| The Potash Corporation of Saskatchewan Inc. has invested 2.8 billion dollars in its Rocanville Division, a potash mine in southeast Saskatchewan. The investment was made to increase site production nameplate capacity from 3.0 million tonnes per annum (MMtpa) (K20) to 5.7 MMtpa (K20). The expansion consisted of three components. First, processing capacity was doubled by building a second mill facility. Second, ore hoisting capacity was increased by converting the existing service shaft into a production shaft. Finally, mine production capacity was increased by nearly tripling the production mining machine fleet and opening new ore reserves. In addition to this, a new (third) remote shaft to act as a new service shaft was also constructed. This thesis covers the design of a mine ventilation system that will meet the operating constraints of the post-expansion production requirements, the publishing of which is unique compared to typical potash mine ventilation practice, which has historically been based solely on field experience. The mine ventilation system was designed by analyzing the minimum requirements for effective production on a 'per machine' basis. Shaft capacities for airflow were also analyzed and mine resistance was estimated using ventilation engineering principles. Design calculations were then verified through extensive computer modeling, and used to generate specifications for fan systems. This thesis also presents the planning of the construction and commissioning and the phased implementation of the system while the mine continued to produce potash. The transition phases were planned to work in conjunction with mine production downtime, complement other 'expansion' related construction activities, and most importantly provide effective ventilation to the mine throughout the entire process. A comparison of the ventilation model to in-field survey data was completed during several of the early transition phases to verify the design calculations. This thesis also presents novel applications of engineering principles used to optimize the design from and aerodynamics and health and safety (sound exposure and local air velocity) viewpoint, perspectives often unconsidered when performing conveyance design, shaft design, and determining fan placement. All of this was done in order to reconcile ventilation requirements with production expectations, allowing for efficient and productive potash mining. |
