Core Drilling with Core Recovery

Advantages of Core Drilling

The core drilling method delivers maximum information value for exploration projects:

• High-quality core recovery — preservation of rock structure and texture reaches 95–100% with proper drilling tool selection
• Precise stratigraphy — continuous sampling enables detailed study of rock sequences and accurate ore body delineation to centimetre precision
• Data reliability — core serves as the foundation for laboratory assays, petrographic and mineralogical studies
• International standards compliance — quality core is mandatory for reporting under JORC, NI 43-101, and KAZRC codes

Core Barrel Sizes and Drilling Diameters

Minerals Operating employs Wireline series core barrels — the global exploration industry standard. Size selection depends on project requirements, drilling depth, and rock characteristics.

Primary sizes:

• BQ — core diameter 36.5 mm, hole diameter 60 mm. Used for deep drilling (up to 1,500 m) in hard rock formations. Optimal for ore deposit exploration with compact ore bodies.
• NQ — core diameter 47.6 mm, hole diameter 76 mm. Universal size for most exploration tasks. Drilling depth up to 1,200 m. Provides balance between core quality and productivity.
• HQ — core diameter 63.5 mm, hole diameter 96 mm. Utilised at depths up to 800 m when larger samples are required for detailed investigations or geotechnical analysis.
• PQ — core diameter 85 mm, hole diameter 123 mm. Applied for shallow holes (up to 400 m) when maximum core size is necessary for metallurgical testing or geotechnical purposes.

All core barrels are equipped with Wireline systems — enabling core retrieval without lifting the entire drill string, reducing operational time and minimising borehole wall collapse risk.

Core Sampling Methodology and Preservation

Core quality directly impacts geological model reliability. Minerals Operating implements protocols aligned with global best practices.

Core Marking

Each core run is marked immediately at the drill site:

• Borehole number
• Depth interval (from–to)
• Core orientation (top–bottom)
• Sampling date

Marking is applied with permanent markers on core trays and duplicated in field documentation.

Preservation and Transportation

To prevent oxidation, desiccation, or mechanical damage, core is preserved immediately after extraction:

• Core is placed in wooden or plastic core trays with compartments
• Voids are filled with foam or soft paper
• Particularly fragile or oxidisable intervals are wrapped in heat-shrink film or waxed
• Trays are sealed for transportation

Transportation is conducted using specialised vehicles with shock absorption systems, preventing vibration and sample deformation.

Storage Conditions

Minerals Operating provides long-term core storage under conditions preventing degradation:

• Covered core sheds with controlled humidity (40–60%)
• Storage temperature: +5 to +20°C
• Protection from direct sunlight
• Cataloguing and rapid sample retrieval system
• Capability for re-sampling for additional assays

Core Documentation

Comprehensive and accurate documentation forms the foundation for quality drilling data interpretation.

Photographic Documentation

Each core tray is photographed in dry and wet states under standardised lighting. Wet photography reveals textural features not visible on dry core. Images are captured in high resolution (minimum 300 dpi) with colour scale and metric ruler.

Core Logging Records

Qualified Minerals Operating geologists maintain detailed core descriptions including:

• Lithological composition
• Textural and structural characteristics
• Mineral composition and mineralisation indicators
• Degree of fracturing and weathering
• Core recovery percentage
• Rock Quality Designation (RQD) index

Data is entered into digital databases and synchronised with laboratory results.

Digital Data Management System

Minerals Operating utilises a specialised GGIS (geological and geophysical information system) for the mining industry. The technology ensures seamless data exchange between drilling sites and head office:

• Geologists upload core descriptions and photographic documentation directly from tablets to a remote server
• Data transmission occurs via secure encrypted communication channels, preventing confidential information leakage
• Office specialists access the database in real time without delays
• The system eliminates manual data entry and minimises error risk
• Clients can track project progress online and receive prompt reports

This approach reduces time from core recovery to final geological data delivery and enhances project transparency.

Quality Assurance and Quality Control (QA/QC) and Project Support

Minerals Operating implements multi-level quality control systems across all drilling stages.

Independent Oversight

Projects are supervised by independent geologists (Competent Person / Qualified Person) who:

• Verify field procedures comply with approved protocols
• Control core marking and documentation
• Audit chain of custody
• Validate drilling data before database entry

Equipment Calibration and Metrological Verification

All equipment undergoes regular calibration:

• Measuring instruments (tape measures, callipers) — annually
• Depth metres and inclinometers — every 6 months
• Weighing equipment — according to metrological service schedule

Minerals Operating works exclusively with accredited laboratories and employs certified reference materials (CRM) for analytical procedure control.

Core drilling services from Minerals Operating guarantee reliable geological data meeting the strictest international requirements. Our expertise, modern equipment, and systematic quality control approach ensure successful project delivery regardless of complexity.