From steel scrap to iron pigments, Uerdingen
Meike Schulz, RHEWUM GmbH
RHEWUM again supplies screening machines for the production of iron oxide to Lanxess AG in Uerdingen, Germany.
In 1999 RHEWUM carried out extensive tests for processing this secondary raw materials. This test lead to an order for screening machines which after 11 years of non stop heavy duty operation are now changed against new machines of same type and size. Scope of supply is one vibrating conveyor type RIU 600x4500 and one linear motion screen type RIUS 1000x2000/2 for the screening of steel scrap and and cast iron splints for the pigment production. Process The production of iron pigments started in 1926 at the chemical plant site Uerdingen after the invention of the process by Dr. Julius Laux in 1925. Originally the aim was to gain a technical usable product from by-products of the aniline production. The process is unique and exemplary in its consequent use of the heat of reaction of the synthesis of iron ore compound. The heat of reaction is used for the generation of steam or hot water for following processing steps. Result is a process which runs nearly complete without heat supplied from outside and which energy efficiency actually is unmatched. The patent dated in 1925 was basis for more then 330 further patents regarding iron oxides. Milestones of development were the production of micronizd pigments in 1964 which were the break through of use of pigments in colours and varnishes as well as in plastics and synthetic fibres. This kind of pigments are easier to disperse and at the same time have a high colour strength and consistency. Basis is an efficient technology to grind the particles to reproducible sizes by use of so called steam jet mills. In 1999 for the first time the iron ore pigments were stoved in circulating fluidised beds. By this red pigments were produced if it is an oxidative process. By running a reductive process black pigments are produced. These pigments are distributed under the name Bayferrox©.
Lanxess Founded in 1863 out of Bayer AG Lanxess is a leading global acting company of the specialty chemistry industry. In 2010 Lanxess gained a turnover of more than 7 Mrd. Euro with approx. 15.000 employees in 24 countries. The company has 45 production sites, main production site for the part “Inorganic Pigments” is Krefeld-Uerdingen, Germany, with 1.900 employees in total of which 600 are working in the pigment production. Capacity of the plant is approx. 240.000 t/a of iron oxide which makes the plant to the world wide largest in production of inorganic pigments. Core business of Lanxess is the development, production and distribution of plastics, rubbers, semifinished products and specialty chemicals.
Sources: Dr. Ulrich Koemm, member of the board of managing directors of Lanxess AG, obn the occasion of the ceremonial act of „80 years iron oxides from Uerdingen“ in 2006. Website Lanxess