{"id":9993,"date":"2025-04-09T20:45:25","date_gmt":"2025-04-09T20:45:25","guid":{"rendered":"https:\/\/northamericanmining.com\/?p=9993"},"modified":"2025-04-09T20:45:27","modified_gmt":"2025-04-09T20:45:27","slug":"achieving-the-best-in-mine-ventilation","status":"publish","type":"post","link":"https:\/\/northamericanmining.com\/index.php\/2025\/04\/09\/achieving-the-best-in-mine-ventilation\/","title":{"rendered":"Achieving the best in mine ventilation"},"content":{"rendered":"\n

Ventilation is often an underground mine\u2019s most significant operating expense. It\u2019s also essential to the health and safety of personnel and equipment. Important, then, yet many take a curiously offhand approach to their ventilation systems. Experts from Chart Industries, Epiroc, Paul\u2019s Fan, and Stantec explain how to get the most from mine ventilation.<\/em><\/strong><\/p>\n\n\n\n

by Jonathan Rowland<\/em><\/p>\n\n\n

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By automatically adjusting fan speed according to real-time conditions, mines can optimize the underground work environment in compliance with regulations while minimizing energy consumption. Pictured: Epiroc\u2019s Serpent Automatic module.<\/strong><\/figcaption><\/figure>\n\n\n

The mining process is, as Todd Elswick, president of Paul\u2019s Fan Company, told North American Mining magazine, \u201can ever-moving target.\u201d This makes maintaining consistent airflow and climate in underground mines a challenge, as Elswick \u2013 who was \u201craised to build mine fans\u201d by his late father and company founder, Paul Elswick \u2013 knows well. \u201cThe mine is continually advancing and adding to the equation of pressure and flow; the overcast and curtains required daily add to this.\u201d<\/p>\n\n\n\n

Jose Pinedo, sales manager, Ventsim Control software at Howden, a Chart Industries company, agreed. \u201cPressure differentials drive airflow in mines. As mines expand and mine deeper, the system resistance of the mining operation increases. All other things remaining equal, an increase in system resistance will reduce volumetric flow in the mine.\u201d Operational factors also challenge consistent airflow, as Pinedo continued. \u201cOperationally, with regards to maintaining consistent airflow, proper installation of ventilation infrastructure (fans, doors, regulators, and stoppings) is the biggest challenge. This includes duct lines being ripped, improper attachments going from fan to duct, doors with excessive leakage, and improper calibration of an actuator on a regulator.\u201d<\/p>\n\n\n\n

\u201cThe presence of hazardous gases, such as methane or carbon monoxide, requires continuous monitoring and adjustment of ventilation systems to ensure safe levels and, if gases are generated from blasting, allow prompt re-entry to minimize downtime,\u201d added Kim Trapani, a ventilation engineer and project specialist at Stantec. \u201cAdditionally, the heat generated by mining equipment and the depth of the mine can significantly impact the climate, making it difficult to maintain consistent temperatures and air quality throughout the mine.\u201d<\/p>\n\n\n\n

\u201cIf a mine is struggling to maintain airflow through its drifts and is also a hot mine, maintaining proper temperatures will be an uphill battle,\u201d continued Pinedo, picking up the theme. \u201cIt must be noted that, as mines increase in depth, the imposed heat load increases, which makes maintaining a conducive environment challenging. With low airflows in hot locations, those areas will heat up more quickly. Recirculation also plays a role in controlling a mine\u2019s climate. If there are sections of the mine that recirculate exhaust air, which is often hot, that will exacerbate thermal comfort challenges.\u201d<\/p>\n\n\n\n

A complex web<\/strong>
Considering these challenges, the design criteria for an underground ventilation system are \u201cnumerous,\u201d said Jon Griffith, PE, product applications lead for underground at Epiroc USA. Factors include, but are not limited to, the \u201cmaximum installed horsepower of the equipment fleet, the total number of employees, environmental factors such as temperature, humidity, influx of water, corrosive or toxic rock properties, and blast gas volume.\u201d<\/p>\n\n\n\n

\u201cDetermining the total fresh air requirement is often the first step in ventilation planning,\u201d said Howden\u2019s Pinedo, added to the discussion. \u201cThis is done based on the air required for the equipment fleet, whether diesel- or electric-powered, considering gas emissions, heat, and dust. It also means considering that mining projects often have extensive lifespans. The design of the ventilation network, fans, and ancillary infrastructure required to support the operation over the asset life must be carefully considered and capable of dealing with these changes.\u201d<\/p>\n\n\n\n

\u201cIn my experience, mining operations do not initially plan for a big enough fan to handle all the added obstacles that come along through the process of mining, and as such, they do not account for the additional needs of ventilation through the advancement of the mine,\u201d added Elswick of Paul\u2019s Fan. \u201cWhen designing a ventilation system, the design should meet the maximum requirements \u2013 and then add at least 30% to 40% to that because of the unknown. Use this number to select the fan that meets those requirements. The mine is continually advancing, and the capital expense of adding a bigger fan and reconfiguring ventilation and ductwork can be tremendous. Considering long-term mine advancement and production within initial capital investment minimizes the lifetime cost.\u201d<\/p>\n\n\n\n

The size and layout of the mine are crucial, as they determine the airflow needed to reach all areas, noted Stantec\u2019s Trapani. \u201cThe mining method and the equipment used also impact, as different activities and machinery produce varying amounts of heat and contaminants. In addition, worker safety regulations must be met, often involving specific ventilation and air quality standards.\u201d These are becoming \u201cmore stringent with regard to airborne pollutants while rising energy costs and ESG commitments are forcing mine planners and engineers to design ever-more optimized solutions,\u201d noted Pinedo.<\/p>\n\n\n\n

Last, there is the placement and size of ventilation shafts. Here, more than anywhere, the need to take a whole-of-life approach is critical, concluded the Howden engineer. \u201cA ventilation shaft cannot be made more prominent once it is excavated, while a mine\u2019s ability to have multiple shafts may be limited, even when site conditions allow it, due to the cost implications associated with shaft sinking.\u201d In addition, \u201cif it is possible to take advantage of any elevation difference between intake and exhaust shafts, this helps the mine to ventilate naturally,\u201d added Griffith.<\/p>\n\n\n\n

Not too hot; not too cold<\/strong>
Climate control is a \u201csignificant factor in mine ventilation, as it requires additional energy to heat or cool the air,\u201d said Stantec\u2019s Trapani. \u201cIn deeper mines, the need for cooling increases due to the higher temperatures from the ventilation auto-compression and strata heat, exacerbated by the heat generated by mining equipment.\u201d<\/p>\n\n\n\n

Conversely, heating is necessary in colder climates to prevent ice buildup and maintain safe working conditions. However, \u201cheating is much simpler approach,\u201d added Pinedo, \u201cas management mostly ensures the air is heated above freezing (39\u00b0F\/4\u00b0C)\u201d.<\/p>\n\n\n\n

The best way to cool a mine is always a trade-off. \u201cFrom a capital expenditure perspective, increasing airflow might be less costly than installing a refrigeration plant,\u201d explained Pinedo. \u201cFrom the operating cost perspective, increasing airflow will always be more expensive given the relationship between airflow and power to the cube. In addition, mine cooling installations can be manipulated with changes in ambient conditions, [such as] to reduce cooling on colder days and months, allowing further operating cost savings. It ultimately comes down to how much cooling is needed and the optimum airflow to achieve that.\u201d<\/p>\n\n\n\n

Both heating and cooling add to the overall energy consumption of the ventilation system, making it essential to find efficient ways to manage these needs, concluded Trapani. \u201cFor example, some mines use heat recovery from available heating\/cooling sources to reduce the energy consumption from the heating\/cooling.\u201d<\/p>\n\n\n

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Mining operations present a moving target, challenging ventilation system design and operation. Photo: Paul\u2019s Fan<\/strong><\/figcaption><\/figure>\n\n\n

Hazardous gases<\/strong>
Hazardous gases such as methane, carbon monoxide, and radon, and particulate matter (diesel, silica, and other dust) pose significant risks in underground mines. In most metal and nonmetal mines, \u201cthe highest concentration of these gases comes from blasting,\u201d noted Tomas Otterberg, global portfolio manager, Tunnelling and Infrastructure, at Epiroc\u2019s Underground Division. \u201cUnderground coal applications present other challenges and require specialized design criteria to prevent a fire, while using BEV technology can reduce gaseous engine emissions and heat in the mine, reducing ventilation requirements.\u201d<\/p>\n\n\n\n

As there is \u201cnot a good way to neutralize these gases other than to keep them moving through the mine and out the shaft, ventilation is the only way to achieve safety for the mine and the miners,\u201d said Elswick of Paul\u2019s Fan. This may mean that the \u201ctotal ventilation in mines where hazardous gases are present is significantly higher than that of a similar mine without hazardous gases,\u201d added Trapani. \u201cThey also require robust monitoring systems to detect gas concentrations and the ability to adjust airflow dynamically. Emergency ventilation plans are necessary to quickly address any sudden release of hazardous gases, ensuring the safety of workers. This could include fire doors in strategic locations and reversible fans.\u201d<\/p>\n\n\n\n

A good part of this challenge goes back to the dynamic mining environment.<\/p>\n\n\n\n

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\u201cIt is hard to see the future other than comparing different mines and seams that have been mined before,\u201d continued Elswick. \u201cMonitoring and predicting these gases is a big deal, although needs may vary depending on the mine type.<\/p>\n<\/blockquote>\n\n\n\n

For example, methane will leak in coal mines after production stops, so most coal mines always require monitoring and an operable fan. When the equipment is shut down in aggregate and hard rock mining, particulate matter mostly settles, so there is less need for continuous monitoring and ventilation.\u201d<\/p>\n\n\n\n

Energy efficient ventilation: ventilation on demand<\/strong>
\u201cIf you look at all the factors, you ultimately want a system adaptable to changing conditions within the mine,\u201d concluded Trapani. \u201cThis adaptable ventilation system can be applied through a ventilation-on-demand (VOD) system, which allows control of key ventilation infrastructure based on the presence of personnel and equipment, monitored air quality, and scheduled events in the mine.\u201d<\/p>\n\n\n\n

\u201cI 100% recommend using a VFD or comparable product, or as an alternative, a secondary fan, to reduce airflow to a minimum in downtime or to unoccupied areas,\u201d said Elswick. \u201cAirflow\/pressure or quantity is directly linked to horsepower, and horsepower is directly related to energy consumption. From my experience, the standard is 1000 horsepower, which equals $100,000 a month in electricity costs. So, anytime you can reduce the flow, you reduce the horsepower, the electricity usage, and therefore the costs.\u201d<\/p>\n\n\n\n

VOD systems can be further optimized \u201cby using geo-fencing to detect the total number of miners and machines in a particular work area, which will prompt the VFDs to increase or decrease air volumes as needed,\u201d added Jon Griffith of Epiroc US. \u201cReal-time monitoring of gaseous and particulate contaminants is also an excellent addition to the mine\u2019s VOD system, helping provide the high-quality, real-time data needed to optimize the system.\u201d<\/p>\n\n\n\n

The more information that can be fed into a mine\u2019s control system, the broader range of possibilities of control strategies that can be implemented, agreed Howden\u2019s Pinedo. \u201cFor example, knowing where vehicles and personnel are allows us to turn fans on and off based on their positioning. Taking that a bit further, if a fan with a VFD monitors airflow in that location, we could vary the speed to supply the required amount of air for that specific heading.\u201d<\/p>\n\n\n\n

\u201cThese technologies can also detect potential issues early, allowing for proactive maintenance and reducing the risk of system failures,\u201d noted Trapani. \u201cHowever, the challenge is ensuring that the monitoring stations are maintained well and calibrated to ensure that the data provided are useful and reflective of site conditions.\u201d<\/p>\n\n\n\n

\u201cIt goes back to the principle of only using what is required,\u201d Pinedo continued. \u201cActivities conducted at a heading require different amounts of airflow. Supplying the right amount of air depending on the activity can generate energy savings of over 50%. This can be done at a small scale and specific levels or on a mine-wide scale by incorporating the main fans.\u201d<\/p>\n\n\n\n

Mines also don\u2019t require high-end automated systems to begin to improve efficiency, added Pinedo. \u201cSomething as simple as timers on fan starters can ensure that, even if a fan is left turned on by mistake, it shuts down eventually.\u201d It is also about doing the fundamentals right, like regularly inspecting rigid ducting and vent bags to ensure they are \u201ckept in good order to prevent leakage,\u201d said Griffith. \u201cDucting should also be sized appropriately to optimize airflow.<\/p>\n\n\n

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Each mine\u2019s ventilation needs vary depending on their<\/strong> unique processes. Photo: Epiroc<\/strong><\/figcaption><\/figure>\n\n\n

Computational modeling and simulation: Helpful, but don\u2019t forget the human factor
<\/strong>Digital technologies \u201callow engineers to create detailed models of the mine and simulate various ventilation scenarios,\u201d explained Stantec\u2019s Trapani. \u201cHowden\u2019s Ventsim, SRK\u2019s VNetPC, and VUMA are the three most common tools. These help identify the most efficient and effective ventilation strategies, predict the impact of changes, and optimize system design and operation. These tools can also test emergency ventilation plans and ensure the system can handle unexpected events.\u201d<\/p>\n\n\n\n

\u201cVentilation modelling software is extremely useful in prefeasibility ventilation design and day-to-day operations management,\u201d added Epiroc\u2019s Otterberg. \u201cAs mine workings expand and grow, the ventilation system will have to grow with the mine. A well-maintained ventilation model will enable the mine to perform sensitivity analyses and quickly decide on upcoming ventilation needs.\u201d<\/p>\n\n\n\n

However, according to Elswick of Paul\u2019s Fan, humans still have a place in monitoring and understanding the mine and its environment. \u201cNothing replaces the human ability to take a handheld monitor and go to that working position and make sure. Double-check! Do not rely completely on the computer or the machine. There\u2019s no substitute for checking with handheld equipment.\u201d<\/p>\n\n\n\n

Integrating mine ventilation and production planning
<\/strong>\u201cBest practices for integrating mine ventilation with overall mine production planning include early collaboration between ventilation engineers and production planners, continuous monitoring and adjustment of ventilation systems, and incorporating ventilation considerations into the overall mine design,\u201d said Trapani. \u201cRegular reviews and updates to the ventilation plan based on production changes are also essential. This ensures that ventilation systems align with production activities and adapt to changing conditions.\u201d<\/p>\n\n\n\n

As Venstim Sales Manager Jose Pinada explained, models and simulation software play a part in this. \u201cUsing a tool like Ventsim that allows users to import their mine plan schedule from mine planning software enables your ventilation planning to inherit all the mine\u2019s attributes already configured in the planning software.\u201d<\/p>\n\n\n\n

\u201cIn my experience, involving all departments in the decision-making process is also good practice,\u201d said Elswick. \u201cOften, our mining folks get involved with engineering and accounting while the maintenance and productivity team is left out. But talking to the people who use fans and know their advantages and disadvantages can help determine whether a particular fan will be a viable unit for long-term production.\u201d<\/p>\n\n\n\n

Measuring capital investment against long-term operating expenses can be overlooked.<\/p>\n\n\n\n

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\u201cPulling a smaller, older fan out of storage for a start-up or temporary situation is not necessarily the cheapest option,\u201d continued Elswick.<\/p>\n<\/blockquote>\n\n\n\n

\u201cYou only end up changing it later, and that cost is multiplied more ways than double because a shutdown is required to make the upgrade, plus the additional work taking the old unit out and back to storage while putting in the proper unit. If the mining company properly integrated their ventilation and production planning first, there would be no downtime, upfitting, or wasted time and costs, just optimal use, energy flow, and all that good stuff.\u201d<\/p>\n\n\n\n

Set and forget?<\/strong>
According to Epiroc\u2019s Otterberg, many mines treat ventilation with a \u201cset it and forget it\u201d attitude, receiving little special thought. Yet, ventilation is often among a mine\u2019s highest daily expenses. For example, \u201cmain fans are typically set at the maximum airflow, which is a significant waste of resources.\u201d Tailoring the mine\u2019s underground ventilation system for real-time conditions will reduce operating costs, ensure a safe and comfortable working environment, and help reduce a mine\u2019s carbon footprint.\u201d Far from setting and forgetting, then, mines have much to gain from giving their ventilation systems the attention they deserve.<\/p>\n","protected":false},"excerpt":{"rendered":"

Ventilation is often an underground mine\u2019s most significant operating expense. It\u2019s also essential to the health and safety of personnel and equipment. Important, then, yet many take a curiously offhand approach to their ventilation systems. Experts from Chart Industries, Epiroc, Paul\u2019s Fan, and Stantec explain how to get the most from mine ventilation. by Jonathan Rowland The mining process is,…<\/p>\n","protected":false},"author":8,"featured_media":9997,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_themeisle_gutenberg_block_has_review":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[4],"tags":[3734,427,578,3736,337],"coauthors":[1635],"class_list":["post-9993","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-features","tag-chart-industries","tag-epiroc","tag-mine-ventilation","tag-pauls-fan-company","tag-stantec"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t