PLATINUM METALS Prior to the World War Russia was not only the leading pro ducer of platinum metals, but was also almost the only producer. Colombia was a very poor second, and other countries hardly en tered the picture. During the war Russian output decreased, while the Colombian increased, and during the years of Russian reor ganization from 1919 to 1923 Colombia was the leading producer. From 1924 to 1933 Russia was again in the lead, but since 1934 Canada has stood first by a wide margin. South Africa developed into an important producer beginning in 1926, and since
the United States has been increasing. In 1938 Canada stood first, Russia second, South Africa third, United States fourth, and Colombia fifth. During the 25 year period, 1913-1937, world production of platinum metals has more than doubled, reaching well over 5oo,000 ounces. On the average, about two-thirds of the total is platinum, and most of the remainder is palladium; the outputs of the other members of the group are comparatively small.
The first production of platinum metals on a commer cial scale in Africa began in 192o, when a small amount of osmiri dium was recovered as a by-product in the milling of the Rand gold ores of South Africa. Within a few years production had in creased to 5,000-6,0000z. annually, and this may be expected to continue. In 1923 a platiniferous lode was discovered in the Waterberg district, and in 1924 additional discoveries were made in the Lydenburg, Potgietersrust, and Rustenburg districts, with platinum metals content of 2 to 7 dwt. per ton. Enormous amounts of ore have been located in these areas, and by some it is thought that there exist here greater reserves of platinum than are known in all of the other sources in the world. Production has been lim ited by the high cost of a complicated metallurgical treatment and the prevailing low prices of the platinum metals, but has been sufficient to keep South Africa in second or third place in the list of world producers. An output ranging from 5,000 to 8,000 oz. annually has been developed in Ethiopia, beginning in 1926. Since 1929 there has also been an output of a few hundred ounces in Sierra Leone, and since 1934 there has been a variable by-prod uct recovery from the copper refinery in Belgian Congo. Little is
known about the extent of the reserves of these smaller producers, but it is pretty well established that the total for the continent is extremely high, but the grade of the ore is so low, and the re covery costs so high, that these reserves will be of much more significance in later years when some of the richer deposits have been more nearly worked out, when prices are higher, or when recovery methods have been further improved and cheapened.
Platinum has been produced in small amounts in several areas in New South Wales, Queensland, Victoria, Papua, and New Zealand, but the total output has never been more than a few hundred ounces annually, and has been declining. Osmiri dium has been reported in New South Wales and Victoria, but there has been no recent output. In Tasmania, osmiridium has been found in several localities, but the deposits have been largely worked out, and the output declined to 191oz. in 1938. Papua also occasionally reports a few ounces of osmiridium. No definite in formation is available on the reserves in any of these localities.
Platinum and osmiridium have been reported in nu merous gold placers in Japan, mostly in Hokkaido, but production has been only ioo-3000z. annually. There is also presumably some by-product recovery from copper refining.
The only source of platinum in Europe is in Russia, which, until recently, was the world's foremost producer, and has, all told, contributed three-quarters or more of the entire world output to date. Platinum was first found in gold mines in the Urals in 1819, and in alluvials in 1823. The primary deposits are in dunites and pyroxenites, and these have been worked on a small experimental scale, but most of the recovery has been from placer deposits along the stream beds leading from the primary sources. Various estimates of the reserves vary from 4,000,000 to 7,000, 000oz., but these are now so old that little dependence can be placed on them. Modern dredge equipment has replaced most of the old hand methods in the alluvial areas. There have been a few reports of platinum occurrences outside of the main Ural areas, but none that seem to be of any great importance.