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Use of boron waste as an additive in red bricks
Waste Management 24 (2004) 217–220 www.elsevier.com/locate/wasman
Use of boron waste as an additive in red bricks T. Uslua, A.I. Arolb,* a Black Sea Technical University, Mining Engineering Department, Trabzon, Turkey Middle East Technical University, Mining Engineering Department, Ankara 06531, Turkey
b
Accepted 9 January 2003
Abstract In boron mining and processing operations, large amounts of clay containing tailings have to be discarded. Being rich in boron, the tailings do not only cause economical loss but also pose serious environmental problems. Large areas have to be allocated for waste disposal. In order to alleviate this problem, the possibility of using clayey tailings from a borax concentrator in red brick manufacturing was investigated. Up to 30% by weight tailings addition was found to improve the brick quality. # 2003 Elsevier Ltd. All rights reserved.
1. Introduction Turkey has the largest known reserves of boron minerals in the world (http://minerals.usgs.gov/. A state owned company is the sole producer of boron minerals. The major mining method is open pit mining, underground mining being practiced in two mines. Run-ofmine ores are enriched by selective crushing, attrition scrubbing and classifying. Concentrates are either directly marketed or treated to produce refined products, namely decahydrate, pentahydrate, perborate and boric acid. Kirka Borax Enterprises in Eskisehir, Turkey, to the west of Ankara, has both the concentration and the refining facilities to treat tincal, natural borax, a sodium borate mineral. As much as 400 000 tpy waste is produced as a result of these operations. The waste is mainly composed of clay minerals; montmorillonite, vermiculite, illite and chlorite and contain up to 15–20% B203 (Ataman and Baysal, 1978). Presently, this waste is collected in tailings dams. Although boron is a known micro nutrient, higher concentrations are reported to be deleterious for plants (Levinskas, 1964) and materials with high boron concentration should be considered a pollutant. In order to alleviate the pollution problem at borax plants, several attempts have been made to handle or use this waste in different ways (O¨zcan
et al., 1986; C¸ebi et al., 1994; Ediz and O¨zdagˇ, 1995; Boncukogˇlu et al, 1999; Yakar et al., 1999). It is well known that borax is a good fluxing agent. It combines with silica and alkalis to form a glassy structure and lower the melting temperature, leading to a stronger body upon solidification (Frederick and Lawrence, 1975; Smith, 1985). The fluxing characteristics of borates have been extensively exploited in ceramic and glass making (Lacource and Stevens, 1978; Prewo, 1989). The waste material of boron mines contains both the clay minerals, the main raw material of brick production and boron compounds, the fluxing agent. Hence, it was thought that using this waste in the production of red bricks will not only remedy the environmental problems associated with it but also might improve the quality of bricks and/or lower the firing temperature leading to cost cuts. In fact, use of wastes from different origins in brick manufacturing has lately attracted some attention (Ediz and O¨zdagˇ, 1995; Nishigaki, 2000; Tu¨tu¨nlu¨ and Atalay 2001; Hamer and Karius, 2002). Ediz and O¨zdagˇ (1995) carried out a similar study to the present one. However, as they added higher ratios of the tailings clay, 80% and above, they obtained rough surfaces as a result of melting of borax. In this study, emphasis is placed on lower addition levels of borax tailings.
2. Materials and methods * Corresponding author. Tel.: +90-312-210-2660; fax: +90-312210-1265. E-mail address: [email protected] (A.I. Arol). 0956-053X/03/$ - see front matter # 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0956-053X(03)00031-X
The tailings clay sample was taken from the tailings pond of Kirka Borax Enterprises. The brick clay sample
218
T. Uslu, A.I. Arol / Waste Management 24 (2004) 217–220
was obtained from a local brick maker in Eskisehir, Turkey. The main constituents of the two samples are given in Table 1. Rather high B2O3 content of the tailings clays can be observed in the table. Bricks were molded in cylindrical molds of 26 mm inner diameter and 38.8 mm length using a press, under a load of 350 kg/cm2. Composition of the bricks was adjusted to contain 0, 10, 20, 30,40, and l00% by weight tailings clays. The mixture was first made into a doughy mud by bringing its water content to around 20%. After molding, the specimens were left to dry in the atmosphere for 1 week followed by oven drying at 100 C for 24 h. The bricks were marked properly for shrinkage determinations. Dried bricks of each composition were fired in a metallurgical furnace at 700, 800 and 900 C for 4.5 h. The heating rate of the furnace was as follows: from room to 200 C 75 min, 200–400 C 120 min, 400– 600 C 120 min, 600–700 C 60 min, 700–800 C 60 min, and 800–900 C 60 min. The fired bricks were slowly cooled in the furnace closed overnight, visually examined for color and appearance, and tested for their compressive strength using a Tinius Olsen test machine of 200 t capacity at 5–6 kg/cm2 loading rate. The bricks with the better compressive strength, color and appearance were subjected to water adsorption, frost resistance, and harmful magnesia and lime tests. ASTM C67-92a (1992), TSE 705 (1979), TSE 4790 (1986) standard tests or modified versions of these tests were used in determining the mentioned qualities of the bricks (Uslu, 1996).
pressive strength tests and to visual observation for color and appearance. Then, the bricks with comparable compressive strength, color and appearance to that of reference bricks were subjected to other tests. In commercial brick manufacturing the firing temperature is usually 900 C. Therefore, the bricks with 0% tailings clay addition (100% brick clay) fired at 900 C were considered as the reference brick. The results of the compressive strength, color and appearance tests are given in Table 2. As seen in Table 2, compressive strength of the reference brick was found 211.70 kg/cm2. At 900 C firing temperature, addition of tailings clays up to 30% caused an increase in the compressive strength of bricks without affecting appearance. However, the color of the bricks changed from dark red to brown. At 40% tailings clays addition level, compressive strength of the bricks started to decrease, the surface of the bricks became rough. Bricks made of l00% tailings clays melted at 900 C producing a white amorphous mass. In order to determine the possibility of lowering the firing temperature to save energy and cut costs in brick manufacturing, bricks with the same compositions as Table 2 Compressive strength, color and appearance of bricks made with different addition levels of tailings clays Tailings clays addition (%) 0
3. Results and discussion The quality of bricks is usually determined on the basis of compressive strength, color, appearance, drying and firing shrinkage, water adsorption, frost resistance, and harmful magnesia and lime presence. In this study, the main aim was to compare the bricks made of all brick clay and with those made with tailings clay addition. A two step procedure was followed: First all the bricks with different compositions were fired at 700, 800, and 900 C. These bricks were subjected to com-
10
20
30 Table 1 Main constituents of tailings clay and brick clay Constituent (%)
Tailings clay
Brick clay
B2O3 SiO2 Al2O3 Fe2O3 CaO MgO K2O Na2O LOI
8.15 18.74 3.24 0.47 21.85 16.63 0.33 6.83 22.83
Trace 41.43 4.17 7.64 10.77 6.27 N/A N/A 27.01
40
100
Tested quality
Comp. strength (kg/cm2) Appearance Color Comp. Strength (kg/cm2) Appearance Color Comp. strength (kg/cm2) Appearance Color Comp. strength (kg/cm2) Appearance Color Comp. strength (kg/cm2) Appearance Color Comp. strength (kg/cm2) Appearance Color
Firing temperatures ( C) 700
800
900
171
192
212
Smooth Brown
Smooth Pale red
Smooth Dark red
174
194
213
Smooth Red
Smooth Red
Smooth Pale red
184
192
219
Smooth Pale red
Smooth Pale red
Smooth Pale red
189
204
229
Smooth Brown
Smooth Brown
Smooth Brown
164
172
205
Rough Yellowish
Rough Yellowish
Rough Yellowish
Cracked upon firing Rough Whitish
Cracked upon firing Rough Whitish
Melted upon firing Rough Whitish
219
T. Uslu, A.I. Arol / Waste Management 24 (2004) 217–220 Table 3 Shrinkage, water adsorption, density, frost resistance and harmful magnesia and lime of bricks Firing temp. ( C)
Tailings clay (%)
Drying shrinkage (%)
Firing shrinkage (%)
Water adsorption (%)
Density (kg/m3)
Frost resistance
Harmful magnesia and lime
900 900 800 700
0 30 30 30
6.35
0.41 2.24 2.16 1.90
16.59 14.38 15.23 16.39
1863 1743 1707 1702
Good Good Good Good
None None None None
8.81
for 900 C were fired at 700 and 800 C. At 700 C firing temperature, compressive strengths of the bricks were substantially lower than those of the bricks fired at 900 C. However, addition of tailings clays up to 30% improved the compressive strength. Similar trends were observed for the bricks fired at 800 C. Appearances and colors of the bricks were acceptable. Higher than 30% tailings clays addition caused a decrease in the compressive strength of the bricks fired at all temperatures. Bricks made of 100% tailings clays had rough surfaces, whitish color and cracked upon firing at 700 and 800 C. These tests indicted that bricks with 30% tailings clays addition could be produced with a favorable effect on the compressive strength and with no adverse affect on color and appearance. Therefore, bricks with 30% tailings clay addition fired at 700, 800, and 900 C were subjected to water adsorption, frost resistance, harmful magnesia and lime tests. The results of these tests are tabulated in Table 3. Drying and firing shrinkages and density of the bricks are also included in the table. No damage was observed on any bricks under study as a result of frost resistance, harmful magnesia and lime tests. Drying and firing shrinkages of the bricks with no tailings clay addition were 6.35 and 0.41%, respectively. Drying shrinkage increased to 8.80 with 30% tailings clay addition without any damage to the shape of the bricks: firing shrinkages were found to be 1.90% for 700 C, 2.16% for 800 C, and 2.24% for 900 C firing temperatures. This indicates that presence of boron in the mixed facilitated glassy mass formation which caused higher firing shrinkage. This finding is also substantiated by water adsorption tests which revealed that water adsorption of the bricks fired at 900 C were higher, 16.59%, with no tailings clay addition than bricks with tailings clay addition which had a water adsorption value of 14.38%, showing that glassy mass formation might have filled or blocked the pores and hence lowered water adsorption. Water adsorption values of the bricks with 30% tailings clay fired at 700 and 800 C were also found to be less than with no tailings clay addition, indicating an improvement in brick quality.
4. Conclusion Tailings clay of Kirka Borax Plant, rich in boron compounds, was tested to determine if this material can be used as an additive in red brick manufacturing. It was found that addition of this material up to 30% improved the brick quality with regard to compressive strength, water adsorption and density without compromising on other qualities. It was also found that firing temperatures lower than of 900 C (generally practiced firing temperature in red brick production) could yield bricks with acceptable qualities if tailings clay is used as an additive in brick manufacturing. An industrial scale investigation as well as a more detailed study of the mechanism underlying the findings of this study are needed to establish the tailings as a viable additive in red brick production.
References ASTM C67-92a, 1992. Standard Test Methods of Sampling and Testing Brick and Structural Clay Tile. Ataman, G., Baysal, O., 1978. Clay mineralogy of Turkish borate deposits. Chem. Geol 22, 233–247. Boncukc¸uogˇlu, R., Kocakerim, M.M., Erc¸ahan, H., 1999. Upgrading of the reactor waste obtained during borax production from tincal. Minerals Engineering 12 (10), 1275–1280. C¸ebi, H., Yersel, E., Poslu, K., Behar, A., Nesner, R., Langerbrick, H., 1994, Solid–liquid separation of Etibank Kırka Borax Plant effluents by centrifugal decantor. In: (Eds.), Demirel and Ersayın, Balkema, Progess in Mineral Processing Technology. pp. 513–516. Ediz, N., O¨zdagˇ, H., 1995. An investigation into the possible use of Kirka Borax Plant Tailings in brick making. Madencilik 34 (4), 27–34. Frederick, V., Lawrence, J.R., 1975. Fluxes. In: Stanley, J.L. (Ed.), Industrial Minerals and Rocks. AIME, New York, pp. 251–262. Hamer, K., Karius, V., 2002. Brick production with dredged harbour sediments. An industrial scale experiment. Waste Management 22 (5), 521–530. Lacource, W.C., Stevens, H.C., 1978. Properties of silica glasses containing small amounts of B2O3. In: Pye, L.D., Fre´chette, V.D., Kreı`c, N.J. (Eds.), Borate Glasses: Structure, Properties, Applications, Material Science Research, vol. 12. Plenum Press, New York, pp. 541–542. Levinkas, G.J., 1964. Toxicology of boron compounds. In: Adams, R.M. (Ed.), Boron, Metallo-Boron Compounds and Boranes. Interscience Publishers, New York. (Chapter 8).
220
T. Uslu, A.I. Arol / Waste Management 24 (2004) 217–220
Nishigaki, M., 2000. Producing permeable blocks nd pavement bricks from molten slag. Waste Management 20 (2–3), 185–192. O¨zcan, E., Bayat, C., Zeki, A., 1986. Study of condition for the manufacture of raw borax, boric acid and perborate from Etibank Borax Plant wastes. Kimya ve Sanayi 30 (147–148), 89–99. Prewo, K.M., 1989. Fiber reinforced glasses and glass ceramics. In: Lewis, M.H. (Ed.), Glasses and Glass Ceramics. Chapman and Hall, London. Smith, R.A., 1985. Boric oxide, boric acid, and borates. Ullman’s Encyclopedia of Industrial Chemistry 4, 263–280. TSE 705, 1979. Standard Test Method for Solid Bricks and Vertically Perforated Bricks. Turkish Standards Institute, Ankara, Turkey.
TSE 4790, 1986. Standard Test Method for Common Bricks and Roofing Tile Clays. Turkish Standards Institute, Ankara, Turkey. Tu¨tu¨nlu¨, F., Atalay, M.U¨., 2001. Fly ash utilization in manufacturing of bricks, New Developments in Mineral Processing. In: O¨nal et al. (Eds.), Proceedings of IX. Balkan Mineral Processing Symposium, 11–13 September, Istanbul, pp. 677–680. Uslu, T., 1996. Usability of Borax Tailings in Building Bricks as an Additive. MSc Thesis, Middle East Technical University Mining Engineering Department, Ankara, Turkey. Yakar, I., Gulen, J., Ozbek, E., Piskin, S., 1999. Evaluation of solid wastes containing boron in cement industry. In: Proceedings of the International Conference on Solid Waste Technology and Management, Philadelphia, USA, 12–15 December, pp. 276–282.
Use of boron waste as an additive in red bricks T. Uslua, A.I. Arolb,* a Black Sea Technical University, Mining Engineering Department, Trabzon, Turkey Middle East Technical University, Mining Engineering Department, Ankara 06531, Turkey
b
Accepted 9 January 2003
Abstract In boron mining and processing operations, large amounts of clay containing tailings have to be discarded. Being rich in boron, the tailings do not only cause economical loss but also pose serious environmental problems. Large areas have to be allocated for waste disposal. In order to alleviate this problem, the possibility of using clayey tailings from a borax concentrator in red brick manufacturing was investigated. Up to 30% by weight tailings addition was found to improve the brick quality. # 2003 Elsevier Ltd. All rights reserved.
1. Introduction Turkey has the largest known reserves of boron minerals in the world (http://minerals.usgs.gov/. A state owned company is the sole producer of boron minerals. The major mining method is open pit mining, underground mining being practiced in two mines. Run-ofmine ores are enriched by selective crushing, attrition scrubbing and classifying. Concentrates are either directly marketed or treated to produce refined products, namely decahydrate, pentahydrate, perborate and boric acid. Kirka Borax Enterprises in Eskisehir, Turkey, to the west of Ankara, has both the concentration and the refining facilities to treat tincal, natural borax, a sodium borate mineral. As much as 400 000 tpy waste is produced as a result of these operations. The waste is mainly composed of clay minerals; montmorillonite, vermiculite, illite and chlorite and contain up to 15–20% B203 (Ataman and Baysal, 1978). Presently, this waste is collected in tailings dams. Although boron is a known micro nutrient, higher concentrations are reported to be deleterious for plants (Levinskas, 1964) and materials with high boron concentration should be considered a pollutant. In order to alleviate the pollution problem at borax plants, several attempts have been made to handle or use this waste in different ways (O¨zcan
et al., 1986; C¸ebi et al., 1994; Ediz and O¨zdagˇ, 1995; Boncukogˇlu et al, 1999; Yakar et al., 1999). It is well known that borax is a good fluxing agent. It combines with silica and alkalis to form a glassy structure and lower the melting temperature, leading to a stronger body upon solidification (Frederick and Lawrence, 1975; Smith, 1985). The fluxing characteristics of borates have been extensively exploited in ceramic and glass making (Lacource and Stevens, 1978; Prewo, 1989). The waste material of boron mines contains both the clay minerals, the main raw material of brick production and boron compounds, the fluxing agent. Hence, it was thought that using this waste in the production of red bricks will not only remedy the environmental problems associated with it but also might improve the quality of bricks and/or lower the firing temperature leading to cost cuts. In fact, use of wastes from different origins in brick manufacturing has lately attracted some attention (Ediz and O¨zdagˇ, 1995; Nishigaki, 2000; Tu¨tu¨nlu¨ and Atalay 2001; Hamer and Karius, 2002). Ediz and O¨zdagˇ (1995) carried out a similar study to the present one. However, as they added higher ratios of the tailings clay, 80% and above, they obtained rough surfaces as a result of melting of borax. In this study, emphasis is placed on lower addition levels of borax tailings.
2. Materials and methods * Corresponding author. Tel.: +90-312-210-2660; fax: +90-312210-1265. E-mail address: [email protected] (A.I. Arol). 0956-053X/03/$ - see front matter # 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0956-053X(03)00031-X
The tailings clay sample was taken from the tailings pond of Kirka Borax Enterprises. The brick clay sample
218
T. Uslu, A.I. Arol / Waste Management 24 (2004) 217–220
was obtained from a local brick maker in Eskisehir, Turkey. The main constituents of the two samples are given in Table 1. Rather high B2O3 content of the tailings clays can be observed in the table. Bricks were molded in cylindrical molds of 26 mm inner diameter and 38.8 mm length using a press, under a load of 350 kg/cm2. Composition of the bricks was adjusted to contain 0, 10, 20, 30,40, and l00% by weight tailings clays. The mixture was first made into a doughy mud by bringing its water content to around 20%. After molding, the specimens were left to dry in the atmosphere for 1 week followed by oven drying at 100 C for 24 h. The bricks were marked properly for shrinkage determinations. Dried bricks of each composition were fired in a metallurgical furnace at 700, 800 and 900 C for 4.5 h. The heating rate of the furnace was as follows: from room to 200 C 75 min, 200–400 C 120 min, 400– 600 C 120 min, 600–700 C 60 min, 700–800 C 60 min, and 800–900 C 60 min. The fired bricks were slowly cooled in the furnace closed overnight, visually examined for color and appearance, and tested for their compressive strength using a Tinius Olsen test machine of 200 t capacity at 5–6 kg/cm2 loading rate. The bricks with the better compressive strength, color and appearance were subjected to water adsorption, frost resistance, and harmful magnesia and lime tests. ASTM C67-92a (1992), TSE 705 (1979), TSE 4790 (1986) standard tests or modified versions of these tests were used in determining the mentioned qualities of the bricks (Uslu, 1996).
pressive strength tests and to visual observation for color and appearance. Then, the bricks with comparable compressive strength, color and appearance to that of reference bricks were subjected to other tests. In commercial brick manufacturing the firing temperature is usually 900 C. Therefore, the bricks with 0% tailings clay addition (100% brick clay) fired at 900 C were considered as the reference brick. The results of the compressive strength, color and appearance tests are given in Table 2. As seen in Table 2, compressive strength of the reference brick was found 211.70 kg/cm2. At 900 C firing temperature, addition of tailings clays up to 30% caused an increase in the compressive strength of bricks without affecting appearance. However, the color of the bricks changed from dark red to brown. At 40% tailings clays addition level, compressive strength of the bricks started to decrease, the surface of the bricks became rough. Bricks made of l00% tailings clays melted at 900 C producing a white amorphous mass. In order to determine the possibility of lowering the firing temperature to save energy and cut costs in brick manufacturing, bricks with the same compositions as Table 2 Compressive strength, color and appearance of bricks made with different addition levels of tailings clays Tailings clays addition (%) 0
3. Results and discussion The quality of bricks is usually determined on the basis of compressive strength, color, appearance, drying and firing shrinkage, water adsorption, frost resistance, and harmful magnesia and lime presence. In this study, the main aim was to compare the bricks made of all brick clay and with those made with tailings clay addition. A two step procedure was followed: First all the bricks with different compositions were fired at 700, 800, and 900 C. These bricks were subjected to com-
10
20
30 Table 1 Main constituents of tailings clay and brick clay Constituent (%)
Tailings clay
Brick clay
B2O3 SiO2 Al2O3 Fe2O3 CaO MgO K2O Na2O LOI
8.15 18.74 3.24 0.47 21.85 16.63 0.33 6.83 22.83
Trace 41.43 4.17 7.64 10.77 6.27 N/A N/A 27.01
40
100
Tested quality
Comp. strength (kg/cm2) Appearance Color Comp. Strength (kg/cm2) Appearance Color Comp. strength (kg/cm2) Appearance Color Comp. strength (kg/cm2) Appearance Color Comp. strength (kg/cm2) Appearance Color Comp. strength (kg/cm2) Appearance Color
Firing temperatures ( C) 700
800
900
171
192
212
Smooth Brown
Smooth Pale red
Smooth Dark red
174
194
213
Smooth Red
Smooth Red
Smooth Pale red
184
192
219
Smooth Pale red
Smooth Pale red
Smooth Pale red
189
204
229
Smooth Brown
Smooth Brown
Smooth Brown
164
172
205
Rough Yellowish
Rough Yellowish
Rough Yellowish
Cracked upon firing Rough Whitish
Cracked upon firing Rough Whitish
Melted upon firing Rough Whitish
219
T. Uslu, A.I. Arol / Waste Management 24 (2004) 217–220 Table 3 Shrinkage, water adsorption, density, frost resistance and harmful magnesia and lime of bricks Firing temp. ( C)
Tailings clay (%)
Drying shrinkage (%)
Firing shrinkage (%)
Water adsorption (%)
Density (kg/m3)
Frost resistance
Harmful magnesia and lime
900 900 800 700
0 30 30 30
6.35
0.41 2.24 2.16 1.90
16.59 14.38 15.23 16.39
1863 1743 1707 1702
Good Good Good Good
None None None None
8.81
for 900 C were fired at 700 and 800 C. At 700 C firing temperature, compressive strengths of the bricks were substantially lower than those of the bricks fired at 900 C. However, addition of tailings clays up to 30% improved the compressive strength. Similar trends were observed for the bricks fired at 800 C. Appearances and colors of the bricks were acceptable. Higher than 30% tailings clays addition caused a decrease in the compressive strength of the bricks fired at all temperatures. Bricks made of 100% tailings clays had rough surfaces, whitish color and cracked upon firing at 700 and 800 C. These tests indicted that bricks with 30% tailings clays addition could be produced with a favorable effect on the compressive strength and with no adverse affect on color and appearance. Therefore, bricks with 30% tailings clay addition fired at 700, 800, and 900 C were subjected to water adsorption, frost resistance, harmful magnesia and lime tests. The results of these tests are tabulated in Table 3. Drying and firing shrinkages and density of the bricks are also included in the table. No damage was observed on any bricks under study as a result of frost resistance, harmful magnesia and lime tests. Drying and firing shrinkages of the bricks with no tailings clay addition were 6.35 and 0.41%, respectively. Drying shrinkage increased to 8.80 with 30% tailings clay addition without any damage to the shape of the bricks: firing shrinkages were found to be 1.90% for 700 C, 2.16% for 800 C, and 2.24% for 900 C firing temperatures. This indicates that presence of boron in the mixed facilitated glassy mass formation which caused higher firing shrinkage. This finding is also substantiated by water adsorption tests which revealed that water adsorption of the bricks fired at 900 C were higher, 16.59%, with no tailings clay addition than bricks with tailings clay addition which had a water adsorption value of 14.38%, showing that glassy mass formation might have filled or blocked the pores and hence lowered water adsorption. Water adsorption values of the bricks with 30% tailings clay fired at 700 and 800 C were also found to be less than with no tailings clay addition, indicating an improvement in brick quality.
4. Conclusion Tailings clay of Kirka Borax Plant, rich in boron compounds, was tested to determine if this material can be used as an additive in red brick manufacturing. It was found that addition of this material up to 30% improved the brick quality with regard to compressive strength, water adsorption and density without compromising on other qualities. It was also found that firing temperatures lower than of 900 C (generally practiced firing temperature in red brick production) could yield bricks with acceptable qualities if tailings clay is used as an additive in brick manufacturing. An industrial scale investigation as well as a more detailed study of the mechanism underlying the findings of this study are needed to establish the tailings as a viable additive in red brick production.
References ASTM C67-92a, 1992. Standard Test Methods of Sampling and Testing Brick and Structural Clay Tile. Ataman, G., Baysal, O., 1978. Clay mineralogy of Turkish borate deposits. Chem. Geol 22, 233–247. Boncukc¸uogˇlu, R., Kocakerim, M.M., Erc¸ahan, H., 1999. Upgrading of the reactor waste obtained during borax production from tincal. Minerals Engineering 12 (10), 1275–1280. C¸ebi, H., Yersel, E., Poslu, K., Behar, A., Nesner, R., Langerbrick, H., 1994, Solid–liquid separation of Etibank Kırka Borax Plant effluents by centrifugal decantor. In: (Eds.), Demirel and Ersayın, Balkema, Progess in Mineral Processing Technology. pp. 513–516. Ediz, N., O¨zdagˇ, H., 1995. An investigation into the possible use of Kirka Borax Plant Tailings in brick making. Madencilik 34 (4), 27–34. Frederick, V., Lawrence, J.R., 1975. Fluxes. In: Stanley, J.L. (Ed.), Industrial Minerals and Rocks. AIME, New York, pp. 251–262. Hamer, K., Karius, V., 2002. Brick production with dredged harbour sediments. An industrial scale experiment. Waste Management 22 (5), 521–530. Lacource, W.C., Stevens, H.C., 1978. Properties of silica glasses containing small amounts of B2O3. In: Pye, L.D., Fre´chette, V.D., Kreı`c, N.J. (Eds.), Borate Glasses: Structure, Properties, Applications, Material Science Research, vol. 12. Plenum Press, New York, pp. 541–542. Levinkas, G.J., 1964. Toxicology of boron compounds. In: Adams, R.M. (Ed.), Boron, Metallo-Boron Compounds and Boranes. Interscience Publishers, New York. (Chapter 8).
220
T. Uslu, A.I. Arol / Waste Management 24 (2004) 217–220
Nishigaki, M., 2000. Producing permeable blocks nd pavement bricks from molten slag. Waste Management 20 (2–3), 185–192. O¨zcan, E., Bayat, C., Zeki, A., 1986. Study of condition for the manufacture of raw borax, boric acid and perborate from Etibank Borax Plant wastes. Kimya ve Sanayi 30 (147–148), 89–99. Prewo, K.M., 1989. Fiber reinforced glasses and glass ceramics. In: Lewis, M.H. (Ed.), Glasses and Glass Ceramics. Chapman and Hall, London. Smith, R.A., 1985. Boric oxide, boric acid, and borates. Ullman’s Encyclopedia of Industrial Chemistry 4, 263–280. TSE 705, 1979. Standard Test Method for Solid Bricks and Vertically Perforated Bricks. Turkish Standards Institute, Ankara, Turkey.
TSE 4790, 1986. Standard Test Method for Common Bricks and Roofing Tile Clays. Turkish Standards Institute, Ankara, Turkey. Tu¨tu¨nlu¨, F., Atalay, M.U¨., 2001. Fly ash utilization in manufacturing of bricks, New Developments in Mineral Processing. In: O¨nal et al. (Eds.), Proceedings of IX. Balkan Mineral Processing Symposium, 11–13 September, Istanbul, pp. 677–680. Uslu, T., 1996. Usability of Borax Tailings in Building Bricks as an Additive. MSc Thesis, Middle East Technical University Mining Engineering Department, Ankara, Turkey. Yakar, I., Gulen, J., Ozbek, E., Piskin, S., 1999. Evaluation of solid wastes containing boron in cement industry. In: Proceedings of the International Conference on Solid Waste Technology and Management, Philadelphia, USA, 12–15 December, pp. 276–282.