Case Study: YZH BA300 Eliminates Underground Grizzly Blockages at Laos Mine — Zero Personnel Entry, Continuous Ore Flow

Project Snapshot

Background: The Challenge of Underground Grizzly Screen Blockages

Underground metallic ore mining in Laos presents a set of operating challenges that are among the most demanding in the Asia-Pacific region. Ore bodies are typically hard, abrasive, and structurally complex. Blasted ore fragments vary widely in size, and the proportion of oversize material reaching the underground ore handling system is significant.

At this particular underground mine in Laos, blasted ore was drawn from stopes and transported via ore passes to a grizzly screen installed at the underground loading level. The grizzly screen's function was to scalp oversize boulders before the ore dropped into the loading pocket below, preventing oversize material from blocking the downstream haulage and crushing circuit.

The problem was straightforward but serious: large boulders — some exceeding 800 mm in their longest dimension — were regularly bridging across the grizzly screen bars, blocking ore flow and bringing the underground loading operation to a halt.

The Manual Clearing Method: Slow, Dangerous, and Unsustainable

Before the YZH BA300 installation, the mine's standard response to a grizzly blockage was to send a team of workers underground to clear the obstruction manually. The procedure involved:

• Suspending ore drawing from the stope above

• Waiting for the area to be declared safe by the shift supervisor

• Workers descending to the grizzly screen level with handheld pneumatic breakers and pry bars

• Manually breaking or dislodging the bridging boulders

• Withdrawing personnel and resuming ore draw

Each clearing event took between 45 minutes and 2 hours, depending on the size and position of the blockage. With three to five blockage events per 12-hour shift, the underground loading operation was losing 2 to 6 hours of productive time daily.

More critically, the manual clearing method placed workers in one of the most hazardous environments in underground mining: directly beneath an active ore pass, in a confined space, working around unstable rock masses, with the constant risk of secondary rock falls from above.

The mine's safety management team had flagged this activity as an unacceptable risk on multiple occasions. The combination of confined space, overhead hazard, and unpredictable rock behaviour created a risk profile that no engineering control could adequately manage while manual entry remained the clearing method.

The mine needed a solution that would eliminate personnel entry entirely — not reduce it, but eliminate it.

Solution: YZH BA300 with 5G Wireless Remote Control

After evaluating several options, the mine's engineering team selected the YZH BA300 pedestal rock breaker boom system, configured with a 5G wireless remote control console for fully remote operation.

The selection was driven by four factors:

1. Reach and Coverage

The BA300's maximum horizontal working radius of 4,880 mm and vertical working radius of 3,270 mm provided full coverage of the grizzly screen from the available pedestal location in the underground chamber. The 360° slewing capability ensured that the hammer could be positioned over any point on the grizzly screen surface, including the corners and edges where bridging events most frequently occurred.

2. Breaking Power for Hard Rock

The ore at this mine is a hard, competent rock with a Uniaxial Compressive Strength (UCS) in the range of 150 to 200 MPa. The BA300's heavy-duty construction and compatibility with high-energy hydraulic hammer configurations provided the impact energy required to break large boulders of this hardness efficiently.

3. 5G Wireless Remote Control — Complete Personnel Exclusion

The defining requirement for this project was the elimination of personnel from the underground hazard zone during clearing operations. The 5G wireless remote control console allows the operator to control all boom and hammer functions from a safe location — outside the underground chamber, at the surface control room, or at any designated safe position within 5G network coverage.

The operator has full visibility of the grizzly screen via the underground camera system and can position the hammer, initiate breaking, and monitor the clearing operation without entering the underground hazard zone at any point. When a blockage occurs, the operator activates the BA300 from the remote console and resolves the blockage without any personnel descending underground.

4. Underground-Ready Configuration

The BA300 was supplied in a configuration appropriate for underground installation: electric hydraulic power unit matched to the mine's underground electrical supply, all electrical components rated for the underground environment, and all major structural components sized for transport through the mine's decline access route and assembly underground.

The complete system — boom, pedestal, HPU, control cabinet, and remote console — was shipped in a single 20GP container, simplifying logistics for the Laos project.

Installation

The BA300 was installed over a period of five days by a YZH-supervised installation team working in coordination with the mine's underground maintenance crew.

The installation sequence was:

1. Foundation preparation: A reinforced concrete pedestal foundation was cast adjacent to the grizzly screen, designed to resist the dynamic loads generated during hammer operation in the underground environment.

2. Component transport underground: All BA300 components were transported underground via the mine's decline access route. The modular design of the BA300 ensured that all components were within the decline vehicle's transport envelope.

3. Pedestal and boom assembly: The pedestal column and boom structure were assembled underground using the mine's underground crane. Assembly was completed in two shifts.

4. HPU installation and hydraulic connection: The electric HPU was installed in a dedicated plant alcove adjacent to the grizzly chamber. Hydraulic hoses were routed and connected to the boom and hammer.

5. 5G network integration and remote console commissioning: The 5G remote control console was integrated with the mine's underground 5G network infrastructure. Signal coverage was confirmed at all designated operator positions, including the surface control room.

6. Commissioning and operator training: The system was commissioned with the mine's operators present. YZH's commissioning engineer conducted a full operator training session covering normal operation, emergency procedures, and routine maintenance tasks.

Total installation and commissioning time: 5 days.

Results

The BA300 has been in continuous operation at the Laos underground mine since commissioning. The results across three key performance dimensions are as follows.

Safety: Personnel Exclusion Achieved

The primary objective of the project — eliminating personnel entry into the underground hazard zone for routine grizzly clearing — has been fully achieved.

Since commissioning, zero personnel entries into the grizzly screen hazard zone have been required for routine blockage clearing. All clearing operations are conducted remotely by the operator from the designated safe position using the 5G wireless remote console. The mine's safety management team has formally reclassified the grizzly clearing task from a high-risk activity to a controlled remote operation, removing it from the site's critical risk register.

The elimination of this single task has had a measurable impact on the mine's overall safety performance metrics and has been cited by the mine's management as one of the most significant safety improvements implemented in the past five years.

Productivity: Blockage Clearing Time Reduced by Over 80%

The frequency of blockage events has not changed — that is determined by blast fragmentation, which is a separate operational variable. What has changed is the time required to resolve each event. Average clearing time has fallen from 45–120 minutes to 8–15 minutes per event, a reduction of over 80%.

Across a full operating year, the mine estimates that the BA300 has recovered 400 to 600 hours of underground production time that was previously lost to manual blockage clearing.

Operational Continuity: Ore Flow Stabilised

Beyond the direct time savings, the mine's underground loading supervisor reports a qualitative improvement in operational continuity. Because the operator can respond to a blockage within seconds of detection — without waiting for a safety clearance, a manual work crew, or a mobile equipment operator to become available — the underground ore flow has become significantly more predictable and consistent.

The downstream haulage and surface crushing circuit now operates with fewer unplanned interruptions from the underground loading stage, improving the overall efficiency of the mine's ore handling chain from stope to surface.

Operator Feedback

"Before, every time there was a big rock on the grizzly, we had to stop everything and send people down. It was slow and everyone knew it was dangerous. Now the operator just picks up the remote and breaks it from outside. It takes maybe ten minutes and we are running again. The team feels much safer and the shift runs much smoother."
— Underground Loading Supervisor, Laos Mine

Equipment Specification Summary

Why the BA300 Was the Right Choice for This Application

The YZH BA300 is specifically listed as suitable for grizzly screens and feeders, underground mining applications, and ore chutes — precisely the combination of requirements presented by this Laos project. Its heavy-duty construction, 360° slewing capability, and compatibility with 5G wireless remote control made it the most direct match for the mine's technical requirements.

The decision to configure the system with a 5G wireless remote control console — rather than a conventional wired panel or standard radio remote — was driven by the mine's existing 5G underground network infrastructure and the desire for maximum operator positioning flexibility. The 5G console provides low-latency control response, high-definition camera integration, and the ability to operate the system from the surface control room when required — capabilities that a conventional radio remote cannot match.

For operations considering a similar underground grizzly application, the BA300 with 5G remote control represents the current state of the art in remote rock breaking technology for underground ore handling systems.

About YZH

YZH has been manufacturing pedestal rock breaker boom systems since 2002. With over 3,000 units installed across 60+ countries, YZH supplies mining and quarrying operations ranging from small aggregate quarries to large-scale underground metallic ore mines.

The BA300 is part of YZH's B Series of heavy-duty pedestal rock breaker boom systems, designed for demanding primary crushing and ore handling applications. The full B Series range covers a wide spectrum of reach, payload, and hammer energy requirements.

For underground mining applications, YZH offers purpose-configured systems with electric HPUs, compact boom geometries for confined chamber installation, and advanced remote control options including 5G wireless console, standard radio remote, and wired panel control.

Interested in a Similar Solution for Your Underground Operation?

If your underground mine is managing grizzly screen blockages, ore pass obstructions, or crusher feed clearing with manual labour, the YZH BA300 — or another model from the B Series — may be the solution you need.

Contact our engineering team with your underground chamber dimensions, ore type, grizzly screen size, and remote control requirements. We will recommend the correct system configuration and provide a detailed quotation.

Phone / WhatsApp:+86-15610128027Email:yzh@breakerboomsystem.comOnline:Submit your project details here

View the YZH BA300 Product Page | View All Pedestal Rock Breaker Boom Systems