MechChem Africa January-February 2022

BBE Consultants and the VUMA simulation advantage The BBE Group has released the 2021 version of its flagship mine ventilation simulation software, VUMA-network, which is being offered free to the mining industry. MechChem Africa talks to Russell Hattingh, MD of BBE Consulting and Hannes Potgieter, Senior Ventilation Consultant for BBE Consulting.

“M y background is mine ventilation and refrig- eration in the mining industry and as a ven- tilation consultant I use VUMA-network software to define mine ventilation systems and determine underground cooling needs. Once the requirements are defined, BBE refrigeration engineers design the specific refrigeration stations,” begins Hannes Pot- gieter, Senior Ventilation Consultant for BBE Consulting. “VUMA software adds a huge amount of value to our offering at BBE. We can use it to simulate a whole range of scenarios in the underground mining environment to help us design better ventilation solutions and to help clients to manage their under- ground environments in terms of energy efficiency, workplace ambient conditions and safety,” adds Russell Hattingh, MD of BBE Consulting. The development of an underground mine, according to Potgieter, starts with accurate knowledge of the ore body. Then,

established relatively quickly by importing data from an AutoCAD model of the mine layout, for example. Once an accurate model has been established, algorithms developed from 20 years of experience in underground conditions are used to calculate how the target air quality and temperatures can be ach i eved . “We typically design to an average working wet bulb temperature of between 27.5 and 28.5 °C. This target temperature directly influences the venti lation and cool ing requirements,” explains Potgieter. Describing heat sources underground, he says heat from rock, machinery and auto compression in deep mines are the main contributors. “At the Mponeng Gold Mine, which is the deepest mine in the world, for example, heat due to auto- compression accounts for almost 50 MW of heat. In addition to this, the typical virgin rock temperature (VRT) at a 2.0 km depth in South Africa will be between 40 and 50 °C, but can be as high as 70 °C in some cases,” he notes.

mine design experts develop the mining methodology and mining methods. “Our role is to design the systems needed to enable people to work safely underground in a well-ventilated atmosphere at tem- peratures that are conducive to the hard work miners do,” he continues. “The first thing we tend to see is a mine plan given to us by the developers. We then identify how best to ventilate and cool the areas where the mining will take place. “Initial mine planning is based on ge- ology, rock engineering and how best to access the ore body. We get involved early in the design process to give guidance on additional requirements for del ivering chilled air, for example, and provide rec- ommendations as to mine plan changes required from a ventilation perspective to enhance economical and safety out- comes,” notes Hattingh. BBE’s VUMA-network software is able to create a 3D model of an underground mine network, which can almost always be

24 ¦ MechChem Africa • January-February 2022