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Stabilization of galvanic sludge by microwave pre-treated pyrolysis
Sadikoglu, H.O. & Ongen, A.
Abstract
The study was aimed examine the effect of
microwave preheated pyrolysis on the characteristics of
volatile metal compounds. In order to monitor the behavior
of volatile metals, samples were preheated with microwave
oven in varying energy ranges and process durations. In
order to determine optimum conditions, 360-, 600- and
900-W microwave power and 3-, 5- and 10-min microwave
irradiation were used. Chemical analyses of samples were
carried out both before and after experiments by X-ray
fluorescence. Pyrolysis experiments were performed in a
laboratory-scale fixed-bed updraft stainless steel reactor in
the presence of 1 L min-1 N2 gas. Content of synthetic gas
product obtained via pyrolysis was analyzed by a continuous
gas analyzer. Microwave preheated pyrolysis resulted
an increase in the weight percentage of calcium oxide,
iron(III) oxide, and chromium(III) oxide in galvanic
sludge. Similar changes were determined for most of the
samples at 600 W and 5 min of microwave preheated
pyrolysis. In this point, the weight percentage of calcium
oxide, iron(III) oxide, and chromium(III) oxide were
measured as 22.47, 16.93, and 5.63 wt% which were 19.86,
10.89, and 3.03 wt% after single pyrolysis. It is concluded
that, future analysis are needed to increase the efficiency of
stabilization by microwave preheated pyrolysis.
Keywords
Thermochemical process; Metal stabilization; Irradiation; Waste management
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