Kinetic Consideration of Clinker Formation in Portland Cement Production Using Demolition Rubbles (Concrete,mortar and plaster) Part I : Burning Ability of Raw Mixes

2005 ◽  
Vol 5 (2) ◽  
pp. 169
Author(s):  
Sumardi P ◽  
I. B. Agra ◽  
I. M. Bendiyasa ◽  
Wahyudi B. S.

Wahyudi B.S.Wahyudi B.S.In general, the main raw materials in Portland cement production are limestone, clay, and corrective materials such as iron sand and silica sand. These raw material come from natural deposits, which are very hard to find in some countries. In this research, Portland cement was made by utilizing the demolition rubble of office and housing buildings. The rubble consists of concrete wastes (mixtures of hydrated Portland cement minerals and some aggregates) and some building bricks as well as mortar/plaster of Portland cement. To meet the cement modulus, which is generally used in Portland cement industries, corrective materials such as limestone (source of CaO) and disposed building bricks are used. The term burning ability is used for Portland cement to measure the CaO free content in the cement clinker produced from specified raw material mixes at a specific operating 'condition of clinkering. The cement modulus used is Ume Saturation Factor (LSF) and Silica Modulus (SM). The minimum Cao free content was found by using LSF: 0.86, SM: 2.14, and clinkering temperature 14000C for 30 minutes. The cement modulus was made from concrete waste, limestone, and disposed red brick with a weight ratio of 1: 3.489: 0.677. Keywords: Burning ability,demolition rubble of buildings, Portland cement, and raw mixes.

2020 ◽  
Vol 10 (1) ◽  
pp. 49
Author(s):  
Suharto Suharto ◽  
Muhammad Amin ◽  
Muhammad Al Muttaqii ◽  
Syafriadi Syafriadi ◽  
Kiki Nurwanti

Experimental study on the use of basalt stone originated from Lampung has been conducted to evaluate its potential for a partial substitute of raw material in production of cement clinker. The basalt stone contains minerals of anorthite, augite, and albite phases that are required for clinker formation. In this study, the main raw materials were 80% limestone, 10% silica sand, 9% clay and 1% iron sand. The raw material in these experiments were mixtures 90% or 80% of the main raw material and 10% or 20% of basalt stone. The effect of adding coal to raw materials was also studied to see the possibility of an increase in clinkerization temperature inside the raw material mixture, and at the same time to see the effect of coal ash on clinker composition. Clinker obtained from heating of raw materials at a temperature of 1100oC had LSF of 94.1% and 95.1% (heating time of 1 and 3 hours). If heating is carried out at 1200oC, the clinker had LSF of 97.7% and 98.0% (heating time of 2 and 3 hours, respectively). Depending on the temperature and duration of heating, the clinker mostly had SM in the range of 2.18-2.40% , and AM in the range of 0,78-1.80%. Characterization using XRD showed that the clinker consisted of larnite and gehlenite phases, and dominated by CaO.Batu basalt Lampung telah diuji potensinya sebagai pengganti sebagian bahan baku utama pembuatan klinker semen. Batu basalt tersebut memiliki mineral-mineral dalam fase anorthite, augite, dan albite yang diperlukan pada pembentukan klinker. Pada penelitian ini, bahan baku utama adalah batu kapur 80%, pasir silika 10%, tanah liat 9% dan pasir besi 1%. Campuran bahan baku klinker adalah 90% atau 80% bahan baku utama dan 10% atau 20% batu basalt. Efek penambahan batubara ke dalam bahan baku klinker juga dipelajari untuk melihat kemungkinan kenaikan temperatur klinkerisasi di dalam campuran bahan baku, dan sekaligus untuk melihat efek abu batubara terhadap komposisi klinker. Klinker hasil pemanasan bahan baku pada temperatur 1100oC memiliki LSF 94,1% dan 95,1% (lama pemanasan 1 dan 3 jam). Jika pemanasan dilakukan pada 1200oC, klinker memilik LSF 97,7% dan 98,00% (lama pemanasan 2 dan 3 jam). Tergantung pada temperatur dan lama pemanasan, klinker hasil percobaan ini umumnya memiliki SM 2,18-2,40%, dan AM antara 0,78-1,80%. Karakterisasi dengan XRD menunjukkan bahwa klinker terdiri dari fase larnite dan gehlenite, dan didominasi CaO.


2011 ◽  
Vol 90-93 ◽  
pp. 3254-3257
Author(s):  
Jing Min Hong ◽  
Ling Wang ◽  
Jing Lan Hong

A cost combined life cycle assessment was carried out to estimate the economic and environmental impact of redmud as aggregate in cement production. Results showed that the raw materials, transport, electricity and coal had the highest contribution to overall cost, while coal production and direct emissions represented the dominant contribution to overall environment impact. Improving energy and raw material efficiency and minimizing raw materials transport distance are the efficient way to minimize overall environmental and economic impacts.


2020 ◽  
Vol 24 (4) ◽  
pp. 36-41
Author(s):  
O.A. Miryuk

There are presented the results of physicochemical studies of the composition and thermal transformations og large-tonnage wastes of beneficiation of scarnified-magnetite ores from Kazakhstan. To determine the composition of materials and thermal transformations, the following methods were used: X-ray phase analysis, differential-thermal analysis, Mцssbauer and infrared spectroscopy. There was revealed the stepwise nature of the transformation of anthropogenic material during roasting, due to polymineral composition of ore beneficiation. It has been established that the chemical-mineral characteristics of natural silicates determine the formation processes and properties of clinker phases. An integrated approach to the study of technogenic raw materials allowed not only to substantiate the possibility and expedience of using scarnified-magnetite ore beneficiation wastes in cement production, but also to determine the preference for the phase composition of cement clinker. Research result from the basis for the development of low-energy cement clinkers with a high content of belite phase.


2019 ◽  
Vol 16 (3) ◽  
pp. 352-365
Author(s):  
A. K. Matyeva

Introduction. The creation of energy-saving materials involves the use of local raw materials for products with improved physic-mechanical properties. The author carries optimization of the rational composition and properties of modified arbolite from plant-gypsum composition (PGC). In addition, the author uses modifiers on new ways of preparing the aggregate according to the method of experimental and statistical modeling.Materials and methods. The author used the cereal straw grown in the Kyrgyz Republic (CS), G-5 and G-7 construction gypsum based on local raw materials, ash from the Bishkek Heat and Power Plant (BHPP), portland cement clinker PCC, natural clay (ganch). Moreover, the clay component of the Toloykonsky deposit was used as the clay component. The author also added the liquid glass, latex SCS, the low-concentration resin LCR-3066 + catalyst of ionic type (CIT) as modifiers for the formation of the porous polymer-silicate systems. The paper marked the plasticizing additives in the manufacture of arbolite as SCS, LCR and CIT components. As a retarder the setting of gypsum was added a partial salt 1-hydroxyethylidene-1, 1-diphosphonic acid with triethanolamine and flame retardants. The tests were carried out according to standard methods. To optimize the composition and properties of the polymersilicate-gypsum composition (PSGC), the author carried out a three-factor experiment according to the B3 plan, where three prescription factors varied: X1 – straw content,%; X2 – content of polymer silicate additives (PSA) + plasticizer,%; X3 – gypsum content + portland cement clinker as a nitroperimethyl phosphoric acid (NPA) and flame gypsum retarder.Results. The research showed that at 28 days of age for cement-free gypsum compositions as the content of straw increased, the strength was almost unchanged. When comparing the strength of the same samples of 2 and 28 days strength with the maximum filling of gypsum, the author defined that the PSA content should not exceed 12% when the straw additive was 26% and further PSA increasing did not increase the strength.Discussion and conclusions. As a result, the author achieves maximum strength of the arbolit, when the content of G-7 gypsum is 28-32%, ash is 18-22% and PSC is 8-10%. The maximum value of strength and water resistance of the material is achieved with a rational ratio of components: straw – 24–28%, G-7 gypsum – 30–32% + NSPL – 0,05%; ash – 18–22%; resin – 3066-8-12% + catalyst – 0,3% (87% sulfuric acid, 13% phosphoric acid); PCC – 3–5%; clay-gypsum (ganch) – 2%; liquid sodium glass – 12%; plasticizers CIT – 0,15%, SCS – 0,2%, LCR – 0,15%; modified hardener – 0,5% and water.


Author(s):  
Ali Benlamoudi ◽  
Aeslina Abdul Kadir ◽  
Mohamed Khodja

The objective of this study is to investigate the performance of incorporating petroleum sludge waste as raw materials into the cement clinker production. The burnability and the structural analysis of the produced clinker were studied. The results showed that the addition of petroleum sludge into the clinker matrices improved the burnability of the clinker by lowering the free lime content. Moreover, 2.5% and 5% of this waste was effective and did not affect the quality of the cement clinker negatively. This study, which is the first to investigate the incorporation of petroleum sludge into cement production, provides also a complete elimination of this waste from the environment.


2018 ◽  
Vol 27 (4) ◽  
pp. 096369351802700 ◽  
Author(s):  
Mehmet Önal ◽  
Gökdeniz Neşer

Glass reinforced polyester (GRP), as a thermoset polymer composites, dominates boat building industry with its several advantages such as high strength/weight ratio, cohesiveness, good resistance to environment. However, proper recovering and recycling of GRP boats is became a current environmental requirement that should be met by the related industry. In this study, to propose in a cost effective and environmentally friendly way, Life Cycle Assessment (LCA) has been carried out for six scenarios include two moulding methods (namely Hand Lay-up Method, HLM and Vacuum Infusion Method, VIM) and three End-of-Life (EoL) alternatives(namely Extruding, Incineration and Landfill) for a recreational boat's GRP hulls. A case study from raw materials purchasing phase to disposal/recycling stages has been established taking 11 m length GRP boat hull as the functional unit. Analysis show that in the production phase, the impacts are mainly due to the use of energy (electricity), transport and raw material manufacture. Largest differences between the methods considered (HLM and VIM) can be observed in the factors of marine aquatic ecotoxicity and eutrophication while the closest ones are abiotic depletion, ozon layer depletion and photochemical oxidation. The environmental impact of VIM is much higher than HLM due to its higher energy consumption while vacuum infusion method has lower risk than hand lay-up method in terms of occupational health by using less raw material (resin) in a closed mold. In the comparison of the three EoL techniques, the mechanical way of recycling (granule extruding) shows better environmental impacts except terrestrial ecotoxicity, photochemical oxidation and acidification. Among the EoL alternatives, landfill has the highest environmental impacts except ‘global warming potential’ and ‘human toxicity’ which are the highest in extrusion. The main cause of the impacts of landfill is the transportation needs between the EoL boats and the licenced landfill site. Although it has the higher impact on human toxicity, incineration is the second cleaner alternative of EoL techniques considered in this study. In fact that the similar trend has been observed both in production and EoL phases of the boat. It is obvious that using much more renewable energy mix and greener transportation alternative can reduce the overall impact of the all phases considerably.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1302
Author(s):  
Andrés Játiva ◽  
Evelyn Ruales ◽  
Miren Etxeberria

The construction industry is affected by the constant growth in the populations of urban areas. The demand for cement production has an increasing environmental impact, and there are urgent demands for alternative sustainable solutions. Volcanic ash (VA) is an abundant low-cost material that, because of its chemical composition and amorphous atomic structure, has been considered as a suitable material to replace Portland cement clinker for use as a binder in cement production. In the last decade, there has been interest in using alkali-activated VA material as an alternative material to replace ordinary Portland cement. In this way, a valuable product may be derived from a currently under-utilized material. Additionally, alkali-activated VA-based materials may be suitable for building applications because of their good densification behaviour, mechanical properties and low porosity. This article describes the most relevant findings from researchers around the world on the role of the chemical composition and mineral contents of VA on reactivity during the alkali-activation reaction; the effect of synthesis factors, which include the concentration of the alkaline activator, the solution-to-binder ratio and the curing conditions, on the properties of alkali-activated VA-based materials; and the mechanical performance and durability properties of these materials.


2021 ◽  
Vol 72 ◽  
pp. 215-222
Author(s):  
Mohanad R.A. Al-Owaidi ◽  
◽  
Mohammed L. Hussein ◽  
Ruaa Issa Muslim ◽  
◽  
...  

The Portland cement industry is one of the strategic industries in any country. The basis of an industry success is the availability of raw materials and, the low extraction in addition to transportation costs. The Bahr Al-Najaf region is abundant with limestone rocks but lacks primary gypsum. An investigation had been carried out to identify the source of secondary gypsum as an alternative to primary gypsum. Twelve boreholes were drilled for a depth of 2 m, as the thickness of suitable secondary gypsum layer ranges from 1 to 1.5 m. The mineralogical study revealed the predominance of gypsum followed by quartz and calcite, with an average of 62.9%, 19.6% and 14.35%, respectively. The geochemical analysis revealed that the content of SO3 is appropriate and ranging from 41.92% to 32.89% with an average of 37.73%. The SO3 content is within an acceptable range. The mean abundance of the major oxides of the study area may be arranged as SO3 > CaO> SiO2> MgO> Al2O> Fe2O3. The insoluble residue was at an acceptable rate. The laboratory experiments for milling secondary gypsum with clinker has successfully proven the production of Portland cement that matches the limits of the Iraqi Quality Standard (IQS) No. 5 of 1984. Great care must be taken when using secondary gypsum; secondary gypsum must be mixed well to maintain the chemical properties before blending with clinker and utilizing in the cement mill in the cement plant.


2020 ◽  
Vol 12 (6) ◽  
pp. 2500 ◽  
Author(s):  
Li Ping ◽  
Gang Zhao ◽  
Xiaohu Lin ◽  
Yunhui Gu ◽  
Wei Liu ◽  
...  

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.


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