A world authority in separation technologies, Eriez Magnetics Europe Ltd demonstrates the efficiency of its rare earth magnetic drum separation system to help produce the highest levels of purity in fine powdery material.
Société Européenne Produits Réfractaires (SEPR) in France, part of the Saint Gobain Group required reducing the ferrous contamination of its very fine (> 0.5mm particle size) refractory cullet to less than 120ppm of Fe whilst maintaining a throughput of 1,000 kg per hour by using a self-cleaning system.
The solution was to use rare earth magnets, which produce magnetic fields up to twenty-five times stronger than ferrite magnets without any increase in size. They remove low mass particles that may have been generated during the grinding process and weakly magnetic materials, such as rust and stainless steel particles rendered paramagnetic through work-hardening.
Tests were carried out at Eriez’s laboratory in South Wales using SEPR material samples. Various drums types and feeder systems were trialled to establish the best equipment for the application. It was found that a high performance, double stage Rare Earth Magnetic Drum model RRS in a vertical housing produced the best results. This two-stage approach achieved the high level of purity SEPR required.
The drums consist of a permanent, rare earth, high strength and high gradient fixed magnetic arc element and a rotating stainless steel shell. Material is fed onto the drum shell surface by an Eriez electromagnetic HS42 vibratory feeder, which ensures an even, controlled feed of material. As the rotating shell carries the fine powder through the magnetic field any fine magnetic particles are attracted and held to the surface of the drum. Once they reach the end of the magnetic arc they are then discharged by gravity into a separate chute. The fine clean feed material simply falls via its normal trajectory from the drum into the clean product discharge chute.
Eriez Europe Sales Director Gareth Meese comments: “The main benefits of our magnetic drum separators are that they allow high volumes of material to be processed, are self-cleaning and require very low maintenance and spare parts.
Our vast experience in this sector enables us to specify equipment to very strict constraints of quality and installation. By using different types of separators with different feeders and configurations we expand significantly the potential applications of Eriez permanent magnetic drum separators in the food, ceramics, and mineral processing industries when high quality of the end-product is paramount, as well as in the recycling industry for the removal of ferrous material. They provide cost-effective solutions to the fine and weakly magnetic iron contamination problems.
Eriez’ Rare Earth drum separators are available up to 1220mm in diameter and up to 3m wide in a variety of configurations. More information is available from the brochure on our website. www.eriez.com/magnetic_drum_separator