It was in 1938 that the building in rue Nicolas Welter, in the very center of Luxembourg City, was built. It became the headquarters of NIZI after the war and has since then been the proud witness of NIZI's activities.
In 1923, Koninkijke Nederlandsche Hoogovens & Staalfabrieken N.V. started the production of steel in IJmuiden, on the basis of basic hematite pig iron was made from the rich low phosphorous iron ores from Sweden and overseas. While Hoogovens produced foundry hematite pig iron for the production of large ingot moulds for their own use, they also aimed to supply other European foundries with pig iron, particularly those foundries making large ingot moulds.
In 1926 NIZI was granted the exclusive agency to sell this hematite pig iron in a very large region covering Luxembourg, Belgium, France, Switzerland, and the Sarre area of Germany. This important agency carried on successfully for nearly 50 years until Hoogovens ceased production of foundry pig iron and became the foundation of the present strong position that NIZI maintains in the pig iron business.
During the period between the two world wars, NIZI started to supply steelworks and steel foundries with additional products. From 1925 to 1940, close links were established to the main Norwegian, French and German producers of ferro-alloys, among them the Norwegian group Tinfos. Thus, NIZI became one of the main suppliers of ferro-silicon, manganese alloys, ferro-chromium, and special ferro-alloys to the steel industry, particularly in Belgium, Luxembourg and the Sarre area. This position was consolidated when Europe returned to peace in 1945. The first exclusive agency agreement with the French ferro-alloy producer Comptoir Français de Ferro-Silicium SA dates back to 1923. Agency agreements were later established with Sociéte d'Electro-Chimie d'Electro-Métallurgie et des Aciéries Electriques d'Ugine in 1931, Compagnie Universelle D'Acétyléne & d'Electro-Metallurgie in 1934 and many other electrometallurgical companies. NIZI's official, exclusive agreements with the Norwegian companies Norwegian Ferrosilicon Producers' Association, Tinfos Jernverk A/S, Porsgrunn Elektrometallurgiske and Ila og Lilleby Smelteverk A/S dated back to 1947.
