Pilot-Plant Classification of Stockpiled Material from the Larson Quarry

Abstract

J. L. Shiely Company has contracted the Natural Resources Research Institute (NRRI) to conduct pilot-plant studies to confirm previous laboratory tests on the classification of minus 3/8-inch material from the Larson Quarry, and to develop the equipment requirements for a commercial plant. In addition NRRI was asked to conduct preliminary tests on a minus 3/32-inch product to determine if this finer feed could be treated in the same equipment as the minus 3/8-inch feed. The pilot-plant tests confirmed the laboratory predictions as to product size and weight recovery. The minus 200- mesh portion of the material supplied for the pilot-plant tests had a much slower settling rate than the previous material which necessitated the use of a flucculent to produce a recycleable thickener overflow. While a successful flocculent was found it may not be the most cost effective and others should be tested. The pilot-plant tests showed that the classification is relatively insensitive to feed rate or percent solids as long as the sand carrying capacity of the machine has not been exceeded.