Coal-tar pitch is used in the manufacture of graphite electrodes for steel arc furnaces. 0000094988 00000 n This type of pitch is produced with the specific aim of fulfilling the requirements for binder and impregnations grades, mainly for carbon (C) anodes and graphite electrodes. Through the ispatguru.com website I share my knowledge and experience gained through my association with the steel industry for over 54 years. 9 and 10. Each industrial facility is also to have a thorough training program for employees and appropriate work processes, as well as safety equipment in place to limit exposure. 0000001580 00000 n The grade of pitch thus produced is dependent on distillation conditions, including time and temperature. Coal tar pitch is non-explosive and non-oxidizing in nature. Google Scholar. It is also used to produce pitch coke, which is used as the C component of electrodes, carbon brushes, and carbon and graphite articles. Modification of coal-tar pitch with unsaturated polyester resins leads to considerable plasticization, and such modified bitumens of significantly lower cancerogenicity can be used as binders with insulating and sealing properties. β-Resin seems to become nuclei for thermal condensation, leading to the rapid solidification of the mesophase. Fig 1 Schematics of the production of coal-tar pitch and anthracene oil-based pitch. Tests were performed for compounds containing 25% of modifying agent by mass, which undergo crosslinking for 0.5–2.0 h, at temperature 160 °C. 2 0 obj At room temperature, the viscosity of coal tar pitch is high. Petroleum Engineering. Its CAS number is 65996-32-2 and EINECS number is 266-028-2. In this case, polymerization occurs via the formation of planar macromolecules and the formation of cross-linked structures. Traditionally, pitch that was used for waterproofing buckets, barrels and small boats was drawn from pine. In order to determine an impact of phenol-formaldehyde resin on properties of coal-tar pitch, the compounds of pitch with 25 and 50% by mass of modifying agent were prepared by homogenization without crosslinking. 1996;75:1543–8. It is also used as a component in the manufacture of activated C, C refractory for blast furnace lining and tap-hole clays. Dependences of complex viscosity (|η*|) versus frequency determined at temperature 118 °C for compound of the pitch with 25% of phenol-formaldehyde resin by mass: open square—pitch/25PF/0; open rhombus—pitch/25PF/0.5; open triangle—pitch/25PF/1.0, Dependences of phase angle versus frequency determined at temperature 118 °C for compound of the pitch with 25% of phenol-formaldehyde resin by mass: open square—pitch/25PF/0; open rhombus—pitch/25PF/0.5; open triangle—pitch/25PF/1.0, Dependences of loss tangent versus frequency determined at temperature 118 °C for compound of the pitch with 25% of phenol-formaldehyde resin by mass: open square—pitch/25PF/0; open rhombus—pitch/25PF/0.5; open triangle—pitch/25PF/1.0. 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. It was decided to measure the changes in viscoelastic properties versus frequency of coal-tar pitch and pitch–phenol-formaldehyde resin compounds (without crosslinking) at as low as possible temperature (109 °C) which reduces to minimum the possibility of crosslinking reaction during measurement. Structures of probably higher average molecular mass and lower solubility in quinoline were formed at applied conditions of homogenization and crosslinking of the pitch with phenol-formaldehyde resin. 0000097743 00000 n Ventilation and automation are the best method for controlling exposure to coal tar pitch volatiles. Testing was aimed at the evaluation of thermal and rheological properties of coal-tar pitch modified with phenol-formaldehyde resin and indication of possible application(s) of such type of materials. 0000001755 00000 n The heating (dry distilling) of wood causes tar and pitch to drip away from the wood and leave behind charcoal. Some products made from plant resin are also known as rosin. Measurements were taken using parallel plates fixture (plate radius 25 mm; gap between the plates 1 mm). 0000002390 00000 n Fuel. Dependences of storage (G′) and loss (G″) modules versus frequency determined at temperature 118 °C for compound of the pitch with 25% of phenol-formaldehyde resin by mass: filled square—pitch/25PF/0 (G′); open square—pitch/25PF/0 (G″); filled rhombus—pitch/25PF/0.5 (G′); open rhombus—pitch/25PF/0.5 (G″); filled triangle—pitch/25PF/1.0 (G′); open triangle—pitch/25PF/1.0 (G″). 3). Physical and chemical properties of the coal-tar pitch and pitch–phenol-formaldehyde resin composition are shown in Table 1. Changes in properties of coal-tar pitch under the influence of phenol-formaldehyde resin were evaluated on the basis of: softening temperature (T Minimum 25% of phenol-formaldehyde resin by mass added to the pitch caused distinct changes in main physical and chemical properties in relation to unmodified pitch [11, 12]. Changes in values of storage and loss modules as well as complex viscosity became greater along with the extension of crosslinking time of the compound (Figs. © 2020 Springer Nature Switzerland AG. All oscillation measurements were taken within the linear viscoelasticity region. Determination of the effects caused by different polymers on coal fluidity during carbonization using high-temperature 1H NMR and rheometry. Test results of changing the thermo-rheological properties of coal-tar pitch under influence of phenol-formaldehyde resin are presented in this research work. High Viscosity Blended Bitumen Pitch,Coal Tar Pitch , Find Complete Details about High Viscosity Blended Bitumen Pitch,Coal Tar Pitch,High Viscosity Blended Bitumen Pitch from Bitumen Supplier or Manufacturer-Waterproof Materials Co., Ltd H��WKo�F��a��/�y�c�o&cf������O�-����!mUW7_�89D��������|7dZ� m�0}G�-�`��Y��� >> This is since oxygen (O2) promotes the formation of free radicals which favour polymerization reactions. All Rights Reserved © 2019, Design & Developed By: Star Web Maker. It is also the highest level of exposure an employee may be exposed to without incurring the risk of adverse health effects. Over the years, the pitch had produced several drops, but none had been recorded. Chasers pitch is a combination of pitch and other substances, used in jewellery making. It is the shiny, dark-brown to black residue produced by distillation of coal tar. In the case of compounds, intersection point moved towards lower frequencies together with increase in modifying agent content. During the carbonization of coal-tar pitch the viscosity of the pitch decreased at 200–360°C, reached a minimum at 360–400°C, and then increased at 400–450°C. T� �7�h�[FGGG�`��c0i IF W�$ d#8 epRPfH!�5i30���b@, ��:� C1�$��{�>0� E�2˱W1�a�˨ǐ=�=�j� Hard pitch is used as a binder for foundry cores. [17]. J Therm Anal Calorim. The main difference between these pitches resides in the quinoline insoluble content (much lower in the impregnating grade coal tar pitch) and in the softening point (around 110 deg C, for binder grade and around 90 deg C, for impregnating grade). 0000006809 00000 n It has both medical and industrial uses. /Length 5325 %PDF-1.4 %���� The coal-tar pitch and compound containing 25% of resin by mass showed highest ability to dissipate energy at highest frequencies, i.e. 1999;79:1583–9. Correspondence to Phenol-formaldehyde resin belongs to duroplastic materials which under the influence of temperature and/or additional substances undergo crosslinking reaction, and in the result hardened resin becomes non-melting and insoluble. The tar predominantly contains a mixture of bi- and poly-condensed aromatic hydrocarbons and also compounds with heteroatoms in rings (predominantly nitrogen bases from the quinoline and acridine series, 1 % to 2 %) and phenols (1 % to 2 %). �����')}Ox2��H��+�K�^�S�X��6'r$ʤ�Ą���F�e�o�uǭu�4�{ �8�" �,"h b��=�J>$��\ݺN�Ӂ�aI�UA�"��d�P/i��Haw���U�"�. https://doi.org/10.1007/s10973-017-6471-5, DOI: https://doi.org/10.1007/s10973-017-6471-5, Over 10 million scientific documents at your fingertips, Not logged in Coal tar pitch is currently produced from coal tar, which is a byproduct of high temperature coking of coal in the manufacture of metallurgical coke. R&B) determined by means of “ring-and-ball” method in accordance with PN-EN 1427 standard. These cutbacks are liquid at room temperature. J Therm Anal Calorim. 0000001012 00000 n /* 300x250, created 1/18/11 */ It implied the occurrence of chemical reactions leading to formation of components of probably substantial molecular masses, as a result of crosslinking, among others. The plots of phase angle (δ) versus frequency, determined at temperature 109 °C for coal-tar pitch and compounds of the coal-tar pitch with phenol-formaldehyde resin (without crosslinking): open circle—pitch, open square—pitch/25PF/0, open triangle—pitch/50PF/0, The plots of loss tangent (tg δ) versus frequency, determined at temperature 109 °C for coal-tar pitch and compounds of the coal-tar pitch with phenol-formaldehyde resin (without crosslinking): open circle—pitch, open square—pitch/25PF/0, open triangle—pitch/50PF/0.