Quality improvement of granular secondary raw building materials by separation and cleansing techniques

Quality improvement of granular secondary raw building materials by separation and cleansing techniques

Xing, W.

Hendriks, Ch.F. (promotor)

Civil Engineering and Geosciences

2004-05-12

Contaminated granular wastes are potentially reusable because they have similar physical and chemical properties as primary raw building materials. From environmental aspects, the reuse must not result in polluting the soil, groundwater and surface water. Therefore the leaching values of inorganic components such as heavy metals and the composition of organics must be under certain limits. From technical aspects, the physical properties must meet the technical requirements of the intended application. Both of environmental contaminants and technical pollutants must be removed or reduced. The main aims of quality improvement are to reduce leaching values and to increase the reusability of materials. For this purpose, the selection of suitable separation and cleansing techniques is important. Effective techniques guarantee the liberation of materials, by which, the useful materials and contaminants are broken apart from each other. Any difference in physical properties of individual components, like size, shape, density, magnetism, surface wettability, electrical conductivity and colour, can be used as the basis for separation of materials. A methodology to improve the quality by separation treatment is proposed in this thesis. Criteria are set up for the selection of techniques, and it discusses how to evaluate separation treatment in a long term by eco-efficiency and in a short term by economic costs and/or benefits. Three waste streams are studied: construction and demolition waste (CDW), municipal solid waste incineration (MSWI) bottom ash and dredged sludge. Suitable techniques are given and cleansed productions are evaluated in environmental quality and technical quality.

contamination
separation
recycling

http://resolver.tudelft.nl/uuid:a6d0a00b-9093-40a0-ae56-5ed481398d9a

90-9017932-1

Institutional Repository

doctoral thesis

(c) 2004 W. Xing