Mineralogical Phases Research Articles

Reduction in CO2 emissions during production of cement, with partial replacement of traditional raw materials by civil construction waste (CCW)

The cement industry is responsible for a significant portion of greenhouse gas (GHG) emissions, generated in the clinkering phase of cement production, which contribute to global warming. The present work proposes the reuse of civil construction waste (CCW) as an alternative raw material in the production of Portland clinker, with partial replacement of limestone–clay mixtures. The raw materials were characterized chemically and by thermogravimetric tests (TG/DTG), with subsequent evaluation of the resulting dosed raw mixes. The results showed that the partial substitution of limestone–clay mixture provides a reduction of up to 8.1% in CO2 emissions from raw materials in clinker production, because CCW acts as an alternative source of calcium in the formulation of the raw mix, partially replacing limestone, without negatively affecting the formation of the main mineralogical phases of cement, especially alite (C3S).

Mineral Carbonation of CO2 in Mafic Plutonic Rocks, II—Laboratory Experiments on Early-Phase Supercritical CO2‒Brine‒Rock Interactions

The potential for mineral carbonation of CO2 in plutonic mafic rocks is addressed through a set of laboratory experiments on cumulate gabbro and gabbro-diorite specimens from the Sines Massif (Portugal). The experiments were conducted in an autoclave, for a maximum of 64 days, using a CO2 supersaturated brine under pressure and temperature conditions similar to those expected around an injection well during early-phase CO2 injection. Multiple techniques for mineralogical and geochemical characterization were applied ante- and post-carbonation experiments. New mineralogical phases (smectite, halite and gypsum), roughness increase and material loss were observed after exposure to the CO2 supersaturated brine. The chemical analysis shows consistent changes in the brine and rock specimens: (i) increases in iron (Fe) and magnesium (Mg) in the aqueous phase and decreases in Fe2O3 and MgO in the specimens; (ii) a decrease in aqueous calcium (Ca) and an increase in CaO in the cumulate gabbro, whereas in the gabbro-diorite aqueous Ca increased and afterwards remained constant, whereas CaO decreased. The geochemical model using the CrunchFlow code was able to reproduce the experimental observations and simulate the chemical behavior for longer times. Overall, the study indicates that the early-stage CO2 injection conditions adopted induce mainly a dissolution phase with mineralogical/textural readjustments on the external area of the samples studied.

Influencia de la presión de cristalización y variación de volumen durante la formación de herrumbre en ambientes marino y continental-urbano: Factores críticos en la exfoliación

Este artículo estudia la capa de óxido formada en acero al carbono expuesto a ambientes marinos naturales y urbano-continentales durante 50 años. La composición de la fase mineralógica de la capa de óxido se evaluó mediante difracción de rayos-X (DRX), se identificaron las fases akaganeita, goetita, lepidocrocita, magnetita y amorfa. La caracterización morfológica de las muestras se realizó mediante microscopía electrónica de barrido (MEB) y microanálisis por dispersión de energía de rayos-X (EDX). La tensión mecánica generada durante la formación del óxido provoca la ruptura mediante exfoliación de la capa de herrumbre. La variación de volumen causada por las transformaciones estructurales y la presión de cristalización (Δp) de las fases cristalinas se analizaron para evaluar la tensión mecánica sobre la herrumbre y se encontró una relación lineal entre el coeficiente de expansión de volumen molar (α) y el parámetro Δp. La Δp más elevada fue producida por la goethita (374.99 MPa), mientras que la akaganeita presentó el valor α más alto (3.29).

A thermodynamic and kinetic study of catalyzed hydrolysis of aluminum nitride in secondary aluminum dross

Aluminum dross, a harmful and abundant solid waste generated in aluminum industry, releases toxic ammonia and causes severe environmental pollution and public health disaster. Secondary aluminum dross (SAD) can be effectively treated by the efficient and complete decomposition of aluminum nitride (AlN). The hydrolysis behavior of AlN in SAD was evaluated by thermodynamic analysis and kinetic leaching experiments. Various factors such as temperature, time, liquid-to-solid ratio, additive type, and additive dosage were evaluated to optimize the hydrolysis of AlN. The chemical composition, mineralogical phases, particle size distribution, and morphology of SAD and leaching residue were determined by X-ray diffraction, X-ray fluorescence spectroscopy, laser particle size analysis, and scanning electron microscopy, respectively. The decomposition of AlN reached 96.24% under the following optimum conditions: leaching time of 180min, leaching temperature of 95°C, additive of 4wt% sodium hydroxide, and liquid-to-solid ratio of 6mLg−1. Meanwhile, the removal efficiency of chlorine and fluorine during leaching reached 95.63% and 69.17%, respectively. The hydrolysis data indicate that the effects of relevant factors on AlN removal are consistent with the shrinking unreacted-core model, where internal layer diffusion is the rate-controlling step. The rate-controlling step was changed to chemical reaction control with the addition of sodium hydroxide, which corrodes bayerite on the surface of AlN. The activation energy of AlN hydrolysis in SAD is 38.64kJmol−1.

From Crystals to Color: A Compendium of Multi-Analytical Data on Mineralogical Phases in Opaque Colored Glass Mosaic Tesserae

This study aimed at laying the groundwork for a compendium on mineralogical phases responsible for the colors and opacity of ancient glasses, with specific reference to mosaic tesserae. Based on the awareness that a comprehensive database of these phases is currently lacking in the available literature, this compendium foresees two main objectives. The first scope was to set the basis for a well-structured database, as a reference point for scholars from different backgrounds for comparative and methodological purposes. The second goal was to provide insights on analytical methods that could be profitably used for achieving an in-depth characterization of coloring and opacifying inclusions; a tailored multi-analytical approach based on easily accessible and widespread techniques like OM, SEM-EDS, μ-Raman, and XRPD is proposed here. Micro-structural and compositional features of glass tesserae, where different types of crystalline phases were detected (Sb-based, Sn-based, Cu-based, Ca-phosphate-based) are presented in well-structured synoptic tables, following a summary on historical–archaeological information on their use.

Valorization of Slags Produced by Smelting of Metallurgical Dusts and Lateritic Ore Fines in Manufacturing of Slag Cements

A pyrometallurgical process was developed for the recycling of Ni bearing dusts and laterite ore fines by direct reduction smelting in DC (direct current) arc furnace. In the course of the performed industrial trials, besides the Ni-recovery in the liquid bath, slag composition was deliberately adjusted in order to produce a series of metallurgical slags with different chemical and mineralogical composition. The aim of this study was to investigate their suitability as clinker substitute in cement manufacturing. Examined parameters were slag FeOx content, basicity and applied cooling media (air, water cooling). A series of composite Portland and slag cements were manufactured in laboratory scale incorporating 20% and 40% of each slag, respectively; the rest being clinker of OPC (ordinary Portland cement) and 5% gypsum. The extended mineralogical analysis and microstructural properties of the produced slags were examined and correlated with the properties of the produced cements. The physical and mechanical characteristics of all examined cement products were found to meet the requirements of the regulation set for cements. The present research revealed that the most critical parameter in the compressive strength development of the slag cements is the mineralogical composition of the slag. Even in cases where rapid cooling to obtain glassy matrix is not feasible, adjustment of slag analysis to obtain mineralogical phases similar to those met in clinker of OPC, even at higher FeO contents (up to ~21wt.%), can result in production of slag with considerable latent hydraulic properties. These results indicate that there is potentially space for adjustments in conventional EAF (electric arc furnace) steel slags composition to allow for their wider use in cement manufacturing with significant environmental and economic benefits resulting from the reduction of energy requirements, CO2 emissions and natural raw materials consumption.

Physical and mechanical properties and micro characteristics of fly ash-based geopolymer paste incorporated with waste Granulated Blast Furnace Slag (GBFS) and functionalized Multi-Walled Carbon Nanotubes (MWCNTs)

Geopolymers are highly durable and have favorable mechanical properties, and are thus regarded as an eco-friendly alternative to traditional ordinary Portland cement binder. In this study, MWCNTs are obtained through a modification method using a compound of nitric acid and sulfuric acid, and are then dispersed using three types of dispersants. Fly ash-based geopolymers are prepared to validate the effectiveness and feasibility of adopting 0.05 wt.%, 0.10 wt.%, and 0.15 wt.% functionalized MWCNTs and substitution ratios of 10 %–40 % of fly ash with GBFS. The structure and dispersity of the functionalized MWCNTs in aqueous solutions are characterized using FT-IR and TEM, respectively. Then, the setting time, water absorption capacity, and mechanical behaviors are evaluated. In addition, SEM-EDS, FT-IR, TG-DSC, 29Si NMR, and XRD are employed to investigate the morphology, elemental components, mineralogical phases, and geopolymerization degree of the gel products. The experimental results show that the functionalized MWCNTs comprise −COOH and −OH groups and can be uniformly dispersed in aqueous solution containing SDS dispersant. Furthermore, geopolymer paste incorporated with 0.1 wt.% functionalized MWCNTs and having 30 % substitution of fly ash with GBFS exhibits a higher compressive and flexural strength and a lower water absorption capacity compared with all other geopolymer pastes.

Indications of risks in geothermal systems caused by changes in pore structure and mechanical properties of granite: an experimental study

The effects of thermal treatment on the pore structure and mechanical property evolution of granite were experimentally investigated to evaluate the risks of traditional and critical geothermal systems. The microstructure of thermally treated granite was studied using an optical microscope and nuclear magnetic resonance, and the mechanical properties of thermally treated granite were studied under uniaxial compression. X-ray diffraction results showed that the mineralogical phase of granite hardly changed during thermal treatment from room temperature to 800 °C, but the granite experienced first a decrease and then an increase in porosity. Although overall porosity decreased at 200 °C, the proportion of pore throat radium beyond 6.3 μm grew increasingly with the treatment temperature, facilitating advective heat transport in the geothermal system. Intergranular microcracks caused by thermal anisotropic properties started at below 400 °C, and transgranular microcracks first appeared in feldspar at around 400 °C, finally extending to quartz at around 600 °C. The granite was strengthened due to decreased porosity at around 200 °C. Then, the granite was weakened and the failure transited from brittle to ductile due to increased porosity, where a sharp reduction occurred at 400–600 °C for α-β transition of quartz. The change in strength by cyclic heating under 200 °C was unnoticeable for temperature memory effect, but the cumulative strain at peak stress increased with the number of heating cycles. The changes in the pore and mechanical properties caused by thermal treatment favour geothermal systems which are not within the tectonic zone. However, increased porosity and strength weakening destabilize nearby faults due to normal stress release and strength weakening.

Multi-Technique Characterization of a Fine Fraction of CDW and Assessment of Reactivity in a CDW/Lime System

This study analysed the fine particle (<5 mm) waste generated during siliceous or calcareous (depending on the composition of the original aggregate) concrete waste crushing. In the absence of industrial applications, such waste is amassed in open-air stockpiles on construction and demolition wastes (CDW) management plant grounds. The aim pursued was to find an outlet for that material in the cement industry. The starting waste, sourced from six Spanish management facilities, was characterised for its chemical and mineralogical composition, physical properties and pozzolanicity. The mineralogical phases in the CDW/lime system and their variations during the pozzolanic reaction were likewise identified. The findings showed that the fine waste consisted primarily in quartz, calcite, micas and feldspars, with smaller fractions of kaolinite and cement anhydrous phases. No portland cement hydration phases were identified. All six types analysed exhibited medium to low pozzolanicity, with the highest values recorded for the siliceous waste. Ettringite, C–S–H gels and calcium aluminate hydrates (C4AH13, C4AcH12) were identified during the pozzolanic reaction in CDW/lime system. Therefore, this type of waste can be reused as supplementary cementitious material with low-medium pozzolanic activity.

Artefatos arqueológicos de cherte de Atapuerca (Burgos, Espanha): caracterização, causas de deterioração e seleção de produtos de consolidação compatíveis

Chert tools from Galería and Gran Dolina Caves, located in the Sierra de Atapuerca site complex (Burgos, Spain), were characterized (macro-visual inspection, mineralogical phases, degree of crystallinity, soluble salts, surface morphology and optical surface roughness) and compared to chert samples collected from the surrounding Atapuerca mountain range. The chert tools were studied to determine their causes of decay and for selecting the most compatible consolidation treatments. It was found that samples solely containing quartz were not significantly altered and required little conservation treatment compared to those that contained quartz and moganite, which were more weathered and powdery, requiring consolidation. The efficacy of the consolidating products traditionally used by conservators (acrylic resin and ethyl silicate) to preserve these chert remains, together with novel nanoparticle-based products (SiO2 and a mixture of SiO2 and Ca(OH)2 nanoparticles) were assessed in this study. Changes produced by these consolidating products in the physical (surface morphology and cohesion) and aesthetic properties of the chert tools were evaluated using non-destructive techniques (peeling test, spectrophotometry and optical surface roughness), followed by destructive techniques, such as SEM and XRD.

Recovery of Cerium Oxide Abrasive from an Abrasive–Glass Polishing Waste through Alkaline Roasting Followed by Water Leaching

Abrasive–glass polishing waste is generated from the polishing process of glass components by using cerium oxide abrasive, which contains the cerium oxide abrasive and the polished glass. This study attempted to recover the cerium oxide abrasive from the abrasive–glass polishing waste through removing the polished glass by alkaline roasting using sodium hydroxide (NaOH) followed by water leaching. The experimental results indicated that the polished glass in the abrasive–glass polishing waste could be fully removed under the optimal alkaline roasting and water leaching conditions of roasting temperature of 450 °C, mass ratio of polishing waste to NaOH of 1:1, roasting time of 30 min, leaching pH of 3, leaching temperature of 25 °C, and liquid–solid ratio of 25 mL/g. The characteristics including elemental composition, particle size distribution, mineralogical phases, and morphology of the recovered cerium oxide abrasive obtained under the optimal conditions were similar to those of the original unused one, which was suitable to be reused for polishing again.

Upper crustal differentiation processes and their role in 238U-230Th disequilibria at the San Pedro-Linzor volcanic chain (Central Andes)

U-series data are combined with major and trace element constraints to construct a detailed view of the magmatic system feeding the San Pedro-Linzor volcanic chain, aiding the understanding of how stratovolcanoes in extremely thick arc crust evolve. Lavas from the Quaternary San Pedro-Linzor volcanic chain (Central Andes) have (238U/230Th) ranging from 1.015 to 1.072, with 238U excess even in the less evolved (~57 wt% SiO2) analyzed lavas. Contrary to well-established trends between fluid mobile elements and 238U excess, (238U/230Th)0 shows no systematic correlation with ratios indicative of fluid-driven melting (e.g. Ba/Hf and K/La). Moreover, the inverse correlation between (238U/232Th) with the amount of slab-derived fluid and the oxidation state of the mantle below Central Andes, which decreases eastwards, suggests that the main control of the 238U excess is not associated with hydration of the mantle wedge. Changes in (238U/232Th) and (230Th/232Th)0 are observed with variations in SiO2 and CaO + Al2O3 contents, and 87Sr/86Sr and Dy/Dy* ratios of the lavas. These changes correspond to increasing (238U/232Th) with decreasing Dy/Dy* and CaO + Al2O3 ratios, which is attributed to changes in crystallization of mineralogical phases within magmatic chambers during differentiation. Also, 230Th in-growth is produced during stagnation within magmatic chambers located below the San Pedro-Linzor volcanic chain. Finally, a positive correlation between (230Th/232Th)0 and 87Sr/86Sr indicates an important role of crustal contamination, and of new mafic inputs during evolution of the volcanic chain with time. Our observations suggest that better constraints of all magmatic processes are needed to fully understand the U-series disequilibria recognized for the different volcanic structures developed within subduction-related tectonic environments.

USO DE ARCILLAS NATURALES PARA LA RECUPERACIÓN DE FOSFATOS A PARTIR DE SOLUCIONES ACUOSAS

A natural clay (NC) mostly identified for quartz, muscovite y montmorillonite is modified by means of ionic exchange to the C-FeMn y C-FeMnAl forms for the phosphate adsorption from aqueous solutions. The mineralogical composition of modified clays determines the formation of new mineralogical phases which are functional groups that improves the phosphate sorption capacity. The maximum sorption capacity is reported at 34.8 mg y 18.2 mg P-PO43-/g for C-FeMn y C-FeMnAl, respectively. The phosphate adsorption is highly influence by the pH of the work solution, so some sorption mechanisms are associated which is validate by the Langmuir isotherm model and intraparticular diffusion kinetic model. First a fast adsorption phase is associated with electrostatic attraction which is followed by a second slow adsorption phase due to the chemical complexation reactions. The phosphate desorption from C-FeMn y C-FeMnAl forms was 20 % which corresponds to the phosphorous labile fraction. C-FeMn y C-FeMnAl can be used for wastewater treatment however their limited use for phosphate sorption – desorption cycles evidence they can be evaluated amendment materials for soils.

Radiocarbon Dating of Dolomitic Mortars from the Convent Saint John, Müstair (Switzerland): First Results

ABSTRACTThe monastery of St. John in Müstair, a UNESCO world heritage site, preserves archaeological remains and stone structures dated from the 8th century to the present. It has been extensively studied archaeologically so that numerous samples of historical materials, including mortar, are available for study. In addition to that, some of the structures have been precisely dated with dendrochronology. The monastery is located in a region characterized by dolomite rocks and the mortars are therefore of dolomitic nature, being perfectly suited to test the possibility of being dated with 14C. Furthermore, the presence of embedded carbon fragments has provided additional independent data to support or deny the results of mortar dating. A comparison of the results obtained from radiocarbon (14C) dating of bulk mortars, sieved fractions enriched in binder, lime lumps and carbon fragments, for two samples is presented, in relation to the petrographic characterization and the mineralogical phase content. This preliminary study shows that the dating of 14C can potentially be applied to the mortar of Müstair, as results in accordance with the established chronologies have been obtained for one sample. However, if the dolomitic sand contamination is very high, further studies are needed to develop a specific sample preparation technique.

Influence of Hydrofluoric Acid Leaching and Roasting on Mineralogical Phase Transformation of Pyrite in Sulfidic Mine Tailings

Under the oxidative roasting process, pyrite, as a major mineral in sulfidic mine tailings, can transform to iron oxides. Generated iron oxides, if exhibiting enough magnetic properties, can be recovered via magnetic separation resulting in partial mine tailings valorization. However, due to the presence of various minerals and sintering possibility, it is advantageous to remove impurities and increase the pyrite content of mine tailings prior to the roasting procedure. In this case, hydrofluoric acid that has no influence on pyrite can be used to leach most inorganic minerals, including aluminosilicates. Therefore, this study investigated and compared the influence of the roasting process with and without hydrofluoric acid leaching pretreatment on mineralogical phase transformation of pyrite and magnetic properties of thermally generated minerals. Several tests and analyses were performed to study mineralogical phase transformation, morphology, elemental composition, surface characterization, and magnetic properties. Results of this study indicated that without acid leaching pretreatment, pyrite was mainly transformed to hematite. However, via acid leaching, fluorine, as a more electronegative element over oxygen, entered the compound and neglected the role of oxygen in thermal oxidation, instead reducing sulfur content of pyrite to only form pyrrhotite.

Chemo-mechanical characterization of hydrated calcium-hydrosilicates with coupled Raman- and nanoindentation measurements

Celitement is a new type of cement that is based on hydraulic calcium-hydrosilicate (hCHS). It is produced by mechanochemical activation of Calcium-Silicate-Hydrates (C-S-H) in a grinding process. Due to the lack of typical clinker minerals, its CaO/SiO2 (C/S) ratio can be minimized from above 3 (as in Ordinary Portland Cement) down to 1, which significantly reduces the amount of CO2 released during processing. The reaction kinetics of hCHS differs from that of classical clinker phases due to the presence of highly reactive silicate species, which involve silanol groups instead of pure calcium silicates and aluminates and aluminoferrites. In contrast to Portland cement, no calcium hydroxide is formed during hydration, which otherwise regulates the Ca concentration. Without the buffering role of Ca(OH)2 the concentration of the dissolved species c(Ca2+) and c(SiO44−) and the corresponding pH must be controlled to ensure a reproducible reaction. Pure hCHS reacts isochemically with water, resulting in a C-S-H phase with the same chemical composition as a single hydration product, with a homogeneous distribution of the main elements Ca and Si throughout the sample. Here we study via nanoindentation tests, the mechanical properties of two different types of hardened pastes made out of Celitement (C/S = 1.28), with varying amounts of hCHS and variable water to cement ratio. We couple nanoindentation grids with Raman mappings to link the nanoscale mechanical properties to individual microstructural components, yielding in-depth insight into the mechanics of the mineralogical phases constituting the hardened cement paste. We show that we can identify in hardened Celitement paste both fresh C-S-H with varying density, and C-S-H from the raw material using their specific Raman spectra, while simultaneously measuring their mechanical properties. Albeit not suitable for phase identification, supplemental EDX measurements provide valuable information about the distribution of alkalis, thus further helping to understand the reaction pattern of hCHS.

The use of biochar for controlling acid mine drainage through the inhibition of chalcopyrite biodissolution

Although chalcopyrite biodissolution plays an important role in the formation of acid mine drainage (AMD), the control of AMD through inhibiting the biodissolution of chalcopyrite has not been studied until now. In order to fill this knowledge gap, a novel method for inhibiting chalcopyrite biodissolution using biochar was proposed and verified. The effects of biochar pyrolysis temperature and biochar concentration on the inhibition of chalcopyrite biodissolution in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans) were studied. The results indicate that biochar significantly inhibited chalcopyrite biodissolution, thus reducing the number of copper and iron ions and quantity of acid released. In turn, this suggests that AMD generation was suppressed under these conditions. Biochar pyrolyzed at 300 °C (Biochar-300 °C) was the most effective at inhibiting chalcopyrite biodissolution and reduced its biodissolution rate by 17.7%. A suitable concentration of biochar-300 °C enhanced its inhibition of chalcopyrite biodissolution. The optimal concentration of biochar-300 °C for inhibiting chalcopyrite biodissolution was 3 g/L. Biodissolution results, cyclic voltammetry, mineral surface morphology, mineralogical phase, and elemental composition analyses reveal that biochar inhibited the biodissolution of chalcopyrite by promoting the formation of passivation layer (jarosite and Sn2−/S0) and adsorbing bacteria.

Integrated acid leaching and biological sulfate reduction of phosphogypsum for REE recovery

Sulfuric acid leaching of phosphogypsum (PG) waste and leachate treatment in sulfate-reducing bioreactor was studied, in order to recover rare earth elements (REE) and remove sulfate from the residual solution. The challenge was to balance efficient REE extraction from PG while maintaining suitable leach solution acidity and sulfate concentration for the microorganisms in the bioreactor. Stirred tank reactor experiments were conducted for PG leaching to form the scope for suitable sulfuric acid concentration and REE leaching efficiency. According to these experiments, moderate REE leaching started already at 0.01 M H2SO4 concentration (yield 6–15%), and increased steadily when increasing H2SO4 concentration to 0.05 M (yield 34–62%). Different leachates were treated in sulfate-reducing bioreactor to understand the limits of acidity and sulfate concentration for the biological system. It was shown that bioreactor requires rather a mild leachate (<0.02 M H2SO4) to perform reliably and also precipitate REE from the influent. Finally, the precipitate from the bioreactor was collected and analyzed for both chemical and mineralogical composition. These results showed that REE were enriched in the precipitate and formed distinctive mineralogical phases in the MLA images. The method described in this research could be used to treat moderately acidic PG waste leachates with potential for REE recovery.

A machine-learning-based surrogate model of Mars’ thermal evolution

SUMMARY Constraining initial conditions and parameters of mantle convection for a planet often requires running several hundred computationally expensive simulations in order to find those matching certain ‘observables’, such as crustal thickness, duration of volcanism, or radial contraction. A lower fidelity alternative is to use 1-D evolution models based on scaling laws that parametrize convective heat transfer. However, this approach is often limited in the amount of physics that scaling laws can accurately represent (e.g. temperature and pressure-dependent rheologies or mineralogical phase transitions can only be marginally simulated). We leverage neural networks to build a surrogate model that can predict the entire evolution (0–4.5 Gyr) of the 1-D temperature profile of a Mars-like planet for a wide range of values of five different parameters: reference viscosity, activation energy and activation volume of diffusion creep, enrichment factor of heat-producing elements in the crust and initial temperature of the mantle. The neural network we evaluate and present here has been trained from a subset of ∼10 000 evolution simulations of Mars ran on a 2-D quarter-cylindrical grid, from which we extracted laterally averaged 1-D temperature profiles. The temperature profiles predicted by this trained network match those of an unseen batch of 2-D simulations with an average accuracy of $99.7\, {\rm per~cent}$.

Geopolymer concrete incorporating agro-industrial wastes: Effects on mechanical properties, microstructural behaviour and mineralogical phases

The increasing effects of environmental degradation and global warming owing to the production of Portland cement for uses in the construction industry premise the need for sustainable construction materials. This study, therefore, harnessed corncob ash (CCA) and ground granulated blast furnace slag (GGBFS) for the production of geopolymer concrete (GPC) at ambient curing conditions. Corncob was dehydroxylated at 600 °C and partially used as replacement for GGBFS at 0%, 20%, 40%, 60%, 80%, and 100%. The activators used were sodium silicate (SS) and sodium hydroxide (SH), while the molar concentrations of SH were varied at 12 M, 14 M, and 16 M. Moreover, mechanical properties, microstructural behaviour and mineralogical phases of the selected samples were examined. The results revealed that up to 40% CCA replacement level exhibited higher strengths than Portland cement concrete (PCC). Besides, a good relationship exists between the experimental results and the proposed model equations. These proposed models can be beneficial in the development of the strength design of GPC and PCC incorporating agro-industrial wastes. Furthermore, the study shows the possibility of incorporating CCA with GGBFS for production of GPC and the tenability of curing GPC at ambient conditions for the structural application was also attained.