Jean-Jacques Daniël Dony (24 February 1759 – 6 November 1819) was an inventor and industrialist. He invented a procedure for the production of pure zinc, and opened a mine in Moresnet.

Dony was born on 24 February 1759 in Liège. He studied to become a priest, but in 1797 took over his father's business as a cattle transporter.^[1]

Dony invented a procedure for the industrial production of totally pure zinc.^[2] In 1806, Napoleon granted him a monopoly for the exploitation of the zinc mines of Moresnet,^[3] now in Liège Province, Belgium. The mines were successful, and his company became Europe's largest producer of zinc.^[4] These mines continued operating until 1880.^[1]

From the exploitation of the Moresnet mines rose the 'Vieille Montagne Association' (French for Old Mountain), which later expanded its operations abroad (to France, Germany and Sweden (Zinkgruvan) among others).^[4] The activities of the association of the Old Mountain were taken over in 1989 by the Union Minière (Mining Union) group, which is known since 2001 as Umicore.^[5][6]

In 1809, Dony opened a factory in Liège, but ran into financial difficulties, and was forced to sell 75% of his stocks. In 1819, he was declared bankrupt, and died in Bois-l'Évêque on 6 November 1819, at the age of 60.^[1]