full2010.pdf - page 1432

1394
Abstract
This paper reports an investigation on the thermal analysis of Ranong Kaolin, Narathiwas Kaolin and
Nakhon Si Thammarat Ballclay. The research aim is to study a suitable temperature for firing Kaolin samples.
Kaolin samples were tested by using a temperature from 50 oC to 1,000 oC under N2 at 10 oC/min rate of change.
The weight losses and phase change were recorded using thermogravimetry and differential thermal analysis
technique respectively. It was found that the endothermic and exothermic reactions were created at 475.13 –
514.53 oC, 'H = 1.66 kJ/g and 991.14 –1001.12 oC, 'H = 0.29 kJ/g for Ranong Kaolin, respectively. The weight
losses of Ranong Kaolin was about 12.55% at 467.74 oC. For Narathiwas Kaolin, the endothermic reaction
and exothermic reaction were found at 467.77 – 504.97 oC, 'H = 1.99 kJ/g and 983.08 – 999.02 oC, 'H = 0.30
kJ/g respectively. The weight losses for Narathiwas Kaolin was about 11.76% at 466.271 oC. Furthermore, the
endothermic reaction and exothermic reaction were also found at 453.73 – 465.63 oC, 'H = 1.45 kJ/g and 960.04
– 967.24 oC, 'H = 0.36 kJ/g for Nakhon Si thammarat Ballclay, respectively. Moreover, the weight losses
Nakhon Si thammarat Ballclay was about 3.47%, 8.99% and 1.85% at 39.33, 418.95 and 751.29 oC, respectively.
Keywords : Ranong Kaolin, Narathiwas Kaolin, Nakhon Si thammarat Ballclay, DTA, TGA, Enthalpy ( 'H)
‡ÎµœÎµ
—·œ µª (China clay) ®¦º ° Á‡Ã°¨¸œ(Kaolin) ‡º °—·œš¸É¤¸ ¸µª ¤¸ nªœž¦³„°nªœÄ®n Áž}œÂ¦n—·œœ·—
Á‡Ã°¨·Åœ˜r (Kaolinite) ¤¸ ¼˜¦šµŠÁ‡¤¸Áž}œ Al2O3 ˜ 2SiO2 ˜ 2H2O (Chandrasekhar, S. and Ramaswamy, S., 2002) ¤¸
ǦŠ¦oµŠÂ Phyllosilicate ž¦³„°—oª¥´Êœ Octahedral ¨³ÂŸnœ Silicon Oxide Tetrahedral Ž¹ÉŠÃ‡¦Š¦o µŠÁ¦¸¥Š
Žo°œ„´œ°¥nµŠ¤¤µ˜¦ ÁœºÉ°Š‹µ„™¼„¥¹ —Ūo—oª¥¡´œ›³Å±Ã—¦Á‹œ (Hydrogen bond) (Melo, J.D.D. et al., 2010)
—·œ µªÁž} œª´˜™»—·š¸É¤¸‡ªµ¤Îµ‡´ Äœ°» ˜µ®„¦¦¤˜nµŠÇ ®¨µ¥ž¦³Á£š Ánœ °» ˜µ®„¦¦¤„¦³—µ¬ ¸
Á‡¦ºÉ°Šž{œ—·œÁŸµ ¥µ‰nµÂ¤¨Š Á‡¦ºÉ°ŠÎ µ°µŠ ¥µ¦´„¬µÃ¦‡ Áž}œ˜oœ (°—»¨¥r ċ˜µ»˜¦ ¨³‡–³, 2545) Á¤ºÉ°šÎµ„µ¦š—°
—·œ µªÃ—¥„µ¦ÁŸµÂ‡¨ÅŽœr(Calcined) Ž¹ÉŠ„Î µ®œ——oª¥°»–®£¼ ¤· Ÿ¨š¸É ŗo‹µ„„µ¦ÁŸµ‹³Ä®o‡ªµ¤®¨µ„®¨µ¥šµŠ
°»˜µ®„¦¦¤ ×¥‹³Ä®o¨´„¬–³¡· Á«¬ °Š¤´˜· œ´É œ‡º° ¤¸‡ªµ¤ µªªn µŠ¼Š ¤¸„µ¦Áž¨¸É ¥œÂž¨Š¤´˜·šµŠÅ¢¢j µ
(Electrical Property) Ž¹ÉŠ¡ªnµ ‹µ„„µ¦ÁŸµ—·œ µªš¸É °»–®£¼¤·ž¦³¤µ– 600 ¨³ 1,100 °Š«µÁŽ¨ÁŽ¸¥Ÿ¨š¸Éŗo‹µ„„µ¦
ÁŸµ ‹³™¼„œÎµ¤µž¦³¥»„˜rčoĜ°» ˜µ®„¦¦¤„¦³—µ¬ „µ¦šÎµ PVC (Polyvinyl Chloride) „µ¦Á‡¨º °¨ª—¨³µ¥
Á‡Á·¨ ¥µŠ „µª Áž} œ˜oœ (Chandrasekhar, S. and Ramaswamy, S., 2002)
„µ¦ª·Á‡¦µ³®rÁ· Š‡ªµ¤¦o°œ (Thermal Analysis) Áž}œÁš‡œ·‡š¸Éª·Á‡¦µ³®r„µ¦Áž¨¸É¥œÂž¨Š¤´˜·°Š›µ˜»š¸É
¹Êœ„´ °»–®£¼ ¤· ¤´ ˜·—´Š„¨n µªµ¤µ¦™šÎµÄ®o›µ˜» Á„· —„µ¦Áž¨¸É¥œÂž¨Š¤ª¨ Á¢(Phase) ¨³¡§˜·„¦¦¤Á·Š„¨
(Mechanical behavior) Ánœ „µ¦ª·Á‡¦µ³®r ÁÁš°¦r䄦µª¸Á¤˜¦¸ (Thermogravimetric Analysis : TGA) Áž}œÁš‡œ·‡
š¸É čoš—°„µ¦Â˜„˜´ª °ŠœÊε ×¥«¹ „¬µ„µ¦Áž¨¸É¥œ¤ª¨´¤¡´œ›r„´°» –®£¼¤· Áš‡œ·‡„µ¦ª·Á‡¦µ³®r ‡ªµ¤¦o°œÁ·Š
°œ»¡´ œ›r (Differential Thermal Analysis : DTA) Áž}œÁš‡œ·‡š¸Éčo 宦´ „µ¦š—°„µ¦Áž¨¸É¥œÂž¨ŠÁ¢ °Š›µ˜»