Assessment of performance and pick consumption of medium duty roadheaders driven in Amasra coalfield

In mining and tunnel excavations, various technologies have been developed in order to reach the goals in faster and more economic ways. In case the roadheaders are selected properly for the purpose of excavation, they would provide safe, flexible, portable and economical performances as well as a faster excavation. Their usability in formations having various rock strengths and in different cross sections provide a positive impact in mining and tunneling projects in terms of time and costs. In order to drive the development galleries in Amasra coalfield, which is the largest basin in Turkey, one DH R60T and two DH R75T model transverse type roadheaders have been purchased by Hattat Energy and Mining Company in 2015 and has begun to excavation. Three roadheaders advanced a total of 3182 m after 41 months of excavation until end of 2017 and recorded an average advance rate of 78 m/month. The average advance rate also varied between 19.7 m and 146 m per month. In this thesis, the performance of roadheaders in Amasra coalfield and a number of parameters such as pick consumption, instantaneous cutting rate, specific energy, and machine utilization ratio were evaluated based on the records derived from roadheader excavations. In addition, the effects of equivalence quartz content and metallurgical properties of different bits on bit consumption, CAI values, average grain size, Schmidt hardness values in the field and their influence on machine performance and specific energy were taken into consideration. In this context, the instantenous cutting rate of the machines ranged from 10 m3/h to 112 m3/h and the specific energy varied between 1,12 kWh /m3 and 7,19 kWh /m3. The average bit consumption in all machines was calculated to be 0,1 pick/m3. It was also found that the machine utilization ratio changed between 2.49% and 21.3%. The cobalt percentage of picks ranged from 4.11% to 11.31% and the wolfram percentage varied between 77.24% and 89.76%. Considering different types of rocks, bit consumption values were found to be between 0.002 – 0.737 pick/m3 while the quartz content ranged from 44% to 68%. According to these results, it was proved that the quartz and cobalt contents are significantly affects the bit consumption rate. Schmidt hammer test results obtained in the field showed that there is a reasonable correlation between the specific energy and instantaneous cutting rate. All these results will guide and shed light to the engineers who will drive a roadheader in another colliery located at the Zonguldak Hardcoal Basin in the future.