Applications
Open-Pit Mining Drilling: Rigs & Compressors Matched to Your Bench
Hole diameter, bench depth and rock hardness drive the rig choice — here is the selection logic for blast-hole drilling in open-pit mines.
1. The drilling task in open-pit mining
Blast-hole drilling in open-pit mines is defined by three numbers: hole diameter, bench depth and rock hardness. Bench blasting typically runs 90-254 mm holes at 21-36 m depths in medium-to-hard rock (f=6-20). The rig must hold line and penetration rate across the bench pattern, shift after shift.
- •Hole diameter 90-254 mm (bench blasting)
- •Bench depth 21-36 m
- •Rock hardness f=6-20 typical
2. DTH vs top hammer — the method decision
For holes up to 127 mm at high frequency, a top hammer rig (KL510/KL511) delivers the fastest cycles in medium-hard rock. For holes above 130 mm or deeper than 25 m, DTH is the working method: the hammer travels with the bit and keeps penetration strong at depth. Most open-pit production benches sit in the DTH range.
3. Integrated or split — where the compressor lives
Integrated rigs (KT5C, KT9C, KT30, KZ5, KZ9) carry the screw compressor onboard — one machine, one operator, fastest setup. Split rigs (KG420B, KG520, KG550, KG940A) take air from a separate KSCY mobile compressor, which suits mines running a central compressor fleet or varying hole sizes across pits.
4. Quick rig map by bench profile
| Bench profile | Rig class | Reference models |
|---|---|---|
| 64-127 mm, high frequency, medium rock | Top hammer, integrated | KL510 / KL511 |
| 90-130 mm, 25 m benches | Mid-size split DTH | KG420B, KG420S, KG430 |
| 105-152 mm, larger benches | Mid-size split DTH | KG520, KG520H |
| 115-254 mm, heavy production | Split DTH, high capacity | KG550, KG940A/KG940AH |
| 76-190 mm, quarry & slope, mobile | Integrated DTH | KT5C, KT9C, KT15i |
| 195-254 mm, heavy blasting | Heavy integrated DTH | KT30 |
5. Air compressor matching
Split rigs need a compressor matched to the hammer: KG420B draws 10-17 m³/min, KG520 draws 15-22 m³/min. The KSCY family (0.8-2.3 MPa) is the standard surface-DTH pairing; dual-mode units like the KSCY-650/20-700/17T let one compressor feed several rigs.
6. Project reference
Kaishan i-series DTH rigs (KT15i) have been delivered in significant numbers to open-pit coal mines in Xinjiang Province, running RTK positioning and 5G remote control with patrol-only staffing on site.
Frequently asked questions
What hole diameter range suits open-pit bench blasting?
Most benches run 90-254 mm holes. Below 130 mm both top hammer and DTH work; above 130 mm DTH is the standard method.
How do I choose between an integrated and a split DTH rig?
Integrated rigs are self-contained and fastest to mobilise. Split rigs let you right-size a compressor fleet across multiple rigs — the right answer for larger mines with varying hole plans.
Can Kaishan rigs work at high altitude?
Components are cold-climate and high-altitude tested. Tell us your site altitude and we confirm the configuration, including compressor derating for thin air.
Need equipment matched to your site?
Send us your hole diameter, depth and conditions — we confirm the configuration within 24 hours.
Request a QuoteMore applications
Water Well
The chassis decision drives half the operating cost of a water-well business — pick by terrain, transport distance, well depth and hole diameter.
Quarrying
Quarries need rigs that move, drill fast and keep the air onboard — the integrated DTH line is built for quarry cycles.
Deep Water Well
Deep wells change the air equation — pressure climbs, flow must hold, and the compressor becomes the bottleneck.
Geothermal
Configure the drilling rig, high-pressure compressor and DTH tooling for deep geothermal wells in hard-rock formations.
Remote Area
Off-grid sites reward equipment that brings its own power, air and parts — diesel-driven rigs and compressors are the remote-site standard.
High-altitude
Above 3000 m, thin air derates engines and compressors — equipment must be configured for altitude, not just delivered.