MMD - Mineral Sizing Equipment, Technology and Services

Mining Machinery Developments (MMD) designs and manufactures mineral sizing (crushing) equipment and services for the mining, metallurgical, industrial minerals, alumina and other industries.

The MMD group of companies was founded in 1978, to design and manufacture equipment for the UK underground coal mining industry. Today, MMD sizes over 60 different minerals worldwide, in many varied process industries.

Minerals processing technology and equipment

MMD provides minerals processing designs and equipment, utilising state-of-the-art technology, resources and materials, aimed at the optimisation of minerals processing systems.

The core products – mineral sizers (crushers) and feeders – offer a solution to problems such as variable ore properties, product requirements, site conditions and environmental issues. MMD aligns these against energy costs, maintenance costs, manpower cost and wear costs, to engineer a system designed with operability and maintainability.

Mineral crushers, feeder-breakers and sizing equipment

MMD sizing equipment is available for surface or underground installations, whether stationary or mobile, and for climatic conditions ranging from arctic to tropical. More than 2,000 installed sizers (crushers), feeder-breakers and feeders provide evidence of our experience and expertise.

Primary, secondary and tertiary sizers

MMD twin-shaft sizers were originally designed to meet the needs of the underground coal mining industry, where traditionally inline breakers had been used. The initial parameters were to design a machine to handle in excess of 1,500t/hr.

Within maximum dimensions of 1,200mm wide by 600mm high, it was necessary to size material accurately, deposit material in the centre of the conveyor belt, and for the machine to be lightweight and completely mobile, with all the breaking forces contained within the frame.

Another requirement was to pass conveyable material without further degradation. Also, if the machine stalled full of material, it must be capable of clearing the blockage quickly, to minimise downtime. Should uncrushable foreign material enter the sizer, it must be capable of withstanding the violent shock without suffering severe damage.

Having successfully achieved this within the demanding underground environment, it became evident that the sizer’s ability to process both hard, dry material, and wet, sticky material, could be applied to other underground and surface applications.

Mineral sizing equipment for underground mine and surface applications

Since 1978, MMD has refined and improved the sizer design, progressing from a 500mm centres machine, through to a 1,500mm centres machine, capable of over 10,000t/hr.

The MMD sizer range now includes primary, secondary and tertiary sizers for wet and dry processing of metallic and non-metallic minerals for mining, industrial minerals and quarrying industries.

Apron plate feeders for crushing plants

To complement the robust twin-shaft mineral sizer, MMD has designed and developed a range of heavy-duty apron plate feeders, which convey unbroken material to the crushing plant. Standard widths available are 1,500mm, 2,000mm, 3,000mm and 4,000mm on D4, D7, D9 and D11 Caterpillar-sealed and lubricated tractor chains.

These heavy-duty feeders are often arranged beneath tipping points and transport raw material to the crushing plant. Their combination of reliability and robustness has been proven to give many years of trouble-free operation with minimal maintenance.

In-pit mine crushing and conveying systems

In open-pit mines, the overburden of increasing thickness has to be stripped and dumped. The resulting effect is that larger volumes of mineral need to be mined and processed for the operation to be economically viable.

As pits get deeper, in-pit crushing and conveying (IPCC) systems will become the transportation of choice. IPCC has been with us for some time now, and many mine planners have already selected this design option over trucking.

Mobile and semi-mobile sizer systems for IPCC

The range of mobile and semi mobile sizer systems produced by MMD are both high capacity and compact with the added benefit of having a verifiable, successful track record stretching back over twenty years.

Just some of the significant milestones being:

• A ground breaking semi mobile unit which proved capable of handling up to 4,000tph of mixed overburden supplied to a customer in Spain to replace an existing gyratory unit in 1989 which was limited to just over 1,000tph
• A fully mobile unit capable of handling over 3000 t.p.h delivered to Canada in 1992
• Four semi-mobile installations capable of handling 4,500tph each delivered to Thailand in 1993 followed by a further three units each capable of 5,500tph each delivered to the same site in 2002 and a number of similar units being delivered to customers in China
• Fully mobile MMD modular units capable of 2000+ tph in hard limestone supplied to plants in Malaysia and Indonesia
• The largest fully mobile IPCC unit in the world, capable of in excess of 10,000tph supplied to a mine in Australia in 2002

The result of these years of experience culminating in the launch of the MMD LPMS Fully mobile mining system in 2010.

These energy-efficient, electrically driven, green mining solutions are all designed to assist mining companies to achieve the double bottom line of being both economic and environmentally friendly.