US1081569A

US1081569A - Method of dephosphorizing ferrotungsten.

Info

Publication number: US1081569A
Application number: US76325?13A
Authority: US
Inventors: Frederick M Becket
Original assignee: Electro Metallurgical Co USA
Current assignee: Electro Metallurgical Co USA
Publication date: 1913-12-16
Anticipated expiration: 1930-12-16

Description

ATEN OFFIGE lumen, STATES rnmmmck M. amour, or NIAGARA FALLS, NEW xonxQhssmnon TO nnno'rno METALLURGICAL COMPANY, 01' NEW YORK, N. Y., A R-POBAT ION or wrzsr VIRGINIA.

nrn'rnon or nnrnosrnoaxzme rnnaoruues'rnn.

1,081,569, Io'Dnwing.

To all 'aqliom it'ntay comm, Z

Be it known that-I, 'Fnnnmio r Bncxn'r,

a subject of the Km of Great Britain, re-.

' tungsten-content .siding' at Niagara alls, in the county of Niagara and fate of iNew= York, have invented certain new anduseful Improvements 'in'! Methods of: hosphorizing Ferrotungsten, of which the tbllowing is a specification. I

I This invention relates to methods of dephosphori'zing ferrotungsten, particularly errotungstenv which by reason of its high brought tothe thinly-fluid condition requisite for continuoustapping or pouring.

Y As is well known, commercial ferrotungsten containing 75-80- percent. or upward of tungsten'is diflicultly. fusible, and requires the application of extremely high tem' tures in order to bring it to a fluid con ition or to melt it into a.homogeneous mass, The solidlfied alloy is however comparatively brittle, and can be easily ground ture sufiiciently high to fuse or a bath. It is therefore desirable that the bath should consist.,'of an ore of the refractory metal which enters into the constitution of the alloy, with such basic addition, usually lime, as vmay be required.- Anillustrative example of my method is as follows: Ferrotungsten, containing 7 580 per cut. of tungsten, is crushed to pass a 10-12 mesh. screen,and is fed in a continuous stream to the surface of a molten bath consisting of scheelite and lime in approxi mately e ual proportions. This bath is maintaine by the passage theret-hrough of an electric current at such temperature will sufiice to fuse or at least to agglomerate I Specification of Letters Patent. h uuua nan April 24, 1913. Serial Ho: 763,250.

cannot economically be' the -unti it becomes'sluggish in its refinin action, after which it is replaced by a resh bath. Duringthe operation" the phosphoruscontent of the bath gradually increases, and when ayou bath has been used as long as is advisable under the particular circumstances, it'is tapped from the 1purified alloy. The bath'may be'used Patented Dec, 16, 1913-,

furnace, permitted to cool, and ti'eated as a: high phosphorus ore of tungsten; that is to say, it may .be smelted with silicon or with carbon for preparation. of a ferroalloy, which, being comparatively high in phosphorus, may be purified by any desired method, for example as above described, or by any of the methods described in my copending application Ser. No. "728,498, filed October 29, 14112. It will of course be un-,

derstood that the reduction of phosphorus in smelting the phosphoriaed bath is by no" means quantitative, so that itis often pra'c .ticable to purify the ferroalloy obtained by. smelting the rejected baths -by dephosp orization in fresh baths without involv ing any serious accumulation of phosphorus in the process. This is particularly the case when the ore employed for the fresh bath is substantially free from phosphorus.

This method is chiefly applicable to the treatment of ferrotungsten which is low in carbon, inasmuch as a similar treatment of high-carbon ferrot-ungsten is apt to entail a reduction of phosphorus from the' bath, particularly when the bath is relatively high in phosphorus, with the result that the alloy is imperfectly dephosphorized. The ap-,

plicability of the method is independent of the tungsten-content of the alloy, and the method is directly applicable to the treatment of products having a tungsten-content of 94- to 98 per cent, such for example as the product known to the trade as tung- .sten powder; and the ,term-ferrotungsten is herein used as including such products.

to the action. of an overlying bath of basic According to the present method, the

li'errotungsten is brought-in solid form. into l rotungsten, which consists in bringing the in Letters PatntNo. 1,081,569.

presence of the basic bath, and undergoes progressive heating-in the bath, encountering during such heating the conditions which accomplish the dephosphorizationu .1. The method of dephosphorizing fer-- rotungstem which consists inbringing the fcrrotungsten in solid form into presence of a molten basic' oxidizing bath.

2. The method of dephosphorizing ferferrotungsten' in solid form into presence of a molten basic oxidizing bath maintained at a temperature approximating or above the fusing-point of the ferrotungsten.

3. The method of dephosphorizing fer- 1'otungsten,'Wl1icl1 consists in bringing the ferrotungstensolid form into presence} of a molten basic oxidizing bath containing an oxygen compound of tungsten.

4:. The' method of .dephosphorizing ferrotungsten, which; consists in bringing the ferrotungsten in solid form into presenceof a molten'basic oxidizing bath containing an oxygen compound of tungsten, said bathmaintained at .a temperature approximating V or above the fusing-point,- of the ferro Witnesses"? tungsten. v

: 5. The method of' dephosphorizing ferion [smLJ 0 r rect rotungsten, which consists in feeding solid fe'rrotungstenin subdivided form to the sur-" face of a molten basic oxidizing bath.

6; The method of -dephosphorizing ferrotungsten, which consists in feeding solid ferrotungsten in subdivided form to the surface of a molten basic oxidizing'bat-h maintained at a temperature approximating or above the fusing-point of the ferro- I tungsten.

7. The method of dephosphorizing ferrotungsten, which'consists in feeding solid \ferrotungsten in subdivided form to, the surrotungsten, which consists in feeding solid ferrotungsten in subdivided form to the surface of. a moltenbasic oxidizing bath conface. of a molten basic oxidizing bath containing an oxygen compound of tungsten, said bathmaintained at a temperature approximating "or above the fusing-point of the ferrotungsten. 3

' In -'testimony whereof I afiix'my signature in presencemf two witnesses.

C. P. Townsnnp, E. DANIELS.

It hereby certified that in Letters Patent No. 1 )8 l,569, granted December 16, r 1913, upon the application :of Frederic M. Becket,,of Niagara. Falls, New York, o an improvemen i Methods of Dephos phorizing Ferrot ungstenz an error appears in printed specification reduiring correction as. follows: Page 1 lines 32 33, for theword depolarized read deplwiyalzoried; and that: thesaidLetters Patent should be read with this correctiontherein that the same may-conform the record of thecase in the Patent Office. I I i i Signed and sealed this 2 0th day of April, D.,191 5;

I J. T. NEWTON, Acid/11g Commissioner of Patents;

' FREDERICK M; BEOKET,