GB1176152A - Improvements in or relating to Horizontal Classifiers - Google Patents

Abstract

1,176,152. Washing granular materials. WILKINSON RUBBER LINATEX Ltd. 23 Nov., 1967 [28 Nov., 1966; 27 Oct., 1967], Nos. 53176/66 and 48972/67. Heading B2H. A horizontal classifier for separating waterborne particulate material, e.g. mineral ore or sand, into different fractions comprises a closed launder to which the water-borne material is fed under pressure via an inlet section which diverges to the width of the launder in the direction of flow, and at least two receiving means for the reception of the different fractions of the material at least one of the receiving means being a hutch on the underside of the launder. In Fig. 1, a launder 17 is connected to a feed pipe 11 by means of a divergent inlet section 14, Fig. 2 (not shown). A valve-controlled clear water pipe 12 opens into the feed pipe 11. The underside of the launder is connected to hutches 20, 21 for the reception of respectively the heavy or coarse and light or fine particles. The hutches are connected to discharge pipes 24, 27, to the horizontal portions 24a, 27b of which are connected valve-controlled clear water pipes 25, 30. The portions 24a, 27b may be connected to hydrocyclones. An outlet section 31 converging to an outlet pipe 34 is connected to the launder 17. A pivotable vane 37 controlled by a wheel 38 is mounted near the mouth of the launder to direct a greater or lesser proportion of solids to the first hutch 20. Even distribution of material to the mouth of the launder may be ensured by vertical vanes (not shown) fixed to the floor of the inlet section 14 and by a cellular distributor preferably disposed at the mouth of the launder. In operation, a mixture of water and particulate material is pumped through the feed pipe 11 and is joined by clear water delivered through the pipe 12. The different fractions of the material are collected in the hutches. 20, 21 and dewatered in the hydrocyclones connected thereto. The slimes or very light or fine particles pass to waste through the section 31 and pipe 34. Alteration of the grading of the material may be effected by altering the output of the pump delivering the mixture; by controlling the flow of clean water through the pipe 12; and by controlling the flow of clean water through the pipes 25, 30, this latter measure having the effect of slowing down or accelerating the settling of the different fractions in the hutches 20, 21 thereby permitting more or less material being carried over in the water stream from the hutch 20 to the hutch 21 and from the latter to the section 31. In a modification, Fig. 4, a single hutch 45 is connected to the launder 41, the fine or light particles being discharged through an outlet section 44. The curved inlet section 43 is divided into upper and lower ducts 53, 54 through which are respectively pumped the water particulate material mixture and clear water.