US1753891A - Apparatus for the reduction of impurities contaminating molten metal - Google Patents

Description

L. JoNgs April 8, 1930.

APPARATUS FOR THE REDUCTION OF IMPURITIES CONTAMINATING MOLIfEN' METAL Filed July 13, 1928 ATTORNEY t atented tit, lli 3 J'LLEWELLYN JONES, OF MUNCIE, INDIANA JQLPPAEATUS FOR THE REDUCTION OF IMPURITIES CONTAMINATING MOLTEN METAL Application filed July 19, 1928. Serial No. 293,963.

This invention relates to an apparatus for be understood that the invention is not conthe reduction of impurities in molten metals fined to the disclosure, being susceptible of and is an improvement on the process and apsuch changes and modifications as shall doparatus described and claimed in my Patent fine no material departure from the salient ti #1,4t72,006 dated Uctober 23, 1923. features of the invention as expressed in the ln carrying out the inventive idea dependappended claim. ence is placed in a converter for the reduction In the drawings of certain impurities by the forcing of air up- Figure 1 is a section of a vessel in which 1 wardly through a charge of molten metal or the reduction of elements such as oxides, w y resorting 120 in w pressure Over e S gases, and metalloids in the molten metal is face of the metal in side blowing converters. carried out. in this case, which is similar to the furnace Figure 2 is a plan view of a perforated disk melt, the metal ebullates rising from the botnormally disposed in line with the open end tom to the surface in order to secure contact. of th l, 15 llt is an object of the present invention to Figure 3 is a view in elevation of the outer provide an apparatus for the reduction of esnd of th 11 1 1 0 t, sential elements in order to improve the qual- Referring more particularly to the drawities of metal, by the use of a slag to cause the 'ings, 1O designates an outer metal shell of a elimination of oxides, gases and metalloids vessel which is interiorly lined with a re- 20 from the molten metal obtained from a cupolafractory material 11.- The vessel is open at or furnace, the molten metal being filtered the top and the bottom is provided witha disthrough molten slag, the slag being removed charge spout 12, which is formed of metal from the level of the molten metal while at from plate stock and may be cast integrally the same time replenishing with fresh slag, with the shell 10 or connected thereto in any -or introducing any factor as a reagent or approved manner.

scavenger to the slag, or air may be The spout tapers from the outer upper end in contact with the metal to hasten reduction 13 to the lower inner end 14 so that the port of the carbon. 15 is of less diameter than the upper end of A further object of the invention is the prothe spout. The spout is provided with a parvision of an apparatus in the form of an open tition 16 at the outer end'thereof which has a vessel partially filled with a filtering'madischarge opening 17 disposed in substanterial, such as molten slag, the open end being tially the same horizontal plane as the. level partially closed with a perforated disk, 19 of the molten metal 20 in the vessel. formed of fire resistant material of ahighly The port 15 is at the outer end of a disrefractory clay, this being provided with a: charge passage 21 formed through the inplurality of perforations, the bottom of the terior lining 11. The discharge opening vessel having an outlet in communication is located sufliciently above the bottom 22 of with the bottom of the vessel for dischargthe vessel that a certain quantity ofthe ing the molten metal at a point approximate molten metal 20 will be entrapped in the ly adjacent the level of the molten metal, the lower end of the vessel. discharge end being of a greater diameter The vessel is provided with a predeterthan the inlet end, with the discharge en d mined thickness of molten slag, which can be provided with a passage normally plugged, prepared in a separate furnace or cupola, if for removing lean slag which is exhausted volume is desired. but a small charge may be and which may be drained from the surface developed by melting glass in a separate vesof the molten metal. sel. The slag is adapted to float upon the top This invention will be best understood of the molten metal 20 when sufiicient liquid "from a consideration of the following de metal has been poured into the vessel to pro- 0 tailed description, in connection with the acvide a level as indicated at 19.

companying drawings; nevertheless, it is to While the vessel is normally open at the 2 as er top, I provide a perforated disk 24 made of a high refractory material which will stand the intense heat of the molten metal when poured from a spout 25. The member 24 consists of a disk having a plurality of perforations 2G of such cross sectional area as will be suitable for the purpose. The portions of the disk, as shown at 27, adjacent the periphery rest upon the upper end of the refractory lining 11 and a flange 28 at the periphery and rising above the outer surface of said disk will aid in preventing the molten metal from splashing over the sides of the perforated disk. The disk also acts to break the fall of the incoming stream of molten metal.

An opening 29' is for-med'at the lower end of the retort through the refractory lining l1 and also in the outer casing 10 to provide a passage for the removal of the molten metal from the vessel whenever it may be desired. A plug 30 composed of clay isadapted to normally maintain the passage closed to prevent the loss of metal during the carrying out of the process.

Passages 40 for the introduction of oxygen or air under pressure, are provided in the walls of the retort. The port slants through the lining 11 and also the casing at an acute angle to deflect air over the surface of the molten metal, when so desired for reducing essential elements. 1

A passage 31 is formed in the lining 11 and also in the casing, 10 at a point which is substantially in the same horizontal plane as the level of the molten metal liquid 20, whereby the weak slag or contaminated slags may be drained off at this point. A plug 32 of clay is adapted to maintain the passage 31 normally closed.

An opening 34: is formed in the upper end of the wall 11 and the casing 10 to permit the exhausted gases to escape and also acting as an inlet for the replenishing of essential compounds for aiding in building up the slag or for bringing the compounds into contact with the metal by the aid of the slag. This port may be closed by a brick when desired.

In carrying out my process the vessel 10 of my apparatus should be conveniently located in line with the pouring spout of a cupola or vessel used in pouring molten metal, or in line with the run spout of a furnace. The passages 29 and 31 are plugged as shown, prior to the pouring of the metal into the vessel. As the molten metal strikes the disk member 29 it is broken into finely divided streams and disintegrated in this manner before it enters the vessel and passes on into the slag which rises to the top of the entrapped molten metal, (not shown).

As the molten metalreaches the level 19 a plug at the throat of the spout is forced back and the metal flows from the port 17. The pouring of the molten metal in its sprayed effect and disintegrated condition through slag an the molten metal.

the slag causes the metal to pass out through the spout 12. Since the metal upon leaving the furnace or cupola has a temperature of approximately 2700 F. the metal heats the slag and maintains it at the same temperature.

The treatment of the metal by the molten slag has a decided use in trapping oil the oxides, metalloids, and gases entrained in the metal due to the fact that the molten slag has an affinity for these elements and therefore the slag acts as a scavenger and a reagent in the fluxing of the metal. In this manner the slag is able to contain and retain elements essential to the quality of the metal. As the molten metal is in a sprayed and disinte grated condition it offers a wide range of attack by the reducing gaseous effects of the compounds or minerals used in connection with the slag, and since some of the compounds are highly volatile they can be retarded and retained by the blanket of slag. Other reducing agents may be resorted to to act upon the metal in this sprayed and disintegated condition.

When necessary a batter of the vessels may be so connected that t ie-molten metal passing through the first vessel will be dis charged through the spout of the first vessel and into a second vessel to provide acontinuous path whereby the molten metal may be acted upon by the chemical condition of the its compounds.

It may be required to divide the volume of the molten metal leaving the spout of a cupola or furnace into a number of streams with each directed to a separate apparatus since the flow may be too great to handle as a single stream.

During the melting down process of the metal the volatilized mineral gases and other elements which contaminate the metal and which are entrapped in the molten metal are acted upon by the reagents and compounds in the molten slag or sinter which float upon It will be noted that the filtering process functions continuously as the metal percolates or passes through the slag and whereby the metal is washed by the slag and cleansed of impurities by reason of the strong aflin-ity of the different slags for the gases. These impurities which contaminate the molten metal if not reduced will injure subsequent castings.

The weak and exhausted contaminated slag is revived but when spent is undesirable and is removed from time to time from the level 19 of the liquid 20 through the passage 31 after the plug has been removed.

Other materials such as re-agents Or scavengers can be introduced through the opening 34 for thereplenishing of the slag during its now possible to revive or build up slags by the present method and apparatus. By tapering the spout 12 it will be seen that a better balance is had between the two columns of liquid, and the slag, and better access to the plug used in the throat of the pouring spout is provided "for,

I claim l An apparatus-for the reduction of the elements from molten metals, which has been.

run directly from a melting unit comprising an open vessel formed of a metal shell, a refractory lining within the shell, said shell and lining being provided with an outlet pas-.

sage adjacent the lower end thereof, a discharge spout connected with the passage and tapering from the outer free end thereof towards the inner end where it is'connected with the passage in the shell and lining, the outer free end of the spoutbeing provided with a discharge port, the shell and lining port of the. spout.

having air inlet passages opening into the vessels at points above but adjacent a horizontal plane passing through the discharge LLEW LLYN JONES.

till

Images