Progressive Plant Extension Applied to the Soil Treatment Facility of the 'Arge Ground Unit' Particularly Enhancement of the Treatment Range and Optimization of the Product Flows: An Example for Successful Urban Mining

摘要

The wet-mechanical soil treatment plant (soil washing plant) of the consortium "Arge Ground Unit',' located at the industrial area Linz (Upper Austria), was ex-tended progressively, Particular mineral processing tech-niques were applied for the enrichment of contaminants and a continuous optimization process was implemented, pertaining all material flows from coarse gravel fraction to filter cake, Considerable quality control improvement and cost reduction were achieved by optimizing the wet-mechanical soil treatment plant. Particularly the disintegra-tion and pre-separation of low-density material from the contaminated input material, the efficiency of the process water cycle and the decontamination of the sand fraction 0/4 mm were improved significantly in regard to higher PAH-contaminated material from the high priority remedi-ation site 'Cookery Linz (076)'. In addition, flotation tests were performed with contaminated sand and dewatered filter cake, which finally led to the final extension step of integrating a two-step froth floatation unit into the existing plant concept for the treatment of the highly-contaminated thickener Sludge. Owing to the plant expansion, the CO_2 reduction within the Operation period of 2009-2015 was in a considerable range of 2,280 metric tons. The current Status and insights gained are subject of this technical note.