Global Utilizations of Cement Kiln Dust

Version	Summary	Created by	Modification	Content Size	Created at	Operation
1		Ali Y. Al-Bakri	--	4558	2022-08-13 08:40:22	\|
2	format	Jason Zhu	-4 word(s)	4554	2022-08-15 04:00:37	\|

This entry is adapted from the peer-reviewed paper 10.3390/su14127022

A large quantity of cement kiln dust is produced daily, associated with ordinary Portland cement production worldwide. Most of these quantities are disposed of in landfills to meet the environmental requirement. Meanwhile, only a small proportion can be recycled in cement manufacturing. Recently, utilizing cement kiln dust (CKD) in many commercial applications has significantly increased due to the potential benefits of adding CKD, in different percentages, to the engineering properties of the prepared product. Moreover, utilizing CKD as a partial replacement for cement in industrial applications reduces the overconsumption of natural resources used for cement manufacturing and promotes sustainability.

cement kiln dust (CKD) sustainability cement application

1. Introduction

Over the past few years, in support of sustainability and due to the technical developments used in the cement industry, global dramatic progress has been made in generating, managing, and reusing Cement kiln dust (CKD). Along with environmental impacts, these efforts reduce costs and reduce dependency on landfills. For example, in 2006, as reported by the Portland Cement Association (PCA) in the US, 1,160,011 metric tons of CKD generated by member companies were utilized in various applications ^[1]. This amount was utilized in soil and waste stabilization, cement additives (blending), mine reclamation, agricultural soil amendments, sanitary landfill liners, concrete products, pavement manufacturing, wastewater neutralization, etc. The soil stabilization had the most considerable utilization, with 533,356 metric tons successfully reused. Cement kiln dust (CKD), a byproduct of the cement industry, has been introduced as a potential material that can provide economic and environmental benefits, as illustrated in many research investigations supported by positive experimental test results.

Although tremendous technical and industrial progress has recently occurred in the cement industry, which contributed to a significant decrease in the quantities produced as cement kiln dust (CKD), there are still amounts generating that constitute an essential concern regarding transportation costs and negative impacts on the environment ^[2]. Therefore, the focus is now on commercial applications that can use CKD.

Through a research, Elbaz et al. (2019) discussed the beneficial use of CKD as well as fly ash (FA) from an environmental and economic point of view ^[3]. As revealed by the literature, the examined CKD and FA waste materials negatively impact the environment if not disposed in an environmentally safe manner. The adverse effects of both investigated materials may include ozone depletion, biodiversity loss, acid rain, reduced crop productivity, and global warming. On the other hand, the study concluded that numerous applications, such as in the agricultural field, waste treatment, soil stabilization, and pollution control, could utilize these byproduct materials for optimization purposes. At the same time, the researchers recommended that by reusing these materials, many advantages could be achieved, such environmental and human health protection and raw materials conservation.

Another study introduced by Saleh et al. (2021) presented the improvement and green sustainability that could be achieved by using CKD ^[4]. As stated, alkaline compounds such as CKD could activate many inert waste materials. Due to containing Portland cement as well as Ca(OH)₂, additional products of cement could be developed. Cement production depends totally on the extraction of resources, such as limestone, fossil fuels, and other natural minerals; one ton of produced clinker is required as well as 1.5–1.7 of raw materials. Moreover, cement manufacturing requires more energy with a temperature of 2000 °C. Therefore, the study concluded that CKD could partially replace cement to produce sustainable products.

2. Soil Stabilization

Ghorab et al. (2007) discussed soil chemical stabilization for producing some building units like tiles, bricks, wall plaster, and paving roads ^[5]. The investigation used many industrial wastes, such as blast furnace and steel slag, powder of red bricks, and cement kiln dust (CKD), to design the mixes later subjected to a compressive test to evaluate their durability. The study’s findings showed that industrial waste, including CKD, could contribute to low-cost housing and other practical advantages. Another attempt was made by Moon et al. (2008) to assess the stabilization of arsenic-contaminated soil using CKD ^[6]. Amounts of 10 to 25% of CKD was utilized for a prepared slurry treatment. Treatment effectiveness was evaluated in a 1–7-day curing period. As the obtained results revealed, arsenic could be immobilized due to CKD treatment. Moreover, the study recommended more investigation for the commercial stabilization and solidification of soil induced by CKD in terms of achieving cost-effectiveness as well as expanding the range of beneficial uses of CKD material.

Sreekrish et al. (2007) evaluated some samples of CKD (fresh and landfilled) for the utilization in soil treatment ^[7]. CKD with 8–20% replacement used for combined soil was tested using unconfined compression, compaction, swell, pH, and Atterberg limits tests. The laboratory study indicated that the fresh sample had sufficient reactivity and potentially could be utilized for soil stabilization due to induced strength improvement and swelling strain reduction, such as the results obtained with 4% Portland cement. As well, the engineering properties of CKD in the stabilization of two modified soil sample was presented by Carlson et al. (2011) ^[8]. Typically, the collected soils were wet and had a geotechnical pose during construction. CKD at 5, 10, 15, and 20% was added and then subjected to drying rate, unconfined compression, standard proctor, and Atterberg limits tests. The investigation results illustrated a significant improvement in the unconfined compressive and drying rate for CKD-treated soil related to increasing CKD proportions. Additionally, a higher percentage of CKD could be utilized for geotechnical construction stabilization purposes and contribute to landfill cost-saving, as the researchers recommended. Ebrahimi et al. (2012) studied the effectiveness of CKD for stiffness improvement of recycled base materials, such as pavement and road surface gravel ^[9]. Testing programs were conducted using resilient and seismic modulus. The percentages of added CKD were 0, 5, 10, and 15% and were evaluated by a reference binder, Portland cement. The outcomes showed improvement in the modulus from 5 to 30 times based on the content of CKD and the base materials type. The study recommended that CKD is suitable for geotechnical applications, considering the change of expansion and modulus during the curing process. Albusoda and Salem (2012) conducted an extensive experimental testing program to determine the geotechnical properties of CKD-stabilized dune sand ^[10]. The course of tests conducted on modified soils included Atterberg limits, compaction, direct shear, triaxial compression, collapse, loading, and time of curing difficulties. As the study concluded, an irregular decrease was induced in the liquid limit by CKD when mixed with sand, in addition to a high value in cohesion with increasing the percentage of CKD. After fourteen curing days, shear strength parameters were constant, inducing no variation. The researchers recommended that soil collapse with CKD could achieve enormous economic advantages; the ultimate bearing capacity could be increased to 250% by adding 8% of cement kiln dust (CKD) materials.

In the same context, Okafor and Egbe (2013) studied the potentiality of CKD in subgrade improvement ^[11]. The study aimed to reduce the construction cost by converting byproducts, such as CKD, into restorative materials used in construction and soil improvement. CKD at 2–24% was utilized to stabilize the collected soil samples. Investigated properties were subjected to unconfined compression strength, compaction, California bearing ratio, and consistency limits tests. Results obtained indicated that increasing CKD content led to optimum moisture content while reducing the plasticity. Likewise, the unconfined compression strength and California bearing ratio improved while CKD content increased. The study also developed a high correlation coefficient model to be used successfully to predict the properties of soil-CKD in the case that experimental soil data are absent. As the investigation illustrated, they yielded the maximum improvement with 24% of CKD. Gupta et al. (2015) used CKD to treat cadmium-contaminated soil to improve the engineering properties and inactivate the present contaminants ^[12]. CKD was added at various percentages of 1, 2, 4, 6, 8, and 10%. Atterberg limits, toxicity characteristic leaching procedure (TCLP), and unconfined compressive strength tests were conducted on the modified soil. The outcomes indicated benefits induced on the engineering properties of the contaminated soil; the maximum stabilization was obtained at 8% of CKD. At the same time, the TCLP test showed that it inactivated 80.70% of the cadmium in the soil. Yoobanpot et al. (2017) used cement kiln dust (CKD) and fly ash (FA) to improve the unconfined compressive strength (UCS) of soft clay material ^[13]. Curing for 3, 7, 28, and 90 days was performed to prepare soft clay stabilized for UCS testing. The researchers also conducted X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques to investigate the reaction product and microstructure changes in the modified clay. The outcomes revealed that 13% CKD and 20% mixtures illustrated the optimum strength at 90 days of curing, such as the stability provided by the 10% content of ordinary Portland cement (OPC).

Arulrajah et al. (2017) investigated cement kiln dust (CKD) and fly ash (FA) as pozzolanic materials to be an alternative binder for construction and demolition aggregates ^[14]. The modified material was tested by undertaking the repeated load triaxial test to evaluate the durability and the unconfined compressive strength test for strength evaluation. A mixture design of 20% CKD and 10% FA achieved the optimum stabilizing performance. As the study concluded, CKD could be used in low-carbon activities of civil construction. Likewise, Mohammadinia et al. (2018) combined CKD and FA to increase the stiffness and strength of the demolition aggregates, containing an aggregate of recycled concrete, reclaimed asphalt pavement, and crushed brick ^[15]. The modified mixture was subjected to the repeated load triaxial test for durability and the unconfined compressive strength test for strength evaluation. The study concluded that the composite sample achieved the optimum engineering properties at 15% CKD and 15% FA. An investigation of the effect of using CKD and periwinkle shell ash (PSA) blends on the plasticity of lateritic soil was carried out by Ekpo et al. (2021) ^[16]. CKD at 0, 5, 10, 15, and 20% was used for soil treatment. The testing program included Atterberg limits, plasticity, UCS, X-ray diffraction (XRD), and scanning electron microscope (SEM) tests. Results concluded that CKD and PSD are viable stabilizers for tropical soils.

The results of studies that utilized CKD for soil stabilization showed that CKD could be added as an activator for pozzolanic materials. It has been successfully mixed with many industrial wastes, such as blast furnaces, periwinkle shell ash, fly ash, and steel slag, with various percentages (from 2–30%) to improve the mechanical properties of soil. Moreover, CKD exhibited strength in inactivating the contaminated soil’s toxic elements, such as arsenic and cadmium, introducing CKD as one of the low-cost solutions in the soil stabilization field.

3. Replacement for Cement

Al-Harthy et al. (2003) investigated the use of CKD in concrete and mortar as a cementitious material ^[17]. The study aimed to add CKD to the mixture of concrete and mortar to evaluate the effect on strength and water absorption. The conducted experimental work included compressive strength, toughness, flexural strength, initial surface absorption, and sorptivity tests. The replacement of CKD included amounts at 0 (control), 5, 10, 15, 20, 25, and 30%. The results showed that the concrete mixtures’ compressive strengths, toughness, and flexural values with 5% CKD were close to the control mix. The study revealed that no strength was gained by substituting cement with CKD for all samples investigated; meanwhile, no negative impact on strength properties occurred when the proper addition of CKD was added. Additionally, better absorption characteristics were achieved by adding a suitable proportion of CKD. Likewise, the effect of adding CKD admixture as a partial replacement for cement was investigated by Mohammad and Hilal (2010) ^[18]. The content of CKD was 10, 30, and 50% of the weight of cement. The study selected three mixes of CKD and one without admixture as a reference mix. A set of tests were conducted on the modified mixes such as compressive strength, splitting tensile strength, ultra-sound velocity (UPV), flexural strength, slump, and static elasticity modulus. Obtained results indicated a significant decrease in the strength of the modified concrete; at 28 days of the curing period, the compressive strength was 28, 25, and 22 MPa for 10, 30, and 50% CKD content, respectively. In comparison, the reference mix gained a 35 MPa compressive strength. Marku et al. (2012) attempted to utilize CKD as a partial replacement for cement to produce mortar and concrete ^[19]. The study prepared various blended materials with 0–45% of CKD. In some blends, fly ash and blast furnace slag were added to CKD. The test program included compressive strength, flexure, and durability tests. The investigation demonstrated a gain in the low strength of CKD–OPC blends due to calcium silicate absence and low fineness of CKD. However, it is possible to combine CKD with pozzolanic materials such as blast furnaces, fly ash, etc.

Through a research, Kunal et al. (2012) discussed the utilization of CKD in cement concrete and its leachate characteristics ^[20]. The research concluded that 5–10% of CKD in the mortar and concrete mixtures could achieve similar engineering properties to the control mixes. CKD could be used as an activator for copper slag, blast furnace slag, and other industrial wastes. In the future, the blend of CKD, slag, Portland cement (CKD–slag–PC) could be potentially considered as an alternative to Portland cement with good engineering properties. CKD–slag–PC blends have low alkali, making them more effective for strength improvement than CKD–PC blends. El-Mohsen et al. (2015) studied the use of CKD as a partial replacement of cement in self-consolidating concrete (SCC) to reduce production costs as well as for environmental reasons ^[21]. The study used a partial replacement of cement with 10, 20, 30, and 40% of CKD to produce four mixes. The engineering properties of modified mixtures were investigated using consistency, compressive and indirect tensile strengths, flexural, and shrinkage tests. The findings indicated the possibility of producing a modified SCC with engineering properties nearly like the control mix, which could introduce a cheaper product and eliminate the negative impact on the environment. SCC with 20% of CKD content was found to be the optimum mix content in terms of flexural, compression, and splitting strengths at 28 days of the curing period compared to the control mix. The values of shrinkage strain also showed that SCC with 10% of CKD is close to the control mix value.

Hussain and Rao (2014) conducted a detailed experimental work investigating CKD and fly ash as a cement replacement in the concrete ^[22]. They obtained fly ash residue from coal combustion and CKD, which reduces the hydration heat, and prepared cubes of 100 cubic mm with various compositions. For 28 curing days, the modified mixture was to compressive strength by destructive and non-destructive tests, such as ultra-sonic pulse velocity (UPV). The outcomes illustrated that concrete integrity is suitable for all mixtures. However, the attained strength of concrete with 10% CKD complied with the target; if CKD increases more than 10%, that reduces the concrete strength. Sadek et al. (2017) evaluated the durability and physico-mechanical properties of concrete containing CKD as a partial replacement and addition to cement in paving blocks ^[23]. Water absorption, compressive and tensile strengths, abrasion resistance, and slip or skid resistance tests were conducted on the designed mixtures. As the study revealed, there is a possibility to utilize a large volume of CKD in paving blocks for environmental considerations and sustainability. At the same content, using CKD as an addition is better than a replacement; adding 20% of CKD could achieve comparable engineering properties to control blocks. Up to 10% of CKD could be used as a partial replacement for cement without any adverse effect on paving block properties.

4. Treatment Agent

Peetham et al. (2009) utilized CKD to treat kaolinite clay and investigate the induced physicochemical behavior ^[24]. CKD with high free lime was used in the treatment process to evaluate its effectiveness. The study’s testing program included tests of unconfined compressive strength, Atterberg limits, and stiffness of compacted soil. At the same time, they compared the obtained results to the results of untreated clay and clay treated with calcium oxide (quicklime). The physicochemical behavior was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray analyses. This step determined the induced morphologic and mineralogical changes on the 90-day curing period specimens. The study concluded that high free lime CKD effectively caused an improvement in the compressive strength, Atterberg limits, and stiffness of the compacted-soil-treated kaolinite clay. Another study conducted by Mackie and Walsh (2012) used CKD as a neutralization agent for acidic mine water treatment in place of quicklime ^[25]. In addition, the evaluated the performance of generated slurries of calcium hydroxide (Ca(OH)₂) from CKD to reduce mine water’s metal concentrations and acidity. The study used techniques to analyze the settled water quality, mine water pH, and micro-flow imaging. The obtained results showed that CKD could achieve viable active treatment by removing 98% and 97% of zinc and iron, respectively, and acidity reduction.

CKD was also successfully utilized as a treatment agent in many fields, such as removing copper and zinc contamination from acidic groundwater ^[26], adding an improvement in aluminum metal matrix composites ^[27], benefiting municipal wastewater as an effective treatment agent ^[28], supporting pozzolanic material production as a sustainable solution ^[29], improving benzene-contaminated groundwater as a capable treatment material ^[30], inducing benefits to magnesium phosphate cement ^[31], and contributing to eliminate the hazard of groundwater contaminated by cadmium ions ^[32]. The utilization of CKD waste material as a treatment agent could provide a wide range of advantages in this field. It creates a potential new market, reducing the cost of chemical treatments and eliminating the negative impact on the environment due to the landfill disposal.

The finding of investigations that used cement kiln dust as a treatment agent showed that CKD has chemical and physical properties that effectively treat a wide range of materials such as kaolinite clay, acidic mine water, and copper- and zinc-contaminated acidic groundwater, as well as aluminum metal matrix composites, municipal wastewater, pozzolanic materials, benzene-contaminated groundwater, magnesium phosphate cement, and cadmium ions in groundwater. The utilization of CKD as byproduct waste from cement manufacturing in the treatment field could provide many advantages related to this field, such as reducing the chemical treatment cost and eliminating the negative impact on the environment.

5. Ceramic and Brick

Aydin et al. (2019) used CKD as a CaO alternative source to produce ceramic wall tiles ^[33]. The researchers investigated the effect of CKD on the composition with various proportions (15% max) and then sintered the shaped samples at 1150 °C. Experimental work conducted to test the physical properties included water absorption, bulk density, linear firing shrinkage, and flexural strength. Meanwhile, the sintering behavior was evaluated using an optical dilatometer. The obtained results revealed CKD as an effective source of CaO and could be sufficiently used in the production of ceramic wall tile. Ewais et al. (2015) exploited CKD and quartz sand with various baths to produce wollastonite ceramics ^[34]. The mechanical properties of the fired batches were investigated using compressive strength and hardness tests. The outcomes indicated that wollastonite ceramics could be successfully produced by adding quartz to CKD.

Mahrous and Yang (2011) conducted a study to investigate the cement and CKD combination properties while producing cement bricks ^[35]. CKD with 0–40% proportions was increased gradually as a replacement for cement in the cement brick mixtures. The modified bricks were subjected to testing programs including density, compressive strength, and water absorption tests. The findings indicated that the properties of the produced cement and CKD brick with 30% of CKD content could meet the Korean standards while 40% of CKD could meet the Egyptian code. The study concluded that the modified bricks with CKD components have beneficial values from a properties and cost perspective. Ogila (2014) studied the effect of utilizing CKD on the red clay brick’s physical and mechanical properties ^[36]. Brick samples were prepared with dimensions of 20, 35, and 70 mm by mixing clay with different proportions of CKD (2, 4, 8, 10, and 12%). The prepared mixture batches were mixed with water to achieve plastic masses and then sintered for three hours at 950–1100 °C using an electric furnace. At the same time, the raw clay control brick was designed with 0% CKD. Atterberg limits, mineralogical composition, color and surface appearance, water absorption, firing linear shrinkage, firing weight loss, and efflorescence were investigated. The obtained results demonstrated that the properties of the produced brick strongly depend on the CKD and firing temperature. As the study concluded, CKD as a clay material substitute could provide a feasible way to make quality bricks. El-Attar et al. (2017) also recycled CKD in the brick industry through an investigation conducted for sustainability by limiting environmental concerns ^[37]. The study also examined the carbon footprint emitted from solid cement brick manufacturing. Mixtures were prepared with 0, 30, and 50% of CKD and evaluated by compressive strength, water absorption, and unit weight. The obtained results showed acceptable properties of produced brick with CKD content up to 50% instead of cement, which provides an economical and environmentally friendly solution for concrete brick manufacturing.

Abdel-Gawwad et al. (2021) utilized CKD with the waste of red clay bricks and silica fume as the main ingredients to produce unfired building bricks ^[38]. The prepared composite of CKD–RCBW–SF was adjusted at various proportions of content. The ready-mix was subjected to the blending, water mixing, and casting stages. Some conditions, such as air, water, and CO₂ gas, were considered in the study for designed mixture curing. The grade of hardened bricks was evaluated based on compressive strength, saturation coefficient, water absorption, and bulk density. The study outcomes indicated that curing in water medium achieved the highest performance, with 47 MPa at 28 days and a proportion of 50 to 20 to 30 for the composite of CKD–RCBW–SF, respectively. CKD was utilized as an alkali material that activated the aluminosilicate in the silica fume and brick waste to yield a hardened product containing calcium silicate hydrate upon hydration. Moreover, the researchers used thermogravimetric and X-ray diffraction analyses to identify the calcium carbonate and calcium silicate hydrate and confirm that the occurrence of both carbonation and hydration reactions were induced with every curing medium.

Udoeyo et al. (2002) used CKD as an additive and replacement material for cement while producing hollow building blocks ^[39]. The properties of the prepared product were evaluated by workability (compaction factor), compressive strength, density, and water absorption. The laboratory investigation results showed that produced blocks with 5, 10, and 20% of CKD as a replacement material achieved an excellent compressive strength value that was higher than the control block strength. The study recommended that CKD as a block manufacturing replacement material has more benefits than concrete blocks, such as low production costs, and advised investigating more properties in the future, such as shrinkage and short- and long-term durability.

Abdulkareem and Eyada (2018) used two types of CKD with sand and cement to produce pressed building brick ^[40]. The investigation was carried out in three phases: choosing a type of CKD and sand, mixing the selected materials with cement and water, and aiming to increase the compressive strength and absorption of brick to 11 MPa without adding more cement to reduce the cost. The obtained results showed that all properties of produced bricks were satisfactory according to ASTM standards, which characterize international applications for the product made by waste. The study concluded that many benefits could be achieved by using CKD in the production of bricks, such as using economic bricks for building, reducing the dependency on natural resources, reducing pollution, and reducing negative impacts on the environment.

In the ceramic and brick industry, cement kiln dust (CKD) was introduced as an alternative partial cementitious source at various proportions (2–50%). CKD was successfully utilized with improved engineering properties in the products of ceramic wall tile, wollastonite ceramics, cement bricks, unfired building bricks, and hollow building blocks. As the gained results revealed, CKD could provide a set of advantages to the ceramic and brick industry, such as improving the product’s properties, reducing production costs, promoting sustainability through protecting the natural resources and environment, and eliminating the pollution associated with these industries.

6. Miscellaneous Applications

Due to the high produced quantities of CKD and its associated disposal cost and environmental concerns, researchers have made great efforts to find various fields that can reuse CKD ^[41]. Moreover, CKD has a chemical composition containing potassium, sodium, and calcium oxides, making it a suitable and inexpensive activator for pozzolanic materials, such as slag and fly ash, compared to conventional activators utilized in the activation of alkali ^[42]. Therefore, CKD could be used in a wide range of practical applications. Colangelo and Cioffi (2013) used CKD with two other solids, marble sludge waste and granulated blast furnace slag, in the process of cold bonding pelletization for the sustainable production of artificial aggregates ^[43]. The study aimed to explore the activation action of CKD components on slag hydraulic behavior by evaluating the phases that are neo-formed and presented in hydrated pastes and, especially, the effect of free lime and sulfate of CKD on slag reactivity. Finally, the produced product proved suitability in cold bonding pelletization to produce artificial aggregates.

7. Mine Backfill

In the mining field, particularly for backfilling applications (cemented paste backfill), Lutyński and Pierzyna (2017) reused CKD as a backfill material and mineral adsorbent for CO₂ due to the high content of free lime (unreacted CaO) ^[44]. The study investigated the slurry properties of CKD and bottom slag through the compressive strength and water content. At 28 days of the curing period, the compressive strength of the slurry of CKD with bottom slag achieved a value of 4.7 MPa, which is higher than the threshold of the standard required strength (0.5 MPa). Excess water, observed at 0.6%, was much lower than the standard value (7%). The investigation findings indicated that CKD with CaO-high content could be considered an activator while mixing with silicate materials, significantly increasing compressive strength. Finally, the study recommended that if the leaching test results showed positive values, the slurry of CKD with bottom slag could be utilized in underground backfilling.

Likewise, Beltagui et al. (2018) utilized the blends of high free lime CKD, fly ash, and cement for mine backfill ^[45]. CKD with 29% free lime content was used as a high alkaline material to activate the pulverized fuel ash (PFA). The mixed and compacted blends in cylinders of 100 mm and 50 mm in length and diameter, respectively, were subjected to a compressive strength test in curing periods of 28 and 56 days to evaluate the achieved properties. Moreover, thermogravimetric and X-ray diffraction were conducted to assess the hydration products. Despite the many applications that can use CKD, reinforced concrete utilization will be impossible since the high chloride level may induce corrosion risk to the reinforcement. The results showed that the compressive strength of CKD–PFA blends ranged between 4.7 to 5.6 MPa and surpassed the required strength (3 MPa) at 56 days and a water–blend ratio of 0.2. At the same time, the maximum content of CKD that could be used and gain the required strength was 90% with 10% cement.

As concluded, the sustainability of using CKD for underground mine backfilling is confirmed through the investigation outcomes. However, some points should be considered, such as the finding that free lime in CKD rabidly absorbs the water; therefore, much water is in demand. Furthermore, mixing a large quantity of CKD with water produces large amounts of heat. Eventually, the fineness of CKD, which makes it challenging to deal with at underground mines, requires preparation on the surface and the pumping of slurry below. As recommended, further work will investigate hydrated paste’s microstructures.

In the mining industry, the daily operations extract vast amounts of materials for further processing and, simultaneously, voids are created. The induced holes may cause concerns from a safety, production, and environmental perspective. Cemented paste backfill (CPB) is a modern technology of backfill used to fill the underground voids in the presence of cement and mine tailings. The challenge related to the CPB method is the cement (binder) cost, which represents a high percentage of backfilling operation costs. The outcomes of studies that utilized cement kiln dust as a partial replacement for cement in this area indicated that CKD could effectively be used with an induced improvement on the mechanical properties of the prepared mixtures. That could provide a possible way to optimize the backfilling process.

References

Adaska, W.S.; Works, P.; Taubert, D.H. Beneficial Uses of Cement Kiln Dust. In Proceedings of the 2008 IEEE Cement Industry Technical Conference Record, Miami, FL, USA, 18–22 May 2008; pp. 210–228.
Alawi, M. Utilization of Using Cement Kiln Dust (Ckd) As a Surfacial Clay Soil Stabilizer Underneath Roads. J. Al-Azhar Univ. Eng. Sect. 2016, 11, 1101–1111.
Elbaz, A.A.; Aboulfotoh, A.M.; Dohdoh, A.M.; Wahba, A.M. Review of beneficial uses of cement kiln dust (CKD), fly ash (FA) and their mixture. J. Mater. Environ. Sci. 2019, 10, 1062–1073. Available online: https://www.jmaterenvironsci.com/Document/vol10/vol10_N11/JMES-2019-10-107-Elbaz.pdf (accessed on 14 December 2021).
Hm, S.; Aa, F.; Aa, S.; Am, E.S. A Review on Cement Kiln Dust (CKD), Improvement and Green Sustainable Applications. Int. J. Nucl. Med. Radioact. Subst. 2021, 4, 1–6. Available online: https://medwinpublishers.com/IJNMRS/a-review-on-cement-kiln-dust-ckd-improvement-and-green-sustainable-applications.pdf (accessed on 14 December 2021).
Ghorab, H.Y.; Anter, A.; El Miniawy, H. Building with local materials: Stabilized soil and industrial wastes. Mater. Manuf. Process. 2007, 22, 157–162.
Moon, D.H.; Wazne, M.; Yoon, I.H.; Grubb, D.G. Assessment of cement kiln dust (CKD) for stabilization/solidification (S/S) of arsenic contaminated soils. J. Hazard. Mater. 2008, 159, 512–518.
Sreekrishnavilasam, A.; Rahardja, S.; Kmetz, R.; Santagata, M. Soil treatment using fresh and landfilled cement kiln dust. Constr. Build. Mater. 2007, 21, 318–327.
Carlson, K.; Sariosseiri, F.; Muhunthan, B. Engineering Properties of Cement Kiln Dust-Modified Soils in Western Washington State. Geotech. Geol. Eng. 2011, 29, 837–844.
Ebrahimi, A.; Edil, T.B.; Son, Y.-H. Effectiveness of Cement Kiln Dust in Stabilizing Recycled Base Materials. J. Mater. Civ. Eng. 2012, 24, 1059–1066.
Albusoda, B.S.; Salem, L.A.K. Stabilization of Dune Sand by Using Cement Kiln Dust (CKD). J. Earth Sci. Geotech. Eng. Sci. Press. 2012, 2, 131–143.
Okafor, F.O.; Egbe, E.A. Potentials of Cement Kiln Dust in Sub-Grade Improvement. Niger. J. Technol. 2013, 32, 109–116. Available online: https://www.ajol.info/index.php/njt/article/view/87394 (accessed on 16 December 2021).
Gupta, S.; Pandey, M.K.; Srivastava, R.K. Evaluation of Cement Kiln Dust Stabilized Heavy Metals Contaminated Expansive Soil-A Laboratory Study. Eur. J. Adv. Eng. Technol. 2015, 2, 37–42. Available online: https://ejaet.com/PDF/2-6/EJAET-2-6-37-42.pdf (accessed on 18 December 2021).
Yoobanpot, N.; Jamsawang, P.; Horpibulsuk, S. Strength behavior and microstructural characteristics of soft clay stabilized with cement kiln dust and fly ash residue. Appl. Clay Sci. 2017, 141, 146–156.
Arulrajah, A.; Mohammadinia, A.; D’Amico, A.; Horpibulsuk, S. Cement kiln dust and fly ash blends as an alternative binder for the stabilization of demolition aggregates. Constr. Build. Mater. 2017, 145, 218–225.
Mohammadinia, A.; Arulrajah, A.; D’Amico, A.; Horpibulsuk, S. Alkali-activation of fly ash and cement kiln dust mixtures for stabilization of demolition aggregates. Constr. Build. Mater. 2018, 186, 71–78.
Ekpo, D.U.; Fajobi, A.B.; Ayodele, A.L.; Etim, R.K. Potentials of Cement Kiln Dust-Periwinkle Shell Ash Blends on Plasticity Properties of Two Selected Tropical Soils for use as Sustainable Construction Materials. In IOP Conference Series: Materials Science and Engineering; IOP Publishing Ltd.: Bristol, UK, 2021; Volume 1036, p. 012033.
Al-Harthy, A.S.; Taha, R.; Al-Maamary, F. Effect of cement kiln dust (CKD) on mortar and concrete mixtures. Constr. Build. Mater. 2003, 17, 353–360.
Mohammad, A.M.; Hilal, N. Re-using The By-product of Cement Industry (Cement Kiln Dust) To Produce the Concrete. Anbar J. Eng. Sci. 2010, 3, 1–14. Available online: https://www.iasj.net/iasj/download/a22646580df16d01 (accessed on 19 December 2021).
Marku, J.; Dumi, I.; Lico, E.; Dilo, T.; Çakaj, O. Ckd in Mortar & Conc Prodctn. Mater. Prot. 2012, 53, 334–344. Available online: http://idk.org.rs/wp-content/uploads/2016/10/8MARKU.pdf (accessed on 19 December 2021).
Siddique, R.; Rajor, A. Use of cement kiln dust in cement concrete and its leachate characteristics. Resour. Conserv. Recycl. 2012, 61, 59–68.
El-Mohsen, M.A.; Anwar, A.M.; Adam, I.A. Mechanical properties of Self-Consolidating Concrete incorporating Cement Kiln Dust. HBRC J. 2015, 11, 1–6.
Hussain, G.S.; Rao, R. Experimental Studies on Concrete Containing Cement Kiln Dust and Fly Ash. Singap. J. Sci. Res. 2014, 6, 85–88. Available online: http://www.sjsronline.com/Papers/Papers/sjsrvol6no2_5.pdf (accessed on 19 December 2021).
Sadek, D.M.; El-Attar, M.M.; Ali, A.M. Physico-mechanical and durability characteristics of concrete paving blocks incorporating cement kiln dust. Constr. Build. Mater. 2017, 157, 300–312.
Peethamparan, S.; Olek, J.; Diamond, S. Physicochemical behavior of cement kiln dust-treated kaolinite clay. Transp. Res. Rec. 2008, 2059, 80–88.
Mackie, A.L.; Walsh, M.E. Bench-scale study of active mine water treatment using cement kiln dust (CKD) as a neutralization agent. Water Res. 2012, 46, 327–334.
Sulaymon, A.H.; Faisal, A.A.H.; Khaliefa, Q.M. Cement kiln dust (CKD)-filter sand permeable reactive barrier for the removal of Cu(II) and Zn(II) from simulated acidic groundwater. J. Hazard. Mater. 2015, 297, 160–172.
Hammood, S.A.; Al-Ethari, H.; Al-Juboori, H.A.H. Effect of cement kiln dust on properties of Al-base composite prepared by P/M. In Proceedings of the 8th International Conference on Mechanical and Aerospace Engineering, ICMAE 2017, Prague, Czech Republic, 22–25 July 2017; pp. 204–208.
Mahmoued, E.K. Application of cement kiln dust for chemically enhanced primary treatment of municipal wastewater. Desalin. Water Treat. 2014, 52, 4698–4704.
Abdel-Gawwad, H.A.; Heikal, M.; Mohammed, M.S.; El-Aleem, A.; Hassan, S.H.; García, S.R.V.; Alomayri, T. Sustainable disposal of cement kiln dust in the production of cementitious materials. J. Clean. Prod. 2019, 232, 1218–1229.
Faisal, A.A.H.; Jasim, H.K.; Naji, L.A.; Naushad, M.; Ahamad, T. Cement kiln dust-sand permeable reactive barrier for remediation of groundwater contaminated with dissolved benzene. Sep. Sci. Technol. 2021, 56, 870–883.
Baghriche, M.; Achour, S.; Baghriche, O. Combined effect of cement kiln dust and calcined dolomite raw on the properties of performance magnesium phosphate cement. Case Stud. Constr. Mater. 2020, 13, e00386.
Faisal, A.A.H.; Ahmed, D.N.; Saleh, B.; Afzal, A.; Sharma, G. Elimination of Hazard Cadmium Ions from Simulated Groundwater Using Hydroxyapatite Coated Filter Cake Made of Sewage Sludge and Cement Kiln Dust. J. Polym. Environ. 2021, 30, 1478–1490.
Aydin, T.; Tarhan, M.; Tarhan, B. Addition of cement kiln dust in ceramic wall tile bodies. J. Therm. Anal. Calorim. 2019, 136, 527–533.
Ewais, E.M.M.; Ahmed, Y.M.Z.; El-Amir, A.A.M.; El-Didamony, H. Cement kiln dust-quartz derived wollastonite ceramics. J. Ceram. Soc. Jpn. 2015, 123, 527–536.
Ali, M.A.M.; Yang, H.S. Utilization of cement kiln dust in industry cement bricks. Geosystem Eng. 2011, 14, 29–34.
Ogila, W.A. Recycling of Cement Kiln Dust in Red Clay Bricks and its Impact on their Physico-Mechanical Behaviors. Int. J. Sci. Eng. Res. 2014, 5, 1072–1080. Available online: https://www.ijser.org/paper/Recycling-of-Cement-Kiln-Dust-in-Red-Clay-Bricks.html (accessed on 22 May 2022).
El-Attar, M.M.; Sadek, D.M.; Salah, A.M. Recycling of high volumes of cement kiln dust in bricks industry. J. Clean. Prod. 2017, 143, 506–515.
Abdel-Gawwad, H.A.; Rashad, A.M.; Mohammed, M.S.; Tawfik, T.A. The potential application of cement kiln dust-red clay brick waste-silica fume composites as unfired building bricks with outstanding properties and high ability to CO2-capture. J. Build. Eng. 2021, 42, 102479.
Udoeyo, F.F.; Rindap, P.I. Cement kiln dust as a material for building blocks. Glob. J. Eng. Res. 2002, 1, 73–78.
Abdulkareem, A.H.; Eyada, S.O. Production of Building Bricks Using Cement Kiln Dust CKD Waste. In Sustainable Civil Infrastructures; Springer: Berlin/Heidelberg, Germany, 2018; pp. 102–113.
Sreekrishnavilasam, A.; King, S.; Santagata, M. Characterization of fresh and landfilled cement kiln dust for reuse in construction applications. Eng. Geol. 2006, 85, 165–173.
Chaunsali, P.; Peethamparan, S. Microstructural and mineralogical characterization of cement kiln dust-activated fly ash binder. Transp. Res. Rec. 2010, 2164, 36–45.
Colangelo, F.; Cioffi, R. Use of cement kiln dust, blast furnace slag and marble sludge in the manufacture of sustainable artificial aggregates by means of cold bonding pelletization. Materials 2013, 6, 3139–3159.
Lutyński, M.; Pierzyna, P. Reuse of Cement Kiln Dust for backfilling and CO 2 carbonation. In Proceedings of the Mineral Engineering Conference MEC2017, Wisla, Poland, 20–23 September 2017; Volume 18.
Beltagui, H.; Sonebi, M.; Maguire, K.; Taylor, S. Feasibility of backfilling mines using cement kiln dust, fly ash, and cement blends. In Proceedings of the 2nd International Congress on Materials & Structural Stability (CMSS-2017), Rabat, Morocco, 22–25 November 2017; Volume 149, pp. 1–5.

© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.

Upload a video for this entry

Information

Subjects: Engineering, Manufacturing

Contributors MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :

Ali Y. Al-Bakri

Haitham M. Ahmed

Mohammed Hefni

View Times: 759

Update Date: 15 Aug 2022

Table of Contents

Video Upload Options

Confirm