US831223A

US831223A - Process of detinning.

Info

Publication number: US831223A
Application number: US26757905A
Authority: US
Inventors: Karl Goldschmidt; Josef Weber
Original assignee: TH Goldschmidt AG
Current assignee: Evonik Operations GmbH
Priority date: 1905-06-29
Filing date: 1905-06-29
Publication date: 1906-09-18
Anticipated expiration: 1923-09-18

Description

110.831,.223x PATENTED SEPT. 18, 1906v K. GOLDSGHMiDT & J. WEBER. PROCESS OF DETINNING.

APPLICATION FILED JUNE 29,1905.

www a Mf/Mm SAT-ES PATEN oFFIoE.

KARL sorinscsihnr inn JOSEF WEBER, or ssssaoseuariuuri,

user/rim. ASSIGNORS To FIRM TH. GQLDSUHMIDT, or ESSEN- on-isnnuns, GERMANR- A senor-respeoat-mums. s y I are. esisss.

Specification of Letters Patent.

Patented Sept. 18, mos.

Aoplicatiou filed June 29, 1966i Serial No. 267.579,

2'0 @513 whom it may concern Be it known that we, KARL GOLDSCHMIDT and doses WEBER, subjects of the King of Prussia, German Emperor, and residents of @ur invention consists insubjecting the tinscraps in is compressed state m e closed vessel to the action of chlorin as and in eltering the pressure in the vesselor receptacle When'the reaction of the chlo'rin on the scraps 'ilisiiife place. A chief point of our invention is to submit the scrap'sfto the action of.

- chlorin in a firmly-com ressed state. It has been found that the c lorin gas enters into the narrowest and the most closed spaces be tween the compressed tin scraps and'mixes' easily with the air contained therein, so that even between the closely-packed surfaces of the tin scraps e suficient action'of the chlorin gas takes place. The chlorin'gas is not employed in a pure state, but mixed with neutral or inert gases, as dry air, and so on.

' I It is of importance to avoid in the process high tern eratures in the mass of the in scraps an to use the tin scraps in a well-dried stete. By this process we get the iron Waste perfectly detinned and with a fine smooth grsv surface. I v

."lhe apparatus used in this process is illustrated in the accompanying drawing in a vertical cross-section.

The receptacle for the compressed tin scraps is marked a and is of course made of s.

material which is not infected by chlorin gas '0'." anhydrous chlorid of. tin. Preferably an iron vessel is used. The-tin scraps are'me- .chanically compressed, so that they form bundles s, and the rece tacle a is filled with these compressed bun les 18 of tin scraps. The bundles are compressed and of suchasize that they can afterward be directiy used in steel works. These bundles may converr,

. iently be, for instance, forty centimeters by sixty centimeters in width and length and eight-fourteenths of a centimeter in h'ei ht,

so that they have aweight from aboutv y to sixty lnlo rams. in order to facilitate the filling oh the vessel, the packets are obtained? brought in baskets, and thme baskets,

i with the bundles of compressed tin scraps,

are tli'en'introduced into t e yessel.

After the apparatus a has been filled with, the bundles of tin scraps and the apparatus, being under ordinary pressure the chlorin gas is admitted from above through the pipe.

The chlorin gas being under a certain overpressure above ordinary pressure. is at first diffused in the upper free space n over the baskets d and is there mixed with the air I of the apparatus. The mixture of chloringas and air acts upon the baskets or bundles of compressed tin scraps, and the chlorin gas is now constantly absorbed by the tin on the tin scraps. Assoonas the chlorin gasv is absorbed and has formed chlorid of tin naturally new partsof chlorin gas come in reaction and are mixed with the air contained in the vessel, and so the mixture is again enriched by freshly admitted and diffused chlor'in gas.- Now the process is so guided that the pressure in the vessel is augoriented, so that at the end of the operation .the overpressure-for instance, of one at-v mosphere above the ordinary pressure-is B the increasing ofthc pressure in'the vessel t echlorin gas comes in contact with all the surfaces of the tin scraps, so that even between the most closely packed surfaces of the tin scraps asufiicicnt actionof the chlorin gas and formation of chlorid of tin takes place. At the commencement of the operation the chlorin gas when passing over the firmly-compressed Waste will naturally be eagerly taken up by the tin on accountof its great aiiinity for the latter; but as soon as. the leading action of the'chlorin gas has taken c place at the easily-accessible parts of the tin scraps the reaction will slow down, and so the parts of the tin scraps-Which are firmlycompressed and where the surfaces are in close contact with one another might easily remain unafl'ectcd; but the mixture of chlorin and air is driven by the increasing pres-- sure into the :narrowest channels or;- inter.-

stices of the tin scraps, so that the whole surfaces are-detinned. ,It is easily to be seen roe that the increasing'of the ressure in the vessel is of greatimpcrtance or finishing the detinning process completely and in a short time. v

It is important to avoid agreat increased 105 temperature.

Instead of increasing the ressure in the vessel it is possible to diminis the same and then to increase it again. process can be carried out in the f0 lowing manner: At first the vessel when filled with tin scraps is closed and then evacuated by an air-pump connected with the pipe f. (Not shown.) Then the chlorin gas is mixed with air admitted to the vessel through the pipe 2, so that at least the common ressure in the vessel results or so that a sligl it overpressure is obtained. Then we can again pum out the mixture of air and chlorin gas or t e air which fills the vessel after the chlorin gas has been absorbed by the tin, and we may intro duce again chlorin gas mixed'with air, into the vessel until the common pressure in the vessel results.

It is of great importance to use the tin scraps in a stron ly-compressed state, which can of course )e effected b mechanical means only. Then it is ossiblh to pack the tin scraps in' strong bum les of fifty to sixty kilograms-for instance, into baskets or crates-so that the vessel in which the process is carried out containsseveral tons of tin scraps. Thereby the cost of labor, which is an essential factor in all such processes, is greatly reduced.

The stronger the tin scraps have been compressed the stronger must be the change in pressure, because only under this varied For exam le, the

pressure the chlorin gas will easily enter the narrowest interstices orchannels and change the tin quickly and completely into tetrachlorid of tin. As already said, the res'sure may be decreased or increased in t e process, but always a varying of the pressure must take place.

By the term inert gas used in the de- 1 scription' and in the following claims we i mean a gas which does not attackthe scrap j or chlorin or any of the products thereof during the process of detinnin Having thus fully described the nature of our invention, what we desire to secure by Letters Patent of the United States is 1. Process of detinning, which consists in compressing loose tin-scrap and treating said compressed scrap in a vessel with chlorin gas.

2, Process of detinning, which consists in compressing loose tin-scrap into compact bun les of relatively small size, and treating said bundles in a vessel with chlorin gas.

3. Process of detinning, which consists in compressing loose tin-scrap and treating said compressed scrap in a vessel with chlorin gas I in combination with an-inert gas.

4. Process of detinning which consists in 1 com ressing loose tin-scrap into compact bun les of relatively small size, and treating said. bundles in a vessel with chlorin gas in combination with an inert gas.

5. Process of detinning, which consists in" treating tin-scrap in a vessel with chlorinjgas in combination with an inert gas, and-altering the pressure in the vessel during the detinmn 9% Process of detinning, which consists in treating tin-scrap in a vessel with chlorin gas in combination with aninert as, and increasing the pressure in the vesse during the detinning.

10. Process of detinning, which consists in treating tin-scrap in a vessel-Withchlorin gas 4 o r 1 7 pressure 111 the vessel dur= e pressure in the vessel urin combination with an inert as,andincreasing the pressure in the vesse during the detinning and then diminishing it. p

11. Process of detinning,-which consists in compressing'loose tin-scrap and treating said compressed scrap in a-vessel withchlorin gas, and altering the pressure in the vessel during the detinning. Y

12. Process of detinning, which consists in compressing loose tin-scrap and treating said compressed scra in a vessel with chloringas, and increasing t 6 pressure in the vessel uring the detinning.

13. Process of detinning, which consists in compressing loose tin-scrap and treatingsaid compressed scrap in a vessel with chlorin as, and increasing t e pressure in thevesseluring the detinnin and then diminishing it.

14.. Process 0 detinning, which consists in compressing loose tin-scrap and treating said compressed scrap in a vessel with chlorin gas, in combination with an inert gas, and altering the pressure in the vessel during the detinnin 15. Process of detinning, which consists in compressing loose tin-scrap and treating said compressed scrap in a vessel withchlorin gas,

in combinationwith an inert "as, and increasing the pressure in the vessel tinnin p 16. Process of detinning, which consists in compressing loose tin-scrap and treating said compressed scrap in a vessel with chlorin gas, in combination with an inert gas, and increasing the ressure in the vessel during the dctinning an then diminishing it.-

In witness whereof we have hereunto set our hands in. the resence of two witnesses. RL GOLDSCHM-IDT. JOSEF WEBER. Witnesses:

' WILLIAM ESSENWEIN.

H. SCHUCHARDT.

during the de-