Mine Access and Development Overview

Mine Access and Development

• Mine development openings are designed to safely and efficiently access ore bodies for men and materials.
• Access is categorized as primary, secondary, and tertiary, based on importance.
• Primary openings include shafts, adits, and declines.
• Secondary openings include haulages, drifts, and ore passes.
• Tertiary openings are internal ramps and crosscuts.
• Developing underground openings is time-consuming and costly.
• Mechanization is paramount to reduce costs and time in development.
• The chosen access method and location are crucial decisions.
• Key factors influencing access decision include: deposit size & shape, surface topography, geological & hydrological conditions, mining method, production rate, climate, local infrastructure, regulations, and sustainability.
• The size of main access development is determined by ventilation needs, tonnage hoisted per day, equipment size, underground personnel, and electricity/water/air demands.

Types of Underground Openings

• Shafts: Vertical or inclined tunnels used for transporting people, equipment, and ore, often located at depth. Used for access and ore movement.
• Declines/Ramps: Inclined tunnels to access ore bodies at depth, suitable for locations with lower gradients.
• Adits: Sloping or horizontal tunnels that access ore from the side of a hill.
• Raises: Steeper inclined openings to connect different levels in a mine. Mostly used for ore transportation, ventilation, and personnel access.
• Drifts: Horizontal tunnels within an orebody, often used to develop an ore body for extraction.
• Crosscuts: Horizontal passages that intersect other tunnels or openings, critical for connecting sections of an underground mine.

Underground Mine Design Considerations

• Shaft Design: Shaft size is crucial, considering monthly tonnage and ventilation demands.
• Mine Infrastructure: Underground infrastructure includes facilities for ore handling, storage, and ventilation.
• Access Protection: Mine access needs protection for the safety of workers and materials.

Underground Mine Development Methods

• Raise Boring: Mechanically drilling a tunnel(vertical or inclined) connecting levels. More efficient and safer than traditional methods to establish access to underground workings.
• Alimak Raising: Semi-mechanized system for vertical shafts and ore passes. Useful when access is limited.
• Adit Development: Excavation of sloping or horizontal tunnels, used when ore bodies are at a higher elevation than the surface.
• Mine Access Protection: Critical for maintaining the safety and stability of mine workings.

This quiz covers the essential aspects of mine access and development. Learn about the different types of openings, including primary, secondary, and tertiary, as well as the factors influencing access decisions and the importance of mechanization. Understand the complexities and costs associated with developing underground openings.