What is Channel Sampling?
In this sampling a channel is cut across the face of the exposed ore, and the resultant cuttings and chips are collected as sample. The surface to be sampled is first cleaned to remove dust, soluble particle, etc. A thin layer of the exposed ore may be removed to avoid cutting the weathered ore. Then a channel outline, 5 – 10 cm in width and extending from the foot wall to the hanging wall of the ore body, is drawn by a chalk or paint.
Then, the channel is cut by a moil and hammer to a depth which should be equal to the width. The resultant pieces are collected carefully on a clean sheet of canvas or any other convenient receptacle. The sides and the floor of the channel should be smooth and uniform so that over cutting (and over representation) is effectively minimized. The channel may be divided into 1 to 2 m section or their multiples in the case of massive and more homogeneous ore bodies, or section of 30 to 50 cm in the case of more heterogeneous distribution and may be separated as per the physical characteristics of the ore.