For some years now SMA Mineral Magnesia AS from Porsgrunn (Norway) has been struggling with a transport problem for lifting their waste product hydrated magnesium. They wanted to be able to recycle their waste product, but not a single screw conveyor builder in Scandinavia could offer a system which could lift the magnesium vertically to the incinerator. Then by chance this problem was mentioned to Van Beek and they offered a solution in the form of a shaftless screw conveyor system.
“SMA Mineral Magnesia AS came into contact with Van Beek through hiring a Dino bulk truck loader; they were so pleased with it that they wanted to buy one”, says Niels Rombouts, operations manager at Van Beek. “When I called by on a company visit, I found they were struggling with another transport problem. They have as a waste product hydrated magnesium, a medium which is difficult to transport, especially when it has to be lifted completely vertically. No one in the whole of Scandinavia would venture to offer a screw conveyor based system. Our test centre is in an excellent position in such a case to look with the client for a solution. When doing so we discovered that humidification has a positive effect on the running properties, this made the magnesium less sticky. Also by choosing a shaftless screw, bridging was considerably reduced and vertical transport did become possible”.
The project was taken on by Van Beek as an all-in project, which means that Van Beek undertook everything from the engineering to the installation on site. The installation consists of a bunker with a capacity of 7.5 m³, in which four type 400 (diameter 400mm) shaftless screw conveyor systems push the hydrated magnesium into a screw feeder. The shaftless buffer tank is mobile so it can also be pushed away. The screw feeder feeds the vertical screw, which is also a type 400 screw.
Screw conveyor systems are made of steel 52, where the trough has a plastic lining. This lining houses the shaftless screw and also serves as a wear part. The drive of the screws is frequency controlled, so the feed capacity can be regulated between 5 to 11 tons per hour. Humidification nozzles are fitted at various points in the installation, these humidify the hydrated magnesium as soon as the running properties fall off. In spite of the fact that this is a vertical screw conveyor, the installation can be fully cleaned and is fitted with a separable body.
SMA Magnesia AS is part of SMA Mineral, the only and biggest producer of MgO in the Scandinavian countries. In their processes they use a calciner for dolomite or limestone and a seawater based production plant for magnesia products. SMA Magnesia AS supplies mainly to agriculture and the paper and chemical industry.
SMA Magnesia AS also produces caustic lime and slurries for the paper and pulp industry in Scandinavia. SMA Magnesia AS has expanded the slurries for the paper and pulp industry to Great Britain, Europe and Asia.
