Boliden Kylylahti Oy has an underground mine in Kylylahti, Polvijärvi. About 650,000 tons of ore is mined every year. There has been mining industry over a hundred years and three different copper-zinc-gold-nickel-cobalt mines have had production in the area over the years 1914 - 1989.The Kylylahti mine began production in the year 2012. The mine constantly seeks development in work safety and increase in production performance. The mine has been using impulse primers so far. Electronic primers have been used to explode large lids. Electronic primers require its own firing system, which Kylylahti does not have. The programming and exploding services have been outsourced to another company. The goal of this thesis was to examine possibilities to decrease production costs by using electronic primers instead of impulse primers, to increase work safety and the feasibility of investing in the firing system.

The impacts of impulse and digi primers for loading effectivity, tremors and quarry holes openness were examined in this thesis. The scan results were used to evaluate if different primer types had impact on ore losses or over quarrying. It was also examined if the expensive equipment of electronic primers and the unit prices could be compensated due to larger explosions and omission of work stages compared to impulse primers.

According to the results there was no significant difference in tremor measurements or scan results regardless the different primer type. Tremors were minor in the mine and quarry quality was good in most cases. According to scan results the most significant aberration was caused by the quality of the rock. There was a significant increase in the loading effectivity by using electronic primers. Due to smaller grain size and larger explosions more rock could be loaded without interruption. By using electronic primers is was possible to decrease stages about three to four times compared to earlier. Due to larger explosions, decreased stages compensate the more expensive unit prices of the electronic primers’. According to the research the company`s own firing system would paid itself back in a year.

According to the total results using electronic primers together with impulse primers proved to be rational. To use electronic primers would be necessary for exploding large lids, in challenging quarry environments and in large quarry productions. Using impulse primers is still more cost-effective in most cases. To buy a firing system for the company would be financially reasonable.