New hammer rocks

The Svappavaara region, in the far  north of Sweden, is mining company LKAB's newest and fastest growing mining area. Located  above the Arctic Circle, Svappavaara has three open pit mines  – Mertainen, Leveäniemi and Gruvberget – with Gruvberget as the cor-nerstone of a plan to increase deliveries of iron ore pellets to 37 Mt/y by 2015.

Its mission is to produce two million tonnes of magnetite and hematite ore annu-ally, giving it an approximate life span of eight years, although geologists say that it may be possible to continue mining here beyond 2018.

In its efforts to reach the goal, Gruvberget uses Atlas Copco equipment for all its drill-ing and blasting, including drill rigs for both tophammer and down-the-hole work with DTH hammers, with all rock drilling tools supplied by Atlas Copco Secoroc.

The mine’s iron ore is a tough chal-lenge and the equipment is subjected to constant wear and tear. However, things have improved considerably over the past year with the arrival on site of a brand new type of DTH hammer – COP 66. It is Secoroc’s newest addition to the COP family and is the successor to the well established and widely used COP 64 Gold.

COP 64 Gold has a solid reputation for speed, reliability and productivity, which has made it a firm favorite among drilling and blasting companies for more than a decade. It was therefore not without some scepticism that the drillers at Gruvberget put the newest addition to the test.

COP 66 was introduced as “a new inno-vation in platform design – faster, lighter and more economical”. It is designed for drilling 165–171 mm holes with a drill bit equipped with 16 or 19 mm buttons, with-out a center flushing hole, and operates with air pressures up to 30 bar. The drillers at Gruvberget wanted to see for themselves if the hammer could live up to its description in their mine environment where rock hardness reaches 300 MPa.
In order to reach the iron ore, a substan-tial amount of waste rock has to be removed – approximately 9 Mt annually. This is achieved by a fleet of three Atlas Copco SmartROC D65 drill rigs, three FlexiROC F9 rigs and one FlexiROC D9.
Leif Kemi, Production Manager and Senior Advisor at Gruvberget, explained that the ore contains high concentrations of iron, up to 65%, and that the mine has been relying more on DTH rather than topham-mer drilling simply because in these condi-tions DTH tends to be more efficient.
Kemi explains: “After using the COP 64 Gold for many years we were not sure what to expect from the COP 66 but it has made a big difference. It’s lighter and shorter which makes it much easier for the guys to handle, but above all it is much faster. This has enabled us to increase our productivity most likely by 15 to 20 percent – and that’s a lot of money saved.”

Epiroc operated under the trademark “Atlas Copco” prior to January 1, 2018.