed to the processing plants from the desired feed” and “minimizing truck operating costs”. To employ the developed model, a software is prepared in Visual Studio with C# programming language. In this computer program, the CPLEX optimizer software is incorporated for solving the developed goal programing model. The case study of Sungun copper mine is also considered to evaluate the presented GP model and prepared software. The results obtained indicate that the developed model increases the mine production above 20.6% with respect to the traditional truck allocation plan, while meeting the desired grade and the stripping ratio constraints.

Remote monitoring systems for high-voltage substations and mining machines at open pit coal mines

The article presents the remote monitoring systems for operation of high-voltage substations and shovels, designed at the Karaganda State Technical University and introduced at Shubarkol-Komir open pit coal mine. The systems measure power consumption parameters and controls power consumers and electrical protection. The high-voltage substation monitoring systems transmit data via rf modem, the shovel operation monitoring systems use GPRS modems to transmit data via Internet to a central operator office. In the course of trial operation of the remote monitoring systems, it was succeeded to save power owing to elimination of idle operation of heavy-duty mining machines; moreover, the scope of the continuous control covered power consumption and electric protection at substations and on shovels.

Rigid multi-body kinematics of shovel crawler-formation interactions

Large capacity shovels are deployed in surface mining operations for achieving economic bulk production targets. These shovels use crawler tracks for effective terrain engagement in these environments. Shovel reliability, maintainability, availability and efficiency depend on the service life of the crawler tracks. In rugged and challenging terrains, crawler wear, tear, cracks and failure are extensive resulting in prolonged downtimes with severe economic implications. In particular, crawler shoe wear, tear, cracks and fatigue failures can be expensive in terms of maintenance costs and production losses. No fundamental research has been undertaken to understand the crawler-formation interactions in challenging and rugged terrains in surface mining operations. This study forms the foundations for providing long-term solutions to crawler failure problems. The kinematic equations governing the crawler-formation interactions have been formulated to characterise the crawler motions during shovel production. These equations capture the motions governing the link pin joint, oil sand terrain joint and driving constraints based on the multi-body rigid theory. Crawler propel is achieved by using prescribed velocities along a translational degree of freedom (DOF) and a translational and rotational DOF. The crawler kinematic solutions show that the 3-D crawler–terrain model results in 132 DOFs and requires dynamic modelling to obtain the unknown degrees of freedom. A 3-D virtual prototype model is built to capture the crawler-formation interaction in MSC ADAMS based on the rigid body crawler kinematics. The virtual prototype simulator is supplied with mass properties of crawler shoe, mass, stiffness and damping characteristics of oil sand and external loads due to machine weight and contact forces to obtain the time variation of position, velocity and acceleration for the crawler–terrain engagement for given driving constraints. The results from the driving constraints yield a non-linear longitudinal motion of the crawler track assembly. The crawler track lateral and vertical displacements during translation-only motion fluctuates with maximum magnitudes of 0.7 and 3.6 cm. Similarly the fluctuating longitudinal, lateral and vertical velocities and accelerations have maximum magnitudes of 0.22, 0.046 and 0.56 m/s and 7.41, 1.73, and 34.9 m/s2, respectively. This research provides a strong foundation for further study on developing flexible crawler track model for predicting crawler shoes dynamic stress distributions, cracks development and propagation and fatigue analysis during shovel operations.

Loading Excavator Analysis for Trajectory Control Improvement

Automatic control assistance to improve the digging and bucket-filling trajectory of loading excavators is moving from concept to industrial applications. Directly controlling the path of the bucket instead of controlling individual hydraulic joints by human operators is possible using robotics. The task may be achieved by redefining the excavator kinematics and enhancing it with a software-controlled “virtual kinematics.” It is necessary to determine what type of kinematics transformation of the excavator would be best from its “as-built” motion pattern to an “as-desired” machine for the loading tasks. If known, this loading kinematics then can be programmed into the machine motion control system. Since no loading movement and bite is exactly the same as the previous one, a man-machine interface is needed for easy access for adjustment. Such loading task is analyzed for cycle time, energy consumption, and machine wear. Static and dynamic forces, torques, energy, and power consumption is evaluated for any given digging bucket trajectory for an EX3500 Hitachi excavator. Typical digging trajectories from published data are used to evaluate the potential benefits of a new bucket loading kinematics by “bucket steering,” a motion kinematics which requires two joysticks control actions only. One joystick serves for interactive adjustment to the trajectory shape, and the other is for loading velocity control. The paper describes the potential benefit to mining front shovel operations.

Numerical Simulation of Digging Shovel Operation of Cassava Root

Based on the methods including modified Mohr-Coulomb yield criterion, Lagrange and smoothed particle hydrodynamics (SPH), the digging shovel - stem - root - soil system dynamics simulation model is established by ANSYS/ LS-DYNA. According to the model, the interaction mechanisms among the digging shovel, soil and root are discovered, and the processes of soil shearing and the changing processes of root's stress are analyzed. The mechanisms of shovel's soil loosening are discovered. The process of soil deformation, fracture and loosening and the changing process of root's stress on micro level are studied. The results show that (1) the main reasons for soil loosening in the digging shovel operation are that the soil on the wedge is bended fracture due to being squeezed and uplifted, and that the soil is sheared and broken in the direction of the wedge's normal, and that the soil has no supporting of the blade so that a lot of fractures appear on the soil and is separated by the shovel blade, and that the upper and lower soil can't be closed; (2) when the wedge's extrusion attains a certain value, the links of root and soil will be destroyed; (3) the soil stress value around the wedge is largest, and the soil shearing rupture develops from bottom to top, and the shearing rupture surface occurs in the widest place of shovel blade in the direction of wedge's normal; (4) when the blade's tail points at the root, the root's effective stress is largest and makes the bending deformation of root forward and upward in the meantime, and when the root's effective stress is too large, the root will be broken and the harvest will be lost.

Research on Automatic Digging Control and Algorithm of the Working Device of Skid Steer Loader

Focus on the trajectory planning problem of shovel operations of skid steer loader, a trajectory curve fitting equation is established. By use of the robotics theory and the D-H method, the functional relationship between the kinematics of the working device of skid steer loader and the displacement, position and orientation of boom bucket cylinder is derived, and the driving equation of displacement cylinder is obtained. Based on the requirements of precise trajectory control, an electro-hydraulic proportional position control system for position and orientation control is designed and the state equation of the system is established. By using fuzzy self-tuning PID control algorithm, the outside interference, parameter uncertainty and the error caused by other factors are weakened. The trajectory tracking simulation results demonstrate that: the biggest shovel tracking error is 12.5mm, the designed electro-hydraulic proportional control system can effectively track the trajectory of the working device of skid steer loader in automatic digging process. The rightness of the established model and the effectiveness of the corresponding controller are also proved.

Hybrid virtual prototype for analyzing cable shovel component stress

In this paper a hybrid virtual prototype is developed for analyzing the stress applied on cable shovel components by integrating flexible bodies into rigid multi-body model. The general mechanical system of the cable shovel is modeled as a seven-bar linkage with four degrees of freedom. The relevant theories applied for the dynamic model are described in terms of Lagrangian dynamics equation. The flexible body stress related to the body deformation is obtained by the dynamic equilibrium equation for a structural component based on the finite element method. A P&H 4100A cable shovel is used to validate the hybrid virtual prototype by loading the motions and loads on the model. Von Mises stress distributions of the boom, handle, hoist rope and sheave are visualized during cable shovel operation 3 sec. The results show that a high stress field is around the hoist rope. The maximum stress of 313.31 MPa occurs at node 441. By comparing the simulation results with reliability analysis results, the former is found to match well with the latter. Attention of this study is devoted to the mechanisms of damage of the cable shovel and also the critical high stress areas.

Parametric Simulation of Shovel-Oil Sands Interactions During Excavation

Hydraulic shovel excavators are widely used as primary production equipment in surface mining for removing overburden and ore materials. Variability in material diggability, unstructured mining environments and limited space, effective machine operation, and machine logistics affect the performance of the hydraulic shovel excavators. A hydraulic shovel simulator is developed to simulate the performance of hydraulic shovels for oil sands extraction in the ADAMS simulation environment. The shovel-oil sands interaction is simulated using a reformulated universal earth-moving model. The simulated digging parameters include the bucket dynamics, oil sands properties, oil sands-bucket interactions, and operating variables. The results show that the simulator is capable for identifying the parameters, which influence the performance of hydraulic shovels. This parameterized simulator provides a powerful tool for performance monitoring, excavation process designs and structural optimization of hydraulic excavators. The method presented in this paper forms the basis for developing comprehensive simulator models for automated shovel operations in constrained mining environments.

Planning, operational and environmental aspects of open cut mining at Boundary Hill Mine, Central Queensland : Parkin, R J Min EngrV148, N327, Dec 1988, P268–275

The author discusses the mine planning functions of an open cut truck and shovel operation at Boundary Hill Mine in Central Queensland. These planning functions include geology, surveying, mining engineering and coal quality. Boundary Hill Mine was the first truck and shovel operation in Central Queensland. It was the first to have an inpit coal crusher, where the coal is conveyed out of the pit via a secondary crusher into a live reinforced earth bunker. Since the coal mined is crushed in the pit and loaded directly into trains, the aspects and importance of coal quality have been discussed in detail. The effects of a programme to de-water the overburden and coal, thus improving overburden operating conditions, and to attempt to decrease the total moisture content of the coal have also been discussed. The following environmental aspects have been outlined: (1) Pre-mining environment - which includes climate, rainfall, temperature, topography, natural vegetation, fauna, land use and capability; (ii) post-mining environment - rehabilitation, water management, dust, noise and ground vibration. 2 refs., 7 figs., 3 tabs.

Optimum Size of Hauling Units

Construction planners are frequently required to analyze operations that consist of a service or loading facility and a number of hauling units. This is typified in truck and shovel operations. The optimum size hauling unit is shown to be directly proportional to the product of the operators' wages, the cycle time of the hauling unit, and the productivity of the loading facility. It is inversely proportional to the ownership and operating costs of the hauling unit. There also exists an optimum combination of time that the hauling units should spend being loaded and transporting the material. After the optimum size hauling unit is determined then the analysis should proceed with finding the number of hauling units required. The paper develops the necessary equations to make this entire analysis. /ASCE/