Replacing Coal by Tire Powder in Ceramic Industry. C. G. Mothé*, H. F. Mothé Filho**

Transcription

1 Replacing Coal by Tire Powder in Ceramic Industry C. G. Mothé*, H. F. Mothé Filho** * Departamento de Processos Orgânicos, Escola de Química/CT/UFRJ, CEP , Rio de Janeiro, RJ, Brazil, cheila@eq.ufrj.br, cgmothe@openlink.com.br. ** Departamento de Geociências, Instituto de Agronomia/UFRRJ, CEP , Seropédica, RJ, Brazil, hmothe@openlink.com.br. Abstract Nowadays preserving nature, recycling or reusing materials are good policy. Around ten million tires are put out by year in Brazil, and it is not known for how long they will remain in environment till their complete its degradation. This research used old tire to replace coal in ceramic processing, this way it helps to protect environment, reduce the consume of minerals deposits and saving money. The results show that tire powder can replace coal to get ceramic material, using one percent of them. Experiments were carried out in TA instruments SDT 2960, in air or nitrogen atmospheres, at heating rate of 10ºC/min., flow 120ml/min. TG/DTA curves of tire and coal have exothermic events at closing temperature, they are near endothermic event of clay, between ºC. Keywords: Recycle; Coal; Tire; Ceramic.

2 Introduction Minerals deposits are drainable, not renewable 1, then they need to be used in a best way. If they can be replace for different material, it must be done. Nowadays some ceramic industries are using about 1% of coal 2 to produce bricks. Industries are saving money because they reduce almost 40% of woods when they put together coal in ceramic process. This research investigated if tire powder can replace coal, because coal is an important source of energy, especially to carbon s chemistry. Rio de Janeiro produced about 8 million/ton of common and ball clay 3 in 2001; if 10% of them, were used to obtain bricks and tiles with 1% of coal, it will be consumed 8 thousand/ton and spent $800, Over ten million of tire carcass are put out each year, in Brazil 4, and they can remain on environment for very long time, and they will become an environmental and economical problem. Old tires can be used as a new source of hydrocarbons, they are made up with fifty materials and the main components are natural rubbers, styrene-butadiene rubber, poly-butadiene rubber, carbon black, oils and catalysts. Tire is a vital component of any national economy and in general, the automobile industry often accounts for a major percentage of tire production. Tire can be found on rivers, lagoons, grounds, and beaches. The resolution number 238/99 of CONAMA (Comissão Nacional do Meio-Ambiente, brazilian agency for environment), determines that in 2004 one tire made, one tire recycled 5. The main objective of this paper is to know if tire can be used to make ceramic material, like brick, by using differential thermal analysis and gravimetric thermal analysis, and predicting process condition such as sintering, temperature, and heating rate. Rio de Janeiro state has two principal ceramic centers 6, Itaborai and Campos dos Goytacazes, and three others, Paraiba do Sul, Volta Redonda and Baixada Fluminense 7, all of them are close to metropolis, so recycle of tire can be more easy. Just Itaborai used 1,500 m 3 of woods/m in

3 Experimental Clay and Tire The clay was dried in room temperature during one week, mechanically separate. The material passed in 250 mesh was used in analysis. The X ray from clay was carry out on Rigaku-Thermoflex The clay is from Seropédica/RJ, it is ball clay with kaolin and gibbsite. The tire was common, and it was used in a popular car. It was milled until to passing 250 mesh. Samples preparation The samples with 2 g of clay were used to XRF, and with 40 g of clay to XRD, with 12 mg of clay and 5,0 mg of tire were to Thermal Analysis. The samples of tire with 5 mg were used to Thermal Analysis. X Ray Diffraction and X Ray Fluorescence The XRD, figure 1, was carried out on Rigaku-Thermoflex, 2013, 40Kv, 30mA, Cu tube, Ni filter, and rate of 1º/min. The XRF, table 1, was carried out on Phillips, PW 2400, and software Super Q. The specimens had a disc geometry, and size corrected for a 30 mm diameter, and were molded in a Carver press at room temperature and 3 ton. TG/DTG/DTA/DSC measurements Thermal behavior was measured on a TA Instruments SDT 2960 at heating rate of 10, 12, 14, 16 and 18ºC/min. in air atmosphere, over the temperature range from 25 to 800ºC or

4 1000ºC to TG and DTA for clay and composites, figures 2 and 3. TG/DTA curves of tire, figure 4, was performed at heating rate of 10ºC/min., air atmosphere and flow of 120 ml/min and over temperature range from 25 to 600ºC. DSC curves were carried out Mettler Toledo instruments, Star System, 822 model Demo Version, at heating rate 10ºC/min., in air atmosphere, room temperature until 480ºC. Results and Discussion Analyse of the clay by XRD, figure 1, shows kaolinite, gibbsite, hydromica, and illite/smectite interstratification. XR Fluorescence shows, table 1, high quantity of Si and Al, medium of Fe, K, Mg and Ti, and low P, Ca, Mn and Zi, and very low Ba, Cl, Cr, Na, Sr. Figure 2 shows TG curves for clay in air atmosphere, with three decomposition stages. Water loss ( 2%) in the first stage at 100ºC, the second at 280ºC loss of hydroxyl ( 1%) of gibbsite, and in the third decomposition range 480 to 550ºC, weight loss of hydroxyl of kaolinite and illite ( 10%) to pure clay. Clay with 1 and 3% of tires show de same decomposition but they have more weight loss than pure clay. Loss of ignition of clays with tires are bigger than pure clay at 1000ºC. Pure clay loss 15%, and clay with 1 and 3% of tire loss 17 and 18%, respectively. Figure 3 shows DTA curves of pure clay and composites. All curves have the same events, the first at 280ºC, endothermic event, loss of hydroxyl of gibbsite and the second loss of hydroxyl of kaolinite and illite. Curves of composite, with tire, show less H than pure clay, and it was understood like tire energy liberation during burn out. Figure 4 illustrates a DSC/Derivative DSC curves of pure clay. They show two changes of base line, around 130 and 410ºC, and two endothermic events, around 150 and 330ºC, water loss and loss of hydroxyl, respectively.

5 Figure 5 illustrates a tire sample TG and DTA curves. TG curve shows three steps that correspond its decomposition, first at 280ºC to volatile, second at 480ºC to rubber and the last at 550ºC to carbon black. The DTA curve shows three exothermic events at 280, 480 and 550ºC. Figure 6 shows curves DTA of coal and powder tire, both in air and nitrogen atmosphere. The exothermic events are intense in air atmosphere, and do not happen in N 2 atmosphere, if the curves are compared. Both coal and tire have same range of temperature for release energy, they burn out around temperature that clays produce principal endothermic event. Air atmosphere coal degradation is more fast 8. Conclusion Powder tire can replace coal to obtain ceramic material. Both of them supply energy at same temperature that clay consumes it. H values obtained, for pure clay or with tire, are too close, and the weight loss between them indicates that is possible to use it without damaging the ceramic process. If Itaborai ceramic center uses tire, it could save about $ 50, by year in woods, and $ 180, for not buying coal. Acknowledgement The author CGM wishes to thank CNPq for financial support. References (1) Abreu, S. F., Recursos Minerais do Brasil, Editora Edgard Blucher Ltda., SP. p. 2-3, (2) Consulta Técnica a Cerâmica Santo Antônio, Seropédica/RJ, março (3) Anuário Mineral Brasileiro, Argila, p , 2001.

6 (4) Mothé, C. G., Carelli, A. C. & Mothé Filho, H. F., Procceding of the 46 th Annual Meeting of the Brazilian Ceramic Society, 2002, ref (5) Ferro, F., Plástico Moderno, 329 ( 2002 ) 37. (6) Motta, J. F. M., Zanardo, A. & Cabral Jr. M., Cerâmica Industrial, 6 (2) (7) Rocha, R. L. S. & Alves, J. N., Anais do I Encontro de Economia Mineral da Região Sudeste/UFRRJ, p. 16, setembro/1994. ( 8) Serageldin M. A. & Pan, W. P., Thermochimi. Acta, 76 (1984) 145.

7 Legend: C = Kaolinite, Gb = Gibbsite, I-E = Illite/ Smectite interstratification, and HM = Hydromica. Figure 1: XRD of clay from Guandu river basin. Table 1: Chemical analysis (titration) of clay from Guandu river basin. Element Percentage SiO Al 2 O Fe 2 O K 2 O 1.73 MgO 1.60 TiO CaO 0.37 SO P 2 O

8 Figure 2: Curves TG s of clay, and clay with 1 and 3% of tire. Figure 3: DTA tests on clay, and clay with 1 and 3% of tire.

9 Figure 4: DSC/DDSC curves of clay in air atmosphere. Figure 5: Curves DTA form coal and powder tire in air and N 2 atmosphere.