TY - THES

T1 - Diesel vs. Electric Rotary Blasthole Drills

AU - Mijic, Carsten

N1 - embargoed until null

PY - 2011

Y1 - 2011

N2 - Rotary drill rigs are typically used in surface mining applications for main production blasthole drilling. Currently they are powered by diesel engines or via electric motor and external electric power source and associated cabling. To date, electric powered drills have been limited to the larger sized (90,000 lbs of pulldown and up) machines, typically with machine weights over 100 tonnes. As energy costs increase and mines are looking to increase their environmental awareness, there is renewed interested from the market place in increased electric drill options. The major drill supplier of Sandvik, Atlas Copco and Bucyrus now offer electric options on drills as small as 50,000 lbs. The question in the market place remains, would you choose diesel or electric drills for your particular application? To determine this, site data, supplier information, and drill performance were evaluated to compare operational performance between drill types and mine sites. Technical variations such as feed mechanism were investigated to confirm their effect on performance. Costing and application models were developed to estimate and compare performance of drills for multiple scenarios and to evaluate the most cost effective drilling solutions. Rack and pinion feed systems were found to be slower than rope or chain feed drills, though they did typically achieve a higher bit life. In many cases though, rope or rack and pinion feeds achieved a lower total drill cost. Energy costs were found to be significantly lower for electric drills, by nearly a factor of 4 in some cases. However, CO2 emissions were far higher for electric drills when assuming a coal fired electricity supply. The Sandvik compressor management system was found to greatly reduce fuel consumption and CO2 emissions on tests conducted thus far with similar savings on electric and diesel powered drills. Drill availability and utilisation was found to very comparable between drill types and appeared to more of a site specific parameter than drill specific. Total operating costs per hour for electric drills were found to be lower than a similar sized diesel drill, mainly due to the lower energy costs, and the reduced complexity of electric motors compared with large diesel engines. Costing estimates by application suggested that diesel drills were more productive in all rock types, but electric drills were cheaper. In soft formations, diesel drills would be preferred, with electric preferred in medium and hard formations. Overall, selecting the correct type of drill depends on a variety of factors including; safety drill application, location, mine geology, hole size, energy costs, and site technical ability. These factors all need to be balanced to give the best possible solution.

AB - Rotary drill rigs are typically used in surface mining applications for main production blasthole drilling. Currently they are powered by diesel engines or via electric motor and external electric power source and associated cabling. To date, electric powered drills have been limited to the larger sized (90,000 lbs of pulldown and up) machines, typically with machine weights over 100 tonnes. As energy costs increase and mines are looking to increase their environmental awareness, there is renewed interested from the market place in increased electric drill options. The major drill supplier of Sandvik, Atlas Copco and Bucyrus now offer electric options on drills as small as 50,000 lbs. The question in the market place remains, would you choose diesel or electric drills for your particular application? To determine this, site data, supplier information, and drill performance were evaluated to compare operational performance between drill types and mine sites. Technical variations such as feed mechanism were investigated to confirm their effect on performance. Costing and application models were developed to estimate and compare performance of drills for multiple scenarios and to evaluate the most cost effective drilling solutions. Rack and pinion feed systems were found to be slower than rope or chain feed drills, though they did typically achieve a higher bit life. In many cases though, rope or rack and pinion feeds achieved a lower total drill cost. Energy costs were found to be significantly lower for electric drills, by nearly a factor of 4 in some cases. However, CO2 emissions were far higher for electric drills when assuming a coal fired electricity supply. The Sandvik compressor management system was found to greatly reduce fuel consumption and CO2 emissions on tests conducted thus far with similar savings on electric and diesel powered drills. Drill availability and utilisation was found to very comparable between drill types and appeared to more of a site specific parameter than drill specific. Total operating costs per hour for electric drills were found to be lower than a similar sized diesel drill, mainly due to the lower energy costs, and the reduced complexity of electric motors compared with large diesel engines. Costing estimates by application suggested that diesel drills were more productive in all rock types, but electric drills were cheaper. In soft formations, diesel drills would be preferred, with electric preferred in medium and hard formations. Overall, selecting the correct type of drill depends on a variety of factors including; safety drill application, location, mine geology, hole size, energy costs, and site technical ability. These factors all need to be balanced to give the best possible solution.

M3 - Master's Thesis (University Course)

ER -