Birtley coal picker
An electric picker that distinguishes between good coal and slate by their different electrical conductivities. It is said to be more accurate than the human slate picker, who, when fatigued, may fail to remove all the impure material. Mitchell
Source: Dictionary of Mining, Mineral, and Related Terms
Sponsor: Buy Advantage for Dogs at lowest price today. Get Extra 12% Off with Coupon Code-BESTMF12 + Free Shipping on all orders across USA. Limited Offer, Hurry Shop Now!