underground coal mine delay data analysis system

Due to the high levels of uncertainty in underground coal mining operations, delays occur regularly which inadvertently reduce the utilisation of mining equipment. In most coal mines delay data is primarily sourced from shift reports, machine monitoring and production systems. The recording process is initiated commonly at the end of a shift to ensure the correct information is recorded for the managerial decision process. An issue that the Australian coal industry faces is the lack of a standardised delay recording process and delay classification system. Tools used within the industry to analyse delay data are mostly mine specific and offer no means of comparing the mine performance to the performance at other mine sites. This paper describes a VBA based delay data analysis tool UCDelay for underground coal mines. UCDelay is an add-in Excel module for classification of delay data into a standardised form

A simulation model to access the impact of underground coal mine logistics strain on an operation

A novel approach has been developed to strategically identify logistical bottlenecks and the impacts that mine planning parameters might have on these at any point in time throughout life of a mine plan. An XPAC-based model is employed at a macroscopic level to understand trends and shifts in logistical strain for a timeframe up to the entire life of mine. However, on a day-to-day basis the XPAC-based model cannot, at a very detailed level, provide information to analyse if logistical strain can be alleviated through finer adjustments. The finer adjustments that can be identified and rectified, can be determined using a discrete simulation FlexSim model. The paper presents details of the FlexSim discrete simulation model and its applications

An approach to solve underground coal mine logistics strain

There is currently no mechanism for mine management and strategic planners to identify potential future logistical supply chain bottlenecks within a mine plan and address them proactively. By identifying any logistics constraints as early as possible, the best opportunity to rectify the problem at the least expense is realised. The paper discusses a novel approach which has been developed to strategically identify logistics bottlenecks and the impacts that mine planning parameters might have on these at any point in time throughout a life of mine plan. The developed system was applied to a real-world Australian mine with actual logistics tracking data input for both calibration and prediction testing. It confirmed that the system was indeed “bolt on” and could predict the number of delivery machines operating at any point in time within the mine’s life

Compressive Strength Testing of Toughskin Thin Spray-On Liner

Thin spray-on liners (TSLs) have been attracting more and more attention as an alternative to the steel mesh in underground roadway support. In order to investigate and compare the compressive strength of glass fibre reinforced ToughSkin TSL developed at the University of Wollongong, a compression test was developed using the cube samples of 40 mm in size. The effect of a small amount of glass fibre in the polymer matrix was tested. The test results indicate that the compressive strength and the material stiffness of the cube samples increased with the increase of glass fibre. All of samples exhibited ductile stress strain curve as they had a yield point and a fracture point. The ductile ToughSkin yield characteristics are very important as sudden brittle failure is considered unsafe for mining practices

Numerical modelling of the groundwater inflow to an advancing open pit mine: Kolahdarvazeh pit, Central Iran

The groundwater inflow into a mine during its life and after ceasing operations is one of the most important concerns of the mining industry. This paper presents a hydrogeological assessment of the Irankuh Zn-Pb mine at 20 km south of Esfahan and 1 km northeast of Abnil in west-Central Iran. During mine excavation, the upper impervious bed of a confined aquifer was broken and water at high-pressure flowed into an open pit mine associated with the Kolahdarvazeh deposit. The inflow rates were 6.7 and 1.4 m3/s at the maximum and minimum quantities, respectively. Permeability, storage coefficient, thickness and initial head of the fully saturated confined aquifer were 3.5 x 10−4 m/s, 0.2, 30 m and 60 m, respectively. The hydraulic heads as a function of time were monitored at four observation wells in the vicinity of the pit over 19 weeks and at an observation well near a test well over 21 h. In addition, by measuring the rate of pumping out from the pit sump, at a constant head (usually equal to height of the pit floor), the real inflow rates to the pit were monitored. The main innovations of this work were to make comparison between numerical modelling using a finite element software called SEEP/W and actual data related to inflow and extend the applicability of the numerical model. This model was further used to estimate the hydraulic heads at the observation wells around the pit over 19 weeks during mining operations. Data from a pump-out test and observation wells were used for model calibration and verification. In order to evaluate the model efficiency, the modelling results of inflow quantity and hydraulic heads were compared to those from analytical solutions, as well as the field data. The mean percent error in relation to field data for the inflow quantity was 0.108. It varied between 1.16 and 1.46 for hydraulic head predictions, which are much lower values than the mean percent errors resulted from the analytical solutions (from 1.8 to 5.3 for inflow and from 2.16 to 3.5 for hydraulic head predictions). The analytical solutions underestimated the inflow compared to the numerical model for the time period of 2-19 weeks. The results presented in this paper can be used for developing an effective dewatering program

Application of Computational Fluid Dynamics (CFD) for Simulation of Acid Mine Drainage Generation and Subsequent Pollutants Transportation through Groundwater Flow Systems and Rivers

Many environmental problems associated with the mining industry involve the understanding and analysis of fluid or gas flow. Typical examples include groundwater flow, transport of contaminants, heat transfer, explosions, fire development and dust movements. Both experimental work and numerical models can provide the necessary information for solution of any particular problem. The long-term pyrite oxidation, acid mine drainage generation and transportation of the oxidation products are noted to be the most important problems that can be modelled in order to predict the transport of thecontaminants through groundwater and rivers flow systems, to interpret the geochemistry and achieve a better understanding of the processes involved

Movements of personnel and materials in Australian underground coal mines

With the desire to optimise the development of roadways in underground coal mines as operations expand, it logically followed that any increase in the development rate will require more efficient logistics management, especially the timely supply of roof support materials (bolts, chemicals and mesh) to each active face area. Logistics management in general was not considered as a key issue when initial or long-term planning of an underground coal mine is undertaken. It is traditionally assumed that whatever production targets are set that logistics can keep up or that it is retrospectively managed after an identifiable bottleneck

APPLICATION OF MATHEMATICAL PROGRAMMING MODELS TO COAL QUALITY CONTROL.

The problem of utilizing blending techniques to control coal quality at the production-consumption phase is considered. Three blending models were developed to provide coal of high thermal content and low pollutants. With the aid of operational mine planning, coal is blended at the coal producing mines such that the best quality of coal is mined during a planning period, while meeting the management production objectives. The first model developed uses 0-1 programming formulation to select potential working areas of a mine on the basis of predicted grade values obtainable from geostatistics. A second model developed combines economically coals produced by different suppliers to meet the specification of a power plant. The second model uses a linear programming formulation to develop coal purchasing strategy. Finally, a multiobjective programming technique is used to determine the tonnages of coal which must be cleaned from various sources (e.g. stockpiles) in order to result in clean coal of high thermal content and low sulfur content. The two objectives used are minimization of total sulfur and maximization of total Btu. Both the operational mine planning and coal purchasing models were tested on actual mine data. The study demonstrated the capability of controlling coal quality by blending technique with the aid of the three models. This can be translated into dollar savings to both the coal producer and the coal consumer

Shuttle car network for roadway development

Australian underground coal mines predominately use the longwill method for coal extraction. In longwall mining at least two parallel roadways known as gateroads are mined to delineate the sides of the longwall block, a longwall installation face is then driven connecting the gatheroads to enable the longwall mining equipment to be installed. Roadway development should ideally be ahead of the longwall so that the longwall equipment can be installed into the newly developed panel with minimal delay to coal production. A discrete event mode of roadway development can help asses how a particular configuration may perform with high levels of variability and uncertainty in operations. One of the major delays assoicated with roadway development is caused by the shuttle car due to its cyclic stop-start nature. Shuttle car travelling paths and machine interactions are normally constraint by the mine\u27s roadway layout and mine safety issues. This paper presents simulations of shuttle car route operations which can be considered at the design stage to minimize the cycle time of a shuttle car as part of a general roadway developemnt simulation model developed using 3D flexsim

Development of a Web-based Underground Coal Mining Information Management System

The development of the Australian Coal Association Research Program (ACARP) funded “one stop shop” information management system for the coal mining industry is described. The site www.undergroundcoal.com.au went live on 28 August 2009 with various sub-modules including an introduction to underground coal mining practices and a handbook of roadway development practice. The site also includes presentations from ACARP six-monthly workshops on current roadway development practice. These workshops provide an invaluable opportunity to share state of the art knowledge in roadway development practice, to learn of emerging Research and Development (Rand D) programs and development of equipment and technology by Original Equipment Manufacturers (OEMs)