A traditional vertical batch lime kiln: thermal profile and quicklime characteristics

John J Hughes, David S. Swift, Peter M.J. Bartos, Philip F.G. Banfill Banfill

Research output: Chapter in Book/Report/Conference proceedingChapter

2 Citations (Scopus)

Abstract

Full scale calcination of high calcium limestone using traditional methods was performed in the batch process Experimental Lime Kiln (ELK). The ELK is equipped to monitor temperature, air flow and gas compositions and also has significant insulation to ensure minimum lateral energy loss during burning. Internal kiln wall temperatures of up to 550°C, and kiln core temperatures of 850°C, within the range of calcium carbonate disassociation have been achieved for several hours with predictable temperature/time gradients. A mixed feed solid fuel: stone ratio of 1:9 was employed resulting in limestone conversion to quicklime of 75% ±9. The heat balance efficiency is approximately 45%. However, this may not be a useful indicator of overall efficiency of binder production, especially in a open-top batch process traditional kiln. The hydration behaviour of the low-temperature traditional quicklime is more varied than high-temperature commercially produced quicklime, made from the same stone. The low temperature material hydrates more slowly, reaches a lower temperature and maintains a peak temperature plateau for longer than die high-temperature quicklime. The traditional quicklime also produces as much as 50% non-hydrated residue during the tests. This suggests an origin for "lime inclusion" texture in historic mortars. Mortars produced using traditional hot mixing processes are petrographically similar to historic mortars. The recognition of distinctive quicklime microstructures may also provide a diagnostic tool for quality control in small-scale traditional lime production.

Original languageEnglish
Title of host publicationMasonry
Subtitle of host publicationopportunties for the 21st Century
PublisherAmerican Society for Testing Materials
Pages73-87
Number of pages15
Volume1432
ISBN (Print)0803134509
Publication statusPublished - 2002

Publication series

NameASTM Special Technical Publication

Fingerprint

Kilns
Lime
Temperature
Mortar
Limestone
Hot Temperature
Calcium carbonate
Hydrates
Hydration
Calcination
Binders
Quality control
Insulation
Calcium
Energy dissipation
Textures
Microstructure

Keywords

  • Masonry conservation
  • Lime:sand mortar
  • Lime kiln
  • Calcination
  • Quicklime
  • Heat of hydration

Cite this

Hughes, J. J., Swift, D. S., Bartos, P. M. J., & Banfill, P. F. G. B. (2002). A traditional vertical batch lime kiln: thermal profile and quicklime characteristics. In Masonry : opportunties for the 21st Century (Vol. 1432, pp. 73-87). (ASTM Special Technical Publication ). American Society for Testing Materials.
Hughes, John J ; Swift, David S. ; Bartos, Peter M.J. ; Banfill, Philip F.G. Banfill. / A traditional vertical batch lime kiln : thermal profile and quicklime characteristics. Masonry : opportunties for the 21st Century. Vol. 1432 American Society for Testing Materials, 2002. pp. 73-87 (ASTM Special Technical Publication ).
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abstract = "Full scale calcination of high calcium limestone using traditional methods was performed in the batch process Experimental Lime Kiln (ELK). The ELK is equipped to monitor temperature, air flow and gas compositions and also has significant insulation to ensure minimum lateral energy loss during burning. Internal kiln wall temperatures of up to 550°C, and kiln core temperatures of 850°C, within the range of calcium carbonate disassociation have been achieved for several hours with predictable temperature/time gradients. A mixed feed solid fuel: stone ratio of 1:9 was employed resulting in limestone conversion to quicklime of 75{\%} ±9. The heat balance efficiency is approximately 45{\%}. However, this may not be a useful indicator of overall efficiency of binder production, especially in a open-top batch process traditional kiln. The hydration behaviour of the low-temperature traditional quicklime is more varied than high-temperature commercially produced quicklime, made from the same stone. The low temperature material hydrates more slowly, reaches a lower temperature and maintains a peak temperature plateau for longer than die high-temperature quicklime. The traditional quicklime also produces as much as 50{\%} non-hydrated residue during the tests. This suggests an origin for {"}lime inclusion{"} texture in historic mortars. Mortars produced using traditional hot mixing processes are petrographically similar to historic mortars. The recognition of distinctive quicklime microstructures may also provide a diagnostic tool for quality control in small-scale traditional lime production.",
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Hughes, JJ, Swift, DS, Bartos, PMJ & Banfill, PFGB 2002, A traditional vertical batch lime kiln: thermal profile and quicklime characteristics. in Masonry : opportunties for the 21st Century. vol. 1432, ASTM Special Technical Publication , American Society for Testing Materials, pp. 73-87.

A traditional vertical batch lime kiln : thermal profile and quicklime characteristics. / Hughes, John J ; Swift, David S.; Bartos, Peter M.J.; Banfill, Philip F.G. Banfill.

Masonry : opportunties for the 21st Century. Vol. 1432 American Society for Testing Materials, 2002. p. 73-87 (ASTM Special Technical Publication ).

Research output: Chapter in Book/Report/Conference proceedingChapter

TY - CHAP

T1 - A traditional vertical batch lime kiln

T2 - thermal profile and quicklime characteristics

AU - Hughes, John J

AU - Swift, David S.

AU - Bartos, Peter M.J.

AU - Banfill, Philip F.G. Banfill

PY - 2002

Y1 - 2002

N2 - Full scale calcination of high calcium limestone using traditional methods was performed in the batch process Experimental Lime Kiln (ELK). The ELK is equipped to monitor temperature, air flow and gas compositions and also has significant insulation to ensure minimum lateral energy loss during burning. Internal kiln wall temperatures of up to 550°C, and kiln core temperatures of 850°C, within the range of calcium carbonate disassociation have been achieved for several hours with predictable temperature/time gradients. A mixed feed solid fuel: stone ratio of 1:9 was employed resulting in limestone conversion to quicklime of 75% ±9. The heat balance efficiency is approximately 45%. However, this may not be a useful indicator of overall efficiency of binder production, especially in a open-top batch process traditional kiln. The hydration behaviour of the low-temperature traditional quicklime is more varied than high-temperature commercially produced quicklime, made from the same stone. The low temperature material hydrates more slowly, reaches a lower temperature and maintains a peak temperature plateau for longer than die high-temperature quicklime. The traditional quicklime also produces as much as 50% non-hydrated residue during the tests. This suggests an origin for "lime inclusion" texture in historic mortars. Mortars produced using traditional hot mixing processes are petrographically similar to historic mortars. The recognition of distinctive quicklime microstructures may also provide a diagnostic tool for quality control in small-scale traditional lime production.

AB - Full scale calcination of high calcium limestone using traditional methods was performed in the batch process Experimental Lime Kiln (ELK). The ELK is equipped to monitor temperature, air flow and gas compositions and also has significant insulation to ensure minimum lateral energy loss during burning. Internal kiln wall temperatures of up to 550°C, and kiln core temperatures of 850°C, within the range of calcium carbonate disassociation have been achieved for several hours with predictable temperature/time gradients. A mixed feed solid fuel: stone ratio of 1:9 was employed resulting in limestone conversion to quicklime of 75% ±9. The heat balance efficiency is approximately 45%. However, this may not be a useful indicator of overall efficiency of binder production, especially in a open-top batch process traditional kiln. The hydration behaviour of the low-temperature traditional quicklime is more varied than high-temperature commercially produced quicklime, made from the same stone. The low temperature material hydrates more slowly, reaches a lower temperature and maintains a peak temperature plateau for longer than die high-temperature quicklime. The traditional quicklime also produces as much as 50% non-hydrated residue during the tests. This suggests an origin for "lime inclusion" texture in historic mortars. Mortars produced using traditional hot mixing processes are petrographically similar to historic mortars. The recognition of distinctive quicklime microstructures may also provide a diagnostic tool for quality control in small-scale traditional lime production.

KW - Masonry conservation

KW - Lime:sand mortar

KW - Lime kiln

KW - Calcination

KW - Quicklime

KW - Heat of hydration

M3 - Chapter

SN - 0803134509

VL - 1432

T3 - ASTM Special Technical Publication

SP - 73

EP - 87

BT - Masonry

PB - American Society for Testing Materials

ER -

Hughes JJ, Swift DS, Bartos PMJ, Banfill PFGB. A traditional vertical batch lime kiln: thermal profile and quicklime characteristics. In Masonry : opportunties for the 21st Century. Vol. 1432. American Society for Testing Materials. 2002. p. 73-87. (ASTM Special Technical Publication ).