The physical chemistry of metals by Schenck Friedrich Rudolf 1870-

Author:Schenck, Friedrich Rudolf, 1870- [from old catalog] & Dean, Reginald Scott, [from old catalog] tr
Language: eng
Format: epub
Tags: Metals
Publisher: New York, J. Wiley & sons, inc.; [etc., etc.]
Published: 1919-03-25T05:00:00+00:00

72

32

40

Fig. 80.

composition Ni3S2; at low temperatures still further compounds exist namely NiS, Ni3S4, NiS2 and apparently also NieSs. As in all nickel containing systems, the tendency to form solid solu-

* Metallurgie, 6, 13 (1908).

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ALLOYS OF METALS WITH CARBIDES, ETC.

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tions is very great; there precipitates from the melt principally solid solutions which separate from the melt in a very complex way.

Alloys Between Sulfides.

In the metallurgy of copper, nickel and lead, there occur as important intermediate products, the so-called mattes, copper matte, lead matte and nickel matte, alloys of the corresponding sulfides with iron sulfide. It is of importance to obtain a picture of their important structural constituents. In many cases compounds occur between the components, in part these are such as occur in nature as ores, we have accordingly before us a field which must arouse the interest of the smelterman to a high degree. Here also metallographic methods give the explanation of the nature and formation of these products.

In most cases the equilibrium diagrams are comparatively simple. Out of the melts, miscible in all proportions the components crystallize on solidification in the pure state. The diagram consists of two curves which cut in a eutectic point. This form we find in all alloys in which lead and zinc sulfide occur as components. The melting points of the components, the position of the eutectic temperature as well as the composition of the eutectic alloy are given in the following table:

♦ Metallurgie, 4, 479 (1907): 4. 672 (1907): •. 114 (1908).

There are also cases in which solid solutions occur between the components; in the system copper sulfide, silver sulfide

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THE PHYSICAL CHEMISTRY OF THE METALS

which has been investigated by Friedrich * there appears to be present complete miscibility in the solid state. The solidification curve has a mijiimum at 677°. The following table shows the dependence of the solidification point on the composition:

According to the investigation of P. Rontgen there are a number of compounds which occur between the components of copper matte; those recognizable by a maximum in the solidification diagram are (Cu2S)3.FeS, Cu2S-FeS and probably a third (Cu2S)2(FeS)5; also in the system silver sulfide—^antimony sulfide we find a maximum at the places on the diagram which represent the composition of the compounds Sb2S3Ag2S and Sb2S3 •3Ag2S. Both occur naturally, the first as miargyrite, and the last as pyrargyrite or ruby silver ore.

The position of the melting point of the components and compounds (maxima) as well as the co-ordinates of the eutectic point are given for the two systems in the following table:

' Metallurgie, 4, 671 (1907).

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We meet very complex relations in the nickel sulfide—iron sulfide alloys. The equilibriimi diagram is given by Bornemann (Fig. 8i). The sulfides FeS and Ni3S2 combine with each other to a compound (FeS) 2 Ni3S2 which is capable of forming solid solutions with the nickel sulfide in all proportions; at low temperatures different transformations go on, the nature of which is not entirely clear. Also the nickel sulfide

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