US1703657A - Art of smelting manganese - Google Patents

Description

PATENT OFFICE.

Anson Gmmm'a ms, or xmmmnoox, NEW YORK.

- AB! 01' BliIF-LTING MANGANESE.

Io Drawing.

This invention relates to the recovery of L manganese from ores, by smelting, particuas spiegeleisen, the principal manganese melarly to its recovery from ores and earthy material containing manganese, of compara-' tively low grade.

The principal object of this invention is to extract manganese b smelting, at low cost, and thereby to utillze low grade mangam'ferous material now considered to be of no, or low value, as well as to recover when .Iesirable certain by-products as may be noted from the following. Other objects will appear from the following description.

Hitherto, crude manganese metal, known as ferromanganese, or in lower grade known tallic products, have in general only been successfully produced from ores that would be considered of exceptionally high grade, if applying to other metals as copper, lead or zinc, for example. The amount 0 high grade manganese ores, low in percentage of silica and deleterious ingredients, compared to lower grade materials still containing con- .siderable percentages of manganese, is beis sufiicient for all requirements, and not so remote from districts where manganese is consumed. As far as I know, these materials are not now being utilized for making ferromanganese, or spiegeleisen'.

Such lower grade manganese material may be a mixture of manganese oxidesand slaty or silicious material and dirt, and may contain considerable percentages of oxide of iron. Some of these materials are known as mang alrxniferous iron ores, more or less silicious.

ere are slaty beds of ma aniferous material in abundance, mangani erous clays containing nodules of manganese oxides and black soft manganese streaks not now saved in mining. There are deposits of rhodonite, silicate of manganese, carrying 20 or more percent of manganese, with much silica. There are large amounts of oxidized rhodonite, consisting of an intimate mixture of silica and manganese oxides, carrying 30% Application filed November 23, 1985. Serial Io. 70,819.-

or more of manganese. My present process 15 believed to be 'adapted'to -all of these materials when carrying suflicient manganese.

Naturally, the details of a process would be varied in treating such a variety of materials, while stilloperating on the same principle in respectof the manganese contents, thevariatious being such as would be applied by one skilled in the art, in view of the present disclosure, to properly provide for and take care of the other ingredients, and to utilize them as far as may be, for valuable byproducts' In the ordinary smelting of manganese, the cost of producing crude manganese metal, is greatly Increase by the presence of even moderate amounts of silica, which is the chief ingredient in the average lower grade manganese material. Also, considerable manganese material otherwise of good or fair grade, is rendered of low value by the presence of considerable iron. The iron appears as an alloy of manganese and makes the'manganese of less value and the cost of reducing iron in a manganese furnace is materially greater than the cost of reducing iron in an lIOIl furnace, thus making a loss on the iron made, in addition.

In my process, instead of smelting the ore to produce crude metallic manganese alloyed with more or less iron, the less iron the better, and also containingparbon, I smelt the ores to produce as princlpal manganese product, a crude, fused sulphide of manganese, herein called a matte which separates separately from the reduced iron, and from the sla containing the silica and fluxes therefor, ound in the materials used, and added specially as flux. This accomplishes the two principal objects, that is, separation from iron, and from silica, by a comparatively cheap process of wide application relatively to various grades and kinds of manganese materials. Of course, if the iron is present in the charge in relatively small amounts, it is not necessarily profitable, and in the process it is not necessary, to make a product of metallic melted iron, but the iron maybe taken from the furnace as a sulphide alloyed with the manganese sulphide as a crudemanganese and iron sulphide. However, in View of the amount of iron that is not objectionable in crude manganese, that is about 1 part of iron to 4 parts of manganese, it is preferable to make a separate product of iron, when iron is present in materially greater amounts,

and in the case of manganiferous iron ores, the recovery of the iron may be a considerable part of the value of the operation and process.

While in the present art of smelting manganese ores to crude manganese metal, very basic and expensive slags must be made, with high losses of manganese in the slag and expolled from the furnace as a fume, with very high temperatures, very expensively produced, these difiiculties very largely disappear, in using my process, because the slag may be made more silicious and therefore cheaper, the operation can be carried out at much lower temperatures and therefore much cheaper on that account, with largely increased output from a given furnace. It

might be mentioned further, that the process provides opportunity to work manganese materials containing considerable phosphorus, as the melted iron collects the bulk of the phosphorus and'removes it from the sd, such procedure would. answer the requirements, but I regard that method as probably impracticable. I may use, principally, iron or calcium sulphides, or equivalents of the latter. Calcium sulphate, gypsum or anhydrite, are equivalents of the latter, as in the furnace, calcium sulphate in presence of fuel, becomes converted into calcium sulphide. Other equivalents are the sulphides or sulphates of sodium, potassium, strontium or barium, but on account of the higher value of the sulphates and sulphides of such elements other than calcium, I regard them more as equivalents chemically, than commercially, and in this description I shall only describe the use of the compounds of calcium in this connection.

In -one example of the process, a slaty or silicious manganese ore is smelted in a blast furnace with an iron pyrite or pyrrhotite ore, limestone or dolomiteas flux for the silica and alumina, and coke for fuel and as reducing agent. The silicious and aluminous matters unite with lime and magnesia to form a slag. More or less sulphur may be expelled, particularl from bisulphide of iron, pyrite, with the urnace gases but large amounts thereof unite with the manganese to form a fused, crude, manganese sulphide, or matte, while iron separates separately as melted iron. The separation of the iron matte and slag, will be well understoodby urnacemen.

Chemically, the following reactionsmay be Written by way of illustration, following the conventional way of representing processes in which chemical change take place.

Pyrite is decomposed at low temperatures, into sulphur and sulphide of iron. This will take place as the charge warms up and the sulphur burns oil? or is volatilized:

FeS =FeS+S Reduction of manganese oxides to lower oxides, approximately represented as follows MnO CO=MnO CO,

Reaction between manganese oxide and .iron sulphide in presence of fuel for reduction, by one or both of the following FeS +MnO C=Fe+MnS+CO FeS +MnO+ CO=Fe+MnS+CO It is not necessary to write equations showing the formation of slag, largely or mainly of calcium silicate. Slag is a chemically indefinite material containing a mixture of oxides of bases and silica, fluxing each other into melted slag.

In another example of the process, the material to be smelted, beside containing manganese and earthy silicious matters, also contains iron oxides, so that the ore is a more or less silicious and impure iron-manganese ore, known as a manganiferous ore, meaning manganiferous iron ore.

In this example, the process is identical,

with the foregoing example, except. that the 1ron oxides are reduced by the agency of fuel, tometal, and the amount of iron produced, is thereby increased to the corresponding extent.

In another example, the formation of manganese sulphide, is, in whole or in part, brought about, by the use of calcium sulphide, which may be conveniently introduced as the cheap and abundant native calcium sulphate, anhydrite or gypsum, the difference in the two being a mere difierence in that gypsum contains water, about 21%. Suflicient fuel is allowed for, and contained in the charge, to effect the chan e of the calcium sulphate to calcium sulphide.

Calcium sulphide then reacts with manganese oxide, whether present in the hot charge as manganese oxide, or combined with silica, as manganese silicate, producing as products,

manganese sulphide, and calcium silicate dis-' solved in and being part of, the slag. The following equation may be written by way of illustr'atlon, although the practical process lacks the chemical definiteness of a pure chemical reaction MnSiO -l-CaS=CaSiO +MnS a product of iron also obtained, nevertheless.

In still another example of the process, the

ore used contains oxides of iron and manganese, each in considerable amounts worth recovering as separate products, beside silicious.

matter. It is obvious that the silicious matter requires a base to flux it into a slag, and lime in the standard and ordinary flux, some times in part replaced by magnesia by using dolomite instead of limestone. The lime for making the slag, however, is not in this example, mainly supplied by the use of raw or burnt limestone, but in the shape of calcium sulphate. In the foregoing example, it has been pointed out that the calcium sulphate,

ields sulphur to make the manganese matte, beside furnishing calcium oxide for the slag, and in this example, the quantities are proportioned, as is readily done by one skilled in the art, so that the calcium sulphate doubly performs the two functions of slag and matte maker, without requiring other flux, for the silica.

In a still further example, using calcium sulphate, the amount of silica present, is not sufficient, to combine with the lime of the calcium sulphate to make the most desirable slag, and both iron sulphide and calcium sulphate are used, thereby cutting down the amount of lime to be slagged, and producing more iron product. I

Crude manganese sulphide is not a commercial product and would be worthless, if used directly, in making steel, where most of the manganese is consumed. It requires to be converted into metal, or other manganese products. I prefer to dothis, by mere oxidation of the sulphide in furnaces, with air, either at relatively low temperature, by the process known for other metals as roasting, or at higher temperatures, in the fused state, by blowlng air through, in the process known as Bessemerizing. In either case, the product is oxide of manganese, and sulphurous gases, which may be condensed and used as sulphuric acid, by well known methods. Such oxide of manganese, practically free from silica, and relatively free from deleterious ingredients, is the ideal material for the production of crude or refined manganese metal for its various uses.

Another method, which I may refer to, as it has some bearing on a phase of the rocess, consists in smelting manganese su phide, preferably in electric furnaces, with lime and carbon, producing crude manganese metal,

and a roduct of calcium sulphide, by substantia y the chemical reaction:

The calcium sulphide is valuable for the process, as part of the smelting charge, be-

.side which, any manganese sulphide contained therein, is merely returned to the process and not lost.

Broadly, the process of recovery consists in smelting the ore with addition of sulphur in some practicable form producing a fused manganesesulphide pr not and converting this into manganese metal.

Since, when iron sulphide ore, etc., is used as the supplier of sulphur to produce manganese sulphide from the manganese of the manganese ore, etc., the iron thereof is recovered as metallic iron, in its preferred form the process gives an additional useful result, the recovery of metallic iron from its sulphide, which is in general a very cheap or practically worthless material.

In the particularly preferred form, the process includes the further step of converting the manganese sulphide to an oxide by oxidation and reducing the oxide to metallic .manganese.

have been thrown away and may be treated I by my process. Also slags from ferromanganese furnaces, and other slags made in connection with iron smelting operations, may be worked for the manganese or manganese and iron contained therein.

The term sulphur-introducing ingredient used in the claims refers to iron or calbefore describe-d, and equivalents, serving to supply the sulphur needed to produce manganese sulphide from the manganese oxide present in the manganese-bearing material to be smelted for the production of manganese sulphide. This term would not include manganese sulphide as manganese sulphide would not have the property of introducing sulphur to other manganese, its affinity for manganese being already satisfied.

What I claim as new and desire to secure by Letters Patent, is:

1. Process of recovering manganese from material containing manganese and silica which consists in smelting said material with addition of a sulphur-introducing ingredient, producing fused manganese sulphide, and fused slag containing the silica of said material.

which consists in smelting said material with addition of a sulphur-introducing ingredient, producing fused manganese sulphide,

cium sulphide or calcium sulphate as hereinfused metallic iron, and-fused ing the silica of said material.

3. Process of recovering manganese from material containing manganese and silica which consists in smeltin saidmat'erial with addition of a sulphide ot er than of manganese, producing fused manganese sulphide, fused metallic iron and fused slag containing the silica of said material.

4. Process of recovering manganese from material containing manganese and silica which consists in smelting said material with addition of iron sulphide, producing fused manganese sulphide, fused metalliciron, and fused slag containing the silica of said material.

5. Process of recovering manganese from material containing manganese and silica slag containwhich consists in smelting said material with addition of iron sulphide, producing fused man anese sulphide, fused metallic iron, and fuse slag containing the silica of said material, and converting said manganese sulphide to manganese metal.

6. Process of recovering manganese from material containing manganese and silica which consists in smelting said material with addition of a sulphide other than of manganese, producing fused manganese sulphide, fused metallic iron and fused slag containing the silica of said said manganese sulphide to manganese oxide and reducing said manganese oxide to metallic manganese.

In testimony my name this 5th day of November, 1925.

ANSON GARDNER BETTS.

material, converting whereof I have hereto signed