Method for isolating a fraction of 3-10 mm of glass cullet of the quality of raw glass and a substantially uniform in colour of glass

摘要

The present invention provides a method for isolation of 3-10 mm fraction of glass cullet of a glass raw material quality and substantially uniform as to the glass color. According to the method, material of a granularity of 0-10 mm comprising glass cullet and substantially free of plastics, is subjected to a vibration drying at a temperature of 250-350°C with separation of fine-grained impurities by suction, and the dried and preliminary purified material comprising glass cullet is subjected to a mechanical abrasive treatment in a de-labeling machine, by moving the glass cullet-comprising material with the use of rotational paddles arranged on a common shaft, and then the sub-grain fraction of a size below 3 mm is screened off, said sub-grain fraction constituting entirely wastes, and the oversized particles constituting purified glass cullet are directed to color sorting, where during screening of the glass cullet-comprising material and during transferring the purified glass cullet to color sorting a suction of paper particles is performed, and the purified glass cullet is subjected to two-step color sorting with the use of an optoelectronic sorter, where in the first step of sorting from the purified glass cullet a main glass cullet stream is isolated that comprises mainly glass cullet of a first color with impurities of stones and ceramics and glass cullet of a second and third colors, and a secondary glass cullet stream comprising mainly glass cullet of the second and third color, as well as a waste stream comprising mainly stones and ceramics, and next the main stream of glass cullet is introduced into the second step of sorting to separate the remaining impurities of stones, ceramics and glass of the second and third colors, to obtain a 3-10 mm fraction of glass cullet of glass of the first color of a glass raw material quality and substantially uniform as to the glass color.