CASE STUDY | Tackling High-Impact and High-Abrasion Raw Coal Conveying

Date: December 12, 2025 | Client: A Large Coal Mine in China

Summary: From 4-Month Wear-Through to 6 Months with Only 1mm+ Loss

A major Chinese coal mine struggled with the rapid failure of the raw coal chute floor in its main transport system, which handled 500 T/h of highly abrasive and high-impact raw coal. The conventional 16mm thick Manganese Steel Plate wore through completely in just 4 months, posing significant safety and continuity risks. HIGHCR introduced its revolutionary 6+6 Chromium Carbide Overlay (CCO) Plate solution, which not only extended the service life to 6 months (a 50% increase) but also resulted in a minimal wear depth of just 1mm+, completely eliminating the risk of wear-through downtime.

---

I. The Client’s Pain Point: Rapid Failure Under High Load

This coal mine is a crucial national energy base, making transport efficiency and equipment safety vital priorities. The raw coal chute, transitioning material from the crusher to the main belt conveyor, was a severe bottleneck due to its rapid wear rate.

Performance Bottleneck of Conventional Mn Steel Plate	Key Data
Application	Raw Coal Chute Floor
Throughput	500 Metric Tons/hour (High Impact, High Abrasion Raw Coal)
Original Material	16mm thick Standard Manganese Steel Plate
Failure Cycle	Worn through and scrapped after only 4 months
Risk & Cost	Frequent downtime for emergency replacement, safety hazards, high maintenance costs

Failure Diagnosis: Single Material Failure Against Compound Wear

• Mechanism: The 500 T/h raw coal contains large quantities of gangue (waste rock), quartz particles, and mudstone, sliding through the chute at high velocity and high impact angles.

• Challenge: Traditional Manganese Steel, while tough against impact, lacks the surface hardness to resist the continuous micro-cutting of quartz and gangue, leading to a rapid, linear wear progression and eventual perforation.

---

II. HIGHCR Solution: The Ultra-Hard Protection of the 6+6 CCO Plate

HIGHCR recommended its HIGHCR 6+6 Chromium Carbide Overlay Plate, specifically engineered for high-abrasion and medium-to-low impact applications. This solution perfectly integrates extreme surface hardness with good base plate toughness.

Core Technical Advantage: Synergistic Action of Two Layers

Component	Structure	Material and Function
Overlay Layer	6mm thick	Chromium Carbide (CrC) weld overlay. This layer, with hardness reaching 58-62 HRC, features densely distributed M7C3 carbide crystals, forming an ultra-hard protective grid that perfectly resists the abrasion from quartz and gangue in the raw coal.
Base Plate	6mm thick	Mild/High-Toughness Steel Base Plate. Provides excellent toughness, weldability, and structural support, absorbing the impact energy of the raw coal and preventing overall brittle failure or cracking.
Model	HIGHCR 6+6	12mm total thickness, offering a lightweight design with superior wear resistance.

Technical Value:

• Hardness Leap: The CCO layer’s hardness significantly exceeds that of Manganese Steel (approx. 18-22 HRC), drastically reducing the wear rate.

• Safety Assurance: The presence of the base plate ensures structural integrity even as the overlay wears, completely eliminating the sudden risk of wear-through and catastrophic failures.

---

III. Performance and Economic Benefits: 50% Life Extension and “Zero Penetration”

The implementation of the HIGHCR 6+6 CCO plate dramatically improved the coal mine’s chute efficiency and maintenance cost structure.

Key Performance Outcomes

Performance Metric	Original 16mm Manganese Steel	HIGHCR 6+6 CCO Plate	Percentage Improvement
Failure Cycle	Worn through after 4 months	After 6 months	50% Extension
Wear Depth	16mm completely worn through	Only $\approx 1 \text{ mm}$ wear (on 6mm overlay)	Near-Zero Wear (relative to total thickness)
Replacement Frequency	3 times annually	$\approx 2 \text{ times annually}$	33% Reduction

Operational Benefit Analysis

• Extended Replacement Cycle: Stable extension of the chute replacement interval to 6 months, significantly streamlining maintenance planning.

• Safety & Reliability: Total elimination of sudden wear-through risks, which previously caused raw coal spillage and unplanned downtime.

• Cost Efficiency: While the initial material cost is higher, the 50% life extension and reduced downtime result in a significant decrease in Annual Total Cost of Ownership (TCO).

---

Client Testimonial

“The performance of HIGHCR’s 6+6 CCO plate exceeded our expectations. The wear depth after 6 months of high-volume conveying was minimal, indicating a service life far exceeding those 6 months. Most importantly, we have entirely eliminated the need for emergency repairs to wear-through failures that plagued us every 4 months, ensuring the safe and efficient operation of the mine.”

HIGHCR is committed to providing safer and more economical conveying system solutions for the energy and mining sectors through high-performance overlay technology.