Hasil untuk "Cement industries"

G. Habert, Sabbie A. Miller, V. John et al.

M. B. Ali, R. Saidur, M. S. Hossain

Sawsan Akram Hassan, Mahir M. Hason, Ammar N. Hanoon et al.

Eco-friendly concrete is produced using the waste of many industries. It reduces the fears concerning energy utilization, raw materials, and mass-produced cost of common concrete. Several stress-strain models documented in the literature can be utilized to estimate the ultimate strength of concrete components reinforced with fibers. Unfortunately, there is a lack of data on how non-metallic fibers, such as polypropylene (PP), affect the properties of concrete, especially eco-friendly concrete. This study presents a novel approach to modeling the stress-strain behavior of eco-friendly polypropylene fiber-reinforced concrete (PFRC) using meta-heuristic particle swarm optimization (PSO) employing 26 PFRC various mixtures. The cement was partially replaced by ground granulated blast furnace slag (GGBFS) with various amounts to make the concrete eco-friendly. The concrete was reinforced with several quantities of PP fiber. Specific cases of beams and cylinders made from PFRC were examined to learn more about their performance. The research contributes valuable insights to eco-friendly concrete design by integrating industrial byproducts (GGBFS) and non-metallic fibers, aligning with sustainable construction trends. The study demonstrates that adding sustainable fibers to concrete improves its structural integrity while lessening its environmental impact. Experimental testing validates the proposed model, showing a significant connection between the expected and actual stress-strain behavior. In terms of absolute relative error (ARE), the dataset proves that the suggested model has both the greatest (ARE 5 %) and worst (ARE > 15 %) frequencies. The proposed model demonstrates promising accuracy (R-value = 0.9975) and highlights the effectiveness of PSO in parameter optimization. Additionally, the usage of GGBFS instead of OPC resulted in CO2 reduction up to 42 %. Comparative analysis of the proposed model against existing models registered an excellent forecasted accuracy.

Kangli Li, Xiaolei Lu, Congcong Jiang et al.

The rapid growth of aluminum and graphite industries has generated substantial stockpiles of red mud and graphite tailings, which pose environmental risks due to their high heavy metal content and potential for soil and water contamination. This study investigated the leaching behavior of heavy metals from these materials post-stabilization using cement and a sulfonated oil-based ion curing agent, thereby evaluating their suitability for safe reuse. Semi-dynamic leaching experiments were employed to measure heavy metal release, supplemented by kinetic modeling to discern key leaching mechanisms. The findings indicated that the heavy metal concentrations in leachates were consistently below regulatory standards, with leaching dynamics influenced by dual mechanisms: the diffusion of ions and surface chemical reactions. A diffusion coefficient-based analysis further suggested low leachability indices for all metals, confirming effective immobilization. These results suggest that cement and curing agent-stabilized red mud–graphite tailing composites reduce environmental risks and possess characteristics favorable for resource recovery, thus supporting their sustainable use in industrial applications.

Prasad Anandji, Singhal Poonam

Coal plays a crucial role in India's energy security, meeting ~55% of the country's energy demand. With one of the largest coal reserves globally (~386 billion tonnes), India's coal is essential for key industries such as power, steel, cement, and fertilizers. However, the quality of domestic coal, especially coking coal, is generally lower than that of international sources, with higher ash content and lower coking properties. Domestic coal production and consumption have doubled over the past decade, reducing the proportion of coal imports by ~20%. Despite this, imports, especially coking coal for the steel sector, remain significant. To reduce dependence on imports, the government aims for 1.5 billion tonnes of domestic coal production by financial year 2030 (FY30), including 140 million tonnes of coking coal. Technological advancements like reflux classifiers and froth flotation cells are essential for improving the quality of domestic coal and enhancing its efficiency. Cleaner coal technologies are crucial for reducing emissions and ensuring sustainable coal use. Proactive government measures have boosted domestic coal supply, but further innovations and policy measures are needed to encourage the adoption of advanced coal beneficiation techniques. This will improve coal quality, reduce imports, and contribute to sustainable economic growth

Ujjwal Niraula, Bhim Kumar Dahal, Sangam Acharya et al.

This research investigates the use of waste stone dust, a crushing industries byproduct, in combination with cement to enhance the engineering properties of high-plasticity silt. The investigation focuses on evaluating improvements in soil consistency, compaction characteristics, microstructure, and long-term strength behavior. Results indicate that the addition of waste stone dust significantly improves plasticity and compaction characteristics, while the combination of cement and stone dust enhances shear strength more effectively than either material alone. The unconfined compressive strength of untreated soil, initially 57.3 kPa after one day of curing, increased up to 19.4 times after 90 days with 10 % cement addition, with further improvements observed when stone dust was incorporated. Moreover, non-linear regression analysis reveals that strength improvement follows a sigmoidal relationship with cement content and a logarithmic trend with curing time. Furthermore, insights from Consolidated Undrained Triaxial tests and Scanning Electron Microscopy provide further strengthen the stabilization mechanisms of the treated soil. The triaxial results show that adding 6 % cement in natural soil slightly increases the friction angle from 20° to 22° and increases the cohesion from 28 kPa to 60 kPa. However, further addition of 30 % stone dust and 6 % cement slightly improved friction angle and reduced the cohesion from 60 kPa to 26 kPa, which infers that cement primarily increased cohesion, whereas stone dust increases inter-granular friction. More importantly, this study offers a cost-effective solution to enhance behavior, addresses environmental concerns, and improve infrastructure resilience for high-plastic-silt-related problems.

U. Mishra, S. Sarsaiya, Amita Gupta

Petr Miarka, Daniel Kytýř, Petr Koudelka et al.

This paper presents the outcome of a study focused on the evolution of internal damage in fresh cement mortar over 25 hours of hardening. In situ timelapse X-ray computed micro-tomography (μXCT) imaging method was used to detect internal damage and capture its evolution in cement mortar hardening. During μXCT scans, the temperature released during the cement hydration was measured, which provided insight into the internal damage evolution with a link to a hydration temperature rise. The measured temperature during cement mortar hardening was compared with an analytical model, which showed a relatively good agreement with the experimental data. Using 20 CT scans acquired throughout the observed cement mortar hardening, it was possible to obtain a quantified characterisation of the porous space. Additionally, the use of timelapse μXCT imaging over 25 hours allowed for studying the crack growth inside the meso-structure including its volume and surface characterisation. The results provide valuable insights into cement mortar shrinkage and serve as a proof-of-concept methodology for future material characterisation.

Sheikh Junaid Fayaz, Nestor Montiel-Bohorquez, Shashank Bishnoi et al.

Cement production, exceeding 4.1 billion tonnes and contributing 2.4 tonnes of CO2 annually, faces critical challenges in quality control and process optimization. While traditional process models for cement manufacturing are confined to steady-state conditions with limited predictive capability for mineralogical phases, modern plants operate under dynamic conditions that demand real-time quality assessment. Here, exploiting a comprehensive two-year operational dataset from an industrial cement plant, we present a machine learning framework that accurately predicts clinker mineralogy from process data. Our model achieves unprecedented prediction accuracy for major clinker phases while requiring minimal input parameters, demonstrating robust performance under varying operating conditions. Through post-hoc explainable algorithms, we interpret the hierarchical relationships between clinker oxides and phase formation, providing insights into the functioning of an otherwise black-box model. This digital twin framework can potentially enable real-time optimization of cement production, thereby providing a route toward reducing material waste and ensuring quality while reducing the associated emissions under real plant conditions. Our approach represents a significant advancement in industrial process control, offering a scalable solution for sustainable cement manufacturing.

Sebastián Rojas-Innocenti, Enrique Baeyens, Alejandro Martín-Crespo et al.

The growing share of variable renewable energy (VRE) sources in power systems is increasing the need for short term operational flexibility, particularly from large industrial electricity consumers. This study proposes a practical, two stage optimization framework to unlock this flexibility in cement manufacturing and support participation in electricity balancing markets. In Stage 1, a mixed integer linear programming (MILP) model minimizes electricity procurement costs by optimally scheduling the raw milling subsystem. In Stage 2, a flexibility assessment model evaluates profitable deviations, targeting participation in Spain manual Frequency Restoration Reserve (mFRR) market. A real world case study in a Spanish cement plant (including PV and battery storage) shows that flexibility services can yield monthly revenues of up to 800 EUR and paybacks as short as six years. This framework offers a replicable pathway for industrial flexibility in energy intensive sectors.

T Yahaya, KA Sani, E Oladele et al.

The potential health risks of cement dust exposure are increasingly raising concern worldwide as the cement industry expands in response to rising cement demand. This necessitates the need to determine the nature of the risks in order to develop appropriate measures. This study determined the effects of cement dust exposure on the weight and blood glucose levels of people residing or working around a cement company in Sokoto, Nigeria. Demographic information was obtained using questionnaires from 72 participants, which included age, gender, educational level, exposure hours, occupation, and lifestyle. The blood glucose levels and body mass index (BMI) were measured using a Fine Test glucometer and a mechanical scale, respectively. The results showed that most of the people living or working around the cement company were middle-aged men (31-40; 42.06%) with a primary (33.33%) or secondary (45.83%) school education. It showed that 30 (41.69%) of the participants were overweight while 5 (6.94%) were obese. Additionally, 52.78% of the participants were diabetic while 31.94% were prediabetic. Participants that were exposed for long hours (> 15 hours per day) were the most diabetic (20% of the participants), followed by smokers (15%), and artisans (7%). It can be concluded that exposure to cement dust from the company increased the risk of overweight, obesity, and hyperglycemia among the participants. These health risks were worsened by daily long hours of exposure, smoking, and artisanal pollutant exposure. Human settlements and artisans should not be located near the cement company, and the company should minimize pollutant emissions.

Xiaoxuan Bai, Peng Li, Weiqing Zhou et al.

High-temporal resolution and timely emission estimates are essential for developing refined air quality management policies. Considering the advantages of extensive coverage, high reliability, and near real-time capabilities, in this work, electric power big data (EPBD) was first employed to obtain accurate hourly resolved facility-level air pollutant emissions information from the cement industries in Tangshan City, China. Then, the simulation optimization was elucidated by coupling the data with the weather research and forecasting (WRF)-community multiscale air quality (CMAQ) model. Simulation results based on estimated emissions effectively captured the hourly variation, with the NMB within ±50% for NO₂ and PM_2.5 and R greater than 0.6 for SO₂. Hourly PM_2.5 emissions from clinker production enterprises exhibited a relatively smooth pattern, whereas those from separate cement grinding stations displayed a distinct diurnal variation. Despite the remaining underestimation and/or overestimation of the simulation concentration, the emission inventory based on EPBD demonstrates an enhancement in simulation results, with RMSE, NMB, and NME decreasing by 9.6%, 15.8%, and 11.2%, respectively. Thus, the exploitation of the vast application potential of EPBD in the field of environmental protection could help to support the precise prevention and control of air pollution, with the possibility of the early achievement of carbon peaking and carbon neutrality targets in China and other developing countries.

B. Ruijven, D. V. Vuuren, Willem Boskaljon et al.

This paper presents a global simulation-model for the steel and cement industries. The model covers the full modelling chain from economic activity, to materials consumption, trade, technology choice, production capacity, energy use and CO2 emissions. Without climate policy, the future projections based on the SSP2 scenario show a rapid increase in the consumption of steel and cement over the next few decades, after which demand levels are projected to stabilize. This implies that over the scenario period, CO2 emissions are projected to peak in the next decades followed by a decrease below 2010 levels in 2050. There is considerable scope to mitigate CO2 emissions from steel and cement industries, leading to resp. 80–90% and 40–80% reduction below 2010 in 2050 for a high carbon tax of 100 $/tCO2 + 4%pa depending on the availability of Carbon Capture and Sequestration (CCS).

Essossinam Beguedou, Satyanarayana Narra, Ekua Afrakoma Armoo et al.

The conventional energy source in cement industries is fossil fuels, mainly coal, which has a high environmental footprint. On average, energy expenditures account for 40% of the overall production costs per ton of cement. Reducing both the environmental impact and economic expenditure involves incorporating alternative energy sources (fuels) such as biomass, solid-derived fuel (SDF), refuse-derived fuel (RDF) etc. However, within cement plants, the substitution of conventional fossil fuels with alternative fuels poses several challenges due to the difficulty in incorporating additional fuel-saving techniques. Typically, an additional 3000 MJ of electricity per ton of clinker is required. One of the most effective solutions to this is thermal optimization through co-processing and pre-processing, which makes it possible to implement additional fossil-fuel-saving techniques. In developing nations such as Togo, waste-management systems rely on co-processing in cement factories through a waste-to-energy relationship. Also, there are some old cement plants with low-efficiency, multi-stage preheaters without pre-calciners, reciprocating huge coolers, low-efficiency motors etc., which still operate and need to be made environmentally sustainable. However, compared to modern kilns which can have up to 95% of energy recovery from waste, an old suspension preheater kiln can recover only up to 60% of its heat energy depending on the cooler type, and due to the lack of a bypass and combustion chamber (pre-calciner). This research paper evaluated the performance of a cement plant incorporating AF and presents the procedures and recommendations to optimize AF substitution in cement plants. To achieve this, a comparative performance study was carried out by assessing the alternative fuel characteristics and the equipment performance before and after the incorporation of the alternative fuel. Data were collected on the optimum substitution ratio, pre-processing and co-processing performance, raw-meal design and economic analysis. Results indicated that the cost to be covered per ton of waste input is €10.9 for solid-derived fuel (SDF), €15 for refuse-derived fuel (RDF), and that the co-processing cost optimization for the cement plant could have a cost saving of up to 7.81€/GJ. In conclusion, it is recommended that appropriate kiln and alternative-fuel models be created for forecasting production based on various AF.

Nathalie Barbosa Reis Monteiro, José Machado Moita Neto, Elaine Aparecida da Silva

Olaytunji Olayiwola, Vu Nguyen, Randy Andres et al.

The possibility for hydrocarbon fluids to migrate through debonded micro-annuli wells is a major concern in the petroleum industry. With effective permeability of 0.1-1.0 mD, the existence of channels in a cement annulus with apertures of 10-300 micrometer constitutes a major threat. Squeeze cement is typically difficult to repair channels-leakage with small apertures; hence, a low-viscosity sealer that can be inserted into these channels while producing a long-term resilient seal is sought. A novel application using nano-silica sealants could be the key to seal these channels. In the construction and sealing of hydrocarbon wells, cementing is a critical phase. Cement is prone to cracking during the life cycle of a well because of the changes in downhole conditions. The usage of micro-sized cross-linked nano-silica gel as a sealant material to minimize damaged cement sheaths is investigated in this study. Fluid leakage through channels in the cement was investigated using an experimental system. With a diameter of 0.05 inches, the impact of the cement channel size was explored. The sealing efficiency increased from 86 percent to 95 percent when the nano-silica concentration of the sealing gel increased from 13 percent to 25 percent. This demonstrates that the concentration of nano-silica in the sealing gel affects the gel's ability to seal against fluid flow. This research proposes a new way for improving cement zonal isolation and thereby lowering the impact of cement failure in the oil and gas industry.

Timo Gerres, José Pablo Chaves, Pedro Linares

Basic materials such as steel, cement, aluminium, and (petro)chemicals are the building blocks of industrialised societies. However, their production is extremely energy and emission intensive, and these industries need to decarbonise their emissions over the next decades to keep global warming at least below 2 °C. Low-emission industrial-scale production processes are not commercially available for any of these basic materials and require policy support to ensure their large-scale diffusion over the upcoming decades. The novel transition to industry decarbonisation (TRANSid) model analyses the framework conditions that enable large-scale investment decisions in climate-friendly basic material options. We present a simplified case study of the cement sector to demonstrate the process by which the model optimises investment and operational costs in carbon capture technology by 2050. Furthermore, we demonstrate that extending the model to other sectors allows for the analysis of industry- and sector-specific policy options.

Rakibul I. Khan, Muhammad Intesarul Haque, Adhora Tahsin et al.

This article presents an investigation into the potential use of ground granulated blast-furnace slag (addressed as Slag cement or ‘SC’) as a replacement to Ordinary Portland Cement (OPC) in hybrid (carbonation and hydration) cured cement-based materials. To investigate the effects of carbonation on mechanical performances and microstructures, 0 %–100 % OPC was replaced with slag cement (SC). Thermogravimetric analysis (TGA) and Fourier transformed infrared (FTIR) spectra were utilized to investigate the carbonation reaction extent, rate, and microstructural phase formations. Slag cement was found to improve the efficiency and rate of carbonation. This study revealed that a minimum of 72 h of carbonation in a CO2-containing environment yields better mechanical performance compared to the traditional curing method. Specifically, the incorporation of 72 h of carbonation curing was observed to increase the strength of concrete up to 30 % after 28 days of total curing duration (carbonation and hydration). The chloride permeability of the carbonation cured samples was observed to reduce by 80 % due to the addition of SC. Finally, it was observed that, the carbonated concrete sample with slag has nearly 60 % lower global warming potential compared to the carbonated and non-carbonated concrete sample with 100 % OPC binder.

Shixin Shi, Hao Li, Hongsong Tang et al.

The issue of overcapacity has become an unavoidable challenge in the rapid development of nations, constraining economic progress, particularly within industries like steel, coal, and cement. This study, using the example of the Chinese steel industry in the context of supply-side structural reform, employs data envelopment analysis (DEA) models to measure capacity utilization, and ordinary least squares (OLS) models to investigate the impact of capacity reduction policies on the steel industry's capacity utilization pathways. The research findings indicate that capacity reduction policies have a significantly positive impact on the capacity utilization in the steel industry. They enhance capacity utilization through four pathways: "equipment optimization and upgrade", "enterprise mergers and restructuring", "technology innovation-driven", and "environmental protection regulations". Among these, "technology innovation-driven" and "environmental protection regulations" play predominant roles, while the effect of "international market expansion" on increasing capacity utilization in the steel industry is not significant. To ensure the sustained effectiveness of capacity reduction policies, the nation should continue to strengthen the "technology innovation-driven" and "environmental protection regulations" pathways. Additionally, it should activate the "national market expansion" pathway, fully exploring the potential for international cooperation to achieve improved capacity utilization in the steel industry.

Christopher Fapohunda, O. E. Osanyinlokun, A. O. Abioye

The field of structural engineering has in recent times begun to widen its scope from the traditional analysis and design, into the development of new structural materials. This is because the use of non-renewable materials in forming and framing structural projects are raising serious environmental concerns bothering on sustainability of materials, especially cement, to produce structural concrete. Cement has been found to be a major contributor to greenhouse gases which affect the environment negatively. Waste from both the industrial and agricultural industries are gradually becoming sources of material to partly replace cement in concrete because of their pozzolanic properties. The agro-based pozzolanic materials include Rice husk Ash (RHA), Saw dust ash (SDA), Palm oil fuel ash (POFA) amongst others. To further widen the scope and resource base of pozzolanic materials for concreting, ternary blends consisting of agro-based pozzolans are being researched into. These research efforts however appear to be uncoordinated, and thus there is a need to juxtapose these efforts together to see the extent of work done on such ternary blends and present their relevant structural properties. This is with a view to helping identify gaps in such research as a means of preventing wastage of research energies. This paper presents a review of structural properties of some agro-based ternary blends used in structural concrete.  It is concluded that more research effort is needed, especially in the development of practical and acceptable guidelines that will aid their application in concrete, for sustainable production of structural concrete.