Application Guide for Rock Reaming Drill Bits: Essential Tool for Efficient Drilling
In fields such as mining, tunnel excavation, and geological exploration involving hard rock fracturing, drilling operations are a core process. When facing complex and variable geological conditions, standard drill bits often fall short in meeting requirements for hole diameter and efficiency. This is where rock reaming drill bits become an indispensable "sharp tool" in engineers' hands. They can efficiently and precisely enlarge the diameter based on an existing small-diameter pilot hole, significantly improving overall operational efficiency. This article delves into the functions and typical application scenarios of rock reaming drill bits.
I. Core Functions of Rock Reaming Drill Bits
The primary task of a rock reaming drill bit is to quickly and stably expand the hole diameter to the designed specifications on the basis of a pre-drilled small hole (pilot hole). Compared to directly drilling a large-diameter hole, reaming technology can substantially reduce energy consumption, minimize equipment wear, and enhance hole formation accuracy.
II. Typical Application Scenarios
Mining Operations
Large-Diameter Blastholes: This is the most central application for reaming bits. First, a small-diameter pilot hole is drilled, followed by stepwise enlargement using the reaming bit to the required large diameter (typically 76mm - 200mm or more), which greatly improves blasting efficiency and ore fragmentation.
Anchor Bolt/Cable Holes: Some support structures require hole diameters exceeding standard drill capabilities, and reaming technology enables precise achievement of this.
Secondary Fragmentation Holes: For secondary blasting of large ore blocks, reaming may be needed to install explosive charges.
Tunneling and Underground Engineering
Tunnel Excavation: When drilling full-face blastholes, peripheral or cut holes sometimes need larger diameters for better blasting results, which reaming bits can achieve accurately.
Support Anchoring: Installing large anchor bolts, hollow grouting anchors, or prestressed anchors often requires reaming to larger diameters (such as expanding from a φ42mm pilot hole to φ76mm, φ89mm, or even bigger).
Pipe Shed Support: Installing large-diameter advance pipe sheds (such as φ89mm, φ108mm, φ127mm, etc.) makes reaming an essential step.
Foundation Engineering and Special Operations
Pile Foundation Construction: In certain rocky foundations, pile holes may require under-reaming (enlarging the bottom diameter) or partial reaming.
Emergency Rescue and Ventilation Holes: Reaming technology is highly efficient for quickly establishing large-diameter lifelines or ventilation ducts.
Geothermal Wells/Water Wells: Completing large-diameter final holes in hard rock layers.
III. Key Points for Usage and Maintenance: Extending Service Life and Ensuring Safety
Standardized Operations: Ensure the pilot hole is straight; start with light pressure and slow rotation, then gradually increase pressure once normal drilling begins; maintain appropriate axial pressure and speed to avoid severe vibrations or slippage of the bit.
Effective Slag Removal: Provide sufficient air or water pressure to ensure rock powder is promptly discharged from the hole, preventing repeated grinding and bit jamming. This is crucial for improving efficiency and protecting the bit.
Avoid Dry Firing: Strictly prohibit impact operations when the bit is not in contact with rock, as this can easily damage the carbide buttons or blades.
Timely Sharpening: For blade-type bits, when the blade angle wears to a certain extent (as per manufacturer recommendations), use a dedicated grinder to sharpen and restore sharpness, which can significantly extend service life. Button bits generally cannot be sharpened.
Regular Inspections: Check the bit threads, carbide buttons/blades for cracks, chipping, excessive wear, or looseness before and after use.
Proper Storage: Avoid impacts, and protect against moisture and rust.
