Patent GB-352931-A (GB)
Title: Improvements in apparatus for the treatment of ores
IPC: C22B3/02
Filed: 1930-03-10
Abstract: 352,931. Apparatus for concentrating ores, extracting metals, &c. LESLIE, N., Kolar, Westbury, Tasmania, Australia. March 10, 1930, No. 7713. Convention date, March 11, 1929. [Classes 82 (i), 82 (ii), and 86.] Ores are concentrated or classified in a chamber having a converging bottom and having mounted therein a vertically adjustable upcast pipe into the lower end of which compressed air or water under pressure is introduced through a nozzle to cause a circulation of the contents of the chamber. A chamber 5, preferably cylindrical and having a converging bottom, is connected by a neck 6 with an auxiliary chamber 7, the passage between the chambers being controlled by a valve 27 mounted on a tubular stem 28 which passes through a packing gland in the inclined bottom of the chamber 7 and can be raised or lowered by a hand-wheel 31, Through the tubular stem and the valve passes a pipe 32 which is connected to a compressed air supply and can be raised or lowered by a handwheel 35. The pipe 32 terminates at its upper end in a nozzle 33 which is positioned below and coaxial with an upcast pipe 19 with a plurality of discharge apertures 20 at its upper end which is mounted on a screwed spindle 11 in the chamber 5 and can be raised or lowered without rotation by a sprocket wheel 14, shaft 13 and worm wheel 12. Provision is made for indicating the positions of the upcast pipe 19, the valve 27 and the compressed air pipe 32 and nozzle 33. At the bottom of the auxiliary chamber 7 is a cock 42 through which the chamber 7 may be put into communication either with a passage 49 leading to a discharge cock 48 or with a chamber 41 at the bottom of which is a worm conveyer 44 operated by a hand-wheel 45 which discharges the contents of the chamber 41 through an opening 46 normally closed by a door 47. To adjust the hydrostatic pressure in the chamber 7 a pipe 59 with suitable cocks connects this chamber with a cylinder 60 provided at the top with a packing gland 62 for a pipe 61 which passes through the lower end of a chamber 63 and is connected to a float ch mber 64 adjustable vertically in guides 65 in the chamber 63. The level of water in the float chamber 64, which has an annular depending skirt 69; is maintained constant by a float controlled valve 70 and the level of water in the chamber 63 and hence the pressure in the cylinder 60 may be varied by means of a valved discharge pipe 68. In concentrating or classifying ores by gravity separation the pulp is introduced into the chamber 5 and circulated by admission of air or water through the pipe 32; the heavier particles settle in the neck 6 and may be passed into the chamber 7 by opening the valve 27 and discharged therefrom. The process may be repeated with varying positions of the upcast pipe and air pipe to obtain different grades of ore. In extracting by amalgamation mercury may be introduced from a reservoir 49a into the chamber 7 and thence into the main chamber 5 where it is circulated with the pulp to form amalgams with precious metals. The amalgam is discharged through a chamber 7 into the discharge chamber 41 and is forced by the worm conveyer 44 through a filter-bag placed over the opening 46. The upper part of the chamber 5 is electrically insulated by an insulating band 52 from the neck 6 and chamber 7 and terminals 53, 54 are provided so that an electric current may be passed through the pulp from the upcast pipe as anode to mercury in the neck 6 as cathode. An electrolyte may be introduced into the chamber 5 and a current passed during amalgamation to keep the mercury clean. Precious metals may be extracted by introducing cyanide solution and pulp into the chamber 5 and circulating the contents, the metals being then extracted either by electrolysis so that the metals are deposited on the mercury cathode in the neck 6 and amalgamate therewith or by adding copper or zinc dust and agitating for a short time with mercury. The upper end of the chamber 5 is provided with an overflow launder 57 with discharge outlet 58 and the apparatus may be used for concentrating by flotation by introducing flotation agents into the chamber 7 through a pipe 70 a, opening the valve 27 slightly so that the agents pass into the pulp in the chamber 5 and then circulating the contents of the chamber. The hydrostatic pressure in the chamber 7 is then increased sufficiently to float the concentrate into the launder 57. Ore pulp remaining in the chamber 5 after any operation may be removed through a pipe 56 either by means of a pump or by siphonic action.