| 摘要 |
<p>Products are mfd. from recovered materials having high specific wt., partic. foundry rolled sand and solid household wastes, using processing machine incorporating at least a twin screw extruder and combining coating and binding materials with the waste materials. The waste materials are firstly riddled to separate fine grained particles, which are then processed, from coarser particles, which are rejected. The milled coating and binding materials, are introduced into the processing machine (16) at a position such that a homogeneous compound is obtained by progressively increasing the temp. to a predetermined maximum of 180[deg]C, the compound melting in the process and the waste materials are then added so that the coating material becomes predominantly distributed on the outer surfaces of the particles and the mixture is introduced inside moulds (27) or similar product forming means, cooled, and stored. Also claimed is plant for carrying out the process including riddle means (6) for separating fine grained particles of 300 - 100 microns for utilisation, containing means (10,14,15) for selectively collecting the waste materials, coating materials, and binding materials, injection means (25), and forming means (27). The processing machine communicates with the containing means via first and second gravimetric batching means (19,22) able to introduce predetermined batch quantities of the respective materials in the same machine, and also communicates with the injection means and with the containing means via third gravimetric batching means (24). The first and second gravimetric batching means (19,22) are provided respectively at first and second loading positions (17,18) having higher and lower heating temps. The forming means is pref. a rotating turntable (28) able to convey the formed products in succession through cooling means and support and conveying means (32) towards a warehouse for seasoning and despatch. Also claimed is product obtained using the process and plant.</p> |
