GB355211A - Improvements in the separation or concentration of solid substances by flotation - Google Patents

Abstract

355,211. Concentrating ores. ELI•, A. D. J., Tananarive, Madagascar. Feb. 13, 1930, No. 4870. Convention date, March 29, 1929. [Class 82 (ii).] In concentrating ores, e.g. graphite, by flotation an emulsion is formed of gas, e.g. air, water or other liquid and a foaming agent, e.g. cresol, turpentine, tar or gasoline, and the emulsion is brought into contact with the ore pulp, which has been previously mixed with a selective agent, e.g. oil, in such a manner that a froth is formed without mechanical agitation. In an elongated vessel 1 is provided a liquidtight cylinder 8 with conical bottom 15 and top 10. The ore mixed with selective agent is introduced through a funnel 12 and passes down a channel 14 formed between the top 10 of the cylinder 8 and a conical extension 13 of the funnel into the annular space 9 between the vessel 1 and the cylinder 8 which constitutes an emulsion chamber, the emulsion containing the foaming agent being introduced into the bottom of the space 9 through a channel 40 formed by a conical baffle 25. The emulsion chamber 9 may be provided with projections or baffles 9a. The froth rises out of the space 9, is deflected inwards by a baffle 22, passes over the top of the baffle into the space 24 and is collected in an inclined trough 6. Liquid may be introduced into the space 23 below the baffle 22 to cause the overflow of the froth, or the froth may be removed by mechanical means, an overflow pipe 29 being provided. The tailings and the degasefied emulsion pass down from the space 9 through a passage 41 between the baffle 25 and a coaxial conical baffle 26 into a settling compartment and thence through an annular space 28 between the vessel 1 and the edge of an inverted conical hood 27 to a discharge outlet. Liquid or steam may be supplied through a pipe 3 to assist the evacuation of the tailings. The degasefied emulsion is withdrawn by suction through a pipe 19 opening under the hood 27 and passes to a pump 18 where it is again mixed with air or other gas and passed to the emulsion chamber through a pipe 17 opening in the channel 40. The pump is provided with a feed tube 20 for foaming agent and air and may have an additional tube 21 if compressed air or a gas other than air is used for the emulsion. In a modification, Fig. 3, the emulsion is made in the settling chamber. Compressed air or gas is supplied by a pipe 33 to a nozzle 34 and draws liquid containing foaming agent up a tube 31 surrounding the nozzle 34 and opening into the channel 40. Additional foaming agent may be supplied through a pipe 30. Several apparatus may be arranged in series, the froth from the first concentration being fed to the second apparatus and so on and, when the external emulsifying pump 18 is used, several separating vessels may be arranged round a common pump.