Closed circuit processing plant for waste cellulosic packaging - produces iron free materials for paper and board

摘要

In the recycling of packaging materials and disposable items generally contg. wood, used for the storage of articles such as vegetables and consisting of baskets, skips, plates, palets, wickerwork, etc., which are assembled by means of nails, staples, etc. The waste is disintegrated and treated by electromagnets, opt. after having been preliminarily screened. Pref. the screening and removal of iron is effected in two stages. The package and storage materials are reduced in size by a hammer mill so that metallic fasteners, originally holding the parts together, are sepd. The metal parts are then removed by magnets before the reduced pieces of wood are screened according the size. The waste packaging materials may be disintegrated into coarse sized pieces before going to the hammer mill. The materials are sepd. in double acting screens producing fragments varying over ranges of sizes. The hammer-milling, sieving, magnetic extraction is carred out in a closed circuit so that fragments rejected by the screens are returned to the hammers, screened and again extracted for metal. By changing the order in which the steps of the process are carried out, a prod. can be obtd. which is absolutely free from metal and can be used as the raw material for board and paper.