Influence of incorporation of fired porcelain scrap as partial replacement of quartz on properties of an electrical porcelain

摘要

Fired porcelain scrap has been recycled as filler to obtain a sustainable high voltage porcelain insulator. Quartz was progressively replaced by 5, 10, 15 and 25 wt% of porcelain scraps in a traditional siliceous porcelain composition. The replacement effect on sintered samples at 1250 degrees C under industrial scheduling using a manufacturing kiln was evaluated by measuring the linear shrinkage, bulk density, porosity, flexural strength, and microhardness. Phase analysis was carried out by X-ray diffraction and micro structural characteristics were studied using a scanning electronic microscope. The results showed that scrap containing samples reached bulk densities around 2.38 g/cm(3) and a porosity percentage close to zero. The maximum flexural strength at both unglazed and glazed state was 67.5 MPa and 89.7 MPa, respectively for 5 wt% scrap containing samples. X-ray diffraction studies revealed higher mullite phase in scrap containing samples. Scanning electronic microscopy images of the polished and etched specimens show the presence of quartz grains and secondary mullite needles embedded in a feldspathic vitreous matrix. The properties displayed by the scrap containing samples are highly attractive, since they show similar and, in some cases, superior values in flexural strength, density, and porosity in comparison to those reported for traditional siliceous porcelain. The most outstanding result was found in the flexural resistance, for unglazed porcelain bodies it was improved around 7%, while in glazed porcelain bodies it was improved around 15% with the addition of chamotte in a traditional porcelain composition. These new porcelain compositions can be used to produce noble porcelain insulators as a more sustainable, affordable, and environmentally-friendly alternative. (C) 2019 Elsevier Ltd. All rights reserved.