The second challenge is the working environment i.e the health and safety of the sampling personnel – sampling at the drill end in the “waterfall” is neither pleasant nor a safe job.
IMA has solved the sample representativeness issue with the Autosampler’s rotating distributor which spreads the wet cuttings evenly on a cone splitter with a sampling chute resulting in representative samples. Sample split ratio can be adjusted from 1% to 25%.
The wet samples are collected into longitudinal sock type bags made of filter fabric. The fabric lets the water to seep through keeping the sample in the sock without loosing fine particles with the water flow. The cuttings are collected from the hole collar by a funnel mounted on the boom front end. Drill cuttings are delivered to the Autosampler via a hose.
See below pictures of the Autosampler mounted on an Epiroc Cabletec drill in a gold mine.
Autosampler has chutes for 8 sample bags. Sample change is done by a remote control unit located in a comfortable and safe place in the drill operators cabin. Only after eight samples are taken the driller needs to go out to change for a new set of sample bags.
The remote control has also a by-pass function with which all the cuttings flow is directed to rejects passing the sample bags. This is to avoid excessive water entering the sample bag when starting the hole or when changing drill rods.
Further, with the remote control unit you can start and stop the sampling function from the cabin at any time while drilling.