GB517148A - Improvements in or relating to ore jigs - Google Patents

Abstract

517,148. Jig-washers. LE TALL, F. W. (Whittaker, J. S.). Aug. 20, 1938,.No. 24585. [Class 82 (ii)] A jig comprises one or more units each having two jig compartments side by side, and having mainly thereunder a further compartment containing a reciprocable obturator by which upward impulses are imparted to the liquid in the two jig compartments alternately. The washer shown comprises a plurality of compartments 1, 2, 3 in series, each compartment being divided into two cells 4, 5 separated by a passage 13 closed at the bottom by a plate. Each cell has a removable grid 15 on which is supported a screen 16 on which are bars 17, the spaces between which are filled with ragging. The screens in the compartments 1, 2, 3 may be inclined so that they form a continuous slope, or they may be horizontal and stepped as shown. The material is fed over weirs 18 on to the screens in the compartment 1 and weirs 19 are provided between the successive compartments. The lower parts of the cells 4, 5 are formed into hoppers by the walls 8, 9 and between and below the walls 9 is a compartment 20 in which works an obturator 21 which may be a piston or a diaphragm. If a piston is used it may fit loosely so that there is some communication between the two sides or it may fit tightly to seal the passage, for example, by connecting it to the walls of the compartment by a flexible diaphragm. The piston is carried by a rod 22 which passes with some clearance through an aperture in the plate at the bottom of the space 13 and is reciprocated by an eccentric, crank &c. 23 on a shaft 24, the shaft 24 being preferably common to the pistons of all the compartments. The piston is preferably hollow and of a buoyancy sufficient to balance its weight and that of the connecting rod and the edges 43, Fig. 4, which take the side thrust of the eccentric may be provided with replaceable wearing strips comprising angle irons 40, the other edges being protected by rounded strips secured to the side walls of the piston. The portion of the compartment 20 above the piston communicates directly with the cell 4 and the portion below the piston communicates with the cell 5 through a passage 26 in the compartment and a passage between the wall 9 and a plate 27, so that pulsion is produced in one cell at the same time as suction in the other. Baffles 28 are provided to prevent the material which passes through the screens from entering the compartment 20 and to direct the flow of the water. Water may be admitted to the compartment 20 by supply pipes 33, 34 which may have non- return valves. The values pass through the screens and are withdrawn, preferably continuously, at outlets 28a. The compartment 20 is provided with a valved discharge 32, or, if a tight-fitting piston or diaphragm is used, a discharge may be provided on each side of the obturator. Air-vents 37 are provided in the passage 13.