Cement Production Research Articles

Evaluation of geotechnical, mineralogical and environmental properties of clayey soil stabilized with different industrial by-products: A comparative study

The utilisation of soil stabilization techniques employing binders like lime or cement enables the use of soils that are classified as disposable, thereby reducing the need for landfills and the consumption of natural resources. However, the production of lime and cement results in significant CO2 emissions. Therefore, the application of industrial by-products (IBP) for stabilizing expansive soils presents an opportunity to minimise the use of traditional binders. This study investigates the geotechnical, mechanical, mineralogical, and environmental properties of four IBP (biomass bottom ash, biomass fly ash, steel slag, and mixed recycled aggregate) combined with a silica-based nanomaterial for road layer applications. The technical feasibility of the use of IBP was demonstrated, especially in combination with nanomaterials, allowing a 66 % reduction in the percentage of added lime, obtaining significant improvements with minimal plasticity and swelling index and bearing capacity CBR values higher than 25 %, applying BBA, BFA and SS. An environmental assessment of leachate analysis was performance, showing an immobilization of heavy metals that makes the application of IBP feasible. In addition, a life cycle analysis study showed the environmental benefits of applying IBP, such as a 50 % reduction in CO2 emissions due to the reduction of lime, resulting from the use of these materials, thus promoting more sustainable economic models.

BINDERS FROM SECONDARY RAW MATERIALS OF COAL ENRICHMENT WASTE FOR CONSTRUCTION OBJECT ERECTION USING THE 3D PRINTING METHOD

Formulation of the problem. The 3D printing construction technology is one of the modern methods of rapid construction, which allows for a significant automation of the building process while achieving high precision in the fabrication of complex configurations using equipment (3D printers) controlled by software to define precise coordinates of the printed structure model. The main materials for construction 3D printing technology are composite mixtures based on binders. Cement or composite binders can be used as binders [1]. The cement production technology involves the firing of its components at 1 450 °C, which requires significant energy resources and affects its final cost and the overall mixture. The utilization of coal enrichment waste, which contains clay minerals, quartz, pyrite, and a small amount of carbonates, impurities, and combustible substances, allows for reducing the consumption of technological fuel and the firing temperature of the binder by harnessing the heat-generating properties of coal inclusions. Thus, coal enrichment waste can be used as a fuel component in obtaining the binder. The purpose. Based on the conducted research, it can be concluded that the use of component binders derived from coal enrichment waste shows promise in the construction of buildings using 3D printing technology. By harnessing the heat-generating properties of these waste materials, it is possible to reduce the consumption of technological fuel and firing temperature required for binder production, consequently lowering CO2 emissions into the atmosphere and reducing the final cost of the construction mixture for 3D printing.

Geological evaluation of black shale as a suitable Supplementary Cementitious Material (SCM) to optimize the use of clinker in cement production

Faced with challenges like resource depletion and climate change, the cement industry needs sustainable solutions. This study explores the potential of geologically-delinaeated black shale from Apersua, Ghana, as a supplementary cementitious material (SCM) to reduce reliance on traditional methods. The researchers analysed the shale's chemical composition and mineralogy, then created laboratory cement formulations with varying black shale content. These were compared to standard formulations without shale. The results show cement with black shale has comparable compressive strength, meeting standard requirements. Even a formulation with only black shale (excluding limestone, a common ingredient) passed strength tests. Overall, the black shale demonstrated good potential as a SCM based on strength, chemical makeup, setting time, and its possible contribution to durability. This research suggests that black shales from Apersua are worth exploring further as a sustainable and potentially cost-effective alternative in cement production.

Environmental impacts of cement production in Ewekoro, Ogun State, southwestern Nigeria from 2005 to 2006 on surface water quality, vegetation, and workers' health

ABSTRACT The present study investigated the environmental impacts of cement production on surface water quality and vegetation in the vicinity of the industry. A 2-year study was conducted, covering both wet and dry seasons. Water samples were collected from the Akinbo River, where the cement industry discharges its liquid waste and effluents, and analysed for physical and chemical parameters using standard procedures. The vegetation around the factory was analysed for chlorophyll, plant density, basal areas, and heights of woody species. The study also assessed the health impacts of cement production on the factory employees and the residents living in the vicinity of the factory. The health assessment was based on hospital information obtained from two clinics in the villages near the factory. The water quality results revealed elevated concentrations of Ca and Fe. All the trees sampled around the study area had small basal areas and short heights. There was also a significant reduction in the chlorophyll contents of the vegetation. The health study showed a high incidence of upper-respiratory tract infections, cardiovascular diseases, arthritis, and dermatitis among factory workers. This study suggests a review of the existing dust-suppressing system put in place by the industry, to protect public health.

EFFECT OF ALTERNATIVE RAW MATERIALS OVER CLINCKER QUALITY AND CO2 EMISSIONS

In the cement industry, the actual challenges are the preservation of the raw materials and energy resources, as well as reduction of pollutant emissions. In this context, the cement producers demand studies to reduce of the production costs and atmospheric emissions. One way to achieve these objectives, is to use alternative fuels or by-product raw materials. Any reduction in the required energy has a beneficial influence both on the viability of the cement plant and on the environment. One of the approaches aimed at reducing thermal energy consumption is the partial substitution of traditional raw materials (limestone, clay, gypsum) with other alternative materials, with a melting effect, among which stand out byproducts of the steel industry such as furnace and steel slag. Another way for preservation of energy resources is using alternative fuels instead of traditional fuels like coal, petroleum coke or gas. The clinkering process and clinker quality can be influenced by any additions, in this study was determined these influences.

Properties of cement raw meals used as sorbents in a calcium looping process

Calcium looping (CaL) is a promising carbon capture and storage (CCS) technology that has the potential to significantly reduce CO2 emissions in cement production. Integrating CaL with cement production provides a viable solution to the high CO2 emissions generated during the calcination process. This study examines the behavior of two industrial cement raw meals from different sites (A-RM and B-RM) under CaL conditions, focusing on phase composition, particle size distribution, and clinker phase evolution up to 1450 °C. Calcination and CaL experiments were conducted in a CO2-rich atmosphere, with materials characterized using quantitative X-ray diffraction (Q-XRD) and high-temperature X-ray diffraction (HT-XRD). The results showed that both raw meals absorbed similar amounts of CO2 during the cyclic CaL experiments. A-RM formed C2S and other silicates, while B-RM retained more free CaO due to a less effective reaction with coarser quartz (SiO2) particles. HT-XRD revealed delayed clinker-phase evolution in the 1000–1400 °C range in CaL-treated raw meals. However, CaL-treated raw meals achieved low free CaO at 1450 °C, suggesting that optimal kiln conditions can produce the desired phase composition. These findings indicate that integrating CaL-treated raw meals into cement production requires careful optimization of operational parameters to maintain clinker quality and minimize energy consumption. Further research should focus on improving the efficiency and reactivity of CaL-treated raw meals to enhance their suitability for industrial cement production.

Techno-economic feasibility of CO2 utilization for production of green urea by Indian cement industries

The cement industry contributes substantially to global carbon emissions, necessitating urgent adoption of mitigation pathways aligned with climate goals. This study investigates the technical and economic viability of capturing carbon dioxide (CO2) emissions from cement plants in India and using that captured CO2 to produce green urea. The research aims to determine the feasibility of the CCUS approach as a practical way to reduce CO2 emissions from cement production while also boosting India's self-sufficiency in producing urea, a crucial fertilizer. The research uses a multi-criteria analysis (MCA) framework to assess various factors, including the technological readiness of CCUS technologies, the capital and operating costs of setting up and running such a system, the market demand for green urea, and the potential reduction in CO2 emissions. The study focused on 32 major cement plants in India, using data from their annual reports to inform the MCA model with an assumption of a post-combustion Monoethanolamine (MEA) scrubbing capacity CO2 capture capacity of 0.5 million tonnes per year per plant and used existing data and modeling techniques to analyze the feasibility of converting the captured CO2 into urea. The key findings indicate that this approach is promising and projects a 12.4% reduction in CO2 emissions from the cement industry if these 32 plants implement the CCUS technology. Additionally, it highlights a favorable market for the green urea produced, with an estimated output of 21.82 million tonnes per year, enough to offset a significant portion of India's reliance on urea imports. Financially, the study projects a six-year payback period and a 16.7% return on investment. It concludes that implementing CCUS technology to create green urea in Indian cement plants is technically and economically feasible. The approach has the potential to significantly reduce CO2 emissions while also supporting India's goal of self-sufficiency in urea production. However, further investigation and pilot-scale projects are recommended to validate the model's findings and optimize various aspects, such as managing flue gas impurities and leveraging waste heat for energy efficiency.

Environmental Levels of PCDD/Fs near Cement Plants in Catalonia, Spain. An Update of Human Health Risks

Cement production is an important industrial activity that generates large amounts of pollutants, including, among others, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). These environmental contaminants are persistent and bioaccumulative, potentially causing serious adverse effects on human health, including cancer. The present paper was aimed at providing an update of the environmental concentrations of PCDD/Fs around various cement plants located in Catalonia, Spain. The non-carcinogenic and the carcinogenic risks associated to PCDD/Fs exposure were also assessed for the population living near the facilities. According to the present results, the environmental burdens of PCDD/Fs were highly dependent on the surroundings, rather than the technical specifics characteristics of each facility. Thus, higher concentrations were found near cement plants located in urban areas, where other emission sources (e.g., heavy traffic, domestic heating, etc.) may be present. The surveillance studies showed long-term stable concentrations in air, while PCDD/Fs levels in soil and vegetation were more variable. Although inhalation was the most relevant pathway of environmental exposure, the main uptake of PCDD/Fs occurs -in general- via dietary intake. Cancer risks were higher for people living near cement plants in urban areas than in rural environments, but at levels that are considered as acceptable by international regulations. In turn, the non-carcinogenic risks suggest a low concern, as the hazard quotient was <1. Long-term surveys conducted in Catalan cement plants indicate that these facilities, which are periodically (every two years) monitored, should not be of concern for human health, in terms of PCDD/F exposure.

Potential of Reducing CO2 Emissions in Cement Production through Altering Clinker Compositions

Potential of Reducing CO₂ Emissions in Cement Production through Altering Clinker Compositions

Feasibility study on the preparation of ternary blended cements with low-kaolinite calcined coal gangue and limestone

This paper presents a feasibility study on the production of ternary blended cements with low-kaolinite calcined coal gangue (CCG) and limestone, considering kaolinite contents varying from 11.7 % to 40.6 % in coal gangue (CG). The ternary systems were designed with 15 %, 30 %, 45 % and 60 % by mass of cement replaced by CCG and limestone with a fixed mass ratio of 2:1. The fluidity and compressive strength of the mortars were measured, followed by the strength efficiency analysis combined with CO2 emission. The potential hydration mechanism was revealed by analysing the hydration kinetics, hydrates and microstructural evolution of these ternary pastes. The results showed that it is possible to use low-kaolinite CCG and limestone to prepare ternary blended cements with adequate mechanical strength that can fulfill the 28-day strength requirement of 32.5 or 42.5 grade cement. In addition, Increasing the kaolinite content in CG can increase the substitution of cement up to 60 %. Microstructural studies indicated that the compressive strength of these ternary mortars at 3 and 7 days was mainly dominated by cement hydration and the pozzolanic reaction between CCG and portlandite (CH), respectively. The precipitation of carboaluminates from the synergy of CCG and limestone significantly reduced critical pore size and increased the volume fraction of fine capillary pores from 7 days, well supporting the strength development of the ternary mortar. The findings of this work underscores the potential of using low-kaolinite CCG as a supplementary cementitious material (SCM) to reduce carbon footprint in the field of construction, and also in contributing to a high-value green utilization of solid waste.

Shrinkage reduction mechanism of low Ca/Si ratio C-A-S-H in cement pastes containing fly ash

Understanding the drying shrinkage of low Ca/Si ratio cement pastes is crucial for promoting the use of low-clinker ratio cementitious materials and reducing the environmental impact of cement production. We prepared well-hydrated cement paste samples with various fly ash replacement and water-to-cement ratios. The long-term drying shrinkage was measured by 1 mm-thick samples. Results showed that fly ash containing samples exhibited lower shrinkage and the irreversible part of drying shrinkage was less compared to those without fly ash. Chemical composition analysis of the calcium aluminate-silicates hydrate (C-A-S-H) was conducted using X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). Additionally, water vapor sorption isotherms and proton nuclear magnetic resonance (1H NMR) relaxometry were used to determine specific surface area and pore structure. By analyzing these results in conjunction with the C-A-S-H model, we attributed the reduced and more reversible drying shrinkage in fly ash cement to lower Ca ion amounts in the interlayer space and fewer trapped larger pores.

Green cement production using sludge from wastewater treatment plants

This study explores the potential of reusing sludge from wastewater treatment plants (WWTPs) as a valuable resource. By calcining the sludge, the resulting ashes are incorporated into cement, leading to the production of eco-friendly or green cement. This method offers a sustainable solution for managing solid waste generated by WWTPs, particularly in Algeria, where waste disposal poses significant environmental challenges. The research focused on evaluating the performance of the green cement by examining the development of mechanical properties, such as compressive strength and flexural strength, over time. The results demonstrate the effectiveness of the proposed valorization process for the sludge studied in this context. Additionally, this approach contributes to reducing the carbon emissions and energy consumption associated with conventional cement production. The incorporation of sludge ash as a partial replacement for clinker also highlights the potential for resource conservation and cost reduction in the construction industry. Overall, this research not only addresses waste management issues but also opens the door for further innovation in the use of alternative materials in cement production. Future studies could explore the optimization of sludge pre-treatment and the long-term environmental benefits of large-scale implementation.

Elastic modulus, water stability and resistivity for loess solidified with white mud based solid waste cementing material: Mechanism analysis and relationship establishment

To increase the engineering application value of white mud based solid waste cementing materials: white mud-slag and white mud-slag-Calcium Carbide Residue (CCR), this paper explored the changes in elastic modulus, water stability and resistivity of loess solidified with white mud based solid waste cementing material. Furthermore, relationships between elastic modulus, water stability and resistivity were established. The following conclusions can be obtained: The alkaline activation effect of CCR was stronger than white mud, therefore the formation rate of C-S-H and C-A-(S)-H cementitious products in CCR-containing solidified loess was more faster than that without CCR. At the same time, white mud not only served as an alkaline activator, but its finer CaCO3 components also helped fill pores, while the irregular fine particles provided nucleation sites for the formation of cementitious products. Consequently, slag-white mud-CCR solidified loess exhibited the best performance in terms of elastic modulus and water stability coefficient. This was followed by slag-white mud solidified loess and lime solidified loess. In addition, the analysis of the relationship between the resistivity of solidified loess and factors such as curing age, dry density, water content, elastic modulus, and water stability coefficient revealed that the main reasons for the increased resistivity of solidified loess were the consumption of internal water and the increase in cementitious products with poor conductivity. Furthermore, the modified resistivity formula was applied to establish the fitting relationships between the resistivity of solidified loess and various parameters. The formula has been successfully applied in the slag-white mud-CCR solidified loess, where the fitting of resistivity with various parameters yielded an R2 of 0.94. This paper facilitates the resistivity method (non-destructive testing) of loess treated with slag, white mud, CCR and promotes the application of these curing agents, contributing to their broader adoption in geotechnical engineering.

Цементное производство в России: заинтересованные стороны и эффективность регионального бизнеса в конце XIX века

The activities of “Petersburg Company for the production of Glukhoozersky Portland cement and other building materials” between 1879 and 1899, although only a initial period segment in its history, provides a holistic overview of phase that enterprise underwent on their path to becoming a large industrial firm. This study aims to improve and expand knowledge about the capacity and difficulties of industrial company to adapt to market changes and maintain their competitiveness, interregional coherence and organizational flexibility. This article explores changes in ownership and management structure and application of new technological practices during this period, which in turn led this enterprise to the status of the leader in the cement industry in capital. A case study of key group of shareholders (military engineers) tests the effectiveness of model of reconciliation of interests on results of twenty years of work of the company.

Occupational Injuries and Its Determinants Among Cement Factory Workers: A Cross Sectional Study

Abstract Introduction: Cement manufacturing industry workers face inevitable circumstances and are unintentionally exposed to different injuries at the workplace. The purpose of this study was to establish the pattern of injuries and their related risk factors. Materials and Methods: This cross-sectional study involved 360 workers from different departments within three cement factories in Chhattisgarh, India. Results: 55% of employees had either abrasion (30%) or dust in their eyes (23%). Workers in open areas (unadjusted odds ratio [UOR] = 3.28 [2.08–5.18]) and those who do not have training in personal protective equipment (UOR = 2.19 [1.42–3.39]) were more likely to get injured. Conclusions: A high number of workers suffered from injuries, as reported by this study; therefore, there is a need for thorough training and safety procedures.

CFD-based redesign of large industrial-scale cyclones

Cyclones represent a cost-effective solution employed for the separation of particles in gas-solid streams, wherein the enhancement of performance relies on the careful balance between pressure drop and collection efficiency. This study employs Computational Fluid Dynamics (CFD) techniques to numerically assess a large-scale first stage cyclone within a cement kiln cyclone tower. Investigating its reported low collection efficiency, we analyze the impact of geometric modifications aimed at enhancing cyclone performance. The introduction of a dipleg proves to be particularly effective, leading to a substantial increase in collection efficiency and a reduction in pressure drop. The most favorable cyclone configuration demonstrates a remarkable 6 % improvement in collection efficiency and a decrease in pressure drop of approximately 1 mbar. Consequently, particle emissions from the first-stage cyclone are reduced by approximately 30 %, while an increase in clinker production by approximately 100 tons per day is achieved. These findings showcase the potential for significant operational and environmental benefits through optimized cyclone design in cement manufacturing processes.

Feasibility of upcycling red mud for low-CO2 cement via calcination: A comparative study with FA and GGBFS based in China

This study examines the feasibility of developing low-CO2 cement using calcined red mud (RM) and explores positive scenarios that simultaneously attain technical, environmental, and economic benefits in reference to conventional fly ash (FA) and ground granulated blast furnace slag (GGBFS) cements. Based on the variables of RM's content and calcination temperature, we investigated the fresh properties (paste rheology and mortar flowability), strength development, microstructure, embodied CO2 emissions, and cost of the RM-blended cement. The results show that there was an optimal range of RM's calcination temperature (400–600 °C) that improved the cement paste viscosity while attaining a higher strength than that of FA cement. Considering the cradle-to-gate CO2 emissions and cost of cement production, the optimal cement composition is comprised of up to 30% RM calcined at 600 °C, where the cement cost is lowered by 19.3% compared to the FA reference having a comparable CO2 footprint. According to the geographical analysis, the calcined RM shows minimal advantages over GGBFS but could substitute FA as a cleaner, cheaper, and more reactive supplementary cementitious material in regions where electricity grid is dominated by clean energy. Therefore, RM offers a plausible solution to future low-CO2 cement in light of the increasing shortage of FA led by the declining use of coal-powered electricity.

Implementasi Data Mining Prediksi Penjualan Produk Semen Menggunakan Metode Linear Regression (Studi Kasus PT. Toyo Mortar Indonesia)

The cement industry in Indonesia plays a vital role in infrastructure development and the construction sector. PT. Toyo Mortar Indonesia, established in 2015 in the Tangerang industrial area, focuses on the production of instant mortar cement. However, the national cement industry faces the challenge of declining sales due to the pandemic, which has affected people's purchasing power and slowed down property and infrastructure projects. To achieve future growth potential, the right strategy is needed in sales planning. This study implements data mining using the linear regression method with the RapidMiner application to predict cement product sales. The data used includes historical sales data and product information from PT. Toyo Mortar Indonesia. In the tests conducted, the data was processed using 12 variables, of which 10 variables influenced the prediction results: TM-168, TM-178, TM-188, TM-189, TM-198, UM-100, UM-101, UM BIRU, raw materials, and other sales. The test results show that the Linear Regression method can predict cement product sales with an average Root Mean Square Error (RMSE) value of 493,125.701 with a standard deviation of 126,330.525. The average Absolute Error is 303,270.965 with a standard deviation of 46,207.586, and the average relative error is 1.89% with a standard deviation of 0.36%, indicating very good prediction accuracy. This can help the company in making decisions related to sales planning using the available sales data.

Fly ash admixture originating from lignite combustion in construction mortars – Time evolution of technical parameters and heavy metals leachability

The production of cement, the predominant construction binder, is associated with high energy consumption, enormous raw material depletion, and a large volume of CO2 emissions, making cement one of the most polluting materials. This study aims to contribute to the sustainability of the construction industry by significantly reducing the proportion of Portland cement (PC) in the composition of mortars. The binder content reduction was achieved by the addition of large amounts of fly ash admixture (FA) from lignite combustion while studying the effectiveness of the immobilization of heavy metals (HMs), which are present in FA, in the PC/FA matrix. Along with the analysis of the FA admixture amount on the properties of the prepared mortars, emphasis was put on the study of the influence of prolonged curing on the development of the physical parameters of the mortars and the immobilization efficiency of the HMs. It was revealed that FA can be added to PC by up to 20 wt%, enabling the production of construction mortars with high strength and low porosity, while confining hazardous substances such as HMs in the matrix. Prolonged curing at elevated relative humidity led to the continuous evolution and solidification of the mortar structure, improving its engineering properties and HMs immobilization efficiency.

A study on fresh, mechanical, and thermal properties of limestone calcined clay cement (LC3) blended with cementitious materials

In light of environmental concerns about cement manufacture, limestone and thermally activated kaolinitic clays are being explored as supplementary cementitious materials with the potential to reduce CO2 emissions and energy usage. The use of calcined clay and limestone for clinker replacement to create a tertiary blend called limestone calcined clay cement (LC3) is one of the most promising emerging technologies for meeting environmental requirements. This paper reports on the evaluation of the fresh-state and hardened properties of cementitious pastes and self-compacting concretes (SCC) prepared using the concrete equivalent mortar method made with LC3 systems containing 30%, 35%, and 40% metakaolin (LC-30MK, LC-35MK, and LC-40MK) in comparison with ordinary Portland cement (OPC). Paste and concrete equivalent mortar specimens were prepared to investigate water demand, setting time, and workability (mini-slump flow test). Also, the compressive strength and drying shrinkage after 7 and 28 days, as well as thermal conductivity after one year of curing, were examined. The obtained results showed that the incorporation of metakaolin resulted in increased water demand to reach normal consistency. The setting time of LC3 mixtures also increased, while the same workability behavior was observed for all mixtures. LC-30MK can provide compressive strength that is comparable to OPC, especially after the first few days of curing. However, the compressive strengths of LC-35MK and LC-40MK are lower than those of OPC. Nevertheless, they demonstrate noteworthy strength characteristics. All LC3 mixtures exhibited relatively low drying shrinkage and reduced thermal conductivity compared to the OPC mixture.