Basic Mine Ventilation Planning and Design Flashcards

Vocabulary flashcards covering key mine ventilation design principles, rock densities, zonal design parameters, air factor requirements, optimum air velocities, allowable leakages, and heat load calculations based on the lecture notes.

General Design Philosophy

The practice of accurately designing ventilation and refrigeration requirements in direct conjunction with the scheduled mine plan to ensure acceptable environmental conditions and maintain target production levels.

Systematic Approach for Design of Ventilation Systems

A 6-step planning guide: 1) Determine mining method and production rate, 2) Define acceptable ventilation standards, 3) Calculate heat increases, gas/fissure water emissions, and dust production, 4) Calculate air and refrigeration requirements, 5) Optimise alternatives, and 6) Select a system.

Planimeter

An instrument used by the Survey department to obtain the area of irregular figures drawn to a known scale from a mine stope plan.

Rock Volume Formula (Stope)

The formula used to measure rock volume in cubic metres: $\text{Rock volume (m}^3\text{)} = \frac{\text{face area (m}^2\text{)} \times \text{stope height (cm)}}{100}$.

Standard Rock Densities

Rough planning parameters for rock densities: Gold bearing reef is $2670\text{ kg/m}^3$ ($2.67\text{ tons/m}^3$), Platinum Merensky reef is $3024\text{ kg/m}^3$ ($3.024\text{ tons/m}^3$), and Platinum UG 2 reef is approximately $4050\text{ kg/m}^3$ ($4.05\text{ tons/m}^3$).

Development Tonnage Formula

The total tonnage calculated as: $\text{Face area (m}^2\text{)} \times \text{face advance (m)} \times \text{rock density} = \text{tons}$.

Reef Strike

The direction of the line of intersection of an orebody's plane with any horizontal plane, usually expressed in terms of compass points.

Reef Dip

The inclination of an orebody's plane from the horizontal; the line of true or major dip is always at right angles to the line of strike.

Centre Gulley and Strike Gulley

In conventional mining, the centre gulley (stope raise line) is blasted on major reef dip, whereas the stope face gullies (strike gullies) are blasted in the reef strike direction.

Zone 1 Workings

Mine workings where the Virgin Rock Temperature ($\text{VRT}$) is $< 37^\text{o}\text{C}$, requiring only ventilation up to the 1st Critical Horizon.

Zone 2 Workings

Mine workings where the Virgin Rock Temperature ($\text{VRT}$) is $< 48^\text{o}\text{C}$, requiring both ventilation and refrigeration between the 1st and 2nd Critical Horizons.

Zone 3 Workings

Mine workings where the Virgin Rock Temperature ($\text{VRT}$) is $> 50^\text{o}\text{C}$, requiring refrigeration beyond the 2nd Critical Horizon.

Planned Air Factor

The standard air requirement for tabular ore bodies, scattered stoping, or longwalling, set at $3.0$ to $3.5\text{ m}^3\text{/s}$ per kiloton per month (or $4.0\text{ kg/s}$ mass flow) at the mean rock breaking depth (MRBD).

Trackless Mining Machine (TMM) Diesel Air Requirement

The ventilation standard requiring at least $0.12\text{ m}^3\text{/s}$ per rated engine $\text{kW}$ for indirect fuel injection diesel machines using low emission fuels.

Diesel Machine Heat Generation Rates

A diesel engine generates $3.2\text{ kW}$ of heat per rated $\text{kW}$ engine power at peak power, and an average of $2.0\text{ kW}$ of heat per rated $\text{kW}$ engine power.

Optimum Shaft Air Velocities

Recommended air speeds are $18$ to $22\text{ m/s}$ for unequipped shafts (upcast or downcast) and $10$ to $12\text{ m/s}$ for equipped shafts.

Optimum Airway and Tunnel Velocities

Recommended speeds include $7\text{ m/s}$ for Intake Airways (IAWs), chairlifts, and inclined shafts; $10\text{ m/s}$ for Return Airways (RAWs); and $3\text{ m/s}$ for conveyor belt tunnels.

Multi-blast Ventilation Quantities

In multi-blast development, the minimum force quantity is $0.25\text{ m}^3\text{/s}$ per $\text{m}^2$ of face, and the exhaust quantity must be not less than twice the force quantity.

Allowable Ventilating Air Leakages

Permissible leakages are up to $5\text{\%}$ of main upcast fan quantity for shaft systems, up to $15\text{\%}$ for Intake Airways (IAWs), and $20\text{\%}$ or less for stopes (with air utilisation $> 80\text{\%}$).

Heat Load from Fissure Water

Heat added by fissure water emissions, evaluated using a factor of $0.2\text{ kW/(\text{l/s})}$ or calculated using $\text{q} = \text{m} \text{c}_{\text{p}} \text{ΔT}$, where $\text{ΔT} = \text{VRT} - \text{Rejection Temp}$.

Heat Load from Fans, Hoists, and Pumps

All fan power used to overcome friction adds heat to the air; for hoists and pumps, only energy inefficiency adds heat to the air, as work done for vertical lifting does not add heat.

Auto-compression and Auto-decompression

Auto-compression adds heat to downcast air according to $\text{Heat added} = \frac{\text{m} \times 9.79 \times \text{Depth}}{1000}$, whereas auto-decompression removes heat from upcast air.