The influence of triethanol amine and ethylene glycol on. Grindability is an index, therefore it has no unit. Clinker and cement everyting for clinker and cement in. The river crushed stone has a lo wer grindability than clinker, especially at the initial stages of grinding, and therefore intensifies the process of clinker cement grinding. The second was a breakability test which assessed the height that a. From the study of commercial and model clinkers, it was concluded that the trace elements. As grindability depends on many unknown factors, hardgrove grindability index hgi is determined empirically using a sample mill, according to the following procedure. As grindability depends on many unknown factors, hgi is determined. Impact this multiscale investigation of fracture properties with the microscratch test highlights the importance of microstructure in clinker grindability. The grindability of a material is the only factor used to determine the required size of a grinding machine. For this purpose, two kinds of clinkers were prepared. Deniz department of mining engineering, suleyman demirel university, isparta, turkey abstract. It is reported that the cement industry has contributed to 57% of the total co2 emission in the world.
The influence of triethanol amine and ethylene glycol on the. Portland cement clinker more than 90%, a maximum of about 5% gypsum which controls the set time, and up to 5% minor constituents as allowed by various standards. Some years ago i had some grindability testing done by magotteaux. The detroit clinker grinder is built for hostile operating environments. For this reason, as the amount of gypsum increases, fineness target 365050 cm2g is obtained thanks to gypsum grindability.
Clinker microstructure and grindability clinker and cement. Hardgrove grindability index hgi linkedin slideshare. The influence of mineralogical, chemical and physical properties on grindability of commercial clinkers with high mgo level. The staff occasionally conducts clinker ing tests in pilot rotary kilns.
Setting times and the mechanical properties of opc and plc cement were also investigated. This paper points out the need for a standard method of determining the relative grinding characteristics of various coals. Its value has to give the result of the grinding operation as a result of unit energy expenditure. Kathua district is connected to jammu, srinagar, pathankot, delhi through national highway nh1a. Modern processing techniques to minimize cost in cement industry clinker and cement. Grinding aids for high performance cements cadd mapei. Clinker with higher percentage of liquid phase shows a higher work index, i. Clinker grinding unit process mechanical engineering.
In all cases, the best clinker is the one that has a vintages fineness close to 15% for the refusal of 100 m. Hardgrove grindability index short hgi is a measure for the grindability of coal. Download as pdf file european cement research academy. Detroit stoker ash handling systems clinker grinder.
This latter gives a wellformed clinker nodules, well homogenized. The grindability test is done by grinding 47 grams of clinker and 3 grams of gypsum all previously crushed to minus 14 inch in a bleuler mill and then measuring blaine fineness on the sample. A look in the microscope can determine the temperature profile in the kiln and provide clues to improve clinker grindability, optimize raw feed fineness, or increase 28day cement mortar strength. The clinker manufacturing process the preheating of the material takes place in preheater cyclones fitted with a precalciner fired with petroleum, natural gas or coal. Both these properties are sensitive to the relative amount of various constituents alite, belite, aluminate, ferrite, alkali sulfates, periclase, free lime, etc. Independent of the raw meal used, the different clinker phases were formed in three stages. It was designed to air quench and cool large quantities of hot clinker rapidly, and to recover and return to the kiln a major portion of the heat from the clinker. These mixtures were prepared at a constant weight ratio of 20. Effect of the storage of cement on early properties of cementitious systems clinker and cement low concrete strength reasons clinker and cement common issues in cement sector clinker and cement clinker microstructure and grindability clinker and cement temperature altitude effects on fans clinker and cement. David, could you explain logic behind your replied perception. It covers both microscopy of various kinds scanning electron and optical and xray diffraction analysis. Clinker grinder in boiler pdf crusher mills, cone crusher. Investigation of the correlation between the grindability.
Porosity and phase characteristics of two clinkers from different furnaces which are using the same raw materials were determined by the application of image processing techniques on sem images of polished surfaces. I would also like to know views of other forum members. Microscopical examination of portland cement and clinker clinker and cement last shared. Analysis of anhydrite gypsum effects on quality of cement. The standard feed is prepared by stage crushing to all passing a 6 mesh sieve, but finer feed can be used when necessary. Clinker dust with abundant belite clusters inferior burnability fundal, 1980 dusty clinker, coarsely crystalline silicates, lowporosity slow temperature rise, higher clinkering temperature, nodules, poor grindability longer time in burning zone and transition zone wolter, 1985. Portland limestone cement part i preparation of cements. Effect of clinker composition on grindability sciencedirect. Mar 08, 2012 the granulometry of clinker affects its grindability, measurable in terms of sp. The kiln and cooler can be further optimized using a multifuel addon application see page 6 for more information. What is the optimum layout of a cement grinding plant. Akcansa cimento was using a combination of imported and local coal with up to 30% petcoke, but was keen to use more petcoke since it is a cheaper fuel.
Clinker and gypsum, being mixed together in predetermined proportions, are fed to the grinding mills. Experimental materials industrial clinker and gypsum from helwan cement company are used for the production of type i portland cement cem i 42. As is known, comparing with clinker gypsum has tendency to be grinded easily and quickly. Portland limestone cement part i preparation of cements 38 cement are required when making cement nomenclature. Grindability was also measured on mixtures of clinker and glass or blast furnace slag. Clinker grinder in boiler pdf bottom ash wikipedia, the free encyclopedia the clinker lumps get crushed to small sizes by clinker grinders mounted under water and fall down into a trough from where a water. Grinding of clinker is the last and most energyconsuming stage of the cement manufacturing. The cement industry has for some time been seeking alternative raw material for the portland cement clinker production. This indicates that the specific grinding energy per specific surface necessary to. This chapter discusses cement and concrete characterization. Clinker, grinding, porosity, image analysis, interstitial phases.
A classification system for clinker grindability hardly, medium and easily grindability was developed on the basis of the test results from a large number of industrial clinkers. Grindability of cement clinker to a great extent determines the economy of cement production. This ratio was found successful in previous research. Two separate tests were performed, the first was the sgi test which assessed the number of revolutions within a test mill that were required to produce a surface area of 350 m2kg. The ball mill for clinker is an efficient tool for fine powder grinding. Variation of feed chemical composition and its effect on. The effect of certain trace elementscr, zn, ba, ni, ti, pon clinker grindability was studied. It is mainly used to grind the clinker and raw materials in cement industry and also can be applied in metallurgy, chemical, electric power and other industries to grind all kinds of ores. The grindability of clinkers is usually compared on a lab scale by using a lab ball mill.
Effect of chemical composition of clinker on grinding energy requirement. After ground separately having three blaine fineness value. Analysis of the grinding behaviour of various portland cement. A comprehensive research project was undertaken to evaluate the effect of liquid or powder water reducers wrs on the grindability and clinker factor optimization during the production of portland cement. Microscopic examination of clinker produced by the wet 121 and dry process brendan m. Oncebhasbeendetermined, themillcanbeusedtoestimate the grindability offinematerials without theneedforreference materials. Testing methods based on the principle of the tumbling mill, roller mill or highpressure grinding rolls are applied for determination. Effect of certain trace elements on the grindability of. A new technology was tested to improve the cooking efficiency of the raw mixture for portland clinker production by the use of nanocaoh2. The kiln uses solid fuel, with oil and gas as back up and warm up fuel. Pdf effect of free lime and lime saturation factor on grindability. An unstable kiln and cooler leads to inefficient production and inconsistent clinker quality.
Assessment of the grindability of cement clinker, part 1. Thus, there is a need to make an innovation in order to overcome the environmental problem. Effects of clinker composition on the properties of. Grinding studies, and the resulting hgi, allow many different types of coal users to evaluate how coals will perform in their mills, allowing them to estimate grinding power requirements and throughput capacities. This results in reduction in clinker grindability and sieve residue of 40. Images of cement and concrete microstructure are important in their own right, for analysis and characterization. The desulfurization slag added can lower the clinkerization. Several methods have been advanced and the authors herein are proposing another which they. The grindability of a coal is a measure of its resistance to crushing. Sio2, the remainder consisting of aluminium and ironcontaining clinker phases and other compounds. Imprint of a scratch test performed on a clinker surface to evaluate the effect of microstructure. Portland cement clinker is a hydraulic material which shall consist of at least twothirds by mass of calcium silicates 3cao. Finally, a study of clinker s grindability enabled us to evaluate the probability of grinding of these samples. Two factors affecting grindability are the moisture and ash contents of a coal.
April 30 may 4, 2000 international cement microscopy. February 1943 since the last publication of tabulated results of grindability tests by the authors1 the total number of ballmill tests made has more than doubled, and rodmill tests have becomeincreasingly important. The grindability index of coal is an important technological parameter for understanding the behaviour and assessing the relative hardness of coals of varying rank and grade during comminution, as well as their cokemaking properties. Standard grindability tests and calculations new york meeting. The basis for this property is a wellburned clinker with consistent chemical composition and free lime. In general, lignites and anthracites are more resistant to grinding than are bituminous coals. The amount of energy consumed in the cement manufacturing has a correlation to the increasing of co2 emission. All grindability tests were performed in a fritsch planetary ball mill pulverisette 6 in a bowl with the. Clinker formation in industrial rotary kilns is very complex due to a vast number of interacting parameters. Grindability is an important factor for the characteristic of the brittle raw materials by the design the mills. Grindability is generally characterized by the grinding work required for a unit weight or a unit volume of material.
The ono version depends on wether there are belite clusters in clicker or not. Therefore, an accurate estimation of the phase content is of high. The correlation between the grindability, texture and production parameters of cement clinker was studied in the course of comprehensive investigations. Relationships between bonds grindability g bg and breakage parameters of grinding kinetic on limestone v.
Testing methods based on the principle of the tumbling mill, roller mill or high pressure grinding rolls are applied for determination. Chemical gypsum, if used instead of natural gypsum, needs to be dried either by natural sun drying or by mechanical drying, before it is used with cooled and dried clinker for inter grinding in mills. A simple test is presented which can detect differences in clinker grindability. Tea molecules easily combine with metal ions of cement minerals. Cemtechconference istanbul, turkey 2629 september 2004. Evaluation of the effect of coal chemical properties on the.
As i know belite formation in clusters even with smaller crystals will make clinker harder to grind compared to clinker with welldistributed individual crystals. Therefore intergrinding is a potential way of saving considerable amount of energy since some mineral admixtures have a clear positive influence on the grindability of clinker. Ono method of clinker characteristics ranked that clinker belite size 2540micron as excellent clinker and 510 micron as poor clinker. Since a substantial amount of energy expended at a cement plant is needed for clinker grinding, improvement in clinker grindability would increase grinding efficiency, thereby improving energy consumption. In a cement grinding circuit, these may be changes in the grindability of clinker or changes in grinding aid composition. For this purpose, having different chemical compositions five clinker and one natural pozzolan were selected. The aim of this research was to investigate the possibility of utilizing iron ore tailings iot to replace clay as aluminasilicate raw material for the production of portland cement clinker.
Grindability is an important factor for the design a coal mill. It is screen analyzed and packed by shaking in a cc graduated cylinder, and the weight of 700 cc is placed in the mill and ground dry at 250 per cent circulating load. The hardgrove grindability index standard reference sample hgisrs is a sample of coal used to calibrate instruments that are designed to determine the ease with which coal can be pulverized. An experimental study on separately ground and together. The airquenching shaking grate clinker cooler was developed more than 20 years ago as an improved heat recuperating cooler for use with rotary kilns. It is influenced not only by changing conditions, such as temperature, presence of surface active substances sas, etc. Clinker grinding test in a laboratory ball mill using clinker. Effectiveness of triethanolamine on grindability and properties of portland cement in laboratory ball and vibrating disk mills ceramics silikaty 58 2 8994 2014 91 the produced cement samples were then studied for their properties. Applications can be installed in as little as a few weeks depending on control requirements. Their chemical compositions are presented in table 1. Grindability of cement clinker from raw mix containing.
Pdf scientific principles and practice in the use of. Grindability as a material characteristic must indicate the suitability for size reduction. Utilization of iron ore tailings as raw material for. The required amount of water for paste normal consistency and the paste spread diameter were. The calcinations of the material begin during this stage, changing its phase to the oxide phase for each component to be ready for the burning process. The main reason for the clinker free lime to change in situation with stable kiln operation is variation in the chemical composition of the kiln feed. If the grinding device was designed only on the basis of the values of grindability of charge, the capacity of the grinder may be insufficient in practical operation. The 20 plant survey reflects the industry emerging from the economic. Imprint of a scratch test on a single belite crystal. Secondly, grindability of the mixture is not the weighted average of the component grindabilities but is even lower than the harder component slag12.
Clinker c was cooled at 10cmin from 1450c and quenched in air at c. It was found that clinker with low percentage of al 2 o 3 and fe 2 o 3 is easier to grind. By grinding several clinkers using the same procedure same amount of material and identical grinding time. A decrease in the free lime concentration after the. The effects of regional clinker porosity and interstitial phase morphology differences on grindability of clinkers have been investigated within the scope of this study. Clinker quality dramatically improved, while reducing fuel use. The cement industry has remarked as an intensive consumer of energy. The hgi value provides information for determining grinding power consumption and pulverizer capacities. Effects of porosity and related interstitial phase morphology.
An investigation of the behaviour of these gbs within cem iiia cements reproduced using a reference clinker characterised by a high c 3a and c 3s content was performed. Determination of the value of hgi grindability is performed at constant pressure between the grinding elements. Four commercial portland clinker samples with different chemical compositions and grindability indices were examined. Here is the old allischalmers bond work index grindability test procedure. It was aimed to determine the effect of clinker composition on various properties of portlandpozzolan cements. The goal of this paper was studying the grindability of clinker and its effects in ball. Clinker grindability and textures of alite and belite. The clinker grinding is responsible for around 40% of the total energy usage during cement production 21. Imst2017 alternative evaluation of the grindability of. Standard bond ball mill grindability test methodprocedure. The effect of raw materials fineness and lime saturation.
The smaller the hgi, the harder is coal texture and less grindable is the coal. Pdf this research aims to investigate the effect of free lime and lime saturation factor on grindability of cement clinker. Clinker grindability, proceedings of the international conference on cement microscopy 1985, 7th, p. Effect of phosphogypsum on the clinker grindability. Minimization of variation in clinker quality science.
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