Patent GB-467358-A (GB)
Title: Improved method and means for the treatment of ores, fuels and the like
IPC: C22B1/10
Filed: 1936-03-23
Abstract: 467,358. Pneumatic conveyers; oreroasting &c. furnaces; gas washers. CLEVELAND, F. J. (Oesterreichische Dynamit Nobel Akt.-Ges.) March 23, 1936, No. 8694. [Class 78 (i)] [Also in Group XII] In apparatus for the treatment of ores, fuels, &c. and more particularly for the roasting of sulphidic ores and metallurgical products, of the kind in which the pulverulent material to be treated is carried by a gaseous reacting agent into a reaction chamber, the entering velocity of the mixture is reduced as far as possible by means such as single or multi-stage enlargement of cross-sectional area, baffle plates, and the like, and simultaneously separation of the constituents of the mixture is counteracted by means which do not exert an accelerating action on the flow of the mixture, such as interposed or built-in elements, whirling or eddying gas currents. The reaction gas feed pipe 1, Fig. 1, opens into a pipe 2 of greater cross-section into which ore &c. is delivered from a hopper 3 by a wheel 4. The pipe 2 is connected to the funnel-shaped upper portion 6 of the reaction chamber 7 by a knee 5. Gas feeding pipes 8 are arranged tangentially to the chamber 7. In a modification, upwardly directed nozzles arranged radially to the reaction chamber are provided for feeding in reaction gases, but these nozzles can be used for the introduction of the mixture of ore and air, and in this case, the pipe 5 is used for the introduction of supplementary air. In a further modification, the mixture is fed from a tapered pipe 10, Fig. 4, against a baffle plate 11 and then falls through the chamber 12 around a baffle member 13. In another modification particularly suitable for roasting sulphidic ores, the mixture is admitted through pipes 15, Fig. 5, into an antechamber 16 adjoining which is an annular chamber 17 serving for the feeding of the gas into the reaction chamber through the annular gap 19. A plant for the roasting of sulphidic ores is shown diagrammatically in Fig. 6. A compressed air supply pipe 21 is connected by valve-controlled pipes 22, 23 to closed containers 24, 25 for the material to be roasted, and by pipes 32, 33 to the top and bottom of the roasting chamber 30. The containers 24, 25 are connected by pipes 26, 27 to a proportioning conveying device 28 which blows the mixture of gas and ore through a pipe 29 into the chamber 30. A pipe 34 connects the chamber 30 to a cooler, e.g. a steam boiler 35 with built-in heating tubes, and a pipe 36 leads from the cooler to the dust separator 37. The lower part 39 of a scrubber is connected to the separator by a pipe 38, and is disposed below a chamber 40, Fig. 8, containing filling material 41, e.g. Raschig's rings, which is sprinkled with hot water supplied by the pipe 42. A chamber 44 above the chamber 40 also contains filling material which is sprinkled with cold water. The outlet 47 opens into a water trap 48, Fig. 6, containing baffle plates 49. An outlet pipe 50 from the deepest point of the trap returns the water to the cold washer 44. A pipe 51 connected to the outlet 74 of the trap leads to a blower 52 which is connected to the chamber 30. By this means cleaned and cooled gas can be returned to the chamber. The lining of the roasting chamber may be provided with helical guiding elements of trapezoidal cross-section. The roasting chamber 61, Fig. 10, has an axially disposed nozzle 62 for feeding in the mixture of gas and ore, and radially. opposed nozzles 64, 65 for the introduction of supplementary air or gases for eddying the stream of ore and gas. The nozzle 62 and the arch 63 of the chamber are shaped as shown for reflecting heat towards the reaction zone and for slowing down the movement of the ore and gas. Gas discharge pipes 66, 67 are provided. Air, or other reaction gases, from the pipe 33, Fig. 6, is passed into the burned material through apertures 74 communicating with passages 75. The chamber may widen out in steps towards the lower end, and may have water pipes or air passages in its walls.