scholarly journals Utilization of lime-dried sludge for eco-cement clinker production: effects of different feeding points

2017 ◽  
Vol 77 (4) ◽  
pp. 960-970 ◽  
Author(s):  
Haihua Cao ◽  
Wei Liu ◽  
Jingcheng Xu ◽  
Jia Liu ◽  
Juwen Huang ◽  
...  
Keyword(s):  
Heterocyclic Compounds ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln ◽  
The Sustainable Development ◽  
Alternative Materials ◽  
Cement Manufacturing ◽  
Dried Sludge ◽  
Production Effects ◽  
Clinker Production

Abstract Co-processing lime-dried sludge (LDS) in cement kilns is an appropriate technique to solve the problem of LDS disposal and promote the sustainable development for cement industry. However, there were limited studies that investigated the effects of feeding points on product quality and cement kiln emissions. In this study, simulated experiments were conducted by dividing the feeding points into high-temperature zones (HTZs) and raw mill (RM). Cement quality and major cement kiln emission characteristics were comprehensively investigated. The results showed that in terms of burnability, compressive strength and microstructure, the optimum co-processing amount of LDS were 9 wt% when feeding at RM, while 6% when feeding at HTZs. Meanwhile, the organic emissions of RM samples were mainly low environmental risk compounds of amides and nitrogenous heterocyclic compounds. Inorganic gaseous pollutions of NOX and SO2, respectively, were 8.11 mg/g DS and 12.89 mg/g DS, compared with 7.61 mg/g DS and 4.44 mg/g DS for HTZs. However, all the cement kiln emissions concentration were still much lower than standard requirements. Overall, RM had a bigger LDS co-processing capacity and higher, but acceptable, cement kiln emissions. Feeding LDS via RM could dispose larger amounts of sludge and provide more alternative materials for cement manufacturing.

scholarly journals Feasibility and Carbon Footprint Analysis of Lime-Dried Sludge for Cement Production

2020 ◽  
Vol 12 (6) ◽  
pp. 2500 ◽  
Author(s):  
Li Ping ◽  
Gang Zhao ◽  
Xiaohu Lin ◽  
Yunhui Gu ◽  
Wei Liu ◽  
...  
Keyword(s):  
Carbon Footprint ◽  
Raw Material ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Drying Process ◽  
Cement Production ◽  
Footprint Analysis ◽  
Cement Kilns ◽  
Cement Manufacturing ◽  
Dried Sludge

Cement manufacturing and the treatment of sludge are considered both energy-intensive industries and major greenhouse gas (GHG) emitters. However, there are still few studies on comprehensive carbon footprint analysis for adding municipal sludge in the cement production. In this study, the lime-dried sludge blended with calcium oxide at the mass mixing ratio of 10% was utilized as raw material for the preparation of Portland cement. The chemical and physical properties of sludge were analyzed. A set of carbon footprint calculation methods of lime-drying treatment of sludge and reuse in cement kilns was then established to explore the feasibility of coprocessing lime-dried sludge in cement kilns. The results showed lime-dried sludge containing CaO, SiO2, Al2O3, and Fe2O3 was ideal for cement production as raw material. However, the water content of lime-dried sludge should be strictly limited. The lime-drying process presented the biggest carbon emission (962.1 kg CO2-eq/t sludge), accounting for 89.0% of total emissions. In the clinker-production phase, the lime-dried sludge as raw material substitute and energy source gained carbon credit of 578.8 and 214.2 kg CO2-eq/t sludge, respectively. The sludge used for producing cement clinker could reduce carbon emissions by 38.5% to 51.7%. The addition ratio of lime and stacking time in the sludge lime-drying process could greatly affect the carbon footprint of coprocessing lime-dried sludge in cement kiln.

scholarly journals Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Li Luo ◽  
Yimin Zhang ◽  
Shenxu Bao ◽  
Tiejun Chen
Keyword(s):  
Portland Cement ◽  
Iron Ore ◽  
Mechanical Performance ◽  
Mineralogical Composition ◽  
Cement Industry ◽  
Raw Material ◽  
Cement Clinker ◽  
Iron Ore Tailings ◽  
Portland Cement Clinker ◽  
Clinker Production

The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT) to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical composition and physical properties of clinker, and hydration characteristic of cement were studied by burnability analysis, differential thermal analysis, X-ray diffraction, and hydration analysis. The results showed that the raw meal containing IOT had higher reactivity and burnability than the raw meal containing clay, and the use of IOT did not affect the formation of characteristic mineralogical phases of Portland cement clinker. Furthermore, the physical and mechanical performance of two cement clinkers were similar. In addition, the use of IOT was found to improve the grindability of clinker and lower the hydration heat of Portland cement. These findings suggest that IOT can replace the clay as alumina-silicate raw material for the preparation of Portland cement clinker.

Characteristics of controlled low-strength materials incorporating cement kiln dust

2007 ◽  
Vol 34 (4) ◽  
pp. 485-495 ◽  
Author(s):  
M Lachemi ◽  
K M.A Hossain ◽  
M Shehata ◽  
W Thaha
Keyword(s):  
Strength Properties ◽  
Cement Industry ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Study Phase ◽  
Strength Material ◽  
Preliminary Study ◽  
Low Strength ◽  
Cement Manufacturing ◽  
Kiln Dust

This paper presents a study that focuses on evaluating the feasibility of incorporating cement kiln dust (CKD) in the development of controlled low-strength materials (CLSM). A preliminary study (phase I) was conducted (based on fresh and strength properties) to understand the behaviour of 12 selected CLSM mixtures where CKD and cement content varied from 4% to 45% and from 2% to 4% of total mass, respectively. Subsequently, four best CLSM mixes were selected for a detailed study (phase II), which investigated fresh and hardened properties, addressed durability issues, and made recommendations for suitable mix designs for field applications. The research suggests that CLSM with acceptable properties can be developed using moderate volumes of CKD (up to 15% by mass). A combination of 2% cement and 10% CKD or 15% CKD and no cement can provide a mix that satisfies the requirements of a CLSM. Sustainable development in the cement industry can be partly achieved by producing CKD-based CLSM, as it consumes cogenerated products from the cement manufacturing process.Key words: cement kiln dust, controlled low-strength material, mix design, fresh–mechanical properties, durability.

scholarly journals Physico-Mechanical Properties of Bricks Manufactured using Cement Kiln Dust

2020 ◽  
Vol 9 (3) ◽  
pp. 1804-1808
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Waste Management ◽  
Industrial Waste ◽  
Cement Content ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Kiln Dust

the actual increase in global industrial production and manufacturing, produces a continuous increase in amount of industrial waste and continues to emit an all-time high amount of air pollutants and greenhouse gas emissions. To fight and mitigate these phenomena, proper Waste Management became the pillar of most environmental strategies worldwide. By reduction of consumption, re-use of goods and recycling of products, waste management aims to preserve the resources and to protect the environment. The Cement industry is one of the most important industrial sectors for society development; however it also has significant negative environmental impacts due to its emissions and production of waste. Cement kiln dust (CKD) is an industrial waste or by product which results from cement manufacturing. CKD is fine grained, solid, highly alkaline particulate material chiefly composed of oxidized, anhydrous, micron-sized particles collected from electrostatic precipitators during the production of cement clinker. This research examines the effects of using large amounts of CKD to replace the cement content in the fabrication of solid cement bricks. It is triggered by the quadruple objectives of reducing the amount of cement consumption, disposing efficiently of its industrial waste and producing economic bricks with safe strength. The purpose of this paper is to assess the properties of solid cement bricks containing different amounts of CKD. Cement bricks produced using different amounts of CKD were tested to find their properties and final comparison has been made to identify the effect of using different CKD/Cement ratio on the performance of bricks compared to the reference specimen produced using cement only with no CKD. For the brick mixes, Ordinary Portland cement (OPC), with two cement content of 200kg/m3 and 250kg/m3 were used throughout this investigation. The physical properties; unit weight, water absorption and mechanical properties; compressive strength, flexural strength, of the produced bricks were determined. Results showed that partial replacement of OPC with CKD reduces the brick compressive strength by 18% to 23% for CKD/OPC ratio of 30% and by 36% for CKD/OPC ratio of 50% and in all cases the strength remains largely higher than the standard limit for load bearing bricks.

Life Cycle Assessment of Comprehensive Utilization of Calcium Carbide Slag in Cement Kiln

2020 ◽  
Vol 993 ◽  
pp. 1487-1495
Author(s):  
Xin Ping Lin ◽  
Ai Wei Liu ◽  
Yun Fa Feng ◽  
Qi Ling Chen ◽  
Tao Chen ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Emission Reduction ◽  
Calcium Carbide ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Cement Production ◽  
Comprehensive Utilization ◽  
Carbide Slag ◽  
Portland Cement Clinker

The recycling utilization of solid waste is an important technical means for the sustainable development of the cement industry in China. Calcium carbide slag is a special solid waste in China, which can be used for cement production with a great advantage on CO2 emission reduction. With an view to providing methodological and data support for the development of policies in the cement industry, this paper quantitatively analyzes the environmental effects/environmental benefits of the comprehensive utilization of calcium carbide slag in cement kiln by comparing the traditional system of Portland cement clinker completely produced by natural resources with the system of cement clinker produced by calcium carbide slag based on the life cycle assessment (LCA) method given in standards and specifications of ISO 14040 series. The results show that the latter system has a better effect in material saving and carbon emission reduction, will increase the energy consumption in cement production process, and also slightly increase other pollutants (e.g. SOx, NOx, etc.) emission. The GWP, AP and EP indicators of the calcium carbide slag cement clinker system decrease compared with those of the Portland cement clinker system, while other indicators do not differ much or even slightly increase.

Thermal Decomposition Characteristics and Drying Process of Municipal Sludge

2017 ◽  
Vol 898 ◽  
pp. 2464-2469 ◽  
Author(s):  
Qi Gang Zhao ◽  
Ya Li Wang ◽  
Zuo Ren Nie ◽  
Hong Liu ◽  
Su Ping Cui
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Municipal Sludge ◽  
Drying Process ◽  
Sludge Stabilization ◽  
Sludge Drying ◽  
Clinker Production

Using cement kiln dispose sludge from sewage plants can achieve the sludge stabilization, harmless, reduction and resource comprehensive utilization purposes. This is Not only to solve the problem of sludge treatment which is difficult to solve by sewage treatment plant, but also to make full use of the sewage treatment plant sludge to replace part of cement clinker production materials. And it makes full use of sludge incineration emitted in the process of low calorific value. Municipal sludge contains more moisture. It is necessary to dry the sludge outside the kiln before entering kiln process. As cement kiln co-processing, it should be combined with the characteristics of NSP clinker production, it is necessary to not only consider the total energy consumption of the drying process, but also the re-use of dried sludge heat value, as well as consider the total of water into the kiln by drying sludge affecting the whole clinker production process. In this paper, with the initial solid content 20%, dry heating value 3400 cal/g sludge as a research object, the moisture morphology, thermal characteristics, drying technological parameters and composition of water after drying in sludge were analysed. This issue combines sludge drying with cement kiln disposal, which can not only solve the heat and odor problem during the individual sludge drying process, but also provide a theoretical basis for cement kilns co-disposal of municipal sewage sludge to achieve the purposes of sludge stabilization, harmless, minimization and resource utilization.

Screening of Energy-Saving Technologies for Cement Production Based on Boston Consulting Group Matrix

2021 ◽  
Vol 1035 ◽  
pp. 988-998
Author(s):  
Yu Chen Zhang ◽  
Xian Zheng Gong ◽  
Yu Liu ◽  
Li Wei Zhou
Keyword(s):  
Energy Saving ◽  
Frequency Conversion ◽  
Waste Heat ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Cement Production ◽  
Group Matrix ◽  
Saving Rates ◽  
High Technologies

Based on the analysis of the development situation of China’s cement industry and the BCG Matrix method, this paper classifies and screens 31 energy-saving technologies in China's cement production, and puts forward guiding suggestions for the application of energy-saving technologies for cement enterprises. The screening results show that the “Energy-efficient powder separation technology” and “New low-calcium cement clinker and production technology” are “double-high” technologies with excellent on both screening indicators. The investment energy saving rates are 17.5 tce/10,000 yuan (tons of standard coal equivalent per 10,000 yuan) and 10 tce/10,000 yuan. The promotion ratio increments are 35% and 25%. “Cement clinker energy-saving nitrogen reduction firing technology”, “Fan drive mode adopts high voltage frequency conversion speed control technology”, “Pure low temperature waste heat power generation technology for cement kiln” are “single-high” technologies with excellent on one of screening indicators. The investment energy saving rates are 0.3tce/10,000 yuan, 4.1tce/10,000 yuan, 3.9tce/10,000 yuan respectively. The promotion ratio increments are 19%, 35%, 31.5% respectively.

Analysis on the CO2 Emission of Calcium Carbide Sludge as Secondary Raw Material in Cement Clinker Production

2013 ◽  
Vol 743-744 ◽  
pp. 516-522 ◽  
Author(s):  
Fei Fei Shi ◽  
Zhi Hong Wang ◽  
Ming Hui Fang ◽  
Bo Xue Sun ◽  
Ming Nan Zhao ◽  
...  
Keyword(s):  
Life Cycle ◽  
Emission Reduction ◽  
Calcium Carbide ◽  
Cement Industry ◽  
Raw Material ◽  
Cement Clinker ◽  
The World ◽  
Secondary Raw Material ◽  
Global Carbon ◽  
Clinker Production

With the development of economy, China has become one of the largest cement producers in the world. However, cement industry is a main contributor of global carbon emissions. Substituting calcium carbide sludge for limestone is an effective method for CO2 emission reduction in cement industry and has developed rapidly in recent years in China. The purpose of this study is to determine the life cycle CO2 emission of cement clinker produced with calcium carbide sludge as secondary raw material. The results show that compared with general cement clinker, the life cycle CO2 emission intensity of cement clinker produced with calcium carbide sludge will be decreased by 39.1% when substitution rate is 80%. And the CO2 emission results from the procedure of cement clinker production accounts for 85.7% of the total emission, in this stage, the CO2 emission declined by 42.2%.

scholarly journals Use of Factory-Waste Shingles and Cement Kiln Dust to Enhance the Performance of Soil Used in Road Works

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Aly Ahmed ◽  
Medhat Shehata ◽  
Said Easa
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Capillary Rise ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Fine Grained Soil ◽  
Stabilized Soil ◽  
Cement Manufacturing ◽  
Kiln Dust

An experimental work was conducted to study the use of factory-waste roof shingles to enhance the properties of fine-grained soil used in road works. Cement kiln dust (CKD), a cogenerated product of Portland cement manufacturing, was used as a stabilizing agent while the processed shingles were added to enhance the soil tensile strength. The effects of shingles on strength and stability were evaluated using the unconfined compressive strength, splitting tensile strength, and California Bearing Ratio (CBR) tests. The results showed that the use of CKD alone resulted in a considerable increase in the unconfined compressive strength but had a small effect on the tensile strength. The addition of shingles substantially improved the tensile strength of the stabilized soil. A significant reduction in the capillary rise and a slight decrease in the permeability were obtained as a result of shingle addition. An optimal shingle content of 10% is recommended to stabilize the soil.

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