Sheldon S.,Orica Mining Services
AusIMM Bulletin | Year: 2011
Scott Sheldon discusses how to assign value to a drill and blast wall control program through reduction in the risk profile. A typical drill and blast improvement program involves changing one or more parameters in the drill and blast process and measuring the impact this change has on the operation. Reaching final pit limits, achieving optimal wall angles, a reduction in the likelihood of wall slips or failures, a reduction in time spent battering down a wall, and not having to introduce remote equipment to work under high risk walls are examples of an economic benefit from a wall control program. The costs involved in cleaning up and remediating wall slips and failures, from loss of resource, single lane ramps, using remote equipment and so on can range from significant to catastrophic. A risk rating is then calculated for the event. If this risk rating is deemed unacceptable then risk mitigation measures are identified and the consequence and likelihood of the event reassessed on the basis of having applied these mitigation measures.
Ouchterlony F.,Lulea University of Technology |
Olsson M.,Lulea University of Technology |
Svard J.,Orica Mining Services
Rock Fragmentation by Blasting - Proceedings of the 9th International Symposium on Rock Fragmentation by Blasting, FRAGBLAST 9 | Year: 2010
The crack patterns from contour blasting in Ø48-mm holes with Orica/Dyno Nobel SSE 0.35, 0.5 or 0.9 kg/m string emulsion charges in the Bårarp gneiss quarry have been studied, using both Nonel and electronic detonators. Some 24 blocks from behind half-casts were sawn and the cracks mapped. The crack lengths caused by simultaneously initiated SSE 0.35 kg/m or packaged Ø17 mm Dynotex 1 were practically the same. SSE 0.5 kg/m gave a roughly 50% increase in length. Nonel initiation resulted in longer cracks, as did water-filled holes. Nonel also gave a rougher remaining rock surface and frequently undetonated charges were found on the muck-pile. Earlier damage zone data were used to develop a suggested addendum to the present Swedish damage zone table. The use of simultaneously initiated decoupled light contour charges (q < 0.6 kg DxM/m) in dry holes has a damage suppressing effect compared to normal pyrotechnic initiation. © 2010 Taylor & Francis Group.
Lawrence J.,Orica Mining Services
Mining Magazine | Year: 2011
Coal & Allied engaged Orica Mining Services to conduct an advanced vibration-management project that would allow it to maintain an efficient mining process, while keeping vibration to agreed levels. The company aimed to conduct blasts within 40m of a high-tension tower, which could supply electricity to a major city. Orica designed the blast pattern for a series of four blasts, using Orica's SHOTPIus-i design software. For each planned blast, the engineers modeled the vibration levels and the probability of exceeding the limit. Hunter Valley Operations and Orica successfully fired four blasts in the first stage of the project. The vibration levels for each blast were below the agreed limit for the high tension tower of 50mm/sec. In the case of wall control, advanced blasting technology reduced overall risk by maintaining the integrity of walls to ensure safe operation, while at the same time increasing production.
Brent G.F.,Orica Mining Services
International Journal of Mining, Reclamation and Environment | Year: 2011
Life cycle management can assist the mining industry in meeting its stated sustainability commitments. This paper demonstrates how sustainability metrics formulated from a life cycle perspective can be quantified at the operational level using a process model of open cut coal strip mining. An understanding of the material and energy flows of a working pit enables the identification of key areas to target for improvement. The effect of operational changes can also be modelled to determine changes in overall mine sustainability metrics, whether they are more local in nature, such as respirable particulates, or of global concern, such as greenhouse gas emissions. This can facilitate the adoption of more eco-efficient methods of operation, particularly where the focus is on maximising the output of the mine's ultimate utility; namely energy. An example is presented of a more ecoefficient method of blasting which reduces in-pit coal losses. © 2011 Taylor & Francis.
Hamilton C.,Stawell Gold Mines |
Degay Jr. B.,Orica Mining Services
11th AusIMM Underground Operators' Conference 2011, Proceedings | Year: 2011
Stawell Gold Mines (SGM) is an underground mining operation located in Victoria, Australia. The mining method employed is long hole retreat stoping, utilising up and downholes and artificial concrete pillars. Stawell is currently mining the Golden Gift and Magdala orebodies. Access to the Magdala and Golden Gift deposits is via 6.0 m wide by 5.5 m high declines developed at a gradient of one in eight to one in seven from the surface to a depth of 1500 m, with a planned depth of 1650 m. From the declines, cross cutting drives are developed to intersect the orebodies. Orebodies in the Gift system are discrete lodes which are generally mined from a bottom up centre retreat to minimise geotechnical stresses. Ore development fronts are currently located between 1000 m and 1500 m below surface, with all ore being hauled to the surface using a fleet of 60 tonne underground trucks. With the use of conventional pyrotechnic long period (LP) delays, broken rock of combined ore and waste is thrown 10 m from the face and the materials hauled to the surface. The majority of the mullock from development is consumed in the underground as backfill. With the use of Orica Mining Services eDev™ Electronic Blasting System for Tunnelling, the waste is thrown up to 40 m from the face, while majority of the ore is left 5 - 10 m from the face, effectively segregating ore and waste. This enables significant recovery of gold values with minimal loss and significantly reduced dilution. By using this technique in ore drives with a 30:70 waste to ore ratio, SGM is able to haul 24 000 tonnes less mullock to the surface annually. Resue mining is applied to narrow vein headings and gives a 40 per cent grade increase at the faces as well as increasing the economic footprint of development. This will also contribute to an improved grade profile for the year from 3.98 - 4.16 g/t Au and allow extra capacity for ore haulage from stoping and for milling. This paper describes the application and the successful blast outcomes achieved using the eDev™ Electronic Blasting Systems for resue mining at SGM. Results to date, since commencement in March 2010, have been achieving significant benefits in terms of ore grade as confirmed by geologists grab sample grades. Face advance have also shown improvement with better breakage of perimeter holes giving improved face profile. These benefits are delivering increased productivity and safety performance when compared to other resue firing techniques.