The Indian mining industry is going through a slow momentum, but there is a lot of scope for improvement, says SUBHAJIT CHAUDHURI, Vice-President-Sales & Projects of MMD Heavy Machinery (India) Private Limited.
India?s next mining boom is on its way as the present government is determined to revive the sector. A few emerging mining equipment technologies to watch out for in 2017.

In-Pit Sizing and Conveying (IPSC) is the emerging mining technology and the twin shaft mineral sizer is the emerging equipment to watch in 2017 and onwards. IPSC systems are a cost-effective and safer alternative to discontinuous material haulage by dump trucks; reducing operating costs, improving safety, and reducing CO2 emissions, dust, and noise pollution. Employing either fully mobile, semi-mobile or static sizer units in conjunction with conveyors, IPSC efficiently processes and transports material out of the mine.

The Indian mining industry is going through a slow momentum in the present scenario, but there is a lot of scope. Many minerals are yet to be exploited and I believe that the Government of India is working actively on this part. One big example is coal block allocation. The Ministry of Coal has very aggressive plans to achieve 1 billion tonnes of coal production by 2020 and thus new technologies such as IPSC solutions need to be adapted to achieve higher throughput. From my perspective, the mining industry has a very positive future. And of course, to increase the throughput capacity and reducing cost, adaptation of the best technology is very much needed. The implementation of fully mobile & semi-mobile IPSC system certainly will help in reducing the greenhouse emissions, saving the high cost of diesel, and maintaining safety during mining operations, all together. Mining can become more environmentally sustainable by developing and implementing the right technologies that reduce the environmental impact of mining operations.

The latest technology breakthrough in this domain.
Global mining is changing rapidly: rising costs, environmental pressures and health and safety have called time on traditional truck and shovel methods. As the industry becomes increasingly aware of the need for "Sustainable Mining", the ecological benefits derived from the elimination of dust and reduction of harmful greenhouse emissions caused by truck and shovel methods are self-evident. MMD?s innovative technology is at the forefront of this revolution.

For the ultimate in cost savings, environmental mining and portability, fully mobile Sizer units (fully mobile IPSC) enable the use of efficient conveyor haulage directly from the mine face. They move frequently to work directly with the excavator, whilst sizing and delivering conveyable material onto the conveyor haulage system, eliminating trucks and their associated costs, safety risks and environmental impact. MMD has, throughout its existence, developed purpose designed mobile units to suit any mining method and material. The whole range of Sizers can be incorporated into a wide range of transport options available to suit the duties and throughput required. Through the use of the well established components such as the twin shaft Sizer and heavy duty apron plate feeder, MMD Fully Mobile units deliver the reliability and robustness required for IPSC operations. Further Features / Benefits includes the followings,

• Throughput capacities up to and over 10,000 TPH
• Automated material handling
• Low carbon emissions and environmental impact by using all electrical power
• Operates in extreme weather conditions
• Maintenance friendly.

MMD has been producing semi-mobile IPSC units since the early 1980?s. It?s generally fed by a small fleet of trucks transporting material over short distances from the mine face. The Sizer unit reduces material in preparation for efficient conveyor haulage out of the mine. As the mining face progresses these units are relocated occasionally to minimise the truck haulage distance. Semi mobile sizer units leverage the flexibility of truck haulage together with the efficiency of conveyor haulage. This provides the ideal efficient solution for many mining scenarios where mining flexibility is vital, such as selective mining (blending), heavily faulted seams or irregular shaped ore bodies. Semi-Mobile units are constructed in easy-to-assemble modules that can be relocated closer to the mine face by the MMD Atlas Transporter. Through the use of the well established components such as the twin shaft Sizer and heavy duty apron plate feeder, MMD Semi Mobile units deliver the reliability and robustness required for IPSC operations.

MMD has, throughout its existence developed purpose designed units to suit any mining method and material as required. The whole range of Sizers can be incorporated into a wide range of transport options available to suit the duties required. MMD are the innovators of the product, which allows the flexibility of a mining shovel to be matched with the cost effectiveness of long distance conveyor haulage.

The 10,000 TPH Fully Mobile Sizer Station is a cost-effective engineering solution, which enables excavating, sizing and conveyor haulage process to take place in unison, along the mine face, advancing as it progresses. An obvious advantage of this system is the elimination of haul trucks in a truck and shovel operation. The Fully Mobile Sizer Station has many attributes and features to enable consistent efficient operation of the complete system.

Why should the MMD Sizer be considered?
The operating principles of MMD Twin Shaft Mineral Sizer provide various unique advantages which is inevitable for green mining solutions.

MMD Sizing Technology:
The basic concept of the MMD Sizer is the use of two rotors with large teeth, on small diameter shafts, driven at a low speed by a direct high torque drive system. This design produces three major principles which all interact when breaking materials using Sizer Technology. The unique principles are; The Three Stage Breaking Action, the Rotating Screen Effect, and the Deep Scroll Tooth Pattern.

Accurate Sizing: Three-Stage Breaking Action

The Rotating Screen effects
The interlaced toothed rotor design allows free flowing undersize material to pass through the continuously changing gaps generated by the relatively slow moving shafts.

The Deep Scroll Tooth Pattern
The deep scroll conveys the larger material to one end of the machine and helps to spread the feed across the full length of the rotors. This feature can be used to reject oversize material from the machine.

With large teeth and small shaft diameters the material is gripped and broken in shear rather than compression force resulting in much lower energy consumption. Absorbed power is 55 per cent on installed power.

The deep scroll tooth pattern acts as a rotating screen allowing already undersize material to pass without any further size degradation or power usage. MMD Sizer technology produces the minimum fines.

MMD Sizer is also the only solution to handle wet & sticky situations with high moisture content in the material.

Minimum Space requirement
Sizer was invented the company?s founder, Alan Potts to facilitate British underground coal mine where space was a constraint. The machine is very compact and requires minimum space to install.

Minimum downtime MMD Sizer requires minimum downtime; the complete single set of worn-out components can be replaced within one to two shifts in the same day. This minimum downtime increases productivity significantly.

Steel structural support
All gearboxes are mounted on the Sizer itself, resulting in correct alignment at all times and does not require a support frame or separate structure. The MMD Heavy Duty Gearbox is specially designed to facilitate the MMD Sizer only. On a twin-drive machine, the gearboxes are mounted on the same end of the Sizer, allowing inline or perpendicular installation without restricting maintenance access to drives.

The robust MMD Heavy Duty Gearbox has been in operation for decades. MMD has more than 4,500 successful global installations worldwide with over 80 different minerals worldwide. The company has more than 350 customers with repeat orders.

Lesser Installation Cost

• Only levelled & compacted civil bed is required depending on the arrangement;
• Due to lesser height & compact size, minimum headroom is required for maintenance;
• Minimum chute work and no heavy structural steel support is required; hence, minimum manpower is required to install the machine;
• Machine Installation time is less (within a day) subject to availability of adequate resources;
• No special tools & tackles required during erection & commissioning; Operational expenditure is very less:
• Electrical consumption is very low.
• Very less spares consumption.
• Consumables requirement is very low.

About the author
Subhajit Chaudhuri, a Mechanical Engineer, is Vice-President-Sales & Projects of MMD Heavy Machinery (India) Private Limited, a part of the MMD Group of Companies, UK. He has worked in different business segments including auto-ancillaries, distillation & brewery and water management, material handling, mineral processing & mining.