Top 10 Core Storage Mistakes in Mining Projects

Why Core Storage Errors Cost Millions

In the mining and exploration industry, accurate geological data is everything. From feasibility studies to ore grade estimation, the reliability of core samples directly influences multi-million-dollar decisions. Yet, many operations still lose valuable data due to one recurring issue — improper core storage and handling.

Core samples can deteriorate, shift, or even become completely unusable when stored incorrectly. The result? Costly re-drilling campaigns, data inconsistencies, and project delays that could have been easily avoided.

In this 2025 field guide, we explore the 10 most common core storage mistakes seen across mining projects — and how professionals can avoid them using modern, sustainable solutions such as plastic core trays and efficient handling systems.

Using the Wrong Tray Size (HQ/NQ/PQ Mix-ups)

One of the most frequent field errors occurs before cores even reach the logging shed: using trays that don’t match the drilling size. Each core diameter — whether BQ, NQ, HQ, or PQ — requires a tray designed for its dimensions and weight.

A mismatched tray can compress, roll, or break core segments, making geological structures appear distorted. For example, storing NQ cores in HQ trays leaves too much room, leading to movement during transport. Conversely, squeezing HQ cores into NQ trays results in sample compression.

✅ How to Avoid It:

• Always confirm the drill string system (HQ, NQ, PQ) before ordering trays.

• Use clearly marked, size-specific trays for standardisation.

• For multi-site operations, consider modular trays that accept size inserts for flexibility.

Proper sizing not only protects samples but also ensures data consistency across exploration campaigns.

Ignoring UV and Weather Resistance

Field conditions in mining regions can be harsh: high UV radiation, fluctuating temperatures, and heavy rain. Using non-stabilised materials causes trays to warp, fade, or become brittle within months.

Wooden trays absorb moisture and deform, while untreated metal trays corrode and stain the cores. Even low-grade plastics deteriorate under sunlight, compromising their structure and longevity.

✅ How to Avoid It:

• Choose UV-stabilised recycled plastic trays that resist sunlight degradation.

• Store trays under covered or shaded areas when possible.

• Avoid placing trays directly on hot ground or metal surfaces in desert environments.

Weather-resistant trays not only extend lifespan but also maintain geological visibility — critical for logging and photography.

Overstacking and Deformation in Storage Yards

Stacking trays too high or without alignment locks is a safety hazard and a structural risk. Over time, the weight compresses the bottom trays, deforming them and distorting core alignment. This can result in inaccurate measurements and even tray collapse.

✅ How to Avoid It:

• Use interlocking tray designs for secure stacking.

• Follow manufacturer recommendations — typically 8–10 trays maximum per stack when fully loaded.

• Store on flat, even surfaces to distribute weight evenly.

• Inspect stacks periodically for warping or instability.

Proper stacking reduces not only damage risk but also ensures safe and efficient field logistics.

Poor Labelling and Depth Tracking

A core tray without accurate labels is as good as lost data. When trays are poorly marked or when numbering systems vary between shifts, even high-quality samples can become unusable.

Inconsistent or missing depth markers lead to mismatched intervals, misinterpretation of lithology, and duplication of sampling.

✅ How to Avoid It:

• Label trays clearly with hole ID, depth range, and orientation arrow.

• Use engraved tags, embossed markings, or permanent paint pens instead of adhesive labels.

• Implement barcode or QR systems to integrate with digital logging software.

Effective labelling ensures traceability from the drill site to the lab, minimising data confusion during analysis or audit.

Using Non-Recycled, Brittle Plastic Materials

Not all plastics are equal. Many cheap trays use virgin polymers that lack flexibility and degrade under environmental stress. Brittle trays can crack under weight or impact, posing risks during handling and transport.

In contrast, trays made from recycled HDPE (high-density polyethylene) are designed to handle extreme temperatures and heavy loads while maintaining structural integrity.

✅ How to Avoid It:

• Select trays made from 100% recycled HDPE with reinforced ribs.

• Avoid low-cost PVC or polypropylene alternatives that can fracture easily.

• Choose trays manufactured using solar energy or circular recycling systems for ESG compliance.

Sustainable trays reduce waste, carbon footprint, and long-term replacement costs — a win for both the environment and operations.

No Drainage or Ventilation in Trays

Core samples often retain moisture from drilling fluids, washing, or rain. Without proper drainage, this water can accumulate in trays, leading to core discolouration, bacterial growth, or chemical alteration.

✅ How to Avoid It:

• Use trays with built-in drainage holes and non-porous surfaces.

• Allow air circulation during storage to keep cores dry.

• Avoid stacking wet trays directly to prevent trapped humidity.

Proper ventilation preserves sample appearance and chemical composition — essential for accurate geochemical testing.

Inconsistent Sample Orientation

Core orientation is vital for structural logging. When cores are stored upside down or out of sequence, the geological data becomes unreliable.

Orientation errors are particularly problematic in HQ and PQ drilling where structural analysis is critical for mine design.

✅ How to Avoid It:

• Always place cores in order of depth — top left to bottom right.

• Maintain orientation arrows drawn directly on the core surface.

• Train field staff to handle core sequences consistently across all shifts.

Consistency in orientation ensures accurate mapping of fault lines, bedding, and fracture angles.

Neglecting Proper Cleaning and Maintenance

Mud, dust, and drilling residue build up on trays over time. Dirty trays not only obscure sample visibility but can also introduce contaminants during geochemical analysis.

✅ How to Avoid It:

• Clean trays regularly with non-reactive detergents and fresh water.

• Inspect for cracks, residue, or drainage blockage before reusing.

• Replace any trays showing UV fatigue or deformation.

Maintaining trays is part of professional field discipline — reflecting both data integrity and operational quality.

Storing in Direct Sunlight for Long Periods

Even with UV-resistant plastic, prolonged exposure to direct sunlight accelerates fading, heating, and material fatigue. Over time, this can lead to embrittlement and cracking.

✅ How to Avoid It:

• Store trays in shaded, ventilated areas such as covered core sheds.

• Use UV-protective covers for outdoor storage.

• Rotate tray stacks to minimise exposure on one side.

Simple shade management can extend tray lifespan by several years — an easy, cost-free sustainability step.

Not Training Field Staff on Tray Handling

Even the best-designed trays fail when handled incorrectly. Dropping trays, misalignment during stacking, or careless loading can undo thousands of dollars’ worth of investment in storage systems.

✅ How to Avoid It:

• Provide basic training sessions for new field staff on tray handling, stacking, and transport.

• Use visual instruction posters in the core shed.

• Assign responsibility for tray maintenance and labelling to designated personnel.

Training improves not only efficiency but also safety — preventing injuries and sample loss.

Building a Reliable, Sustainable Core Management System for 2025

In 2025, the mining sector faces tighter budgets, higher ESG standards, and an ever-growing need for accurate geological data. Core trays and boxes — though often overlooked — play a foundational role in achieving these goals.

Avoiding the common mistakes listed above transforms core management from a logistical burden into a strategic advantage. With high-quality, UV-resistant, recycled plastic core trays, operations can achieve:

• Longer tray lifespans and reduced replacements.

• Improved geological accuracy and visual consistency.

• Safer, more organised core storage facilities.

• Alignment with sustainability and circular economy principles.

Every correctly stored core is a piece of the geological story that defines your project’s value. By investing in proper materials, training, and best practices, mining teams ensure that story remains complete — from drilling to data analysis.