Hi Mr 47,
TTC is correct when saying RC drilling is faster and cheaper, but is also gives a less accurate sample of the sections per sae.
A pre-collar is just terminology that is used to describe an RC hole drillied before a diamond drill (coring) hole is then extended from that RC (pre-collared) hole.
Diamond drill core is a far much more representative (and far more expensive - probably 600-700% more), relevant and accurate sample of what is accurately drilled. Given 100% core recovery it is 99.99% representative.....and human error would make up that other .01%.
An RC sample for example is bagged off in approxiamtely 1m samples that are blown via high pressure air back up, through the rod string (drill rods), then through a cyclone and bagged up as nothing more than pulversided rock samples in calico bags. A rather impricise sampling method compared to diamond drill core sampling/drilling.
Because of poor surface ground conditions and target ore bodies quite often being at depth, you will often here of holes being drilled, 'RC with diamond tails'....and this refers to the exactly same thing Jutt will be continuing on with and commencing in late July. That is, they will be drilling diamond core (tails) and extending the R.C holes previously drilled in the campaign just finished.
Hope this helps.
Cheers.
K-Man.
Disclosure: I am a diamond drilling supervisor in China with 12+ years experience (albeit underground), but with little RC drilling knowledge.
JUT
jutt holdings limited
