In mines, quarries, and blast sites there are sometimes areas where the drilled blast holes tend to collapse. In many cases, these holes cannot be used for blasting, which causes serious issues like leaving too big blast stones which need to be redrilled and blasted again. Using of casings in these most problematic areas would solve the issue. However, steel casings cannot be used as a high amount of steel is not allowed among the blast stones due to the crushers.
The latest development from TerraRoc has solved this problem. By using plastic casings in these highly fractured areas it is possible to support the holes and prevent them from collapsing providing a significant time-saving.
Plastic casings do not harm the crushers and thus can be used without issues. The low amount of steel from the ring bits can be taken away from the blasted stone for example with a magnet.
Terraroc says Installation of the plastic casings is simple. The application can be done with almost any drill rig with minor adjustments and after some basic training for the driller, anyone can install plastic casings.
To drill fast and efficient, the system has been designed to directly drill the blast hole after installing the casing with its drill-through pilot bit. With this feature, the whole process of installing casing and drilling the blast hole can be done with the same rig and in one go.
The system is proof tested in arctic environment showing its capabilities even in extreme -30C conditions.
The main benefits of Model D are also the possibility to modify the system to suit different needs in different locations for example based on the blast hole diameter to length of the casing.
It can be used in all applications with short-cased depth and medium-deep open rock hole below the casing. Best are applications where the casing is drilled single pass i.e. cased depth is maximum of rig feed length. There is no limitation to the rock hole depth, but practical depth is between 0-20m. The system can be used with both DTH and top-hammer equipment.
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