Valorization of Foundry Sand in Clay Bricks at Industrial Scale

Abstract

In this article, foundry sand as waste material has been valorized in ceramic brick manufacturing at industrial scale. The employment of a waste coming from one industry as an input for another is one of the key concepts of industrial ecology. To study the environmental behavior of the ceramic bodies in different life cycle stages, three leaching tests have been developed. We used an EN 12457 equilibrium leaching test with distilled water and a Wastewater Technology Centre acid neutralization capacity (WTC-ANC) leaching test with different acidic leachates to carry out the environmental evaluation under different granular scenarios to ascertain the possibilities of the reuse or disposal of this granular material at the end of its useful life (end-of-life stage). Finally, we used a NEN 7345 diffusion leaching test for construction materials, with the aim of studying the environmental assessment at the use stage. Regulated pollutants in both stages have been evaluated. Furthermore, other soluble salts have been analyzed because they are closely related to the efflorescence phenomenon in bricks. Results indicate that core and green sand from the foundry industry can be used to replace clay content in construction materials, and that these foundry-sand-based ceramics improve some soluble salt results. Despite this fact, at the end-of-life stage in an inert waste landfill, lead, arsenic and chromium can be an environmental problem, both for commercial bricks and for foundry-sand-based bricks. This work can contribute to the determination of viability of sustainable processes of brick manufacturing that use foundry wastes as raw materials.

Evaluation of potential applications of recycled moulding and core sands to production of ceramic building materials

“…are still much lower than the admissible levels for the two remaining categories of wastes: hazardous waste and other than hazardous and neutral. Moreover, it can be concluded, that similarly to published data [13,28], among heavy metals analysed in present paper and showed in Table 3, slight increase in leachability comparing to control sample (WK-I) can be observed only in case of Pb, Ni and As. In case of other heavy metal ions, the leachability stays on the same level, or even decrease.…”

“…Hence on the grain surface there is still a thin, adhesive and water-insoluble layer of the binder agent. That is why silica materials obtained from the moulding mix recycled in the manner described before can be used only in those manufacturing technologies that involve their heat treatment [7][8][9][10][11][12][13], At high temperatures the remainders of binder agents, particularly of organic origin, are oxidised and thus formed gaseous products shall be released to the atmosphere, together with the flue gas. The main products of the oxidation reaction are CO 2 and H 2 O which are not particularly noxious, however there is also a possibility of atmospheric emission of dioxins and furanes, posing a threat to all living organisms.…”

Construction and demolition waste: Comparison of standard up-flow column and down-flow lysimeter leaching tests

“…5 and discussed in Section 3.5), reflecting typical differences between aged (CDW3 and CDW4) and fresh samples (CDW1, CDW2 and CDW5). However, CDW3 and CDW4 had visible masonry content (see Table A.1): the level of carbonation may not be the only reason for the observed differences, as masonry can also affect leaching in a similar manner (Alonso-Santurde et al, 2010;Galvín et al, 2013;Strufe et al, 2006). For example, decreasing Ca concentrations, and increasing Al and Si concentrations as a function of L/S were observed in masonry samples by Hjelmar et al, 2014 andKarius et al (2002).…”

Using mixture design of experiments to assess the environmental impact of clay-based structural ceramics containing foundry wastes

“…Particularly, the potential use of industrial wastes in ceramic processes has been widely investigated by various authors, demonstrating that products showing good technological properties could be obtained [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Nevertheless, just like at the end of its useful life and landfill deposition, compliance leaching tests are used to assess the environmental impact of the alternative product that incorporates the upgraded waste.…”