GUT Giesserei Umwelt Technik GmbH

One main focus of GUT foundry plant design is the sand reclamation of mono and compound sand systems in the nobake-area. The reclamation with basically mechanical elements can be expanded by pneumatical and thermal elements as well as grinding reclamation. Our keynote is that any grain of sand available in a foundry is to be kept in circuit regarding economy and ecology.
We provide pneumatic conveyor systems from type SF for a gentle transportation of sand in all common power classes and our cooler-classifier (CRKS) is a field proven component for the batch wise cooling and dedusting of sand. Beside a compact construction the main advantage is the constant temperature of the sand which allows the use of a minimum amount of binder in the mixer. A constant quality of sand is paying off.

We emphasize especially the elimination of subversive elements from the sand circuit. With an appropriate screening technique and magnetic separators impurities in the sand circuit are reduced to a minimum.

The focus lies on partially mechanized no-bake moulding lines for cold-resin-bounded moulding materials. The target is among other issues the division of production of medium-large castings with piece weights up to 7,5t, which cannot be produced on fully automatic plants because of a small lot size.
The G U T moulding line (G U T-form) includes as system solution different components, which are installed in the individual foundry according to the boundary conditions. The different components consist of transportation systems (cranes, roller conveyors, transfer trolleys, etc.) mixer stations, coating stations optionally with final drying oven and separator systems for flask and model.

In comparison with silica sand chromite sand features a higher temperature resistance and a better thermal conductivity. These attributes predestinate this kind of sand especially for no-bake moulding-lines with high material accumulation and for casting materials with high casting temperatures as they are for example in steel casting. On the one hand chromite sand guarantees a high quality for several casting products, on the other hand this kind of sand amounts the cost of moulding material, if there is no internal circuit. Chromite sand is around a multiple more expensive than silica sand.

The amalgamation of chromite sand and silica sand, which arises inevitably at the shake-out station, may lead to quality problems of the casting, in case of reuse of the reclaimed sand.

With G U T plants chrome ore sand can be separated sorted from silica sand and can easily be re-used in the sand circuit for cores and moulds. The separation of single grained and dust-free sands occurs in four steps by a combined technology, two magnet-steps and “density-separation”, as well as screening technology.

In the first separation step (I) silica sand is separated by a high power magnetic drum from the magnetic particles. The silica sand can be reused directly in the sand circuit. The magnetic particles pass through the next three steps (II – IV) of the plant, where the chromite sand is refined. During this process step subversive elements like exothermic riser material are eliminated to a large extent from the sand. This procedure makes an important contribution to the amelioration of the casting’s surface.