Physicochemical characterization of ash from hazardous waste for use in civil construction

ABSTRACT

Actions for the treatment, reuse and proper disposal of hazardous waste (WH), such as those generated in health services, agroforestry activities and mechanical workshops gain importance, noting that improper disposal can cause environmental problems. Some researches have pointed to the use of ash from WH, in partial replacement of Portland cement or as a fine aggregate in cementitious matrices, according to the properties of the materials. The objective of this research was to identify the physical, chemical and mineralogical characteristics of the ash generated in a RP incinerator located in the state of Bahia/Brazil, which were subjected to characterization tests, both in natura and after the calcination step at 1000 °C, called heavy ash (AH) and calcined ash (AC), respectively. The granulometric distribution, loss on fire, thermal properties, chemical composition, morphology, total organic carbon and reactivity were determined, and the samples were classified according to the ABNT NBR 12653/2014 standard. The results obtained indicate significant differences between the analyzed materials, in the physical, chemical and mineralogical aspects. The use of techniques and methods made it possible to classify the studied samples in a way that they do not meet the minimum normative requirements, however, it is not possible to rule out the use of AC in cementitious matrices.

Keywords
Technological characterization; Reuse; Cement matrices