Soler, Aurora, Conesa, Juan A., Ortuño García, Nuria
Inhibiting fly ash reactivity by adding N- and S- containing compounds
Chemosphere. 2018, 211: 294-301. doi:10.1016/j.chemosphere.2018.07.177
URI: http://hdl.handle.net/10045/79490
DOI: 10.1016/j.chemosphere.2018.07.177
ISSN: 0045-6535 (Print)
Abstract: 
The inhibitory effect of thiourea (TUA), ammonium thiosulfate (TSA) and amidosulfonic acid (ASA) on the reactivity of fly ash air was investigated using a thermobalance at different heating rates (5, 10 and 20 K min−1). A model fly ash (activated carbon + 50 wt% CuCl2·2H2O, pyrolyzed at 700 °C and washed) was used as carbonaceous material. Adding CuCl2·2H2O to the activated carbon led to an increased rate of decomposition with the air's oxygen. TUA and TSA behaved in a similar way, accelerating the decomposition of the model fly ash. ASA also accelerated the decomposition but to a lower extent. We postulate that the increase in decomposition rate is caused by a reaction between carbonaceous material and N and S-containing compounds. The formation of nitrogenated and sulphured compounds was confirmed by TG-MS. A kinetic model based on a single reaction of order 0.6 showed very good correlations with all the heating rates tested in oxidant atmosphere.
Keywords:Inhibition, Thiourea, Ammonium thiosulfate, Amidosulfonic acid, Model ash, Thermogravimetry
Elsevier
info:eu-repo/semantics/article