USRE12801E - Heinbich colloseus - Google Patents

Description

HEINRICH ooLLosEUs, or BERLIN,

NEW YORK, N. Y.,

GERMANY, ASSIGNOR TO WILLIAM AND EDWARD JOHN VAVASOUR EARLE, OF LONDON, ENGLAND.

Ross WARREN, or

PROCESS FOR MANUFACTURING CEMENT FROM BLAST-FURNACE SLAG.

Specification of Reissued Letters Patent.

Reissued June 2, 1908.

0rigina1 No. 837,918, dated December 11,1906, Serial No. 251,446. Application for reissue filed February 29, 1908 Serial No. 418,621.

To all whom it may concern:

Be it known that I, HEINRICH CoLLosEUs, chemist and doctor of philosophy, a subject of the German Emperor, residing at 29 Pragerstrasse, in the city of Berlin, Kingdom of Prussia, and German Empire, have invented a certain new and useful Process for Mann-' facturing Cement from Blast-Furnace Slag, of which the following is a specification.

This invention has reference to the manufacture of cement from blast-furnace slag; and it consists in a process wherein an addition of solutions of calcium salts, aluminium and tri calcium, aluminium, or

salts, and magnesium salts is made to the slag, according to its composition, on the discharge of the slag from the blast-furnacethat is to say, while it is yet in a liquid condition.

It is a well-known fact that blast-furnace slag of the most usual compositions, both the flour-like powder as well as the owdered granulated slag, possesses hydrau ic qualities; but these powders will set only after several days and either do not attain at all the strength required of cement or, in the case of particularly favorable compositions of slags, only after some months, so that they cannot be regarded as cements proper, practically speaking.

My present invention consists in introducing into the liquid blast-furnace slag salts of lime, of alumina, or of magnesia, in solution, one or more of these, according to the proportion of lime, al silicic acid contained in the slag and according to the hydraulic qualities dependent.

thereon.

The process is carried out as follows: The stream of liquid sla when it runs out from the blast-furnace 1s nely distributed, and at the same time an aqueous solution of calcium salts, of alum, of sulfate of magnesia, or of any other salt or salts of one or more ,of these three metals is allowed to act upon this finely distributed sla Water-vapor will then be evolved and also small quantities of vapors of sulfur dioxid formed by oxidation.

The salts dissolved in the solution, whether they are calcium, alum, or magnesium salts or all three together, combine apparently with the silicic acid, with the lime, and the alumina of the blast-furnace slag to form di magnesium present in the silicates. The sulfuric acid umina, magnesia, and

salts or produced by oxidation acts upon some of the calcium sulfid contained in the blast-furnace slag, so as to form the valuable calcium sulfate. The liberated water causes a rafid cooling of the slag which, results in a kin of clinker that resists the action of the air, so that, particularly with foundry-iron slags, which are very rich in lime, a disintegration in air that would form the so-called smelters flour is avoided. This slow disintegration destroys, largely or wholly the cement-like qualities of the product. The vapor produced from the a ueous solution by the contact with the hot s ag is a very efficient agent in effecting a disruption of the sla which assists in incorporating the salts with the hot slag. It is obvious that by a mere melting together of the alkaline-earth constituents of the salts with, the slag this object of the chan e of physical properties can not be obtaine and 1t 1s not ossible to have the salts so finely distribute as to produce the decomposition desired. The thus treated slag is distinguished from the untreated slag, apart from its chemical composition, in the following points as regards physical properties; first, as compared with the above-mentioned slnelters fiour, disintegrated fiour-like slag, and water granulated and air-treated slag, slags treated according to the process herein described react considerably more readily; second, While the disintegrated flour, the dried water-granulated slag, and the air-treated slag of the most usual compositions either do not harden at all in most cases or only after some Weeks, so

as to form a kind of cement, the slag treatedaceording to the process herein described exhibits the physical behavior of a good Portand cement.

Chemically speaking, the slag treated ac cording to the recess stated differs from smelters flour, isinte rated-slag flour, wator-granulated slag, and slag that has underone an air treatment by the fact that the sul- %d of lime, which is generally contained in very large quantities in the smeltersflour, in the water-granulated slag and in the air treated slag is part] oxidized.

The amount of sa ts to be used varies with the composition of the particular slag. If, for example, blast-furnace slag is to be treated containing approximately from twenty-six to thirty-two per cent. of silica,

from twelve to eighteen per cent. of alumina and iron, and from forty-five to fifty per cent. of lime, it is sullieient toinject into thefreshlyprepared molten slag from six to ten per cent. of the solutions of salts containing, as an instance, about five per cent. of nitrate or sulfate or other suitable salt of the abovementioned metals. It has, however, been found that slag containing a higher pro )or tion of silica and less lime can also be ma e to harden in the same manner as cement-that is to say, it can also be used for the manufacture of cement, answering the necessary requirements if solutions containing a higher percentage of. salt-for instance, up to ten per cent.are injected, thus increasing the roportion of salts in relation to the slag. ith sla s of approximately the composition hereinbefore mentioned I prefer to use sulfate of magnesia alone in the majority of cases; but with slags of different composition the best salt or combination of salts for producin the desired result can only be ascertaine by experiment. If the slag is thick in flowing or is not perfectly liquid, it is desirable to reduce t e percentage of solution used, at the same time increasim its strength in proportion. The object of t 's is not to cool the slag too much in the operation.

I am aware that salts, and in particular sodium salts in a dry state, have been added to hot liquid slag in order to remove some impurities of the slag by mutual decomposition and subsequent skimming off the prodnets of decomposition. This is, however, entirely different from my invention, inasmuch as in my invention the actioninvolves a change of physical properties, as above outlined, and a very fine state of distribution of the salts and a disruption of the slag, due to the fact of adding the salts in aqueous solution, while the chemical reactions which are set up are also entirely different from those set up by the melting together of the reagents with the slag.

I am also aware that attempts have been made to improve the quality of slag cement by treating molten but not necessarily freshl prepared and very highly.heated slag wia a mixture of lime andchlorid of lime, in which the lime is greatly in excess of the chlorid of lime, so as to form a paste of lime containing a small percentage of chlorid of lime, in order to increase the amount of lime to be incorporated with the slag; but this also is not t 6 object of my invention, which aims to reduce a product having the desired cementike qualities without any subsequent addition of lime to the molten sla and merely by the changes set up b the issociation produced upon the addltionof the small quantities of solutions of salts of alkaline earths and of the earth metals to the slag, as above outlined, and without an further addition of alkaline or alkaline-earth oxid or of any other ingredient not already present in the slag, with the exception of said salts.

\Vhat 1 claim, and desire to secure by Letters Patent of the United States, is-

1. The process herein described of manufacturing cement from blast-furnace slag, which consists in treating freshly-pre )ared hot liquid blast-furnace slag with a so ution of any water-soluble salt of the earthy oxidforming metals and without any further addition.

2. The process of manufacturing cement from blast-furnace slag which consists in act ing upon freshly-prepared hot liquid blast furnace slag with relatively small uantities of the solution of any water-solub e salt of the earthy oXid-forming metals and Without any further addition.

3. The process of manufacturing cement from blast-furnace slag which consists in acting upon freshly-prepared hot liquid blastfurnace slag with a solution of any water soluble salt of the earthy oxid-forming metals, the slag being largely in excess of said solution, and without any further addition, and then allowing the product to cool.

4. The process of manufacturing cement from blast-furnace slag which consists in acting upon freshly-prepared hot liquid blastfurnace slag with a solution of any watersoluble salt of the earthy oXid-forming metals, most deficient in the composition of the sla the slag being largely in excess, and wit iout any further addition and allowing the product to cool.

5. The process of manufacturing cement from blast-furnace slag which consists in acting upon freshly-prepared hot liquid blastfurnace slag with so much of a solution of any water-soluble salt of the earthy oxidforming metals, the slag being lar ely in excess, as to avoid chilling of the s ag during the operation, and without any further addition, and then allowing the product to cool.

6. The process herein described of manufacturing cement from blast-furnace slag, which consists in acting upon the hot liquid slag with a solution of any one or more water soluble salts of the earthy oXid-forming metals, the specific quantity and character of said solution being such with reference to the com osition of the slag to be treated as to pro uce the desired cementlike qualities therein.

7. The process herein described of manufacturing cement from blast-furnace slag, which consists in treating the hot liquid slag while in a finely distributed state w1th a solution of any one or more water soluble salts of. the earthy oxid-forming metals, the specific quantity and character of said solution being such with reference to the composition of the slag to be treated as to produce the desired cement-like qualities therein. 4

8. The process herein described of manufacturing cement from blast furnace slag, slag with a solution of sulfate Ofilllfigllfisilllll, which consists in acting u on the hot liquid the specific quantity and character of said soslag with a relatively small quantity of a solution being such with reference to the com- 15 lutlon of any one or more water soluble salts position of the slag to be treated as to pro- 5 of the earthy oxid-forining metals. the spe duce the desired cement-like qualities therein. ciiic quantiq and character of said solution In testimony whereof I have hereunto being such with reference to the composition signed 111 name to this specification in the of the slag to be treated as to produce the depresence of two subscribing witnesses.

sired cement-like qualities therein. HEINRICH COLLOSEL S. 10 9. The process herein described of inanu- 1tnesses:

facturing cement from blast -furnace slag RICHARD EYRE,

Enwlx SEGER.

which consists in actin u on the hot 1i id.

Correction in Reissue Letters Patent No. l2,80l.

It is hereby certified that in Reissue Letters Patent No. 12,801, granted June 2, 1908, upon the application of Heinrich Colloseus, of Berlin, Germany, for an improvement in Processes for Manufacturing Cement from Blast-Furnace Slag, an error occurs in the printed specification requiring correction, as follows: In line 53, page 1,

1 after the word and," a comma and the word or should be inserted; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of June, A. D., 1908.

[SEAL] C. C. BILLINGS,

Acting Commissioner of Patents.