Morphological and Chemical Characterization of Calcium-Hydrate Phases Formed in Alteration Processes of Deposited Municipal Solid Waste Incinerator Bottom Ash

2000 ◽  
Vol 34 (23) ◽  
pp. 5030-5037 ◽  
Author(s):  
C. Speiser ◽  
T. Baumann ◽  
R. Niessner
Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 838
Author(s):  
Sebastian Keber ◽  
Thomas Schirmer ◽  
Tobias Elwert ◽  
Daniel Goldmann

Municipal waste incinerator bottom ashes contain copper contents comparable to those of low-grade ores in addition to other valuable metals. While the processing of coarse fractions (>2 mm) is state of the art, the fines with their residual metal content are landfilled. This paper presents the results from a mineralogical characterization of fine fractions from the processing of municipal solid waste incinerator bottom ashes. From the results, possible approaches for a recovery of copper from the fine fraction are derived. Spatially resolved phase analysis reveals that the material contains a very heterogenic mixture of naturally occurring compounds as well as particles of alloys, metals, artificial oxides, and sulfides. The most interesting element to recover is copper. Copper can be found in the form of alloys, simple sulfides (XS), and oxides (XO). During the incineration process, new phases are generated that differ from natural ones and therefore can be called artificial minerals. Additionally, several components are partially altered due to oxidation, especially after the prolonged outside storage of the bottom ash. Crystalline silicate and glass particles are only sporadically enriched in Cu. Based on these results, different processing techniques are discussed. Due to the small particle size distribution and the physical and physico-chemical properties of the particles, flotation seems to be the most promising technique for the enrichment of copper from municipal solid waste incineration bottom ash (MSWI-BA) fine fractions.


2020 ◽  
Vol 11 (1) ◽  
pp. 107
Author(s):  
B. Simões ◽  
P. R. da Silva ◽  
R. V. Silva ◽  
Y. Avila ◽  
J. A. Forero

This study aims to evaluate the potential of incorporating fly ash (FA) and municipal solid waste incinerator bottom ash (MIBA) as a partial substitute of cement in the production of self-compacting concrete mixes through an experimental campaign in which four replacement levels (i.e., 10% FA + 20% MIBA, 20% FA + 10% MIBA, 20% FA + 40% MIBA and 40% FA + 20% MIBA, apart from the reference concrete) were considered. Compressive and tensile strengths, Young’s modulus, ultra-sonic pulse velocity, shrinkage, water absorption by immersion, chloride diffusion coefficient and electrical resistivity were evaluated for all concrete mixes. The results showed a considerable decline in both mechanical and durability-related performances of self-compacting concrete with 60% of substitution by MIBA mainly due to the aluminium corrosion chemical reaction. However, workability properties were not significantly affected, exhibiting values similar to those of the control mix.


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