Considerations and Development of a Ventilation on Demand System in Konsuln Mine Seth Gyamfi Civil Engineering, master's level (120 credits) 2020 Luleå University of Technology Department of Civil, Environmental and Natural Resources Engineering Master Programme in Civil Engineering, with specialization in Mining and Geotechnical Engineering Considerations and Development of a Ventilation on Demand System in Konsuln Mine Master thesis, 2020 Division of Mining and Geotechnical Engineering Department of Civil, Environmental and Natural Resources Engineering Luleå University of Technology SE-97187 Luleå Sweden ACKNOWLEDGEMENT All glory and honor be to the Almighty God for seeing me through my studies successfully and for giving me strength throughout my time at LTU. I will like to thank my supervisors, Dr. Adrianus (Adrian) Halim and Dr. Anu Martikainen for their guidance, technical support, and editorial insight. I humbly express my profound gratitude to Mr. Michael Lowther (Manager for SUM project at Konsuln) for granting me the opportunity to carry out this study at the mine. I am also grateful to Dr. Matthias Wimmer (Manager, Mining Technology, LKAB - Kiruna) and Mr. Jordi Puig (Department Manager) for giving me the opportunity to be part of such a world class company like LKAB and to make a value-added contribution through this research. A very special gratitude goes to all the wonderful people at the R&D department of LKAB. The teamwork and the love shown are well appreciated. To Mr. Michal Grynienko and Mr. Mikko Koivisto, thank you for the underground time and inputs. To Ms. Stina Klemo (Ventilation engineer, NGM), I thank you for your contributions. I wish to thank Associate Professor David Siang, Dr. Musa Adebayo Idris, together with my fellow graduate students (Gloria, Adam and Rayan) at the Division of Mining and Geotechnical Engineering, LTU, for their support, discussion, and encouragement. It gives me great pleasure to thank the many individuals for their cooperation and encouragement which have contributed directly or indirectly in preparing this report. To David Vojtech (production manager at Konsuln), Tomas Bolsöy (EOL Vent Mining AB) and the entire employees at Konsuln, I say thank you. To my Pastor Dr. Stephen Mayowa Famurewa and family, Dr. Musah Salifu, Dr. Esi Sari, Miss Dorine Andreasson, Mr. Senzia Warema, and all the lovely friends in my life, I am grateful to everyone for making my stay at LTU a memorable one. To my family, I say thank you for your unwavering support and sacrifices throughout my studies in Sweden. Seth Gyamfi September 2020 Luleå, Sweden. i ABSTRACT Ventilation on demand (VOD) concept has earned significant worldwide attention by several mining companies in recent years. It is a concept where airflow is provided only to areas that require ventilation. The implementation of the concept has resulted in significant savings in annual energy consumption and cost for several companies globally. The research presented in this thesis sought to present the VOD system as an alternative solution and strategy to improve the ventilation system of Konsuln mine. The system is expected to cope with a planned increase in production rate and meet requirements in the new Swedish Occupational Health & Safety (OH&S) regulations, Arbetsmiljöverkets förtfattningssamling (AFS) 2018:1, which is based on the EU directive 2017/164 where Threshold Limit Value (TLV) for gases have been significantly reduced and provide safe work environment for workers in the mine. The thesis work started with planning and execution of a PQ (Pressure – Quantity) survey to calibrate the existing ventilation model of Konsuln mine. This was to ensure that the model is reasonably accurate to give reliable simulation predictions of the performance of Konsuln ventilation system in its current state and for the future. The good correlation between the modelled and underground measured values validated the model for further ventilation planning. The study further investigated and analyzed the current and future ventilation demand of LKAB test mine, Konsuln, to design a VOD system for its operations.The work outlined three main VOD design scenarios I, II, and III based on the proposed production plan, schedule, and the mining process that present the underground working conditions on the three main levels (436, 486 and 536) of Konsuln mine. Diesel, battery-powered, heat, and blast simulations were carried out for all the scenarios in the calibrated ventilation model using VentSim Design simulation software. The model was again used to estimate the annual ventilation power cost for the VOD scenarios to highlight the benefit and cost savings advantage under the VOD design system to deliver enough airflow quantity compared to the conventional system of ventilation. Simulation results showed that about 15.6% – 49.1% and 76.4% - 86.7% of significant cost savings will be achieved for diesel and battery-powered machineries respectively, while still supplying the needed amount of air to working areas to keep contaminants below their Threshold Limit Value -Time Weighted Average (TLV-TWA) and provide a good working environment. ii For additional benefits and savings of the Ventilation on Demand (VOD) system implementation, some considerations for equipment, personnel positioning and identification, monitoring system, and stations have also been discussed in this work. These include; (i) Utilization of LKAB’s database system, Giron, in addition to mounting tags with unique IDs on machineries, to track the route of LHDs and trucks to deal with the challenge of airflow supply shortfall associated with auxiliary fans adjustment to affect target locations. (ii) Installation of temperature sensors, flow meters, gases and Diesel Particulate Matter (DPM) monitoring systems at specific, appropriate, and optimal locations in the mine for efficient implementation of the VOD system strategy. The heat simulations for both diesel and battery-powered machineries were carried out for the month of July when the highest temperatures in Kiruna are often recorded for the summer. They predicted the highest temperatures in working areas to be well below the limit used in Australia, 28°C Wet Bulb (WB). Four scenarios A, B, C and D were also considered for blast clearance time simulation using both the ramp and exhaust shaft. The blast simulation results indicated that the time to dilute and clear blast fumes through the exhaust shaft saves some clearance time compared to exhaustion through the ramp, although the shaft exhaustion will require additional financial commitment to purchase and install exhaust fans on each of the three main levels of the mine. Nevertheless, major ventilation work and practices such as removal of regulator in front of primary fans, additional radon measurement, and good auxiliary ventilation practices have been recommended to improve and actualize the benefits outlined in this work. iii TABLE OF CONTENTS ACKNOWLEDGEMENT ..................................................................................................................... i ABSTRACT ........................................................................................................................................... ii TABLE OF CONTENTS .................................................................................................................... iv CHAPTER 1 .......................................................................................................................................... 1 Introduction ....................................................................................................................................... 1 1.1 Background and motivation ................................................................................................. 2 1.2 Aims and objectives .............................................................................................................. 3 1.3 Methodology .......................................................................................................................... 3 1.4 Thesis outline ......................................................................................................................... 4 CHAPTER 2 .......................................................................................................................................... 5 Konsuln mine ..................................................................................................................................... 5 Introduction ....................................................................................................................................... 5 2.1 Ventilation system at Konsuln ............................................................................................. 9 CHAPTER 3 ........................................................................................................................................ 12 3.1 Ventilation and its importance, airflow requirement and determination ...................... 12 3.2 Ventilation surveys .............................................................................................................. 13 3.2.1 Air quantity survey ........................................................................................................ 13 3.2.2 Pressure survey ............................................................................................................. 14 3.3 Ventilation Control Devices ..............................................................................................