Compact design, controlled material reduction and application-specific engineering help MMD Group address the challenges of underground mining.
Underground mining places unique demands on crushing and material handling equipment. Restricted installation space, variable ore characteristics and the need to maintain reliable production all influence equipment selection. For MMD Group, these challenges have shaped the development of its Mineral Sizer technology, providing mining operations with an efficient, engineered approach to material reduction.
A Technology Born Underground
MMD’s roots lie in underground mining. Founded in 1978 to develop equipment for the UK coal industry, the company introduced its patented twin-shaft Mineral Sizer in 1980. The technology was developed to address practical material handling challenges, with compact equipment capable of breaking down large lumps and helping prevent blockages in conveyor systems.
Today, MMD Sizer™ are used across a wide range of mining applications, from coal and industrial minerals to hard-rock operations. Their continued development reflects the company’s focus on adapting proven technology to changing materials, operating conditions and production requirements.
Designed for Space-Constrained Operations
Space is a critical consideration underground, where equipment must integrate with existing infrastructure, access routes and material handling systems. The MMD Sizer’s compact, low-profile design provides flexibility when planning crushing and sizing installations.
Its twin counter-rotating shafts are fitted with specially engineered teeth that grip incoming material and exploit its natural weaknesses. Rather than relying primarily on compression, the Sizer uses bending, tensile and shear forces to break material progressively.
This controlled action helps deliver a consistent product with minimal fines, supporting efficient downstream conveying and processing. By allowing suitably sized material to pass through without unnecessary further breakage, the technology can also help reduce wear and energy consumption.
Handling Variable Ore Conditions
For underground operators, material characteristics can vary considerably across an orebody. Hard, abrasive rock presents different challenges from softer, wetter or more cohesive material, requiring equipment designed around the specific application.
MMD™ has developed its Sizer technology to handle a broad range of materials, including demanding hard-rock applications. Specialist tooth designs, heavy-duty shafts, bearings and gearboxes can be incorporated to suit the forces and wear conditions associated with harder ores.
The technology is also well suited to wet and sticky materials, where conventional crushing arrangements may experience material build-up. The Sizer’s continuous agitation and tooth configuration help limit accumulation, with additional features such as side cleaning combs available where required.
Engineering for Reliable Production
Ultimately, successful underground sizing depends on more than the machine alone. Equipment selection must consider feed characteristics, throughput targets, product specifications, installation constraints and maintenance requirements.
MMD combines its established Sizer technology with application-specific engineering to develop solutions around these operational priorities. For underground mines seeking controlled reduction, efficient material handling and dependable performance, this approach provides a practical foundation for improving productivity and supporting long-term operational efficiency.
With a heritage rooted in underground mining and experience spanning diverse minerals and operating environments, MMD continues to develop sizing solutions designed around the realities of modern mining.
To find out more, contact MMD Group via the website https://www.mmdsizers.com/contact
