US1358014A

US1358014A - Apparatus for manufacture of alkali-metal cyanid

Info

Publication number: US1358014A
Application number: US265388A
Authority: US
Inventors: Floyd J Metzger
Original assignee: Air Reduction Co Inc
Current assignee: Airco Inc
Priority date: 1918-03-16
Filing date: 1918-12-05
Publication date: 1920-11-09
Anticipated expiration: 1937-11-09

Description

F.1. METZGER.

APPARATUS FOIR MANUFACTURE 0F ALKALI METAL CYANID.

APPLICATION FILED DEC.5| 1918.

1,358,014, PatentedN0v.9,1920.

I jf I has encountered the 'notable obstac FLOYD J. METZGER, 0F NEW YORK, N. Y.,

ASSIGNOR TO AIR REDUCTION COMPANY,

INC., A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Nov. 9, 1920.,

Original application led March 16, 1918, Serial 110.222,812. Divided and this application led lDecember 5, 1918.

To all 'Lc/wm t may 00H ocra:

yBe it known that l, FLOYD J. METZGER, a citizen of the United States, residing at New York city, inthe county of New York, State of New York, have invented certain new and useful Improvements in Ap aratus for lllanufacture of Alkali-Metal yanid; and l do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. The present invention relates to the production of alkali metal cyanids, and more particularly to an apparatus adapted for use in carrying out the method described in my co-pending application Serial No. 222,812, filed March 16, 1918, of which the present application is a division.

The process referred to involves the treatment of mixtures 0f alkali metal carbonates or alkali metal hydroxids (or both) together with coke, charcoal or equivalent carbonaceous material, and with or without the addition of catalytic material such as iron, the operation being conducted at an elevated temperature and in the presence of nitrogen or a nitrogencontaining gas.

'While the reactions involved in this general procedure are well known, various practical difficulties have been encountered in such endeavors as have been heretofore made to introduce the process into commercial use. For instance, in order to bring about the fixation of the nitrogen for the production of cyanid in such processes, it is necessary, as above indicated, to maintain a high temperature (approximately 850 (3.40000 (j.) which, of itself, introduces complications in the construction and maintenance of the apparatus employed. So also, at the temperature necessary for reaction, the alkali metal carbonate or hydroxid (or both), are in a molten or semi-uid condition, so that the entire 'furnace charge 1s more or less plastic, 1n which state it opposes `serious obstacles to the well-distributed contact between the nitrogen gas andthe fur`- nace charge, necessary for an efficient and uniform procedure. Y

l-lcretofore, the endeavor to realize an industrial utilization of the general process e that Serial No. 265,388.

the semilplastic charge adheres, to a large extent, to the inner walls of the furnace, in the absence of any` rovision for preventing such adhesion. o meet this objection, it has been proposed, for example, to maintain a protective layer of coke or other carbonaceous material (not containing alkali) -many of the proposals heretofore made, has

probably been due to the fact that during the operation the furnace charge shrinks toa very great extent (the amount of shrinkarge, of course, depending upon the nature and proportion o-f the ingredients entering into the composition of the charge) and may amount to as much as one`-third or more of its original volume. During this shrinking, the contents of the furnace become channeled and this channeling allows the nitrogen gas to pass through'the furnace charge` with a corresponding diminution of the desired contact, and with a resultant low and irregular yield of the alkali metal cyanld desired.

The present inventionprovides a mode of operation, which, in overcoming thedifiiculties hereinbefore referred to, supplies a satisfactory solution of the industrial or commercial problem of producing 'alkali metal cyanids from mixtures of the general character appropriate to that manufacture.

The accompanying drawing illustrates the preferred form of apparatus involved in the practice of the invention, the structure being shown partly in side elevation and partly in section.

Referring to the drawing, 2 represents conventionally any suitable heating furnace, provided with a grate 3, fuel charging door 4. ash pit door 5, baliles G, and stack 7 The details of. -this furnace structure may be chosento provide the desired heating effect,

and may be widely varied, as will be underf stood by those skilled in the art.

Extending 'through the furnace is a cylinvdrical metal tube 1, preferablyE of an alloy containing essentially nickel, chromium and.

or without small vquantities of iron, with etc., 'the relative propormanganese, silicon,

tions of the constituents of theV alloy being such that the tube will withstand, to a satisfactory "degree,

y gases at the requiredcomparatively high 'i temperature.

The upper and lower ends of cost, .such as iron, so asto diminish the ex- -ten feet for'l that may be of metal of less traverses theheating side of the furnace,

ense of thestructure.

The metal tube or retort 1, isicarried on roller thrust bearings 8, on which it can be rotated, these bearings being suitably mounted to efficiently sustain the weight imposed upon them. The angular inclination of lthe tubular retort may be varied more or less in accordance with the nature, both chemical and physical, of the mixture making up the charge,-a `suitable angle being, for instance the angle shown in the drawing. The upper end of the tubeml is provided with a conveyer an elbow pipe 12, whereby the retort can be y be desired. The

fedwith the. furnace charge automatically, and continuously or intermittently, as may. lower end of the tubular retort .is provided with a gear 9 driven by the gear 10 from the driving shaft gear 11,

or the like, so as to rotate the tubular retort' at` the rate desired, suitable means- (not shown) being provided for varying the speed of rotation.

rThe lower end of the tubular retort 1 is received Within a stationary casing 14 closed at its upper end, suitable packing being provided, as shown at 15, to prevent the escape of gas at the joint between thestationary 'casing and the rotatable retort. A discharge screw the treated charge received (from I 16 projects into the lower end of the tubular retort 1;,it is carried by a shaft 17 which passes through the casing 14 and is driven from any suitable source of power by the bevel gears 18. The casing 14 is provided with a pending therefrom, and at the lower end'of the hopper is a discharge valve 2O by which the retort may be discharged without permitting the escape of gasesfrom the casing and without admitting atmospheric air therethrough..

Y The nitrogen or nitrogen-containing gases are admitted to one end of the tubular retort and pass through the charde therein, and the reaction gases are allowed at the opposite end: Inthe drawing, a pipe the action of the furnace and of a length of about 'ture passes through lin the walls of the furnace,

13 discharging into f 'vtated continuously by means of the driving gear and, at the same time, the nitrogen or discharge hopper 19 de-A to lescape astenia for the inlet" ofv the nitrogen. or nitrogencontaining. gases is shown at 21, connected to endof the tubular retort,

' may be allowed to escape through the feeding devices for the charge, may be desired.v

ln the use of consisting of a suitable .mixture of alkali metal carbonate? orv alkali metal .hydroxid (or both) and coke, charcoal, or other carbonaceous material, ywith or without a catalyst, such as iron, is fedI into the upper part of the tubular retort 1, which portion of the or. otherwise, as

retort constitutes a' preheating zone" for the.

charge. From the preheating zone, the mixand thence into the'cooling zone, that is to say, the'lower portion of the retort projecting beyond the furnace wall. The chargeisinally withdrawn from the retort,

the apparatus, the charge,

the reaction zone Withwith the assistance of the discharge screw 16, and drops into the hopper 19 from`whichit maybe removed, as desired, by the discharge-valve 20.

rlhe operation is preferably va continuous one, the retort being maintained substantially lled with the charge 'throughout the operation, and the rate of discharge of the furnace charge being determined by. the operation of the discharge'screw 16. rIhe ree tort, fwithvthe furnace charge therein, is roadinitted to nitrogen-containing gases are The nitrogen or nitrogen-containing gases Y pass up throughthe portion .of the charge in the cooling-zone, Land take up heat therefrom, so that the gases are preheated before they enter the reaction zone of the retort. So also, the temperature. of the treated charge is reduced by the cooling ei'ec't of the nitrogen or nitrogen-containing gases.

Within'thereaction Zone of the tubular retort, the charge is thoroughly agitated by therotation of the retort, thereby efectually preventing caking of the charge' and adherence thereof tothe walls of the retort and also preventing the formation of channels or fissures through the charge'. Within this reaction zone, the charge, although reduced to a pasty or semi-plastic condition, is thus `presented to the `best advantage to uniform and well distributed contact with the reac-V tion gases, so that a correspondingly high and regular yield of alkali metal cyanid re sults.

The upper end of the retort, constituting the preheating zone. beyond thev furnace walls, being more or less ille'd with the in- 'coming charge, serves as a condenser for any volatile product or fume carried. along out of the reaction Zone, and the incoming charge is, at the same time preheated byy means of the outgoing hot gases which pass through it. l'

As the charge shrinks in the reaction zone of the retort, the shrinkage is continuouslyV and automatically taken care of by the supply of charge from the preheating zone, so that the reaction zone is kept completely filled. From the reaction zone, the treated charge,f-still in a plastic or semi-fluid condi-f' tion, enters continuously the cooling zone, and immediately begins to solidify. ln so doing, the rotation of the tubular retort causes the material to become nodulizedinto lumpsor nodules of relatively small size, particularly appropriate to the subsequent use for which the treated charge is especially intended, that is to say, as the means for obtainingammonia by the passage of, steam therethrough or the extraction of cyanidtherefrom. 'llhe-exit of the charge from the cooling zone`is assisted and regulated, as hereinbefore noted, by the conveyer screw 16, which may be opera/ted continuously or intermittently, as desired. i

It will be apparent that, instead of operati ing the entire process continuously, as preferred in most cases, the apparatus is likewise well adapted for operation intermittently, that is to sayby supplying 'it with a given amount of furnace charge, treating and discharging the same in its entirety, and

f then supplying its place with a succeeding batch to be treated. The nitrogenous gas, (whether nitrogen per se, or a gas or mixture of gases containing nitrogen) may be obtained from any desired and suitable source as will be well understood by those skilled in the art.

Having thus described my invention, what I claim is:

l. An apparatus for the production of alkali metal cyanids by the treatment of a mixture of an alkali and acarbonaceous'ma- :,terial, with a nitrogenous gas, comprising the combination of a tubular retort mounted at an incline to the horizontal, a furnace'inclosing a portion of the retort intermediate the ends thereof, said portion constituting the reaction zone of the retort, the lower portion of the retort extendingy beyond the furnace and providing a cooler noduli'zing zone for the product, means for rotating ythe retort on its axis, feeding devices for feeding the charge to the upper end of the retort, and a conduitcpmmunicating with the lower end of the retort` f or the introduction of nitrogen gas.

2. An apparatus for the production of lalkali metal cyanids by the treatment of a mixture of an alkali and a carbonaceous ma- -terial with a nitrogenous gas, comprising the combination of a tubular retort mounted at anincline to the horizontal, afurnace'vin-y closing a portion of the retort intermediate the ends thereof, means for .rotating the re tort on its axis, feeding devices for feeding the charge to the upper endx of the retort,

means for assisting the discharge of thev treated 'material from the lower end' of the retort, and a conduitl communicating with one enc'l of the retort for the introduction of the nitrogenous gas; substantially asl (described. v v

3. An apparatus for the production of alkali metal cyanids by the treatment of a mixture of an alkali and a carbonaceous material with a nitrogenous gas, comprising the combination of a tubular retort'mounted f at an incline to the horizontal, a furnace inclosing a portion of the retort intermediate the ends thereof, means for rotatlng the retort on its axis, feeding devices for feeding the combination of .a tubular retort mounted at an incline to the horizontal, a furnace inclosing a portion of the retort intermediate jthe ends thereof, s'aidv portion constituting the reaction zone of the retort, means for the charge to the upper end of the retort, y

ion

rotating the retort Eon its axis, feeding devices for feeding the charge to the upper end of the retort, a closed casing spaced from the furnace and connected to the reaction zone by a portion of the retort which provides a cooling zone, and a lconduit connected with the casing for the introduction of the nitrogenous gas; substantially as described.

5. Anapparatus for thel production of alkali metal cyanids by the treatment of a mixture of an alkali metal compound and a carbonaceous material with a notrogenous gas, comprising the combination of/an inclined tubular retort, a furnace `inclosing a Y.

portion of theretort intermediatey its ends, means for rot'atingthe retort about its axis, means for feeding the chargeto the upper 'end of the retort, means for assisting the discharge of the treated material from the lower end of the retort and means for introducing nitrogenous gas to the retort.

In testimony whereof l aiiix my signature,

` FLOYD J. METZGER