Dony, Jean-Jacques Daniel

SUBJECT AREA: Metallurgy

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b. 24 February 1759 Liège, Belgium

d. 6 November 1819 Liège, Belgium

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Belgian inventor of the horizontal retort process of zinc manufacture.

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Dony trained initially for the Church, and it is not known how he became interested in the production of zinc. Liège, however, was close to extensive deposits of the zinc ore calamine, and brass had been made since Roman times in the region between Liège and Aix-la-Chapelle (now Aachen). William Champion's technique of brass manufacture was known there and was considered to be too complicated and expensive for the routine manufacture of brass. Dony may have learned about earlier processes of manufacturing zinc on the European continent from his friend Professor Villette of Liège University, and about English methods from Henri Delloye, a friend of both Villette and Dony and who visited Birmingham and Bristol on their behalf to study zinc smelting processes and brass manufacture at first hand. By 21 March 1805 Dony had succeeded in extracting zinc from calamine and casting it in ingots. On the basis of this success he applied to the French Republican administration for assistance and in 1806 was assigned by Napoleon the sole mining rights to the calamine deposits of the Vieille Montagne, or Altenberg, near Moresnet, five miles (8 km) from Aachen. With these rights went the obligation of developing an industrially viable method of zinc refining. In 1807 he constructed a small factory at Isle and there, after much effort, he perfected his celebrated horizontal retort process, the "Liège Method". After July 1809 zinc was being produced in abundance, and in January 1810 Dony was granted an Imperial Patent giving him a monopoly of zinc manufacture for fifteen years. He erected a rolling mill at Saint-Léonard and attempted to persuade the Minister of Marine to use zinc sheets rather than copper for the protection of ships. Between 1809 and 1810 Dony reduced the price of zinc in Liège from 8.60 to 2.60 francs per kilo. However, after 1813 he began to encounter financial problems and in 1818 he surrendered his commercial interests to his partner Dominique Mosselman (d. 1837). The horizontal retort process soon rendered obsolete that of William Champion, and variants of the Liège Method were rapidly evolved in Germany, Britain and the USA.

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Further Reading

A.Dony, 1941, A Propos de l'industrie belge du zinc au début du XIXe siècle, Brussels. L.Boscheron, "The zinc industry of the Liège District", Journal of the Institution of

Metals 36 (2):21–6.

H.Delloye, 1810, Recherches sur la calamine, le zinc et les emplois, Liège: Dauvrain. 1836, Bibliographie Liégeoise.

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