Speciation of Copper in Ash from a Fluidized-Bed Boiler Fired with Municipal Solid Waste

Abstract

Copper is one of the most important trace elements in municipal solid waste (MSW) combustion. Knowledge of the speciation of copper is fundamental for the understanding of the effects of copper compounds on the combustion chemistry, the evaluation of the environmental effects of copper in ash leachates, and the development of methods to recover copper from the MSW combustion ash. In this work, an investigation of the speciation of copper in four ash flows from a bubbling fluidizedbed boiler using synchrotron-based X-ray absorption spectrometry is reported. The results showed that copper occurs in oxidation states 0, +1, and +2 in the bed ash and the cyclone ash, i.e., 10−20% Cu 0 , 25−35% Cu I , and 50−60% Cu II , whereas the filter ash contained copper only in oxidation state +2. The most common copper compounds in the bed ash are copper metal, Cu 2 O, CuO, and mixed oxides, such as CuCr 2 O 4 . The cyclone ash probably contained a mix of copper metal, Cu 2 O, CuCl, Cu(OH) 2 , and CuSO 4 ·5H 2 O, possibly also CuO. Copper sulfate was found as one of the major species in the filter ash together with a mix of hydroxides and chlorides.

Leaching for recovery of copper from municipal solid waste incineration fly ash: Influence of ash properties and metal speciation

“…The CuCr 2 O 4 , as well as CuO and metallic Cu, have all been identified in other ash fractions (e.g. bottom bed ash) from the same boiler and on the same occasion (Lassesson et al, 2013). Metallic copper pieces may have been covered by glass melt in the combustion bed.…”

“…An investigation of the copper speciation in the different ash flows from a bubbling fluidized bed boiler fired with MSW using XAS methods has recently been carried out by Lassesson and coworkers (Lassesson and Steenari, 2013). The results showed that copper occurred mainly as copper metal, copper oxides (CuO and Cu 2 O) and mixed oxides (e.g.…”

Chemical association and mobility of trace elements in 13 different fuel incineration bottom ashes

“…It was observed that Cr existed inside the structure of the matrix particles (some Cr also found in micro wood pieces in ash), while Cu in addition to these places, was also was found condensed on surface of coarser ash particles and As was found associated with Ca in the ash. Similarly, Lassesson and Steenari [15] investigated Cu association in MSWI bottom ash using X-ray absorption spectrometry and X-ray diffraction (XRD/XAS) and reported that it was a mixture of Cu(0), Cu(I), and Cu(II) in the relative concentrations of 10-20% Cu(0), 25-35% Cu(I), and 55-65% Cu(II) and were most likely oxides (Cu 2 O, CuO, CuCr 2 O 4 ).…”

Effect of municipal solid waste incinerator types on characteristics of ashes from different air pollution control devices

“…These crystal species correspond to the common diffraction peaks of the MSWIs ash spectrum. [27,32] In addition, aluminium silicon oxides and copper oxides were detected in MB-BA, and iron oxides …”