Rather, it is characterized by a softening point (the temperature at which a given viscosity is reached). Its CAS number is 90640-84-9. Physical properties (density, viscosity, and interfacial tension) of water, select reference fluids, and field aged/weathered DNAPLs—including chlorinated solvents, mixed DNAPLs, MGP coal tar, and coal tar creosote—are presented in Table 2-1. Time of the order of decades is required for a value of the viscosity of a coal tar pitch to be obtained in this way. The first drop exited in December 1938 and seven further drops between then and November 2000. The applicability of three equation forms to these results has been assessed. Examples are medium soft pitch or very hard pitch. Thus coal tar from coke ovens contains relatively small amounts of aliphatic hydrocarbons.
On the other hand, high temperature tars, i.e., those produced at high heats of carbonization of coal, yield on distillation only traces of paraffinic hydrocarbons, the predominating hydrocarbons being those of the benzene, naphthalene and anthracene series. The light boiling fraction (light anthracene oil) has a high content of phenathrene, anthracene, and carbazole, while the higher boiling fraction (heavy anthracene oil) has a high content of fluoranthene and pyrene. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Viscosity of coal tar pitch at elevated temperatures. Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. The amount of ‘free carbon’ is also small. << Unlimited viewing of the article PDF and any associated supplements and figures. Copyright © 2020 Elsevier B.V. or its licensors or contributors. 1 0 obj Working off-campus? Although some preliminary work on two low-temperature pitches indicates a different regime, the work on coke-oven pitches shows a clear relation between viscosity rise and the formation of toluene- and quinoline-insolubles by what appears to be consecutive reactions from tar oils, during which the rheological behaviour becomes increasingly pseudoplastic. Viscosity of coal tar pitch at elevated temperatures Derek K. H. Briggs British Carbonization Research Association, Wingerworth, Chesterfield, Derbyshire S42 6JS, UK (Received W October 1979) At temperatures up to about 200the viscosity of pitch, of approximately 100 Ring and Ball Soften- ing Point, follows a predictable variation with temperature. Pitch is a viscoelastic polymer which can be natural or manufactured, derived from petroleum, coal tar, or plants. Coal tar pitch is the tar distillation residue produced during coking operations (NIOSH 1977). The full text of this article hosted at iucr.org is unavailable due to technical difficulties. It is acidic in nature and is water insoluble. Incompatible Materials Water, Oxidizing agent Hazardous Decomposition ProductsNone under normal use conditions Hazardous Polymerization Hazardous … The aromaticity of the coal tar increases while the content of paraffins and phenols decreases when the carbonization temperature increases.
We use cookies to help provide and enhance our service and tailor content and ads. Many of these additives function to increase sealer viscosity. Creosote oil – It is also known as wash oil and has boiling range of 230 deg C to 290 deg C. It is reported to have some 162 compounds. Use the link below to share a full-text version of this article with your friends and colleagues. "R}~Q:~pgg'������"���l���/���������O�:OϽV�ޞ�~ @����������zo��7��g;)�Kߜӗ���;�����=�d�������'}z��8}����7w�7?���I�������u��w?ݾw��~�����i�����k�������u��=���� ��f.�蟗��y_�j6}Yɗ���2�3 �> q�B�-��i����%�m���Si��=�J{����������uL�Ã{��!��B�431 �� \�~��iww�#��ׅLJe��~�i�]z��p������w��h��킑�K�����|g�����ާ ����dw����e[�Ӭ-�����ݞSL2���&�˺���m�"[��\�{�{���*+�6�Ӧ*�?+�ٿ�e4�j�>��:Бh��>}����}�������jy�h>~ �����x�f؉ʨ(�}�K��iz�0�K�|�%Ti��Q����B�m�h˃��/�^��NSUq�ϰ�JK� ����o���ώz���ΟP[0��4�|����A�0JE��ރ� �� �e4�cL��p��3n��|�Qv;|�>���pl��mTe�W;b�ABX��R���Sv�Ա�?G� BJt��ܭ.��R�t��[p�Àf�a���c��B6�(��f�=��(��"�y�;3�:��b8C�~�j�Ӈ � ;݆��F!-��6*�� =: ���B7/nd���J�{��p,�8�#���gg��>7ή�ՃX'�5�\���݈��������� �W��wR��{{�0��C�(��� }H�v. %���� This is borne out by the comparatively low ‘free carbon’ content of tars from heavily charged ovens. The percentage of ‘free carbon’ is generally high. and you may need to create a new Wiley Online Library account. Coal tar is a by-product generated during the high temperature carbonizing of coking coal for the production of the metallurgical coke in the by-product coke ovens. It contains besides small amounts of naphthalene, naphthalene derivatives, indole, diphenyl, acenaphthene, diphenylene oxide, fluorene, phenol derivatives (2 %) and quinoline base (4 % to 6 %).
By continuing you agree to the use of cookies. ), which all have been used as raw materials or intermediates materials in various chemical industries (as anti-oxidant, anti-septic, resin, softener ingredient in plastic industry, paint, perfume, and medicine etc.).
However, only a limited number (lesser than 20) are at levels exceeding 1 % but these constitute the major portion of creosote oil. © copyright 2020 QS Study. Although some preliminary work on two low-temperature pitches indicates a different regime, the work on coke-oven pitches shows a clear relation between viscosity rise and the formation of toluene- and quinoline-insolubles by what appears to be consecutive reactions from tar oils, during which the rheological behaviour becomes increasingly pseudoplastic. On heat treating at a constant temperature of 400 °C the viscosity rises. The unit of viscosity is the “Poise”, named after Poiseuille. It is slightly soluble in water at 20 deg C. The dynamic viscosity of anthracene oil at 80 deg C is in the range of mPas to 14 mPas. It is complex combination of hydrocarbons and consists primarily of aromatic and other hydrocarbons, naphthalene, phenolic compounds, benzothiophene, and aromatic nitrogen compounds.
Its colour is yellow to dark brown. Its flash point is less than 90 deg C. The ignition temperature of creosote oil is greater than 500 deg C. The oil is not self-igniting and is not an explosion hazard.
The fraction consists primarily of condensed ring aromatics, including 2–6 ring systems, with minor amounts Coal tar pitch – It is a dark-brown-black, shiny, amorphous residue produced during the distillation of coal tars. In the lightly charged ovens, in which there occurs a good deal of free space, part of the gas and probably some of the tar is ‘cracked’ into lighter materials and ‘free carbon’, and this latter substance to a very large extent is carried up the ascension pipes and arrested by the tar in the hydraulic main. It is a flammable liquid which has moderate solubility in water.