The manganese trade

Although manganese was mined in Merioneth from at least 1823 (see History for details), the earliest recorded use of Welsh manganese ores was during 1835–1840 for the manufacture of bleaching powder in the chemical works around Glasgow [Halse 1887: 104]. However, this use was insignificant compared with the demand after 1883 from the iron and steel industry for manganese ores. In this sector, manganese was (and is) a mineral of strategic importance. In World War 1 (1914–1918) – for example, lack of manganese was a major problem facing the German steel makers. Currently, at least 90% of world manganese ore production is used by the iron and steel industry.

The British and World trades in manganese have been influenced primarily by the development of new markets in steel-making, but temporarily also by wartime demands. Extraction of low grade ores in Wales has been largely influenced by the discovery of richer overseas sources and by interruption of those overseas supplies due to wars.

Prior to the large-scale requirements for manganese in the iron and steel industries, world output was in the 100,000–150,000 tons/annum range, with British production (almost entirely from mines in England) of the order of 1,000–8,000 tons/annum (1–5%). In the mid 1880s when manganese steels became commercially viable, world output began to increase, from 150,000 tons in 1888 to 250,000 tons five years later. British output increased, to 12,1000 tons per year during this period, almost all of which was produced from the Merioneth mines. However, this was negligible however when compared with British imports. In the 1850s and again in the 1880s the manganese mines of Devon and Cornwall were made uneconomic by the discovery of ores in Germany. Imports, under 30,000 tons/annum prior to 1884, had increased to 140,000 tons in 1890 and ten years later to more than 250,000 tons. The twin problems facing British mines were summed up by Hunt in 1863: ‘Large importations of Manganese from Spain, of a high quality, and sold at a low price have stopped all the Devonshire and Cornish Manganese Mines.’

The problems of cheap high-quality imports were equally difficult problems for the later Welsh mines, although in their case their competitors were Russia, Brazil, India, Chile and Turkey. In 1937, when world production of manganese ores was 6 million tons, 83% of that was produced by Russia, India, South Africa and the Gold Coast.

The combination of quality and price has always prevented Welsh ores from being of significance. As the following table shows, Welsh ores were among the lowest grades worked:

New Zealand5328.07

The grade of Welsh ore was very variable, but rarely exceeded 35% and was frequently around 25% manganese. Also, it contained particularly high amounts of impurities such as silica. Hence it was at a disadvantage when specifications (e.g. Ministry of Munitions) required at least 45% manganese and less than 10% silica. Generally, ores had to contain at least 40% manganese before they were acceptable in world trade. (For strategic reasons the USA adopted a 35% cut-off grade.) Consequently, Welsh ore was only marketable in the UK.

The Welsh ores were too low grade and too impure to enable them to be used for ferro-manganese production (although in the 1880s the ores were said to have been sent to Flintshire and Lancashire for this purpose). Consequently, their main value was in spiegeleisen or as a direct addition to the blast furnace. (However, Rees [1969: 86] states that at the Mostyn furnaces ores from the Harlech area formed only a small proportion of the charge.) In the 1940s around 100,000 tons/annum of ore were imported for direct blast furnace addition. Welsh ores would have been technically suitable as substitutes, but it seems that the wartime supply position did not reach the stage where their exploitation was required.

Prices of manganese ores were set on a per unit basis. Before World War I (1914–1918) a typical price for imported ores (c.i.f. British ports) was 4–5p/(ton) unit, a unit being 1% manganese. Thus, a 50% manganese ore with a price of 5p/unit sold for £2.50/ton. In 1920 the price was up to 20p/unit, thereafter steadying at around 10p/unit. Deductions would be made for impurities, particularly if silica exceeded 8–10%. Ores exceeding 12% silica could be rejected at the buyer’s option, which emphasises the effect that the impurities in the Welsh ores had on their exploitation. This is clear when the price paid for Welsh ores is compared with that for imported ores.

Welsh Ores
£ / ton
Imported Ores
£ / ton

Consequently, it was difficult to work Welsh ores profitably, and they could not be sold in direct competition with imported ores except in certain circumstances. Imports of ore increased prior to 1910, then steadied for a few years before declining until 1926. This pattern broadly matches the overall activity of the iron and steel industry. Welsh production, on the other hand, struggled along (at under 2,000 tons/annum in most cases) with three exceptions, 1886–1891, 1904–1908, and 1917–1920, when production exceeded 12,000 tons/annum. The earliest of these periods of activity seems to have been due mainly to the development of several mines by Mostyn Ironworks (these mines closed when they were found to be uneconomic). The other periods were caused respectively by the Russian-Japanese war (which prevented the UK from importing its usual amounts from Russia) and World War 1 (1914–1918).

The effect of war on the industry was first recorded in 1874 when the price of spiegel dropped by half to about £7/ton due to the ending of the Franco-Prussian war. The most dramatic example came from World War 1 when the Welsh output increased from 3,437 tons in 1914 to 17,456 in 1918. However, this increase is small compared to USA production which rose from 2,635 tons in 1914 to 122,275 tons in 1917 and to 114 million tons in 1918. Due to the loss of Russian supplies, Brazilian output increased from 180,680 tons to 524,434 tons from 1914 to 1917, although almost none of this came to Britain. UK manganese came almost wholly from India during that period, although there were severe problems with shipping. One writer, commenting on the strategic significance of manganese, saw a portent in the fact that German output increased from 92,000 tons in 1912 to 330,000 tons in 1913 – but ignored the fact that British imports showed a similar trend.

Although wartime conditions brought temporary benefits to the Welsh manganese industry, the production increases were insignificant compared to national needs. Even with the reopening of the Caernarvonshire mines in 1940 by the Ministry of Supply to supply local furnaces, production only totalled just over 60,000 tons up to the end of 1945, when manganese mining in Wales ceased, probably for ever.

[Down 1980: 10–12]

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