Analysis of Truck Downtimes Using Log Dispersion Plot

It is becoming increasingly clear that improved equipment availability is a key to optimising return on mine investment. Well-maintained equipment is safe and provides reliability to protect the operator as well as the equipment. Unplanned downtimes conflict with this maintenance function and result in costs to a mine in various causes. To minimise the occurrence of unplanned downtime, data should be recorded in logical and easily understood format which will enhance management decision making. This paper uses log dispersion plot to analyse downtimes of a fleet of 22 dump trucks from theNchanga Open Pit, Zambia over a period of two months. Downtimes were categorised into breakdown codes to determine which ones were acute, chronic or a combination of both. The breakdown codes which were critical to the reduction of unplanned downtime and improvement of truck performance were prioritise

Reducing Drill and Blast Cost through Blast Optimisation – A Case Study

This paper studied the current cost trends associated with the drill and blast operations of Golden Star Resources, an open pit gold mine in Ghana, and further developed a suitable, cost-effective drill and blast geometric parameters for the mine. The study was conducted on three operational pits of the mine, namely Blocks A, B and C. The surface mine was challenged with high cost trends in its drilling and blasting operations. The current and two proposed sets of blast geometric parameters for each active pit, for ore and waste zones, were assessed with the Kuz-Ram fragmentation model. The estimated mean fragment size for the proposed blast parameters were within the desired fragment size range (25 – 65 cm) of the mine, and explosive energy was effectively utilised per in-situ material blasted. The estimated total volume of in-situ material blasted using the proposed blast parameters increased by 14.3 to 50.0% for ore zones and 12.5 to 50.0% for waste zones over current blast parameters. The estimated total drill and blast cost savings if the proposed blast parameters were adopted ranged from 5.3 to 12.2% for ore zones and 2.9 to 14.8% for waste zones.Keywords: Burden, Spacing, Explosives density, Powder Factor, Cost savin

ICT Development at University of Mines and Technology (UMaT)

The University of Mines and Technology (UMaT) has adopted IT and later ICT to enhance, teaching, learning and research for sometime now and in this paper the authors who were part of the team that introduced ICT at UMaT describe this adoption of ICT. The concept of ICT preparedness index is introduced and used to assess the advancement of UMaT in the areas that are most critical to the adoption of ICT in a university and to identify areas of strength and weakness in ICT at UMaT

Computer-Aided Cut-off Grade Optimisation for Open Pit Mines

A mine planning team is tasked among other duties with designing a feasible mine plan which in turn maps out the daily running of the mining project. A mine plan revolves around a cut-off grade which is thoughtfully and uniquely selected while considering various aspects such as grade tonnage distribution, economic and operational parameters specific to a mine. Selection of a cut-off grade can be a daunting task often involving iterative and lengthy mathematical formulas which take huge amounts of time to execute, often leaving room for error. In the occurrence of such errors, a mining project can be faced with sequential outcomes that could even lead to premature closure. The cut-off grade is therefore a strategic variable that determines the economic viability of a mine, and hence return on investment. It is critical that the cut-off grade is optimal so as to maximise the net present value. Lane’s approach is a model that utilises several steps to yield one cut-off grade value. This algorithm is flexible and can be adjusted to include other factors specific to a mine. Regrettably, many mining companies continue to operate using inaccurate cut-off grades wrongly calculated or assumed. This has continuously led to frustrations due to losses and prematurely abandoned mines. This study focused on the development and implementation of an easy to use computer application based on Lane’s approach that runs on Windows platform, and hence targeting a larger user base for choosing an optimum cut-off grade for open pit mines. Keywords: Cut-Off Optimisation, Cut-Off Optimiser, Optimum Cut-Off Grades, Whittl

Performance Evaluation of Training Algorithms in Backpropagation Neural Network Approach to Blast-Induced Ground Vibration Prediction

Abstract Backpropagation Neural Network (BPNN) is an artificial intelligence technique that has seen several applications in many fields of science and engineering. It is well-known that, the critical task in developing an effective and accurate BPNN model depends on an appropriate training algorithm, transfer function, number of hidden layers and number of hidden neurons. Despite the numerous contributing factors for the development of a BPNN model, training algorithm is key in achieving optimum BPNN model performance. This study is focused on evaluating and comparing the performance of 13 training algorithms in BPNN for the prediction of blast-induced ground vibration. The training algorithms considered include: Levenberg-Marquardt, Bayesian Regularisation, Broyden–Fletcher–Goldfarb–Shanno (BFGS) Quasi-Newton, Resilient Backpropagation, Scaled Conjugate Gradient, Conjugate Gradient with Powell/Beale Restarts, Fletcher-Powell Conjugate Gradient, Polak-Ribiére Conjugate Gradient, One Step Secant, Gradient Descent with Adaptive Learning Rate, Gradient Descent with Momentum, Gradient Descent, and Gradient Descent with Momentum and Adaptive Learning Rate. Using ranking values for the performance indicators of Mean Squared Error (MSE), correlation coefficient (R), number of training epoch (iteration) and the duration for convergence, the performance of the various training algorithms used to build the BPNN models were evaluated. The obtained overall ranking results showed that the BFGS Quasi-Newton algorithm outperformed the other training algorithms even though the Levenberg Marquardt algorithm was found to have the best computational speed and utilised the smallest number of epochs.   Keywords: Artificial Intelligence, Blast-induced Ground Vibration, Backpropagation Training Algorithm

Optimising Shovel-Truck Fuel Consumption using Stochastic Simulation

Stochastic simulation was conducted to analyse the fuel consumption of a shovel-truck system. An example shovel-truck system, comprising a single shovel and four trucks was considered. At 95% confidence interval, the monthly simulated fuel consumption by the shovel-truck system was found to be about 198 127 litres against the actual fuel consumption of 203 772 litres, registering a variance of -2.70%. About 22 000 litres of fuel was consumed per month due to truck waiting. Optimising the fuel consumption and truck waiting time can result in significant fuel savings. The paper demonstrates that stochastic simulation is an effective tool for optimising the utilisation of fossil-based fuels in mining and related industries. Keywords: Stochastic, Simulation Modelling, Mining, Optimisation, Shovel-Truck Material Handlin

Application of Discrete Event Simulation in Mine Production Forecast

Mine production forecast is pertinent to mining as it serves production goals for a production period. Perseus Mining Ghana Limited (PMGL), Ayanfuri, deterministically forecasts mine production which sometimes result in significant variation from the actual production. This paper developed an innovative stochastic discrete event simulation model to predict production for two excavators at a pit in PMGL site using Arena® Software. Time and motion studies of the shovel-truck system were conducted to build the stochastic model and production was predicted for four weeks. The results showed a total average production of 210 414.86 BCM ± 3 301.59 BCM at 95% confidence interval. The total average production reflected a variance of 2.34% from the actual production of 215 341 BCM. The deviation was low as compared to the deterministic planned production variance which was 5.44%. Keywords: Stochastic, Simulation, Deterministic, Production Forecas

An Evaluation of Teaching – Learning of Drawing at School of Applied Arts, Takoradi Polytechnic

Drawing is described as the bases of all art work when an art idea is conceived. It can only materialize into concrete form when it has gone through a process of designing which basically involves drawing. The ability of an artist to draw is very paramount in the art profession. The bases for selecting students to pursue an art programme is their ability to pass the requisite examination which includes drawing but still this research would show that standard of drawing among some students in Takoradi Polytechnic is very low. Descriptive research method based on qualitative research approach was adopted. This method was used to describe research methodology, through results discussion and findings. This paper examines the problem of poor drawing standards in an attempt to find solutions. The paper would provide insight into the problems which include poor foundation of students drawing abilities, inadequate facilities for teaching drawing in the polytechnics, the methodology used in teaching and the general attitudes of students towards drawing lectures. The paper finally prescribes remedies that would address the listed problems above. Keywords: drawing, teaching, learning, methodology, facilities

Exploration of Textures on Tree Barks as a Medium for Decorating Ceramic Tile Murals

This paper presents comprehensive methods of exploring textures on tree barks to decorate ceramic tile murals and their results. The bark of different tree spices has been explored extensively in conjunction with modern technologies to design tiles. Materials used for the tile production were Abonko clay and grog. A plasticity and shrinkage test were conducted on of the Abonko clay.  Therefore, a composition of 90% Abonko clay and 10% grog fired at 1050 oc was suitable for ceramic tile murals. The study concluded that textures on tree barks could be exploited to obtain designs to serve as a medium for decorating ceramic tile murals. It is therefore recommended among other things, that care should be taken when felling trees from our environments since textures of tree barks could be of interest to ceramic artists or designers in design processes. Keywords: Clay, Tree barks, textures, and tiles. DOI: 10.7176/ADS/101-06 Publication date:September 30th 202

The perceived helpfulness and acceptability of a bespoke psychological therapy service for registered nurses experiencing psychological distress: A qualitative study

Aim: To understand the perceived helpfulness and acceptability of a bespoke psychological therapy service for registered nurses. The service provided a free and confidential specialist mental health service to all healthcare professionals, including nurses and nursing students. Design: An exploratory study using a descriptive qualitative approach. Methods: A purposive sample of 20 registered nurses accessing a bespoke psychological therapy service in Wales participated in audio-recorded semi-structured interviews in January 2022. Transcribed data were analysed using reflexive thematic analysis. Results: Four interrelated themes were identified from the data analysis: COVID [SARS-CoV-2] changed things; You're a nurse, you're human; I've got ‘me’ back; and pretty close to miracle workers. Conclusion: Participants attempted to live up to an idealized image of a nurse, generating self-stigmatizing beliefs that negatively affected their mental health. The psychological therapy service enabled participants to put their roles into perspective, that is, separate themselves from their role, be vulnerable, and develop confidence and adaptive coping strategies. Participants valued the minimal barriers and ease of access to support. Implications for the Profession and/or Patient Care: The complex relationship between nurse identity and the challenges of the workplace needs to be central to nurse education. Nurses can benefit from rapid access to a timely, confidential, and independent self-referring psychological therapy service. Impact: This qualitative study explored the helpfulness and accessibility of psychological support for nurses. The main themes were that COVID changed things; You're a nurse, you're human; I've got ‘me’ back; and pretty close to miracle workers. The findings will impact how nurses are supported in the United Kingdom and worldwide. Reporting Method: This report adheres to the standards for reporting qualitative research (SRQR). Patient or Public Contribution: No patient or public contribution