3. On the production of slag rich in bases._Scientific American Supplement, No. 315, January 14, 1882

These different conditions may be obtained with but slight variations

at the different works, but the condition of a high temperature is one

of the most important considerations, not only for the alloys of

manganese, but equally as well for the alloys of iron, manganese,

silicium, those of chromium, of tungsten, etc. It is also necessary to

study the effects produced either in the crucible or in the blast

furnace, and to examine the ores which for a long while have been

regarded as not reducible.

The works of Terre Noire especially made at the same time, in the

blast furnace, ferro-silicon with manganese, alloys which are daily

becoming more important for the manufacture of steels tempered soft

and half soft without blowing.

These alloys, rich in silicon, present the peculiarity of being poor

in carbon, the amount of this latter element varying with the

proportions of manganese. In addition to the alloys used in the iron

and steel industry, we shall proceed to relate the recent progress

obtained in the metallurgy of other materials (especially copper) by

the use of _cupro-manganese_:

+---+---------+-------+---------+---------+------+------------------------------

| | Mn. | C. | Si. | S. | P. |

+---+---------+-------+---------+---------+------+

| A | 18 to 20| 2 to 3| 10 to 12| Traces | |Extra Quality for soft metals.

| B | 15 to 18| 3.00 | 10 to 8 | scarcely|About |} Medium Quality

| C | 15 to 10| 3.25 | 8 to 6 | percep- |0.100.|}

| D | 5 to 10| 3.50 | 4 to 6 | tible. | |Ordinary for hard metals.

+---+---------+-------+---------+---------+------+------------------------------

The first alloys of manganese and copper were made in 1848, by Von

Gersdorff; soon after Prof. Schrötter of Vienna made compounds

containing 18 or 20 per cent. of manganese by reducing in a crucible

the oxides of copper and manganese mixed with wood charcoal and

exposing to a high heat.

These alloys were quite ductile, very hard, very tenacious, and

capable of receiving a beautiful polish; their color varies from white

to rose color, according to the respective proportions of the two

bodies; they are particularly interesting on account of the results

which were obtained by adding them to certain metallic fusions.

It is well known that in the fining of copper by oxidation there is

left in the fined metal the suboxide of copper, which must then be

removed by the refining process, using carbon to reduce the copper to

its metallic state. M. Manhès, taking advantage of the greater

affinity of manganese for oxygen, found that if this last element was

introduced into the bath of copper during the operation of refining,

the copper suboxide would be reduced and the copper obtained in its

metallic condition. For this purpose during these last years real

cupro-manganese has been prepared, occupying the same position to

copper as the spiegel or the ferro-manganese does toward the

manufacture of steel. M. Manhès used these same alloys for the fusion

of bronze and brass, and recommended the following proportions:

3 to 4 kilog. of cupro-manganese for 100 kilog. of bronze.

0.250 to 1 do. do. do. brass.

0.150 to 1.2 do. do. do. copper.

In every case the alloy is introduced at the moment of pouring, as is

the case in the Bessemer or Martin process, taking care to cover the

fusion with charcoal in order to prevent the contact with air,

together with the use of some kind of a flux to aid in the

scorification of the manganese.

According to M. Manhès a slight proportion of manganese added to

bronze appears to increase its resistance and its ductility, as is

shown in the following table, provided, however, that these different

alloys have been subjected to the same operations from a physical

point of view; that is, pouring, rolling, etc.

--------------------------+-----+-----+------+----------+------------+

| Cu. | Sn. | Mn. | of | Elongation |

--------------------------+-----+-----+------+----------+------------+

Ordinary Bronze | 90 | 10 | | 20 kil. | 4.00 |

Bronze with Manganese, A, | 90 | 10 | 0.5 | 24 " | 15.00 |

Do. do. B, | 90 | 10 | 1.0 | 26 " | 20.00 |

--------------------------+-----+-----+------+----------+------------+

The White Brass Co., of London, exhibited at Paris, in 1878, manganese

bronzes of four grades of durability, destined for different uses and

corresponding to about 20 to 25 kilos of the limit of elasticity, and

36 to 37 kilos of resistance to fracture; the number 0 is equivalent

after rolling to a resistance to fracture of 46.5 kilos, and 20 to 25

per cent. of elongation.

Such results show beyond contradiction the great interest there is in

economically producing alloys of copper, manganese, tin, zinc, etc. In

addition, they may be added to metallic fusions, for deoxidizing and

also to communicate to the commercial alloys (such as bronze, brass,

etc.) the greatest degree of resistance and tenacity.

While many investigators have tried to form alloys of copper and

manganese by combining them in the metallic state (that is to say, by

the simultaneous reduction of their oxides), the Hensler Bros., of

Dillenburg, have found it best to first prepare the _metallic

manganese_ and then to alloy it in proper proportions with other

metals. Their method consisted of reducing the pure pyrolusite in

large plumbago crucibles, in the presence of carbon and an extra basic

flux; the operation was carried on in a strong coke fire, and at the

end of about six hours the _crude manganese_ is poured out, having the

following composition:

Manganese 90 to 92

Carbon 6 to 6.5

Iron 0.5 to 1.5

Silicon 0.5 to 1.2

By refining, the manganese can be brought up to 94 to 95 per cent. of

purity. It is from this casting of pure manganese that is obtained the

substance used as a base for the alloys. This metal is white,

crystalline, when exposed to the damp air slowly oxidizes, and readily

combines with copper to form the _cupro-manganese_ of the variety

having the composition--

Copper 70

Manganese 30

Cast in ingots or in pigs it becomes an article of commerce which may

be introduced in previously determined proportions into bronze, gun

metal, bell metal, brass, etc. It may also be used, as we have already

mentioned, for the refining of copper according to Manhès's process.

Tests made from this standpoint at the works of Mansfield have shown

that the addition of 0.45 per cent. of cupro-manganese is sufficient

to give tenacity to the copper, which, thus treated, will not contain

more than 0.005 to 0.022 of oxygen, the excess passing off with the

manganese into the scorias.

On the other hand, the addition of cupro-manganese is recommended,

when it is desirable to cast thin pieces of the metal, such as tubes,

caldrons, kitchen utensils, which formerly could only be obtained by

beating and stamping.

The tenacity obtained for tubes of only three centimeters in diameter

and 1.75 millimeters in thickness is such that they are able to

withstand a pressure of 1,100 pounds to the square inch.

The _manganese bronze_, which we have previously referred to, and

which is used by the White Brass Company of London, is an alloy of

copper, with from one to ten per cent. of manganese; the highest

qualities of resistance, ductility, tenacity, and durability are

obtained with one to four per cent. of manganese, while with twelve

per cent. the metal becomes too weak for industrial uses.

+-----------+---------+-----------+-------------+------------+

+-----------+---------+-----------+-------------+------------+

| A | 96.00 | 4.00 | 19.00 | 14.60 |

| B | 95.00 | 5.00 | 20.62 | 10.00 |

| C | 94.00 | 6.00 | 20.80 | 14.60 |

| D | 90.00 | 10.00 | 16.56 | 5.00 |

+-----------+---------+-----------+-------------+------------+

The preceding table gives some of the experimental results obtained

with the testing machine at Friedrich-Wilhelmshütte on the crude cast

ingots; the resistance is increased, as with copper, by rolling or

hammering.