Reverse Circulation Rotary Clause Samples
Reverse Circulation Rotary. During the drilling process, cuttings from the bit are sent up the drill pipe and initially into a cyclone for homogenization and mixing. From the cyclone, cuttings are fed into a rotary splitter that takes a representative split (usually a ¼ split), sending one split portion to the sample port, and the larger through the reject port. Cuttings are placed in 10” x 17” sample bags that are clearly marked using the drill hole number and a numeric sequence prepared beforehand using a spreadsheet. An example of the sampler’s logging sheet is included as Appendix 12-1, Sample Sequence). This sheet is used to track bag numbers and footages, standards, blanks, and duplicates. A small portion of sample is also kept for logging purposes and is placed in a chip tray compartment that is clearly marked as to footage and sample number.
Reverse Circulation Rotary. The normal truck-mounted reverse circulation drill in Nevada uses 20’ drill rods, and the sampler collects 1 sample every 5’. Such was the case with the Atna drill program. Samples were submitted for assay, as collected on the rig, in addition standards, blanks and duplicates were inserted into the sample sequence as described below in 12.5, 12.6, and 12.7.
Reverse Circulation Rotary. Reverse circulation sample recovery was excellent, with full 5-10-lb. bags collected from every interval of every hole, with the exception of about 15 samples in the entire Atna set of approximately 6100 samples. The missing samples occurred in isolated zones of badly broken ground.