Pathway towards a High Recycling Content in Traditional Ceramics

Abstract

The present work shows the path towards the industrial production of ceramic tiles containing a high amount of recycling materials in the substitution of natural raw materials. Starting from the applied research at laboratory scale, which is able to demonstrate the work feasibility, other important milestones consist of pilot scale production until the proper industrial production. Finally, when all these steps are positively achieved, the practice is consolidated and it is possible to reach the concrete sustainability benefits (social, environmental and economic). The results of an industry driven project that aimed to produce porcelain stoneware tiles containing 85% of recycled materials were selected to show this path. This innovative ceramic product—containing soda-lime scrap glass from urban-separated collection (post-consumer waste) and unfired scrap tiles from industrial ceramic process (pre-consumer waste)—was sintered about 200 °C lower than a traditional porcelain stoneware tile. It maintains high technical performances belonging to class BIa of the International Standard of ceramic tile classification (EN ISO 14411). Moreover, this product fulfils the standard requirements for dry-pressed ceramic tiles with low water absorption (≤0.5%), and it obtained the certification UNI Keymark. The LCA study was also performed and the results showed a significantly lower environmental impact of this innovative product compared to a traditional porcelain stoneware tile.

Reusing Ceramic Waste as a Precursor in Alkali-Activated Cements: A Review

“…Ceramic products like bricks, roof tiles, wall/floor tiles or sanitary ware are generally used worldwide and as previously reviewed by Reig et al [1], the amounts of manufactured ceramic products have substantially grown in recent years. Most ceramic companies reuse all clay waste generated before sintering ceramic products, and the ceramic sector is making many efforts to incorporate waste from the pieces fired during the manufacturing process [2]. However, the huge quantities of ceramic products manufactured worldwide (16,093 million m 2 of ceramic tiles globally produced in 2020 or 6.3 million tons of bricks/roofing tiles manufactured in Spain in 2021) [1] still imply significant volumes of ceramic waste (CW) because about 3-7% of ceramic products are commercially discarded due to technical imperfections.…”

Waste Glass-Derived Tobermorite Carriers for Ag+ and Zn2+ Ions

“…Recent research to explore alternative options to upcycle waste container glass (also known as cullet) into value-added products includes the production of zeolites [2][3][4][6][7][8][9][10], silicate minerals [5,[11][12][13][14][15][16], geopolymers [17][18][19], and ceramics [20][21][22] for applications in catalysis, sorption/separation technology, and construction. In this respect, several studies have utilized a facile one-pot hydrothermal method to synthesize the layer-lattice calcium silicate phase, 11Å tobermorite (Ca 5 Si 6 O 16 (OH) 2 •4H 2 O), from a mixture of waste glass cullet and lime or other calcium-bearing wastes [2,5,[11][12][13][14]23].…”