GB461249A - Improvements in or relating to methods of and means for classifying ores - Google Patents

Abstract

461,249. Wet-separating apparatus. DAMAN, A. C. Aug. 9, 1935, No. 22540. [Class 82 (ii)] Ore pulp is fed to a primary classifying vessel and subjected therein to agitation and aeration, the finer matter in suspension being directed upwardly to a point of overflow and the coarse material being permitted or induced to settle in a quiescent zone located beneath the agitation zone and being discharged from the primary classifying vessel and subjected to a second classification or dewatering treatment whilst being conveyed upwardly to a point of discharge. The primary classification is effected in an element A comprising a circular weir 6 having an adjustable rim 8. Pulp fed by a launder 12 passes between concentric tubes 9, 10 to the lower portion of the vessel 5. The tubes 9, 10 are rigidly connected by cross tubes 15 and an apertured flange 16 and are driven by a worm wheel 13. The tube 10 has an enlargement 17 to receive the pulp from the launder and shields 18 to direct upwardly moving material into the cross tubes 15. Apertures 19 in the tube 9 are controlled by a slide valve 20 to vary the amount of pulp and air passing into the inner tube. An impeller 22, carried by a central vertical shaft 21, is housed in a conical baffle 24 carried by the tubes 9, 10. A stationary baffle 26 overlaps the baffle 24. Scrapers 27 are connected with the baffle 24 or may be carried by a vertically adjustable ring 35 around the mouth 17 of the feed tube. An element B, serving as a secondary classifier or dewatering element and as a conveyer, comprises a tube connected by a flexible elbow 30 with the outlet 7 of the element A : sand discharges at 31. A vibratory movement, which may be differential, is imparted to the element B and, if desired, to the element A, by electric vibrators 32. Water is supplied at 33 and, if desired, at 34. Oversize material discharged at 31 may be conducted to a ball mill and returned to the apparatus. The impeller functions in conjunction with the tubes 9, 10 as an aerator by the creation of a vortex. The apparatus may be used as a conditioner for flotation agents. If desired, the feed may be introduced directly into the tube 9 by opening the valve 20 and plugging the tube 10 at 36. In modifications, a third conical baffle surrounds the baffle 26 ; the element B comprises one or more reciprocating rakes or a helical conveyer moving over the sloping bottom of a tank in which the element A is disposed ; a second impeller is provided.