A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production Applications
Pyroprocessing is an important stage in cement manufacturing. In this process, materials are subjected to high temperatures so as to cause a chemical or physical change. Its control improves efficiency in energy utilization and hence enhances production for good quality assurance. Kilns used in ceme...
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Wiley
2020-01-01
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| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/2020/5640218 |
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| author | Protus Nalobile Jackson Muthengia Wachira Joseph Karanja Thiong’o Joseph Mwiti Marangu |
| author_facet | Protus Nalobile Jackson Muthengia Wachira Joseph Karanja Thiong’o Joseph Mwiti Marangu |
| author_sort | Protus Nalobile |
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| description | Pyroprocessing is an important stage in cement manufacturing. In this process, materials are subjected to high temperatures so as to cause a chemical or physical change. Its control improves efficiency in energy utilization and hence enhances production for good quality assurance. Kilns used in cement manufacturing are complex in nature. They have longer time constants, and raw materials used have variable properties. They are therefore difficult to control. Additionally, the inclusion of various alternative fuels in burning makes the process more complex as the fuel characteristics remain inconsistent throughout the kiln operation. Fuel intensity standards for kilns using fuel oil are very high, ranging from 2.9 GJ to 7.5 GJ/ton of clinker produced. Grinding of clinker consumes power in the range of 2.5 kWh/ton of clinker produced. These and other pyroprocessing parameters make cement production costly. The pyroprocessing process in kilns and the grinding technologies therefore have to be optimized for best processing. This paper discusses the cement manufacturing and grinding processes. The traditional kiln technologies and the current and emerging technologies together with general fuel and energy requirements of cement manufacturing have been discussed. From the discussion, it has been established that the cement manufacturing and grinding technologies are capital-intensive investments. The kiln processes are advanced and use both electricity and natural fuels which are expensive and limited factors of production. The raw materials used in cement manufacturing are also limited and sometimes rare. The calcination of the raw materials requires external energy input which has contributed to the high cost of cement especially to low-income population in the developing countries. Self-calcining materials, in which the pozzolanic materials burn on their own, are potential pozzolanic materials with great potential to lower the cost of cement production. Such materials, as shown from the previous research study, are rice husks, broken bricks, spent bleaching earth, and lime sludge. There is a need, therefore, for research to look into ways of making cement using kiln processes that would use this property. This will be cost-effective if successful. It can be done at micro- and small-scale enterprise. |
| format | Article |
| id | doaj-art-9e5c436abfba4606be178962d3f2c4b0 |
| institution | Kabale University |
| issn | 1687-8086 1687-8094 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
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| series | Advances in Civil Engineering |
| spelling | doaj-art-9e5c436abfba4606be178962d3f2c4b02025-08-20T03:38:43ZengWileyAdvances in Civil Engineering1687-80861687-80942020-01-01202010.1155/2020/56402185640218A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production ApplicationsProtus Nalobile0Jackson Muthengia Wachira1Joseph Karanja Thiong’o2Joseph Mwiti Marangu3Department of Chemistry, Kenyatta University, Nairobi, KenyaDepartment of Physical Sciences, University of Embu, Embu, KenyaDepartment of Chemistry, Kenyatta University, Nairobi, KenyaDepartment of Physical Sciences, Meru University of Science & Technology, Meru, KenyaPyroprocessing is an important stage in cement manufacturing. In this process, materials are subjected to high temperatures so as to cause a chemical or physical change. Its control improves efficiency in energy utilization and hence enhances production for good quality assurance. Kilns used in cement manufacturing are complex in nature. They have longer time constants, and raw materials used have variable properties. They are therefore difficult to control. Additionally, the inclusion of various alternative fuels in burning makes the process more complex as the fuel characteristics remain inconsistent throughout the kiln operation. Fuel intensity standards for kilns using fuel oil are very high, ranging from 2.9 GJ to 7.5 GJ/ton of clinker produced. Grinding of clinker consumes power in the range of 2.5 kWh/ton of clinker produced. These and other pyroprocessing parameters make cement production costly. The pyroprocessing process in kilns and the grinding technologies therefore have to be optimized for best processing. This paper discusses the cement manufacturing and grinding processes. The traditional kiln technologies and the current and emerging technologies together with general fuel and energy requirements of cement manufacturing have been discussed. From the discussion, it has been established that the cement manufacturing and grinding technologies are capital-intensive investments. The kiln processes are advanced and use both electricity and natural fuels which are expensive and limited factors of production. The raw materials used in cement manufacturing are also limited and sometimes rare. The calcination of the raw materials requires external energy input which has contributed to the high cost of cement especially to low-income population in the developing countries. Self-calcining materials, in which the pozzolanic materials burn on their own, are potential pozzolanic materials with great potential to lower the cost of cement production. Such materials, as shown from the previous research study, are rice husks, broken bricks, spent bleaching earth, and lime sludge. There is a need, therefore, for research to look into ways of making cement using kiln processes that would use this property. This will be cost-effective if successful. It can be done at micro- and small-scale enterprise.http://dx.doi.org/10.1155/2020/5640218 |
| spellingShingle | Protus Nalobile Jackson Muthengia Wachira Joseph Karanja Thiong’o Joseph Mwiti Marangu A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production Applications Advances in Civil Engineering |
| title | A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production Applications |
| title_full | A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production Applications |
| title_fullStr | A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production Applications |
| title_full_unstemmed | A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production Applications |
| title_short | A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production Applications |
| title_sort | review on pyroprocessing techniques for selected wastes used for blended cement production applications |
| url | http://dx.doi.org/10.1155/2020/5640218 |
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