Quarry Waste as Precursors in Geopolymers for Civil Engineering Applications: A Decade in Review

Abstract

Carbon footprint reduction of paving materials could be explored through recycling mining by-products into different applications, which will preserve natural resources and decrease environmental issues. One possible approach is to reuse quarry dust and mining ore waste as precursors in geopolymer applications. geopolymers are mineral polymers rich in aluminosilicates with an amorphous to a semi-crystalline three-dimensional structure. The current review aims to summarize the studies conducted during the past decade on geopolymers containing quarry dust and mine tailings. The first section discusses various precursors used for geopolymer cement production such as metakaolin, ground granulated blast furnace slag (GGBFS), fly ash, and quarry/mining ore wastes including silt, tungsten, vanadium, copper, gold, zinc, marble, iron, basalt, and lithium. Different calcination treatments and curing conditions have been summarized. In some cases, the precursors are required to be calcined to increase their reactivity. Both ambient temperature and elevated temperature curing conditions have been summarized. Less attention has been paid to room temperature curing, which is necessary for field and industrial implementations. Engineering properties such as compressive strength, density, durability and acid resistance, water absorption and abrasion of geopolymers containing mining waste were reviewed. One of the main barriers preventing the widespread use of waste powders, in addition to economic aspects, in geopolymers could be due to their unstable chemical structure. This was shown through extensive leachate of Na+ or K+ cations in geopolymer structures. The review of over 100 articles indicated the need for further research on different aspects of quarry waste geopolymer productions before its full industrial implementation.

Recovery of Silicon Dioxide from Waste Foundry Sand and Alkaline Activation of Desilicated Foundry Sand

“…The leaching conditions that yielded the optimum recovery of silica were then used to leach foundry sand to generate DFS for the development of geopolymers. It is reported that sodium is the better reagent for the preparation of geopolymers, as compared to potassium [28]. This is due to Na + cation being better in promoting alumino-silicates than K + cations [28].…”

“…It is reported that sodium is the better reagent for the preparation of geopolymers, as compared to potassium [28]. This is due to Na + cation being better in promoting alumino-silicates than K + cations [28]. Geopolymers were developed by mixing DFS with NaOH solution as the alkaline activation reagent.…”

Optimization of the Mix Formulation of Geopolymer using Nickel-laterite Mine Waste and Coal Fly Ash

“…The reactive aluminosilicates in both the NMW and CFA may have been easily dissolved by the SH, so less of the hydroxide is needed before the geopolymerization process. Thus, SS is considerably needed as a binding source and promoter of hardening [38].…”

“…This model indicates that the proper selection of precursors needs to be determined using characterization methods. Lastly, Ioptimal design of experiment can help us fine-tune the mix design of the geopolymer for the sampling and selection of a new precursor source [38]. The numerical optimization tool of the Design-Expert software was used to find the optimal point on the response surface to maximize the unconfined compressive strength of the synthesized geopolymer.…”

Preliminary Evaluation of Cement Mortars Containing Waste Silt Optimized with the Design of Experiments Method

“…Quarry waste has been used in various applications such as geopolymer production [ 4 ], soil stabilization [ 5 ], pavements [ 6 , 7 ] and production of artificial aggregates [ 8 ]. Studies and experimental applications have also highlighted the possibility of using quarry waste in cementitious materials.…”