Modern Mining September 2015

PRODUCT News

On-site testing and emulsions solution for reactive ground

product suitable for use in reactive ground – an emulsion that is not affected by the sulphides encountered under such con- ditions,” said BME GM (South Africa) Albie Visser. The problem of reactive ground is often encountered when drilling in shale overburden on coal deposits and in the coal seams themselves. Fine sulphides cre- ated by drilling can dissolve in the water in the drill-hole, raising its acidity. This acidic water can in turn react with nor- mal emulsion explosive, causing it to heat up and potentially risk the performance of the blast – perhaps even resulting in unplanned detonation. The first prong of BME’s response was therefore to develop an emulsion that would not react under these conditions, further enhancing the safety of the blast environment. Emulsion products already boast a safety advantage, as they are not explosive until sensitised in the drill-hole; JBSS’s scope of supply includes eleven ‘Eagle Series’motor control centres, seven of which will be installed into modified marine containers and three on outdoor skids. Incomers are typically rated for 2 500 A at 525V, and fault levels up to 50 kA. Intelligent electronic overloads are used, and the com- munication protocol is Ethernet. Starter sizes vary between 4 kW and 250 kW. In addition, 16 remote I/O panels, 30 VSDs, 15 soft-starters, 14 DBs, 70 field isolators and a PLC panel will also be sup- plied by JBSS. JB Switchgear, tel (+27 11) 027-5804

up to that point, their status as a 5.1 oxi- diser makes them safe to transport and handle. “To establish whether there is reactive ground on the drill site, our customers must be able to test the ground conditions, but sending material for testing can be time-consuming,” said Visser. “So the sec- ond prong of our solution is a service that saves customers valuable time; we have developed our own in-house ‘tech-truck’, which includes mobile laboratory facilities that can be employed on site for testing of the ground to be blasted.” The BME team members first conduct a visual inspection of the site, applying their extensive experience of blasting in a range of different conditions. The possibility of reactive ground can often be indicated by white patches around the drill holes – resulting from the high acidity of water dissolving the sulphide fines. “If we suspect that the ground may be reactive, the tech-truck can be brought in to conduct laboratory testing on site,” Visser said. Results from these tests can indicate where reactive ground may present chal- lenges, avoiding the risk of discovering the problem only after the emulsion has been pumped into the drill holes. This ensures that blast planning schedules are met and production is not delayed by unforeseen blast-related challenges. BME’s innovative ‘portable laboratory’ has been developed based on research by universities in South Africa and Australia, to design and verify a testing procedure that is effective for dealing with reactive ground. BME, tel (+27 11) 709-8765

Rock that reacts with emulsion explosives can cause real headaches for blasting per- sonnel but BME’s double-edged solution allows customers to quickly identify reac- tive ground and apply the appropriate product. “Among the range of cold emulsions we have developed over the past 30 years is a BME has developed a double-edged solution that allows customers to quickly identify reactive ground and apply the appropriate product.

MCCs ordered for Lesotho diamond project JB Switchgear Solutions (JBSS) was recently awarded a multi-million rand contract for the design, manufacture and supply of motor control centres (MCCs) for the Liqhobong diamond mine in Lesotho. Well-known project house DRA placed the order on behalf of the client and manu- facturing is expected to be completed by March 2016.

The Liqhobong mine is located at the head of the Liqhobong valley in the Maloti mountains of northern Lesotho. Ownership of the mine is held by Firestone Diamonds (75 %) and the Lesotho Government (25 %).

52  MODERN MINING  September 2015