Fabrication of geopolymer bricks using ceramic dust waste
Introduction
Conventional solid waste management by dumping or land-filling has a negative impact on the surrounding environment leading to many types of pollution in addition to the cost needed to get rid of these wastes. But if waste is properly managed, it can be used as a raw material in many industries. Many researchers and investigators have aimed at utilizing all types of wastes in environmentally friendly and economic ways as materials in the construction industry such as fly ash, blast furnace slag, recycled aggregates, red mud, etc. [1], [2], [3].
Geopolymers are classified as a type of inorganic material with ceramic-like properties which can be produced at ambient or slightly higher temperatures [4]. However, they follow a totally different reaction path than the ordinary pozzolanic cements. While the gain in strength for pozzolanic cements depends mainly on the presence of calcium to form calcium-silicate-hydrates (CSHs) that of geopolymers depends on the poly-condensation of a pozzolanic material normally containing silica and alumina in presence of an alkaline solution [5].
Typical pozzolanic raw materials for geopolymers are meta-kaolin [6], [7], bagasse [8], fly ash from coal combustion [9], [10], granular bottom resulting from incineration of municipal solid waste [11], slag waste from metallurgical industries [12], [13], [14], glass wastes [15], [16], [17], etc. On the other hand, greenhouse emissions resulting from the production of geopolymer concrete are markedly lower than those released from the manufacture of ordinary Portland cement concrete [18], [19].
The nature of raw materials and the preparation conditions of geopolymer systems have a direct impact on the properties of the final product. In this respect, Hardijito [20] found that increasing the curing temperature from 30 to 90 °C while using fly ash leads to an increase in the compressive strength from 35 to 65 MPa. Curing time [21], [22], calcination temperature [23], type and concentration of activators used [5], [4], [24], [25], [26] also affect the final properties of the prepared geopolymer.
The traditional route for the preparation of geopolymers involves mixing meta-kaolin with strong caustic solution. In the present paper, most of the caustic soda component was substituted by the much less costly slaked lime. Also, the use of ceramic waste fine dust helps eliminating the grinding cost of kaolin although it still have to be fired to 800 °C to produce meta-kaolin. The utilization of these wastes also reduces the negative effects of their disposal. In this paper a priceless waste is utilized that also helps minimizing pollution therefore offering an economic and environmentally friendly solution for producing geopolymer bricks.
Section snippets
Raw materials for bricks
The raw materials used consist of ceramic wall fine dust waste and alkali activators. Ceramic dust waste consists of kaolin clay, quartz, limestone, potash feldspar and bentonite; this is the product from cyclones following the spray drying step during wall tile body mix preparation in ceramic tiles industry. The alkaline activators used were calcium hydroxide and sodium hydroxide.
Ceramic fine dust was analyzed by X-ray fluorescence (XRF) and wavelength Dispersive (WD-XRF) Sequential
Chemical analysis of raw material
Table 1 shows the average chemical composition of meta-kaolin produced by firing the ceramic wall dust waste obtained from ceramic industry cyclones at 800 °C for 2 h.
Mineralogical analysis of raw material
The crystalline phases of the powder used were investigated using XRD. The pattern revealed that it consisted mainly of quartz, calcite and feldspars (Fig. 2).
Combined XRF and XRD results point out that the non-crystalline nature of meta-kaolinite formed on firing cyclone dust at 800 °C resulted in the presence of silica as the
Conclusions
In the present study, a geopolymer body was prepared by calcining the fine waste obtained from the cyclone residue in wall tiles making, with slaked lime and caustic soda.
Minimum percent water absorption was obtained at 0.5% NaOH which coincided with a maximum bulk density. This is since water absorption increases with increasing porosity while the bulk density of bricks decrease.
As curing time and temperature increase, the bulk density of cured samples decreases while their water absorption
References (41)
- et al.
Solid wastes generation in India and their recycling potential in building materials
Build. Environ.
(2007) - et al.
Strength of sustainable non-bearing masonry units manufactured from calcium carbide residue and fly ash
Constr. Build. Mater.
(2014) - et al.
Synthesis and mechanical properties of meta-kaolinite based geopolymer
Colloids Surf. A
(2005) - et al.
Geopolymer from kaolin in China: an overview
Appl. Clay Sci.
(2016) - et al.
Coal fly ash as raw material for the manufacture of geopolymer based products
Waste Manage.
(2008) - et al.
New synthesis method for the production of coal fly ash based foamed geopolymers
Constr. Build. Mater.
(2015) - et al.
Geo-polymerization behavior of Cu–Ni slag mechanically activated in air and in CO2 atmosphere
Int. J. Miner. Process.
(2012) - et al.
Utilization of zinc slag through geo-polymerization: influence of milling atmosphere
Int. J. Miner. Process.
(2013) - et al.
Slag with a high Al and Fe content as precursors for inorganic polymers
Appl. Clay Sci.
(2013) - et al.
Strength and microstructure evaluation of recycled glass fly ash geopolymer as low carbon masonry
Constr. Build. Mater.
(2016)
Waste glass from end of life fluorescent lamps as raw material in geopolymers
Waste Manage.
An environmental evaluation of geopolymer based concrete production
J. Clean. Prod.
Carbon dioxide equivalent (CO2) emissions: a comparison between geopolymer and OPC cement concrete
Constr. Build. Mater.
Utilization of fly ash in a geopolymeric material
Appl. Geochem.
Effects of calcination temperature of kaolinite clays on the properties of geopolymer cements
Constr. Build. Mater.
Effect of sodium hydroxide concentration on chloride penetration and steel corrosion of fly ash based geopolymer concrete under marine site
Constr. Build. Mater.
Geopolymer (alumino-silicate) composites: synthesis, properties and applications
Adv. Ceram. Matrix Compos.
Effect of alkali-activator types on the dynamic compressive deformation behavior of geopolymer concrete
Mater. Lett.
Geopolymerization kinetics 2
Chem. Eng. Sci.
Effect of Na2O content, SiO2/NaO2 molar ratio, and curing conditions on the compressive strength of FA-based geopolymer
Constr. Build. Mater.
Cited by (71)
The effects of desulfurized gypsum on the mechanical properties of dredged clay with high initial water content stabilized by ternary geopolymer
2024, Case Studies in Construction MaterialsMechanical properties, high temperature resistance and microstructure of eco-friendly ultra-high performance geopolymer concrete: Role of ceramic waste addition
2023, Construction and Building MaterialsPerformance of eco-friendly fly ash-based geopolymer mortars with stone-cutting waste
2023, Materials Chemistry and PhysicsDesign optimization of a recycled concrete waste-based brick through alkali activation using Box- Behnken design methodology
2023, Journal of Building EngineeringChemical functionalization of drinking water treatment residuals with calcium silicate hydrate to treat metal-enriched waters
2023, Journal of Water Process Engineering