US1829438A - Reduction of ores, oxides, and the like - Google Patents

Description

Oct. 27, 1931.

H. E. COLEY AND THE LIKE REDUCTION OF ORES OXIDES,

Filed Jan 5. 1931 4 Sheets-Sheet H. E. COLEY REDUCTION OF ORES, OXIDES, AND THE LIKE 4 Sheets-Sheet 2 Filed Jan 5, 1931 Oct. 27, 1931. H E COLEY 1,329,438

REDUCTION OF ORES, OXIDES, AND THE LIKE Filed Jan. 5. 1951 4 Sheets-Sheet 3 I V LL /0 3 7 UCTION OF ORES. OXIDES, AND THE L Filed Jan. 5. 1931 Patented Got. 27, 1931 PATENT OFFICE HENRY EDWIN COLE-Y, OF LONDON, ENGLAND REDUCTION OF ORES, OXIDES, AND THE LIKE Application filed January 5, 1931.

This invention relates to the reduction of ores, oxides and the like. The invention is particularly adapted for reducing zinc ores, although it is to be distinctly understood that it is applicable also to many other kinds of ores as well.

One of the objects of the invention is to provide a new method of internally heating the chamber in which reduction of the material is effected consisting in cracking a hydrocarbon by bringing it into contact with heated ore, oxide or the like within the reducing chamber and burning the combustible vapours produced by means of separately introduced air. A further object of the invention is to utilize a hydrocarbon to efi'ect both the heating of the material to be reduced and its reduction contemporaneously by cracking the hydrocarbon by bringing it into contact with a body of the ore, oxide or the like heated to its reducing temperature and admitting air to the region where such cracking takes place sufficient to efiect combustion of the combustible vapours produced and the production of a non-oxidizing atmosphere.

By meansof this method reduction of the ore or the like is effected by means of nascent carbon or carbon in its atomic condition as distinct from carbon in its ordinary or molecular condition whilst by the separate admission of just suflicient air for the purpose in the region where the cracking of the hydrocarbon takes place the combustible vapours given off are burnt without producing an oxidizing atmosphere.

Apparatus suitable for carrying the invention into efl'ect is illustrated in the accompanying drawings in which Fig. 1 is a longitudinal vertical section through a reducing chamber of the rotatable tube type adapted for reducing volatile metals such as zinc and embodying means for introducing a hydrocarbon and air for carrying the present invention into effect.

Fig. 2 is a fragmentary section to an enlarged scale of the means illustrated in Fig. 1 for introducing a non-cracked hydrocarbon into the body of ore or the like in the reducing chamber.

Figs. 3 and 4.- illustrate a means for clear- Serial No. 506,731.

ing the outlets of the hydrocarbon feedpipes.

Fig. 5 is a transverse vertical section to an enlarged scale through the hydrocarbon feeding mechanism illustrated in Fig. 1.

Fig. 6 is a fragmentary vertical section of the same reducing chamber illustrating a modified means for introducing the air for combustion.

Fig. 7 is a transverse section on an enlarged scale through the reducing chamber illustrated in Fig. 1 showing two positions of the air inlet pipes and the operation of the automatic valves controlling the inlet end of such pipe.

Referring to the drawings the reducing 5 chamber illustrated is in the form of a rotatably mounted tube 1 having openings 2 and 3 at opposite ends, said openings being suitably sealed against the free ingress of air the opening 2 being for the removal of the vapourous products of reduction and the opening 3 for the removal, by way' of the chute 4 of the gangue or residue. The ore, a bank of which is indicated at 5 in position along the interior of the reducing chamber is fed in by way of the opening 2 by means comprising an inclined chute 6, a communicating horizontal or substantially horizontal tube 7 and a worn or other conveyor 8. These ore feeding means are supported by and extend 3 through a water-jacketed tower 9 in which is effected the condensation of the metallic vapours and their separation from the other gases produced by the reduction as described in the specification of my pending applica- 35 tion for Letters Patent No. 301,889. Extending longitudinally through the centre of the reducing tube is a stationary tube or hollow girder 10 which is supported at opposite ends by supports 11 and 12. Through the interior of this tube or girder water is continuously circulated, the inlet for such water being at one end and indicated at 13 and the outlet at the opposite end, being indicated at 14. such outlet discharging into the interior of the aforesaid condensing tower 9. Extending radially and at spaced intervals from the tube or girder 10 are a plurality of nozzles. the construction of which is indicated clearly in Fig. 2. These nozzles com- L00 prise a comparatively small inner tube 15 each of which is water-jacketed to its extremity by means comprising inner and outer spaced tubes 16 and 17, the latter tube closing in against the extremity of the small inner tube 15. The interior of the tube 16 communicates with the interior of the tube or girder 10 by means of an inlet opening 16a and similarly the interior of the outer tube 17 also communicates with the interior of the tube or girder 10 by means of an outlet passage 17a. Water from the interior of the tube or girder 10 is thus caused to circulate through the spaces formed by means of the concentric tubes 16 and 17 in the direction of the arrows shown in Fig. 2. The inner small tube 15 is thus always maintained comparatively cool. As an additional precaution in this direction the outer tube 17 is enclosed by means of an outside casing 18 having an interposed packing 19 of any suitable heat insulating material.

The inner tubes 15 which at their extremities open into the interior of the reducing chamber are adapted to deliver. in a noncracked and comparatively cool condition, a liquid hydrocarbon and for this purpose each such tube communicates at its inner end with a tube 20 which latter tubes extend longitudinally through the water space within the interior of the tube or girder 10. These tubes 20 project through the left hand end closure of the tube or girder 10 and are thus outside of the reducing chamber and such exposed extremities are each fitted with feed or inlet pipes 21 communicating with the main hydrocarbon supply.

As will be seen from Fig. 5 the watercooled hydrocarbon supply nozzles extend into the interior of the reducing chamber at an angle to the vertical so that during the rotation of the reducing tubes the outlets of these nozzles are always normally covered by the bank of ore.

Means are provided, in the example illus trated, for preventing the outlets of the hydrocarbon delivery pipes or tubes 15' from becoming choked with coke such means comprising pricker rods 22 which extend down through the centre of each such pipe 15 and are adapted to be periodically reciprocated by means of a crank connection 23 between such pricker rods and further rods 21 located within the longitudinal teed tubes or pipes 20 which latter rods may be oscillated or partially rotated for the purpose from their outer extremities 25.

As shown in Fig. 5 the water-cooled tube or girder 10 may be additionally protected against the radiant heat within the reducing chamber by means of an exterior shrouding 26 and an interposed packing 27 of a suitable non-conducting material.

By these means a liquid hydrocarbon is conveyed in a non-cracked condition into actual contact with a bank of ore heated to its reducing temperature. As a result of the contact between the comparatively cool hydrocarbon and the hot ore the hydrocarbon is cracked in situ producing carbon in its most active form, namely, in its atomic or nascent form and in this form eflects the reduction of the ore.

When a hydrocarbon is cracked there are given off a quantity of combustible gases which it is one of the objects of this invention to use for the purpose of heating the ore to and maintaining it at its reducing temperature within the reducing chamber. This object is attained according to the present invention by separately introducing air into the reducing chamber in proximity to the region or regions where the cracking of the hydrocarbon takes place the quantity of air thus admitted being sufiicient to effect complete combustion of the said combustible gases without producing an oxidizing atmosphere within the reducing chamber. In the arrangement illustrated in Figs. 1, 2, 3, 4, 5 and 7 this air is introduced into the interior of the reducing chamber by means of a lurality of tubes 28 which extend radially t rough the wall of the reducing chamber. In practice it is found to be essential to prevent this air from being projected directly onto the exate by gravity and remain closed until the rotation of the reducing chamber brin s the tubes to a position where their inner en 5 project through the bank of hot ore as shown most clearly in Fi 7. In this position of the reducing cham er the valves fall open automatically and, allow air to enter and by reason of the particular location of the air tubes relatively to the hydrocarbon inlets, to support combustion of the combustible gases evolved by the cracking in situ of the introduced hydrocarbon. During the remaining revolution of the reducing chamber the valves 29 remain closed.

In the modified arrangement illustrated in Fig. 6 the air is introduced by means of a plurality of longitudinal tubes 32 of varying lengths. As the outlets of these tubes serve to discharge the air away from the bank of hot ore the provision of controlling valves as in the former arrangement, is rendered unnecessary.

' What I claim is 1. In the reducing of ores, oxides and the like effecting the reduction by bringing a hydrocarbon in a non-cracked condition into contact with material to be reduced which has been heated to its reducing temperature by keeping the same artificially cooled whereby such hydrocarbon is cracked by reason of asaaaae contact with such heated material and main= taining the reducing temperature of the material by burning the combustible vapours produced by the cracking of the hydrocarbon with separately introduced air.

2. A method of reducing ores, ox1des, and the like com rising the steps, chargin the retort with t e material to be treated, eating the same to a cracking temperature for a m hydrocarbon, introducing a liquid hydrocarbon into the retort, artificially cooling the same during its introduction into the retort whereby it reaches the heated material in a non-cracked condition and is thereby cracked w by contact with the heated material and maintaining the temperature within the retort by burning the resulting combustible vapours by separately introduced air.

3. A method of internally heating retorts for the reduction of ores and the like and simultaneously reducing such ores comprising the steps charging the retort with the material to be reduced, heating the material in a reducing atmosphere to a temperature at which a hydrocarbon will crack introducing a hydrocarbon into the retort, artificially cooling the same during its introduction into the retort whereby it reaches the heated material in a non-cracked condition and is thereby cracked by contact with the heated materiaiand burning the resulting combustible vapours within the retort by separately introduced air so as to heat the material to its reducing temperature, Without destroying the reducing atmosphere within the retort,

and cause reduction to be efi'ected.

4. In the reducing of ores, and the like effecting the reduction by bringin a liquid hydrocarbon in a non-cracked con 'tion into an contact with the material to be reduced, which has been heated to its reducing temperature in a reducing atmosphere, by means of a water-cooled conveyor whereby said hydrocarbon is cracked by its contact with the heated material and maintaining the reducing temperature of the material by burning the combustible vapours, produced by the cracking, with separately introduced air.

Signed at London. England, this 18th day an of December, 1930.

HENRY EDWIN COLEY.

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