CC BY
86
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Delgerjargal A., lecturer, Department of Chemical Technology, School of Chemistry and Chemical Engineering, National University of Mongolia, e-mail: delgerjargala@num.edu.mn
Battsengel B., doctor of chemical sciences, professor, Department of Chemical Technology, School of Chemistry and Chemical Engineering, National University of Mongolia, e-mail: b_battengel@web.de
Oyunjargal J., researcher, Center of Nanoscience and Nanotechnology, Department of Chemical Technology, School of Chemistry and Chemical Engineering, National University of Mongolia
Delgertsetseg B., researcher, Center of Nanoscience and Nanotechnology, Department of Chemical Technology, School of Chemistry and Chemical Engineering, National University of Mongolia
Ganzorig C., doctor of engineering, professor, Department of Chemical Technology, School of Chemistry and Chemical Engineering, National University of Mongolia, e-mail: ch_ganzorig@num.edu.mn
Дэлгэржаргал А., преподаватель, отделение химической технологии, школа химии и химической инженерии, национальный универитет Монголии, e-mail: delgerjargala@num.edu.mn
Баттсэнгэл Б., доктор химических наук, профессор, отделение химической технологии, школа химии и химической инженерии, национальный универитет Монголии
Оюунжаргал Ж., научный сотрудник, Центр нанонаук и нанотехнологий, отделение химической технологии, школа химии и химической инженерии, национальный универитет Монголии
Дэлгэрцэцэг Б., научный сотрудник, Центр нанонаук и нанотехнологий, отделение химической технологии, школа химии и химической инженерии, национальный универитет Монголии
Ганзориг С., доктор технических наук, профессор, отделение химической технологии, школа химии и химической инженерии, национальный универитет Монголии, e-mail: ch_ganzorig@num.edu.mn
УДК 666.9 © B. Tserenkhand, R. Sanjaasuren, P. Solongo
COMPOSITION OF SOME IRON ORES AND POSSIBILITY TO USE THEM IN THE CEMENT PRODUCTION (WESTERN REGION OF MONGOLIA)
Chemical and mineral compositions of some iron ores in the Mongolian western region were studied. Also the effect of calcium fluoride on decomposition temperatures of calcite in the raw mix to obtain cement clinker was investigated. The results showed that iron oxide in iron ores of western Mongolian constitutes 87.23% in Uvgondatsan ( Khovd), 85.00% in Suul Лhar (Khovd) and 89.29% in Khargant (Uvs). Iron ores of "Kharganat" and "Uvgundatsan" mostly contain magnetite while iron ore of "Suul Khar" -hematite. The decomposition temperature of calcite was reduced at 5, 10 and 15oC when calcium fluoride from the raw mix obtaining cement clinkers of "Shokhoit" limestone, "Shal" clay and "Kharganat" iron ore with 0.5%, 1.0% and 1.5% additives.
Keywords: iron ore, magnetite, magnetite, saturation coefficient, cement clinker.
B. Tserenkhand, R. Sanjaasuren, P. Solongo. Composition of some iron ores and possibility to use them in the cement production (western region of Mongolia)_
Б. Цэренханд, Р. Санжаасурен, П. Солонго
СОСТАВ НЕКОТОРЫХ ЖЕЛЕЗНЫХ РУД И ВОЗМОЖНОСТЬ ИХ ИСПОЛЬЗОВАНИЯ В ПРОИЗВОДСТВЕ ЦЕМЕНТА (ЗАПАДНЫЙ РЕГИОН МОНГОЛИИ)
Изучен химический и минеральный состав некоторых железистых руд в западном регионе Монголии. Исследован эффект использования фторида кальция на температурное разложение кальцита в сырьевой смеси для получения цементного клинкера. Результаты показали, что оксид железа в железных рудах Западной Монголии Увгондацан (Ховд) составляет 87,23%, Зуул хар (Ховд) - 85,00% и Харгант (Увс) - 82,29%. Железистые руды Харганата и Увгандацана содержат в основном магнетит, в то время как железистая руда Зуул Хара - гематит. Температурное разложение кальцита уменьшилось на 5, 10 и 15oC при использовании фторида кальция с смеси, содержащей цементный клинкер известняка «Шохойт», глины «Шол» и железистой руды «Харгант» с добавками 0,5%, 1,0% и 1,5% .
Ключевые слова: железистая руда, магнетит, гематит, коэффициент насыщения, цементный клинкер.
Iron ore is a mineral that contains high Fe2O3 and a mixture of alumosilicates. In order to reduce module of Alumina in cement production, minerals that have high iron containment are used [1, 2]. Minerals such as magnetite (Fe2O3-FeO), hematite ^Оз), limonite (P-FeO(OH)), goethite (a-FeO(OH)), lepidocrocite (P-FeO(OH)), siderite (FeCO3) and ilmenite (FeTiO3) are contained in iron ore. As a result of the geological survey in Mongolia, approximately 200 iron ore mine were explored. The main objective of the study is to determine the chemical and mineral composition of the Western Mongolian iron ores and to investigate possibilities to use them in raw mix for obtaining cement.
Iron ores from "Kharganat" in Uvs aimag and "Suul Khar", "Uvgundatsan" in Khovd aimag, and chemical pure calcium fluoride were used in this research. "Kharganat" iron ore deposit is located 45 km northwest from the center of Naranbulag soum and 3.2 km from lake Sharburd. The deposit length is 1200 m and width is 12-30 m. The geographic coordinates of Kharganat iron ores are 49o3700// (north latitude) and 92o1100// (east longitude). "Uvgundatsan" iron ore is located 105 km from Khovd city and 60 km northwest from Myangad soum. The geographic coordinates of Uvgundatsan iron ores are 48o24/24// (north latitude) and 91o51/00// (east longitude). "Suul Khar" iron ore is located 22 km from Khovd city and 45 km from Buyant soum. The geographic coordinates of Suul khar iron ores are 47o51/00// (north latitude) and 91o48/00// (east longitude). Chemical pure calcium fluoride (CaF2) is used to study the effect of a mineralizing agent on the decomposition temperature of calcite in raw mix for obtaining cement clinker.
Experimental procedure
We used standard methods for taking and preparing samples. The mineral composition of raw materials was determined by X-Ray diffraction (XRD) and thermal analysis (TG/DTA); the chemical composition was determined by X-Ray fluorescence (XRF) analysis and calculation of cement raw mixture by Kinds method [1-3].
Results and discussion
Chemical composition of iron ores. The chemical composition of iron ores was determined by energy disperse X-ray fluorescence (ED-XRF) analysis. Table 1 shows that contents of iron oxide (Fe2O3) in the Western Mongolian iron ores such as "Kharganat", "Uvgundatsan", "Suul Khar" are higher than in "Tumurt" (№4) iron ore, which is presently used in cement production.
Table 1
Chemical composition of iron ores, %
Iron ores SiO2 AI2O3 Fe2O3 CaO Mn2O3 MgO SO3 Na2O K2O Loi Z
№1 7.07 1.02 89.29 0.53 - 0.15 1.02 1.02 0.01 - 100.11
№2 9.684 1.164 87.227 1.408 0.129 - - - - 1.18 99.995
№3 3.945 0.671 85.002 0.485 - 0.001 - 0.003 0.004 9.88 100.001
№4 8-20 0.5-4 58-74 1.8-6 - 3.5-7 2-7 8.5-20 0.5-3.6 2-7
№.1 "Kharganat" in Uvs aimag, №.2 "Uvgundatsan" in Khovd, №.3 "Suul Khar"in Khovd, №4 Tumurt
Mineral composition of iron ores. DTA/TG studies. The mineral composition of iron ores was investigated by TDA analysis. TG/TDA were undertaken. Derivatograph Q-1500, Hungary, thermo analyzer at a heating rate of 10oC/min using a-Al2O3 was used as a reference material. The results are shown in the Fig. 1-3.
1000сс
Fig. 1. DTA/TG curves of the "Kharganat" iron ore
From Fig. 1, we can see that:
1. A small amount of heat was emitted due to the water evaporation in p-limonite [P-FeOOH) as in the case of p-Fe2O3-H2O] at 210oC. At this point, sample weight was reduced by Am = -4.5 mg ~ 0.3% and it can be calculated from weight loss curve. Iron oxide in p-limonite amount to 2.67% [4].
2. Heat absorption was observed due to the y-iron oxide (y-Fe2O3) in lepidocrocite composition (y-FeOOH) as well as (y-Fe2O3-H2O) was transformed into a-hematite (a-Fe2O3) at 545oC. At this point, sample weight was reduced by Am = -3.0 mg ~ 0.2% and it can be calculated from weight loss curve. Iron oxide in lepidocrocite amount to 1.78%
3. Heat absorption occurred due to transformation of a-hematite into p-hematite at 725oC. In this transformation phase, sample weight increased by Am =19 mg ~ 1.27%. The reason is that, during the process of a-Fe2O3 to P-Fe2O3, density increases from 3.3 to 4.28 mg/cm3 [4].
Fig. 2. DTA/TG curves of the "Uvgundatsan" iron ore.
From Fig. 2, we can see that,
1. A small amount of heat was emitted due to the water evaporation in ß-limonite [ß-FeO(OH), as ß-Fe2O3-H2O] at the 220oC. At this point, sample weight was reduced by Am = -4 mg ~ 0.2% and it can be calculated from weight loss curve. Iron oxide in limonite amount to 1.87% [4].
2. Heat absorption was observed due to the ß-iron oxide (ß-Fe2O3) in lepidocrocite composition (y-FeOOH) as well as y-Fe2O3-H2O) transformed into a-hematite (a-Fe2O3) at 523oC. At this point, sample weight was reduced by Am = -3 mg ~ 0.15% and it can be calculated from weight loss curve. Iron oxide in lepidocrocite amount to 1.4% [4].
3. Heat absorption occurred due to the transformation of a-hematite into ß-hematite at 740oC. In this transformation phase, sample weight increased by Am =25 mg ~ 1.316%. The reason is that, during the process of a-Fe2O3 to ß-Fe2O3, density increased from 3.3 to 4.28 mg/cm3.
From Fig. 3, we can see that,
1. A deep endotherm peak was formed due to the hydro-hematite water evaporation at 310oC. At this point, sample weight was reduced by Am =110 mg ~ 7.38% and it can be calculated from weight loss curve. Iron oxide (Fe2O3) in hydro-hematite amount to 65.601% [4]
2. An exothermic effect occurred due to the process of y-Fe2O3 to a-Fe2O3 in magnetite composition at 570oC. In this transformation, sample weight reduced at m = -14 mg ~ 0.9395%. The reason is that, during the process sample density decreased from 4.28 to 3.3 mg/cm3.
B. Tserenkhand, R. Sanjaasuren, P. Solongo. Composition of some iron ores and possibility to use them in the cement production (western region of Mongolia)_
Fig. 3. DTA/TG curves of the"Suul Khar" iron ore.
X-ray studies. X-ray diffraction (XRD) analysis was conducted by DRON-2 tool with iron cathodes and voltage of X-ray tube on 30 kV, ampera at 20 mA, width of slot at 1x10/0,25x6. Spacing between diffracting, which was minerals set, were calculated using ASTM card and directory and results are shown in the Fig. 4-6.
Fig. 4 showed that there are high intensity diffraction lines of magnetite at d=2.53 Â, medium intensity magnetite lines at d=2.95; 2.09 A, medium and low intensity diffraction lines of hematite at d= 4.88; 3.68; 2.69; 2.205 A and low intensity diffraction line of goethite at d=3.34 A; as in Fig. 5, which is for "Uvgundatsan" iron ore, there high and medium intensity diffraction lines of magnetite at d=4.85, 2.97, 2.72, 2.53, 2.41, 2.09, 1.71, 1.61 A, low intensity diffraction lines of hematite at d=3.69, 2.72, 2.69, 2.31, 2.20, 1.86, 1.69 A, quartz lines at d=4.27, 2.28, 2.00 A low intensity diffraction lines at d=3.34 A; as in figure 6, which is for "Suul Khar" iron ore, high and medium intensity diffraction lines of magnetite at d=2.97, 2.51, 2.45A, medium and low intensity diffraction lines of hematite at d=3.69, 2.2, 2.58, 2.30, 2.20, 2.18 A, quartz lines at d=2.34, 2.25 A and low intensity diffraction line of goethite at d=4.20, 3.34 A etc, respectively [5].
Fig. 5. X-ray Diffractogram of "Uvgundatsan" iron ore
Fig. 6. X-ray Diffractogram of "Suul Khar" iron ore
The results of mineral analysis showed that iron ores of "Kharganat" and "Uvgundatsan" mostly contain magnetite (Fe3O4), whereas iron ore of "Suul Khar" - hematite (Fe2O3).
The research result of the effect of calcium fluoride on decomposition temperature of calcite in raw mix for cement production. Raw mix used in cement clinker production that consists of "Shokhoit" limestone, "Shal" clay and "Kharganat" iron ore was calculated by Kinds method. Silica module was n=2.2 while Saturation coefficients (SC) were at 0.83, 0.88 and 0.93 in this calculation. The results are shown in Table 3 and chemical composition of the initial materials [6] which are used to make raw mixes is shown in Table 2.
According to the result of raw material evaluation, it can be observed that amounts of iron ore in 100 kg cement are approximate for every saturation coefficient level and modules (Table 3), in clinker composition they are within the limit of Portland cement standard [7]. In conclusion, it could be assumed that these iron ores can be used in cement production.
Research was conducted as follows: Calcium fluoride at 0%, 0.5%, 1.0% and 1.5% of raw material weight were added to limestone of "Shokhoit", clay from "Shal" and iron ore of "Kharganat" at saturation coefficient of SC=0.93 and silica module at n=2.2 (Table 4). The effect of calcium fluoride on decomposition temperature of calcite in raw mix for obtaining cement we determined by DTA analysis. Result is shown in Fig. 7. From Fig. 7 shown, weak exothermic effect was observed due to the water evaporation of clay minerals in raw material composition at 325-185oC, deep endotherm peak was observed due to the decomposition of calcite (CaCO3), which is the main component of composition, at 865-870oC. The sample weight loss was 32.52% when calcium fluoride was not available, the loss was 33.4% when calcium fluoride was added 0.5% while it was 1.0% the loss was 32.78%, and when it was 1.5% the loss was 32.96%. From Fig. 7 we can see that, the decomposition temperature of calcite (CaCO3) was reduced by 5oC, 10oC, and 15oC when calcium fluoride (CaF2) in the raw mix for obtaining cement clinker that consists of "Shokhoit" limestone, "Shal" clay and "Kharganat" iron ore was added up to 0.5%, 1.0% and 1.5%.
Table 2
Chemical composition of raw material, %
Name of raw material SiO2 Al2O3 FeA CaO MgO SO3 Na2O K2O Mn2O3 other Loi Z
Limestone of Shokhoite 0.85 0.10 0.25 54.64 0.25 0.20 0.22 - - 0.62 42.87 100
Clay of Shal 58.33 15.4 3.12 5.13 3.58 0.222 2.7 2.89 - 0.298 8.33 100
Iron ore of Kharganat 7.07 1.02 89.29 0.53 0.15 1.02 1.02 0.01 - - 100.11
Iron ore of Uvguntsan 9.684 1.164 86.435 1.408 - - - - 0.129 1.18 100
Iron ore of Suul khar 3.945 0.671 85.002 0.485 0.001 0.003 0.004 - 9.89 100.001
Table 3
Composition and characteristics of mixes for obtaining cement clinkers
Mix Component content, (mass. %) SC Modules
Lime stone Clay Iron ore SM AM
A-1 73.90 23.98 2.23 0.83 2.2 1.3
A-2 75.17 23.05 2.15 0.88 2.2 1.29
A-3 75.73 22.20 2.07 0.93 2.2 1.31
B-1 73.80 23.86 2.32 0.83 2.2 1.29
B-2 74.80 23.86 2.24 0.88 2.2 1.29
B-3 75.77 22.11 2.16 0.93 2.2 1.25
C-1 73.66 24.02 2.32 0.83 2.2 1.29
C-2 74.65 23.11 2.23 0.88 2.2 1.26
C-3 75.60 22.26 2.15 0.93 2.2 1.3
Mix A was calculated from Kharganat iron ore. Mix B was calculated from Uvgudatsan iron ore. Mix C was calculated from Suulkhar iron ore
Table 4
Composition of raw mixes with addition CaF2
Mix Amount of mix, (m. %)
Amount of initial mix, (m. %) Addition CaF2, (m. %)
A-3a 100 =
A-3b 99.5 0.5
A-3c 99 1.0
A-3d 98.5 1.5
Б. Цэрэнханд, Б. Баяраа, Г. Долмаа. Химический и минералогический состав некоторых глин Убснурского аймака (Монголия)_
Conclusion
Based on the studies, the following conclusion can be drawn:
• The chemical investigation result showed that iron oxide (Fe2O3) in the Western Mongolian iron ores is contained in Uvgondatsan (in Khovd) - 87.23%, Suul khar (in Khovd) - 85.00% and Khargant (in Uvs) - 89.29%. Therefore, these iron ores can be used in cement production.
• X-ray diffraction and DTA analysis results show that iron ores of "Kharganat" and "Uvgundatsan" are mostly contained magnetite (Fe3O4) while iron ore of "Suul Khar" is mostly contained hematite (Fe2O3).
• A calculation of raw mix for obtaining cement clinker was done by using iron ores, clay of "Shal" and limestone of "Shokhoit", and calculated modules that from clinker compositoin (n=2.2 p=1.25-1.30) are within the limit of Portland cement standard.
• The decomposition temperature of calcite (CaCO3) was reduced by 5oC, 10oC, and 15oC when calcium fluoride (CaF2) in the raw mix for obtaining cement clinker that consists of "Shokhoit" limestone, "Shal" clay and "Kharganat" iron ore was added up 0.5%, 1.0% and 1.5%, respectively.
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3. Lotov V.A. Structure, properties of the cement raw mix preparation and properties of the Portland cement clinker. - Tomsk, 2006. - P. 2-7.
4. Sunjidmaa N. The characteristics of Mongolian Portland cement and the effect of some additives in it: diss. ... doc. of chemistry sciences. - Ulaanbaatar, 1997. - 268 p.
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6. Novenkov E.D., Gantsog Ts. General methods of X-ray analysis. - UB, 1987. - P. 72-73.
7. Kamenica F. Guide to X-ray examination of minerals. - L.: Nedra, 1975. - 159 p.
8. Tserenkhand B. Physical and chemical studies obtaining Portland cement at low temperature using by raw materials in Hovd aimag. - Erdenet: Khukhdel print, 2007. - P. 65-72.
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Tserenkhand B., candidate of chemical sciences, Depatment of Chemical Technology, School of Chemistryand Chemical Engineering, National University of Mongolia, e-mail: tseren_hand@yahoo.com
Sanjaasuren R., doctor of chemical sciences, professor, Rеsearch Center of Chemistry and Technology of New Materials, National University of Mongolia, e-mail: r_sanjaas@yahoo.com
Solongo P., postgraduate student, Depatment of Chemical Technology, School of Chemistry and Chemical Engineering, National University of Mongolia, e-mail: solongo_sun@yahoo.com
Цэренханд Б., кандидат химических наук, отделение химической технологии, школа химии и химической инженерии, национальный университет Монголии, e-mail: tseren_hand@yahoo.com
Санжaaсурен Р., доктор химических наук, профессор, научный центр химии и технологии новых материалов, национальный университет Монголии, e-mail: r_sanjaas@yahoo.com
Солонго П., аспирант, отделение химической технологии, школа химии и химической инженерии, национальный университет Монголии, e-mail: solongo_sun@yahoo.com
УДК 549 © Б. Цэрэнханд, Б. Баяраа, Г. Долмаа
ХИМИЧЕСКИЙ И МИНЕРАЛОГИЧЕСКИЙ СОСТАВ НЕКОТОРЫХ ГЛИН УБСНУРСКОГО АЙМАКА (МОНГОЛИЯ)
Исследован химический и минералогический состав глин (белая, желтая и красная глина) в районе Хартэрмэса Убснурского аймака. Полученные данные показывают, что глины относятся к полиминеральной группе. В результате химического исследования установлено, что белая глина (А1203 - 9,58%) является полукислой глиной по содержанию А1203, желтая содержит А1203 - 16,11% и красная (А1203 -14,29%).
Ключевые слова: глина, рентгенграмма, рентгенфлуоресценция, химический состав глин, микроэлементы
