Marble Waste Valorization through Alkali Activation

Abstract

In the present study, the valorization potential of marble waste in the presence of metakaolin via alkali activation was explored. The activating solution used consisted of NaOH and sodium silicate solutions. The effects of marble waste to metakaolin ratio, particle size of raw materials, curing temperature, and Na2O/SiO2 and H2O/Na2O molar ratios present in the activating solution on the main properties and the morphology of the produced alkali-activated materials (AAMs) was evaluated. The durability and structural integrity of the AAMs after firing at temperatures between 200 and 600 °C, immersion in deionized water and 1 mol/L NaCl solution for different time periods and subjection to freeze–thaw cycles were also investigated. Characterization techniques including Fourier transform infrared spectroscopy, X-ray diffraction, mercury intrusion porosimetry and scanning electron microscopy were used in order to study the structure of the produced AAMs. Τhe highest compressive strength (~36 MPa) was achieved by the AAMs prepared with marble waste to metakaolin mass ratio of 0.3 after curing at 40 °C. The results indicated that the utilization of marble waste in the presence of metakaolin enables the production of AAMs with good physical (porosity, density and water absorption) and mechanical properties, thus contributing to the valorization of this waste type and the reduction of the environmental footprint of the marble industry.

The effect of marble powder on physico‐mechanical and microstructural properties of kaolin‐based geopolymer pastes

“…The results showed that a 30 wt% incorporation of marble powder increased the fluidity of mortar by almost 22% but yielded an almost 20% decrease in compressive strength. Some studies suggest that the valorization of marble powder for synthesizing geopolymers is promising, but the development of mechanical and microstructural characteristics of geopolymers with marble powder needs further examination 54–57 …”

“…54 However, combining marble powder with other aluminosilicates with high concentrations of Si and Al may improve the reactivity and geopolymerization. Very recently, Komnitsas et al 55 activated marble powder in conjunction with metakaolin, NaOH, and Na 2 SiO 3 , forming geopolymer. It is reported that incorporation of marble powder into the metakaolin-based geopolymer enables the formation of geopolymer with better physicomechanical properties, as well as contributing to the utilization of the waste and reducing the detrimental environmental effects of marble waste.…”

“…Some studies suggest that the valorization of marble powder for synthesizing geopolymers is promising, but the development of mechanical and microstructural characteristics of geopolymers with marble powder needs further examination. [54][55][56][57] Aside from the selection of aluminosilicates for the preparation of geopolymers, the type of alkaline activators and their concentration are critical in understanding the dissolution of minerals. In general, sodium NaOH and KOH are usually utilized as activators for clay-based geopolymers.…”

New Metakaolin-Based Geopolymers with the Addition of Different Types of Waste Stone Powder

“…[24], geopolymer composites were prepared with dolomite quarry dust using fly ash-based geopolymer. The properties of marble waste in connection with the metakaolin via alkali activation were also studied [25]. However, the comparison of five different WSP (feldspar, limestone, marlstone, dolomite, marble) has not been reported so far.…”

Low‐temperature synthesis of mullite‐based ceramics from Moroccan naturally occurring andalusite and marble waste

“…Therefore, they are either stored in warehouses for future use in other applications or disposed of in landfills, which can cause environmental issues. Some attempts have been done to use marble waste as a replacement of aggregates, additive in concrete production, and as well as starting material substitution of red clay up to 30 wt.% for the manufacturing of bricks [16][17][18][19]. It was found that the addition of marble waste can enhance the technological properties of manufacturing materials and contribute to significant economic and environmental benefits [16,20].…”