Purification of iron and steels a continuous effort from 2000 BC to AD 2000

The evolution of metal and alloys preparation has been directed, since the beginning of the history of metallurgy towards (1) the research of better p roducts - better properties, better reproducibility, larger production -, ( 2) the invention of new tools and machines for production - furnaces, blowi ng machines, hammers, pure oxygen, chemical analysis - and (3) the discover y of new scientific or empiric descriptions of matter. An important point i s that new tools and machines were produced by using new iron and steels, a nd new scientific ideas, coming from technicians and workers gave a more pr ecise description of what is meant by "better" product. This continuous cir cle running from technical application to science and from scientific descr iption to application has been effective from the beginning of metallurgy: without a new product there is no progress of science and without new scien tific ideas there are no new products. Examples are taken in ancient and to day metallurgy to show that the enormous effort starting 4000 years ago for iron production or more - 6000 years - for copper is not finished. Today, it is as difficult as before to increase the purity of metals and alloys, b ecause the overall purity has been increased. However, the new developments towards better alloys depend on new chemical or physical analysis methods and on the conception of new metallurgical processes, including new machine s and new ideas, as in the ancient times.