Vale's Coleman mine has extracted minerals from 200-1,700 m depth for over 50 years and is currently expanding 1,850 m. At depth, autocompression effects superimposed on summer climatic conditions, generate increasingly adverse thermal working conditions with temperatures exceeding 40°C DB and 28°C WB. These require heat exposure management through work:recovery regimens and stop work conditions. Through mine planning, Vale recognized they would need cooling, and in 2016 engaged BBE to investigate novel cooling and traditional technologies, assessing both underground and surface options to provide focused to the 170 Orebody. It was identified that although the cooling aspect was feasible, providing the required electrical power, clean water supply, and locating the heat rejection without impacting mine activities would be problematic. In 2019, Vale again engaged BBE to design and supply a surface cooling plant, this included investigating alternative mechanical options, opportunistic coolth storage solutions, and the final provision of an operating turn-key system for the summer of 2020. Considering the 18-month timeline, the capital costs, unproven technologies, and production loss risks, most of the options reviewed were discounted and Vale opted for a conventional vapor compression mechanical system. This paper discusses the challenges of surface and underground cooling, novel options, the installation, and operational challenges of a surface air cooling plant in a northern climate.

The Waste Isolation Pilot Plant (WIPP) facility, operated by the U.S. Department of Energy (DOE), is the only transuranic waste repository in the United States. The facility is located approximately 35 miles east of Carlsbad, New Mexico. The facility is designed for the permanent disposal of transuranic radioactive waste generated through nuclear weapons production and research. On February 14th, 2014 a continuous air monitor (CAM) alarmed indicating a radioactive contamination event had occurred in the active emplacement panel underground. The ventilation system automatically switched to a filtration mode where all exhaust air is sent through a bank of filters including High Efficiency Particulate Air (HEPA) filters. The DOE has decided to maintain the WIPP facility for TRU waste disposal and to this end has authorized several significant capital projects. These projects, which are currently under construction, includes a dust and water extraction system on surface combined with one of the world's largest HEPA filtration systems. The new Safety Significant Confinement Ventilation System (SSCVS) will be capable of filtering up to 540,000 cfm. The dust extraction system will contain six 100,000 cfm capable filtration units to remove salt dust and water before the air reaches the HEPA filters. The second project is a new 28 ft diameter intake shaft 2,150 ft in depth capable of passing 500,000 cfm. New surface intake fans are designed for this shaft. An intake shaft at the site is being reconfigured as an exhaust for the new intake fans. Both capital projects are significant with expenditures expected to exceed $400 million. This paper describes the analyses performed to size the new fans, filtration units and shaft to support work activities and to maintain proper flow alignment in the underground. The status of the capital projects will also be described.

Mine ventilation planning using trackless diesel equipment is well known in the industry. Battery Electrical Vehicle (BEV's) type equipment is increasingly replacing diesel vehicles underground and different ventilation design methodologies need to be evaluated for safety and health of workers. Planning further evaluate the heat loads of equipment to counter their negative impact on the ventilation system. It is therefore important to evaluate the overall ventilation system when comparing Diesel vs BEV's thereby accounting for other aspects such as blasting and re-entry periods for the mine including multi-blast development ends. In general, is it anticipated that replacing diesel vehicles with BEV's will imply reduced air quantity in a mine, therefore contributing positively towards overall mine power and an improved return on an investment. BEV's and other types such as trolley assisted vehicles all fall within the heat and airflow reduction application philosophy and the ventilation planning needs to be addressed to ensure designs don't under-or-over-estimate their positive contribution in underground mines as we always need to determine the in-mine heat load for shallow and deep mines to ascertain compliance with design parameters. This paper elaborates on ventilation design parameters for comparison with diesel vs BEV application.