Recycling of foundry sand residuals as aggregates in ceramic formulations for construction materials

Abstract

The utilization of residual materials in the fabrication of new products has a strong impact on the preservation of non-renewable natural resources, diminishes energetic consumption and avoids the costs and problems that imply the final disposal of them. The aim of this work is to investigate the recycling of waste foundry sand coming from the process of cast iron for use as aggregate in the manufacture of red clay bricks and tiles. The raw materials, waste foundry sand and clay soil were chemically and microstructural characterized and different samples were designed. Compact bodies were prepared with 10%, 20%, 30%, 40% and 50% (wt%) of waste. They were thermally treated in the range 950-1000ºC. The experimental conditions were established taking into account those used for commercial products. The characterization of raw materials and products was carried out using various techniques. The results allow one to conclude that it is feasible to incorporate important quantities of waste foundry sand into the manufacture process of clay bricks and tiles. The best properties were obtained in samples with 30 and 40 wt% of waste added, taking into account the characteristics required for commercial applications.

Ceramic tiles adding waste foundry sand to different clays

“…It can be seen that it has quite a homogeneous distribution in size, compact rounded particles without the presence of marked edges or angles. The presence of small proportions of different grains can be noted, with the appearance of molten phases, which were analyzed by EDS and found to be composed of Si, Ca and O, assuming them as calcium silicate [10]. Figure 2 shows the microscopic appearance of clay material.…”

“…The measured values of permanent linear expansion, expressed as volume change in percentage, and weight loss on ignition, expressed as a percentage, are presented in Figure 5, in graphics for commercial and common clay (soil) [10]. It is possible to observe a clear trend of the samples to contract due to the sintering, process much more pronounced in the case of common clay, where the reference samples without waste content, show a contraction of about 14% in volume.…”

“…In previous work [10] clay with a major content of soil was used, as is customary in traditional brickworks. The obtained pieces showed high porosity due to the combustion of the organic matter present.…”

Emissions analysis from various industrial wastes to be used as raw material for ceramics

“…The production of ceramic materials from clay and several kinds of this waste have been studied in previous works [1][2][3][4][5][6][7].…”

Estrategias de gestión de arenas descartadas de fundición en función de sus características químicas y ambientales

“…En Argentina, se han concretado varias investigaciones sobre valorización de ADF en hormigones (Sota et al 2007), cemento portland (Elizalde et al 2010), mezclas asfálticas en caliente (Marcozzi et al 2008), cerámica (Quaranta et al 2009) y para uso de suelo vial (Appolloni et al 2010). Sin embargo, no existe en Argentina una reglamentación que favorezca el uso beneficioso de ADFs.…”