Maurice Jones reports on the problems of efficient supplies transport and handling system
Selecting supplies transport and handling system to suit all requirements can be one of the trickiest problems in underground mining.
The typical method study engineer’s answer would be to try and eliminate or minimise the problem by cutting the amount and variety of supplies required. Depending on the ground conditions and mining method it may, for example, only be necessary to ship in sufficient quantity of rock bolts, but mining life is rarely that easy.
Supplies required to be transported to the mining district can range in size and weight from detonators to powered supports. Clearly then, a major requirement of most mines will be maximum versatility in safe supplies transport. There may also be other considerations such as security (eg, for explosives and detonators), critical delivery times (for mixed concrete etc.), and cleanliness for machine service parts. Frequent and/or bulk requirements are likely to be best transported by rail rolling stock, but in small mines or for varied requirements, trackless vehicles are likely to be preferred. The types of connection to the surface will also be a major factor, ie incline or vertical shaft, although these will be decided largely by the depth of the mine and mineral haulage needs.
Traditionally the usual means of supplies transport would be carrying the material in a mine tub or on a flat car for manual handling at the delivery or transfer point, perhaps with a manual chain hoist if the miners were lucky. With the advent of more definitive safety regulations relevant to materials handling stage of materials transport and handling involving miners has to be analysed for risk.
Slide-on/slide-off cassette system
The Normet range of mobile plant from Finland includes versatility as a major theme through most of its models. The Normet Utimec models are, however, dedicated vehicles requiring full carriers, such as the MF and LF series of concrete mix carriers. The Multimec system features a slide-on/slide-off cassette system to vary the carrier’s purpose to sit different loads. Similarly the Variomec models have interchangeable work modules but with different means of changeover.
Concrete transport presents a particular challenge in that the material must be kept workable until needed, and in the required quality. This may be aided by the use of special mix additives but means of transport also plays a part. For relatively short distances or wait times pumping or conventional bulk cars may be used, but remixer trucks on rail rolling stock or trackless carriers offer more controlled conditions over greater distances.
For example the Normet Variomec MF 060 M features an articulated carrier for easier manoeuvrability. The work modules can be a concrete remixer that can be interchanged with a dumper for rock haulage or an access boom for lifting. Changeover using standardised connections takes around two hours. The MF 050 M has a 4.4-m3 concrete drum capacity.
Image: (Normet Variomec MGF 060 D – 71kB) Part of the Normet Variomec M-series, the MF 060 D with interchangeable dumper body and an articulated carrier
Images: SPRAYMEC 1050 WP(C) Caption: Diesel or electro -hydraulic spraying equipment with articulated steering for underground mining with medium or large mine tunnels
Image: (Multimec_MF_100_cover ) The MULTIMEC MF 100: Multimec provides an innovative system for material transport in mines: a multipurpose system that allows the operator to perform several jobs with only one vehicle
Image (Utimec_MF500_Transmixer_lr) Utimec MF 500 Transmixer with practical concrete transport capacity of 4.4 m3 is designed for concrete transportation in underground mines and tunnels where tramming height is 2.4 m (8.0 feet) or more
Video: http://youtu.be/1mont2XH5Jw Caption: Concrete transport presents a particular challenge in that the material must be kept workable until needed, and in the required quality
Video: http://youtu.be/oocvrvlwLBk Caption: Normet's Multimec system features a slide-on/slide-off cassette system to vary the carrier’s purpose to sit different loads
Better images requested from Normet