Recovering ceramic rejects is a well known problem that exists in the ceramic industry and the most suitable solution, seeing the high costs of disposal and consequent environmental impact, is the possibility of recycling them in productive systems through extremely efficient Technology that creates advantageous objectives in terms of economy (cost of raw materials), technology, (using the Chamotte in the mixture without lengthening the milling cycles) & environment.
Manfredini & Schianchi has developed various types of plants to recuperate the following types of waste materials:
- Fired pressed rejects
- Fired extruded rejects
- Unfired pressed rejects
Fired pressed and extruded rejects
The double rod extraction valve thanks to its particular shape was designed especially to pre-crush ceramic waste even with feed dimensions up to 300 mm permitting perfect feeding to the mill for the successive milling phase.
The P.I.G. Mill however, thanks to its great efficiency (up to 15 t/h < 1mm) is able to reduce the ceramic rejects into powder with a particle size curve characterized by a high percentage of ultra-fine material.
This solution makes it possible to use the outlet powder directly in the successive milling stages (both dry & humid).
In case a rigorous sifting control is required, a successive phase suitable to that operation will be resorted to, followed by secondary milling by means of a Secondary Finishing Mill type P.I.G. or Rotating Ring Mill type ARO.
The average production capacity varies from a minimum of 4 t/h up to a maximum of 30 t/h (using the finishing mill) and utilization of different types of ceramic waste to be treated (heavy clay products, single fired, porcelain stoneware & sanitary ware), whilst global maintenance costs do not ever rise above 4 € per ton of product.
Unfired pressed rejects
Recovering of unfired pressed rejects (glazed & unglazed) is an excellent solution for factories that do not have their own raw materials preparation plant and purchase body compositions from external suppliers.
This solution noticeably reduces the disposal costs of raw materials; and also contributes to reduce the environmental impact caused by transportation of unfired waste material on trucks.
The plant is mainly based on the use of a Hammer Mill type MSF1 complete with calibrated grid which thanks to a suction system installed downstream the mill itself and a dosing device capable of accurately feeding the conveyor belt of spray dried material without causing problems in the successive pressing stage
Production capacity of this plant is approximately 500 Kg/h with marginal running & maintenance costs.