RAW MATERIALS HANDLING AND RECOVERY OF PRODUCTION SCRAPS

For a correct batching of raw matertials, a plant made of a series of hoppers can be used; each hopper is served by a weighting extracting belt for batching of raw materials. As an alternative, or a plant made of one or only two hoppers through which storage silos are charged, also equipped with weighting extracting belt for batching of raw materials.

The industrial scraps in powder are put again in the production cycle in low percentage within the body mixture. They are sucked and collected in dedusting filters and sent to batching silos placed in the raw materials batching area.

The green industrial scraps are put again in the production cycle as raw materials. Normally, there’s a dedicated hopper from which the material is extracted and batched with a weighting extracting belt. LB offers green scraps crushing plants to re-use it directly at the press, mixing it with new spray-dried material.

The fired industrial scraps are put again in the production cycle as raw material (up to 6÷7%). Normally, there’s a dedicated hopper from which the material is extracted and batched with a weighting extracting belt. To be used again in production cycle, the fired scraps must be pre-ground at a dimension < 3÷5 mm. LB offers solutions for fired scraps grinding, with thickenss up to 20 mm.The main process machine may be the impact mill MHP (production capacity  20000 kg/h, 80% < 3 mm, 57% < 2 mm), or an innovative machine with opposed cylinders (85% < 3 mm, 70% < 2 mm). Before this, a crusher for the treatment of slabs up to 1400 mm wide can be installed.

The dry pre-grinding of the hard part of the body (feldspar, sands, etc.), with D90 45 um, allows to increase the production capacity of the wet grinding up to 33÷35%. Keeping the production capacity of the continuous mill unchanged, it is possible to reduce the grinding residue (improvement of the technological features of the finished product and/or decrease of the firing maximum temperature).

Lorenzo Battaglioli, LB Officine Meccaniche (Fiorano, Italy)