Clay Waste Research Articles

Novel synthesis and application of zeolite-Y from waste clay for efficient CO2 capture and water purification

In the present study, the microwave-assisted hydrothermal method using sodium hydroxide (NaOH) has been used to synthesise zeolite-Y from three different waste clays (WC) from Teesside, Northeast of England, UK. The effects of microwave time intervals and WC type were investigated to produce crystalline zeolite-Y. All WCs and synthesised zeolites were characterised by scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller surface area measurement (BET). The characterisation results showed that the zeolite-Y samples synthesised at 6 min intervals exhibited larger total pore volumes, higher surface areas, and higher crystallinity compared to the samples synthesised at 4 min intervals. Especially, the synthesised zeolite-Y from Clay 1 displayed high CO2 adsorption capacity, achieving 5.23 mmol/g at 298 K and 1 bar, with a maximum methylene blue removal of 94.3 %. This sample showed a surface area of 485 m²/g and a pore volume of 0.24 cm³/g, alongside an Si/Al ratio of 3.7, highlighting its excellent thermal stability at elevated temperatures. The high CO2 adsorption capacity combined with the high methylene blue removal efficacy makes the synthesised zeolite-Y from WC an excellent candidate for efficient CO2 capture and removal of methylene blue from contaminated water. Additionally, this study illustrates the potential for waste valorisation through the conversion of low-value WC into high-performance, value-added materials. This transformation not only mitigates waste disposal issues but also contributes to sustainable resource management and environmental protection by offering a practical solution for treating industrial effluents and gas emissions.

Performance and Life Cycle Cost Analysis of Recycled Concrete Utilising Waste Clay Brick

Performance and Life Cycle Cost Analysis of Recycled Concrete Utilising Waste Clay Brick

Preparation and properties of alkali-activated fly ash-waste brick porous building materials

This study explores the development of sustainable porous building materials through the alkali-activation of fly ash and waste clay brick powder. Utilizing Class F fly ash and brick powder from demolished buildings, a series of alkali-activated mortars with varying brick powder replacements (0 % to 50 % by mass) were formulated and analyzed. The results reveal that a 10 % brick powder replacement optimizes the compressive strength, reaching 73 MPa at 28 days, attributed to enhanced nucleation and calcium-rich gel formation. However, higher brick content reduces strength due to the dilution of key reactive materials, with a 50 % replacement leading to a strength of 27 MPa. Porosity increases proportionally with brick content, achieving a maximum of 42 % at 50 % replacement, suggesting potential applications in insulation-centric scenarios. Microstructural analysis confirms the formation of a porous network and identifies the phase compositions and reaction products. This research demonstrates the potential of repurposing construction waste into efficient and environmentally friendly building materials, contributing to waste reduction and offering a greener alternative to traditional practices.

Rational Use of Waste from Oil Extraction Production — Bleaching Clay Waste

The results of studies of the physic-chemical and sorption properties of bleaching clay waste, the prospects for its use for the purification of polluted waters, as well as the possibility of subsequent disposal of used materials are presented. Using the method of low-temperature nitrogen adsorption-desorption, it was found that the studied bleaching clay waste has a specific surface area of 185.53 m2/g and has a mesoporous structure. The sorption properties of clay waste were studied and it was found that at a dosage of 1.5 g/dm3, the purification efficiency of the standard solutions containing Cu2+ ions with a concentration of 10 mg/dm3 is 96.7 %. It has been found that the maximum sorption capacity, determined under static conditions for clay fired at a temperature of 350 °C, is 0.41 mmol/g. The use of bleaching clay as filler pigments in the manufacture of paints and varnishes has been proposed and demonstrated.

Exploring the Potential of Using Waste Clay Brick Powder in Geopolymer Applications: A Comprehensive Review

Exploring the Potential of Using Waste Clay Brick Powder in Geopolymer Applications: A Comprehensive Review

Recycling Clay Waste from Excavation, Demolition, and Construction: Trends and Challenges

The recycling of clay waste from construction debris highly depends on the chemical and mineralogical composition of the waste. Clays and clay minerals are known to be among marginal construction waste, representing an interesting opportunity and platform to produce other low-cost and low-carbon materials due to their possibilities for functional material design, such as adsorbents, drug delivery, catalysts and photocatalysts, and nanocomposites. The present review analyzes a wide variety of mechanisms for encapsulating organic and inorganic species between the layers of clay minerals. Through the compilation of advances in acid activation, exchange of inorganic cations, intercalation, and pillarization, new applications for clay materials are generated, paving the way to a nanometric world with functional, magnetic, adsorption, and catalytic capabilities. New trends are consolidated in the reuse of recycled clays in infrastructure projects, such as hydraulic concrete, water purification, soil fertility, pigments and paints, food packaging and storage, and ceramic appliances. It is concluded that clay waste is suitable to reuse in many industrial products and construction materials, enabling a reduction in the consumption of raw materials.

Study on the Effect of Carbonation on the Mechanical Properties of Lime Modified Waste Clay

Study on the Effect of Carbonation on the Mechanical Properties of Lime Modified Waste Clay

Effect of TiO2 Nanofiber Content on Compressive Strength of Geopolymers Fabricated from Waste Clay

Effect of TiO2 Nanofiber Content on Compressive Strength of Geopolymers Fabricated from Waste Clay

Study on performance and application of O-QGS soil curing agent for waste clay with low liquid limit

To reuse industrial solid wastes and waste clay with low liquid limit, a kind of soil solidification material by using cement, quicklime and industrial solid wastes such as ground granulated blast-furnace slag (GGBS), silica fume (SF) was developed in this study. Response surface methodology (RSM) based on central composite design (CCD) was used to design the experiment and optimize the mix ratio of GGBS, quicklime and SF under certain cement content conditions (i.e., the content ratio of cement, GGBS, quicklime, and SF was 5: 9.14: 1.7: 2.13). A soil solidification agent named O-QGS was developed to solidify waste clay with low liquid limit. To clarify the solidification mechanism of solidified soil, a series of laboratory experiments such as UCS test, water stability test, and scanning electron microscopy (SEM) test were carried out to capture the mechanical properties, water stability, and microstructure of O-QGS solidified soil and cement solidified soil. For practical purpose of O-QGS, a method for forming prefabricated pile by using O-QGS solidified soil was developed, and a method for strengthening soft foundations with prefabricated O-QGS solidified soil pile was proposed. Based on the results of load tests, the bearing capacity of prefabricated O-QGS solidified soil pile and cement high-pressure rotary jet grouting pile, as well as the composite foundations bearing capacity of prefabricated O-QGS solidified soil pile and cement high-pressure rotary jet grouting pile used for strengthening soft foundations, were analyzed. The feasibility of prefabricated O-QGS solidified soil pile used for strengthening soft foundations was verified in practice. The present study shows that the UCS of O-QGS solidified soil is 7.25 MPa at 28 days, and the water stability coefficient of O-QGS solidified soil is larger than 0.8. Compared with the method of cement high-pressure rotary jet grouting pile to reinforce soft foundation, the bearing capacity of prefabricated O-QGS solidified soil pile to reinforce soft foundation is higher, and the cost can be saved by 22.4 %.

Optimization of glass scrap recovery and reuse in road construction for promising physicochemical stabilization

Waste glass is hugely present in Morocco, and can be recycled for many geotechnical purposes, including road construction. In contrast, earthworks often produce significant amounts of clay waste that lack the necessary technical criteria for use as barriers. The present work aimed to study the influence of the addition of glass waste on the evolution of the mechanical characteristics of clays stabilized with crushed glass (particles less than 63 μm). The work consists of carrying out CBR, Proctor, and shear tests on natural clay taken as a reference and mixtures (clay-crushed glass) at different percentages. Results showed that the addition of glass to clay decreases the swelling and compaction indices along with modifying the intrinsic characteristics of the clay.

Using construction and demolition waste materials to alleviate the negative effect of pavements on the urban heat island: A laboratory, field, and numerical study

In this study, construction and demolition waste (CDW) materials, including waste clay bricks, concrete, and glass, were used as aggregates of chip seal layers to enhance the reflectivity and reduce the temperature of asphalt pavements as an urban heat island (UHI) mitigation policy. UHI is an urban area that has a higher temperature in comparison to its suburbs. As considerable parts of cities are covered with asphalt pavements, their heat absorption and heat release can directly affect the UHI. Four types of chip seal layers, containing CDW aggregates were prepared in this study. The reflectivity and cooling effects of asphalt pavement coated with the developed chip seals were then evaluated with laboratory, field experiments, and computational fluid dynamics (CFD) simulation. Regarding the laboratory methods, UV-Visible-NIR spectrometer reflectance, a trident thermal properties measurement, and solar simulation cooling effect were used. Besides, the albedo and cooling effects of the developed chip seals were evaluated with a pyranometer and thermocouples through a field experiment. The indoor reflectance test showed yellow and red brick chip seals reflected almost 136 % higher than the aged asphalt pavement, followed by concrete chip seals with 80 % higher solar reflectance. Besides, the surface temperatures of yellow brick, red brick, and concrete chip seals were 23 %, 18 %, and 15 % cooler than the hot mix asphalt (HMA) specimens. More importantly, clay brick chip seals had the lowest nighttime heat release, followed by the concrete chip seal. The field test indicated that the albedo of yellow brick was 2 and 6 times higher than the aged and new HMA, causing 17 % and 27 % lower surface temperatures. The numerical models also revealed that using the yellow brick and concrete chip seals decreased the surrounding air temperature at least by 18 % and 14 % respectively. Overall, the numerical modeling, laboratory, and field tests showed similar results, indicating the benefits of using clay bricks and concrete aggregates for chip seal development, which can mitigate the UHI effectively.

Formulation of geopolymer binder based on volcanic-scoria and clay brick wastes using rice husk ash-NaOH activator: Fresh and hardened properties

The present study investigated the influence of the replacement of waste clay bricks (WB) by volcanic scoria (Zg) on the fresh and hardened properties of geopolymer binders for potential construction applications at ambient temperature. Geopolymer paste samples were prepared using Zg as raw material blended with WB ranging from 0 to 50 wt% of total raw materials. Alternative alkaline activator used for the geopolymer synthesis was prepared by mixing rice husk ash (RHA) and 6 mol/L of NaOH solution. The geopolymers were cured at room temperature for 28 days, then subjected to mechanical property tests; microstructural and macrostructural characterization studies. Results showed that both flowability and setting time of geopolymer mixtures decreased with increases in WB content. The reduction in workability could be attributed to increase in the relatively rough surface of WB particles, which resulted in inter-particle friction. Flexural strength increased from 4 to 12 MPa while the compressive strength 24–52 MPa with the increase in WB up to 50%. The WB powders enriched Al content in mixtures, establishing the Si-O-Al bonds, confirmed by 27Al MAS NMR spectroscopy exhibiting the more Al(IV) sites integrating the N-A-S-H network. Incorporating the WB powders contributed to the development of densified matrix.

Optimizing the compressive strength of low-grade hydrous clay and copper slag‐based sustainable ternary blended geopolymer mortar

Ternary blended geopolymers represent a new class of sustainable binders with improved properties when compared to mono and binary blended geopolymers under ambient conditions. The study focuses on low grade industrial waste materials; locally sourced hydrous clay (HC) waste and copper slag (CS), to create novel Ternary Blended Geopolymer Mortars (TBGM). The addition of CS had a positive effect on strength development. The incorporation of 40 % CS as fine aggregate replacement, improved the proportion of HC in precursors from 10 % to 30 %. The design parameters considered were sodium silicate to sodium hydroxide solution ratio (SS/SH) at (2,2.5,3), the alkaline solution (AL) to binder (B) material ratio (AL/B) at (0.35,0.4,0.45), and the molarity of the sodium hydroxide solution (M) at (8,10,12) respectively. Box Behnken Design (BBD) with response surface methodology (RSM) was used to reduce the number of trial experiments to 15 from a total of 27 and, to statistically optimize and evaluate the interactions of SS/SH, AL/B, and M on the performance of TBGM. The compressive strength of 72 N/mm2 at the SS/SH, M and AL/B as 2.5, 12 and 0.4, respectively, was in good agreement with the experimental result of 78 N/mm2 at similar proportions. From the diagnostics and response plots of RSM, it can be inferred that the molarity of NaOH and AL/B and its combined interaction had more critical influence on the compressive strength of TBGM compared to SS to SH ratio. The microstructural and durability investigation further validated the optimization studies, as the optimum mortar specimen exhibited a denser microstructure with reduced shrinkage and sorptivity values.

Synergistic effects of Reflux Flotation Cell's downcomer and reverse fluidization bed in rejecting clay entrainment during particle separation

The Reflux Flotation Cell (RFC) technology is heralded as an innovative game-changer, promising significant advancements in particle separation, and offering generational benefits for the resources industry. This paper meticulously assessed the RFC's capabilities in tackling another critical industry challenge in resources processing— severe entrainment of waste clay particles during flotation separation and compared the performance with conventional mechanical flotation. Through flotation tests where kaolinite particles were separated from combustible materials, in-situ particle aggregation measurements and calculating air fractions in both flotation systems, this study identified the superior performance of the RFC in reducing kaolinite entrainment and producing a high product quality. This was attributed to a synergistic function between the RFC's downcomer for kaolinite dispersion and the RFC's fluidization bed for generating a low air fraction in reducing kaolinite entrainment. While kaolinite dispersion avoided the blocking of water drainage channels between air bubbles by aggregates, a low air fraction ensured a large gap between air bubbles to allow the displacement of entrained fine particles with fluidization water. Herein, the research findings will guide the resources industry to process low quality resources by successfully rejecting clay and other fine waste materials.

Effect of waste clay brick powder on microstructure and properties in blended oil well cement pastes at HTHP conditions

The use of waste materials to improve the thermal stability of oil well cement (OWC) at high temperature and high pressure (HTHP) conditions has received increasing attention. This study investigated the performance of sustainable blended OWC pastes by recycling waste clay brick powder (CBP) as a partial substitute for commercial high temperature resistant additives (silica flour, SF). The main objective was to assess the impact of these substitutions on the hydration, microstructure and mechanical properties of blended OWC. CBP was incorporated at substitution rates of 25 wt%, 50 wt%, 75 wt% and 100 wt% by weight of SF. These pastes were firstly precured at 50 °C for 7 days (to simulate the primary cementing operation prior to steam injection), and then thermally cycling cured at 300 °C/13.0 MPa (to simulate the steam injection process). The study conducted comprehensive tests and analyses, including compressive strength, gas permeability, hydration products and microstructural analyses. The results showed that the suitable substitution rate of CBP in this study was 25 wt%-50 wt%. At these substitution levels, the blended OWC pastes had good compressive strength (18.5 MPa and 17.9 MPa) and low gas permeability (3.1 × 10−3 mD and 4.51 × 10−3 mD). From the environmental and economic analyses, the energy intensity and CO2 emissions of all blended OWCs were significantly lower compared to those of conventional OWC. Meanwhile, the cost of blended OWC in this study was significantly lower compared to that of the commercial SF-OWC system. Overall, this study highlighted the potential of recycling waste materials to promote raw material sustainability and improve the performance of OWC pastes at HTHP conditions.

Optimizing flotation separation of fluorapatite from Florida waste clay using a multiscale approach

This study combines flotation experiments and ab initio simulations to improve the anionic flotation of fluorapatite from Florida waste clay (FWC) by investigating the depressing effects of sodium silicate and citric acid, in presence of sodium oleate (NaOl), on dolomite, quartz, and fluorapatite. First, we show that the order of natural floatability with NaOl of the three pure minerals is fluorapatite > dolomite > quartz, in agreement with the first-principles calculations. Second, sodium silicate has a strong calculated affinity with fluorapatite surface, which explains the dramatical drop observed experimentally in the floatability of this mineral. From ab initio simulations, citric acid exhibits a poor affinity for fluorapatite surface but a strong affinity for dolomite and quartz surfaces, even stronger than NaOl, related to strong differences in the adsorption mechanisms. This trend in terms of affinities is consistent with the trend in terms of floatabilities, observed on pure minerals. Consistently, during FWC flotation, citric acid allows an efficient and satisfactory depression of gangue minerals (quartz and dolomite) and enhances P recovery and grade by 14 % and 2 %, respectively. Using citric acid in FWC flotation makes possible the efficient beneficiation of this material with a cleaner product compared to the classical processes.

Synthesis of geopolymer powder and beads based on red clay waste for the adsorption of methyl orange dye from aqueous solutions: Characterization, application of response surface methodology, and cost analysis

The current research focuses on the valorization of red clay waste (RCW) to develop alumino-silicate geopolymer binders (GPP) and geopolymer spheres obtained from GPP powder modified with sodium alginate (Alg/GPP). GPP and Alg/GPP were applied in the environmental field for the retention of methyl orange (MO) from an aqueous solution. The raw material and the synthesized geopolymers were characterized by various physico-chemical methods. The results of XRF, XRD, and FTIR confirmed the successful synthesis of GPP and Alg/GPP, while the SEM/EDX findings revealed the homogeneous surface of the adsorbents. A significant specific surface area was detected for GPP (73.56 m2/g) and Alg/GPP (91.24 m2/g) with a high cation exchange capacity around 122 meq/100g for GPP and 185 meq/100g for Alg/GPP. The removal process was performed using the response surface methodology according to the Box-Behnken design, optimizing the retention efficiency of MO by different factors, including temperature, initial concentration, solution pH, and contact time. The obtained data was treated through the analysis of variance (ANOVA) and fitted by a quadratic polynomial model based on multiple regression analysis. In an acidic medium at 45 °C, the optimal conditions for MO retention were estimated to be 120 mg/L of MO concentration in 55 min using GPP and 180 mg/L of MO concentration in 20 min using Alg/GPP. The pseudo-second-order kinetics were more appropriate for describing the MO removal onto GPP and Alg/GPP adsorbents. The Langmuir model identified a high retention capacity of MO around 94.78 mg/g via GPP and 224.85 mg/g via Alg/GPP. The thermodynamic data confirmed that the elimination of MO dye onto GPP and Alg/GPP adsorbents was endothermic, favorable, and spontaneous. This study provided insights into the valorization of composite materials based on solid waste in dye retention, which can potentially be employed in wastewater treatment.

Preparation and Performance of Ceramic Tiles with Steel Slag and Waste Clay Bricks.

Steel slag and waste clay bricks are two prevalent solid waste materials generated during industrial production. The complex chemical compositions of these materials present challenges to their utilization in conventional alumina silicate ceramics manufacturing. A new type of ceramic tile, which utilizes steel slag and waste clay brick as raw materials, has been successfully developed in order to effectively utilize these solid wastes. The optimal composition of the ceramic material was determined through orthogonal experimentation, during which the effects of the sample molding pressure, the soaking time, and the sintering temperature on the ceramic properties were studied. The results show that the optimal ceramic tile formula was 45% steel slag, 35% waste clay bricks, and 25% talc. The optimal process parameters for this composition included a molding pressure of 25 MPa, a sintering temperature of 1190 °C, and a soaking time of 60 min. The prepared ceramic tile samples had compositions in which solid waste accounted for more than 76% of the total material. Additionally, they possessed a modulus of rupture of more than 73.2 MPa and a corresponding water absorption rate of less than 0.05%.

Influence of Solid Waste Material Content on the Properties of Steel Slag-Waste Clay Brick Ceramic Bricks

Steel slag and waste clay brick are two common solid wastes in industrial production, and their complex chemical compositions pose challenges to the production of traditional alumina silicate ceramics. To investigate the influence of steel slag and waste clay brick on the performance of CaO–SiO2–MgO ceramic materials, this study examined their effects on the mechanical properties, crystal composition, and microstructure of the ceramics through single-factor experiments. The results demonstrate that when keeping the dosage of waste clay brick and talcum powder constant, a 43% dosage of steel slag yields optimal performance for the ceramic materials with a modulus of rupture of 73.01 MPa and a water absorption rate as low as 0.037%. Similarly, when maintaining a constant dosage of steel slag and talcum powder, a 41% dosage of waste clay brick leads to superior performance of the ceramic materials, with a modulus of rupture reaching 82.17 MPa and a water absorption rate only at 0.071%. Furthermore, when keeping the dosage of steel slag and waste clay brick constant, employing a talcum powder dosage of 24% results in excellent performance for the ceramic materials with a modulus of rupture measuring 73.01 MPa while maintaining an extremely low water absorption rate at only 0.037%. It is noteworthy that steel slag contributes to akermanite phase formation while talcum powder and waste clay brick contribute to diopside phase formation.

RECOVERY OF BORON WASTES WITH INORGANIC ACID

Approximately 73-74% of boron mineral reserves all over the world are located in the Western Anatolian region of Turkey, in the provinces of Eskişehir, Kütahya, Balıkesir, and Bursa. The most intense minerals extracted from these fields are colemanite, ulexite, and tincal minerals, respectively. The general principle in the recovery of these minerals is to extract the raw ore and obtain it by size reduction processes of concentrates in high grade. In addition to concentrates, boric acid (H3BO3) production is also possible in Balıkesir and Kütahya. The production of this acid in question includes a series of processes from dissolution with sulfuric acid at high temperatures to crystallization. In this study, except for the aforementioned high concentrations, boron recovery from clay waste, which is high in boron content and is collected from plant waste ponds, is investigated. For this purpose, ulexite-colemanite-containing slime wastes of the Bigadiç (Balıkesir) Plant were dissolved in 7% solids at 60°C in different sulfuric acid concentrations (1-6% H2SO4) and were obtained with 83-97% B2O3 recovery. When the boron wastes are evaluated, issues such as the discovery and establishment of a new waste pond/dam will be solved, the valuable content in the wastes will be recovered, and the environmental problems of boron and other contents in clay will be eliminated. This article includes information about the characterization of the structure by considering the dissolution of boron and other compounds, as well as obtaining boric acid from inorganic acid and boron wastes.