Review on the Recovery of the Platinum-Group Metals
No definite date can be ascribed to the discovery of platinum; rather it became gradually known to the Western World as a distinct metal of unique properties over a period of two centuries, between 1500 and 1700. The first source to be exploited was the p
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Review on the Recovery of the Platinum-Group Metals
1.1 Historical Perspective No definite date can be ascribed to the discovery of platinum; rather it became gradually known to the Western World as a distinct metal of unique properties over a period of two centuries, between 1500 and 1700. The first source to be exploited was the placer deposits in New Granada (now Colombia) where it was initially regarded as a nuisance in the gold extraction operations. By about 1750 however it was beginning to be exploited for its own sake and had found uses for decorative purposes . The development of the technology of these metals can be divided into four stages: Period of Discovery, 1750 to 1820
During this period major progress was made in separating the various platinum metals and in establishing many of the basic characteristics of their chemistry. Thus, for example Scheffer established in 1751 the fact that NHt ions precipitated Pt as an insoluble salt from Cl- solutions - a technique used in its recovery and refining up to the present day. By 1804 various techniques had been used to isolate five of the six metals (Pt, Pd, Rh, as, Ir) from Colombian ores. At the same time much attention was also paid to the physical metallurgy of the new metals, especially of Pt and to methods of fabricating them. The techniques of extraction, refining, and fabrication developed during this period thus laid the foundation for the industrial exploitation of the metals. First Industrial Period 1820 to 1900
This period is distinguished by four major developments in the industrial applications of the platinum metals. These were: (a) The development of industrial-scale integrated refining processes for the metals. Starting with Breant in 1822, these processes included steps such as aqua regia leaching , distillation of as, precipitation of Pt as (NH4l2PtCle and precipitation of Pd as PdCl2(NH3l2 . (b) The establishment of industrial companies whose major business was the extraction, refining, and fabrication of the platinum metals. These include Johnson Matthey, Hereaus, and Desmontis Quennessen early in the period, and Bishop and Baker-Engelhard later on . (c) The establishment of international trade in the metals and their ores, firstly from Colombia alone, but later and almost exclusively from new deposits in Russia. (d) The development of satisfactory methods of fabricating the metals and their usage as corrosion-resisting linings, especially in sulphuric acid boilers - the major use for Pt till after the turn of the century. Gmelin Handbook PI Suppl. Vol. A 1
G. J. Bernfeld et al., Pt Platinum © Springer-Verlag Berlin Heidelberg 1985
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Second Industrial Period 1900 to 1960 Platinum metals were obtained from a wide variety of sources dur ing this period . Placer deposits in Colombia and Russia were still exploited, but the recovery of byproduct plat inum metals from Cu-Ni ores from Sudbury, Canada became an important source from about 1920 and by the late 1930sthis source was dominant in the market. This situation continued until th
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