Engineering & Mining Journal

FEB 2018

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

Issue link: https://emj.epubxp.com/i/938385

Contents of this Issue

Navigation

Page 48 of 59

FEBRUARY 2018 • E&MJ; 47 www.e-mj.com OPERATING STRATEGIES Network Center of Excellence), Mining Innovation Rehabilitation and Applied Re- search Corp. (MIRARCO), a not-for-profi t research and development organization owned by Laurentian University, Electrale Innovation Ltd., and Reasbeck Construc- tion Inc. Victaulic is a core sponsor. HACs offer a more energy effi cient and reliable approach to air compression, but historically, they have relied on the existence of a nearby water source, which was one of the factors that prevented their widespread adoption in deep mining applications. The HAC technology being tested includes a number of innovations, including the use of open- and closed-loop confi gurations (no nearby water course needed), co-solute addition to control gas solubility, temperature manipulation and compression of gases alternative to air, all of which have yet to be proven in a large- scale, real-world environment. In executing this experiment, a 30-m-high HAC Demonstrator rig was installed in a former elevator shaft at Dynamic Earth, Science North's earth sciences center in Sudbury, Ontario, Can- ada. The lower part of the unit is installed in the sub-surface and so the team faced the real-world challenges in operating in a mining environment, and the upper part, which houses the header/forebay tank and tailrace tank, stands approximately 15 m above the shaft collar level. The key design variables of the operat- ing head, water fl ow rate, operating pres- sure, downcomer and riser areas for fl ow for the HAC Demonstrator were modeled on a compact design for the Peterbor- ough Lift Lock HAC, which operated for 60 years on the Trent-Severn Waterway in Ontario. The HAC Demonstrator, however, incorporates a major design difference; circulating pumps develop the head in- stead of relying on the fall between up- per and lower reaches of the canal. In this confi guration, the electricity input to drive the pumps is less than the electric- ity input to a mechanical compressor of the same delivery pressure and free air delivery and this is principally due to the system's nearly isothermal compression process. So although this modern version is not confi gured to exploit renewable energy, it is being established as an en- ergy-effi ciency technology that aims to reduce the cost of compressed air pro- duction for mines and other industries. The team is excited by the fact that the latest results obtained at the demon- strator plant show that the compression effi ciencies, free air deliveries and com- pression temperature differences ob- served are close to those predicted two years before the plant was constructed. While there are numerous elements of the demonstrator program still to execute, this has led to high confi dence of use of the process model of the system to design commercial scale units. Past, Present and Future HAC technology has the potential to change the game for cooling ultra-deep mines. It is energy-effi cient technolo- gy that promises up to 50% savings in lifecycle cost of air compression for mine operators. With the improved HAC sys- tem proven for applicability in deep mine cooling, the project team looks forward to seeing full-scale HACs operating in ul- tra-deep mines for years to come. The author, Wayne Johnson, works in sales for Victaulic, a producer of mechanical pipe joining solutions with more than 40 locations worldwide.

Articles in this issue

Links on this page

Archives of this issue

view archives of Engineering & Mining Journal - FEB 2018