Increasing the quality of roofing and waterproofing materials involves developing new formulas for polymer-asphalt materials and technologies for adding the ingredients to composites [1][2][3][4][5][6][7]. However, in our opinion, the quality of the polymer-asphalt binders can be increased by improving the technology for production of high-melting roofing and waterproofing asphalts.Roofing asphalts BNK 40/180 and BNK 4/190 (GOST 9548) are usually finally oxidized in a battery of still reactors developed by VNIIPKneftekhim at the beginning of the 1960s. This technology did not spread to oil refineries (OR) due to the low output of these reactors and was used by consumers of asphalts for manufacturing small product lots [8].Production of high-melting asphalts in equipment of this type is characterized by a brief contact time of air with the oxidized mass and as a consequence, high concentration of oxygen in exhaust gases and coking of the gas space of the reactor [9, 10]. Oxidation of asphalts in reactors of this design can only be intensified by incorporating activating additives to the feedstock or reaction zone. Unfortunately, the information on the use of such additives only relates to technology for production of paving and construction asphalts.We will generalize the published data on enhancing oxidation of vacuum resids. The results of studies of this process can be transposed to final oxidation of roofing asphalts. One method of accelerating oxidation of heavy petroleum residues (HPR) is to incorporate additives containing different metal atoms in the oxidation zone. The results of an enormous number of studies in this 349 direction are generalized in monographs [11,12]. More than one hundred compounds capable of accelerating oxidation of vacuum resids into asphalts are known, for example: manganese dioxide; sodium carbonate; potassium chlorate; zinc, copper, aluminum sulfates; copper, lead, manganese, cobalt, iron, chromium naphthenates; some metal oxides [12]. Iron chlorides were industrially tested in [11]. Feeding them into the reaction zone caused instantaneous decomposition of the substance with formation of hydrogen chloride and an active hydrocarbon radical capable of carrying out a chain oxidation process. The asphaltenes formed have a molecular weight 2-2.5 times higher than the asphaltenes formed in traditional oxidation. The rate of the process increases and the quality of the construction asphalts are improved as a result [12].Iron chloride crystal hydrate, FeCl 3 ×6H 2 O, was tested in an industrial asphalt production unit [13]. The iron chloride was previously melted at 40-80°C in a steam-heated drum and then diluted with water to a concentration of 80% and fed into the oxidation tower by a plunger pump. Consumption of iron chloride was 0.1 wt. % in feedstock. Vacuum resid with a softening point of 30-31°C was used as the feedstock.The process was conducted at 265-270°C and air flow rate of 2700 m 3 /h. The reactor output in feedstock increased from 30 to 40 m 3 /h and the oxygen content in ...
A comparative analysis of domestic and foreign standards and technical specifications for paving asphalts is reported. A LUKOIL -Nizhegorodnefteorgsintez OAO draft corporate standard (DCS) for viscous paving asphalts which totally agrees with the foreign specifications was developed. Data from a pilot-industrial run on manufacture of commercial BND asphalt that satisfies the requirements of the DCS and is characterized by elevated plasticity and thermal stability are reported. The compositions of the feedstock and commercial asphalt and the process conditions of oxidation of vacuum resid were refined.The modern paving industry imposes stiff requirements on all materials used in construction and maintenance of highways, including paving asphalts and other binder materials made from them. Despite the enormous amount of data published in the scientific and technical literature, the quality level of viscous paving asphalts and the list of quality indexes and validation of the standards for them are still being debated.The state of the roads in our country shows that the lifetime of newly constructed and overhauled road surfaces almost universally fails. According to the data from Voronezh Oil Refinery's RosDor SRI, important erosion and peeling begin in the first year of use, while the lifetime of surfaces abroad is 18 years. In addition, the problem of bringing the domestic standards into agreement with the foreign standards has still not been solved. There is no correlation between the requirements for asphalt concretes and the quality indexes included in the standards for asphalt, and problems related to their production technology require solution.The requirements in foreign standards for paving asphalts are generalized and the necessity of changing the domestic standards and bringing them into agreement with the requirements in the foreign standards is justified ____________________________________________________________________________________________________ LUKOIL -Nizhegorodnefteorgsintez OAO. Moscow State Academy of Precision Chemical Engineering.
The possibility of getting polymer-bitumen binders (PBB) based on straight-run tar (heavy resid) has been studied. It is shown that tar-based PBB composite is characterized by improved performance properties and reduced materials consumption for their production.Present-day road industry places high demands on all materials usable for construction of automobile roads. The current practice in the Russian Federation for getting polymer-bitumen binders (PBB) in asphalt and concrete plants (ACP) envisages use, based on the present standards, of oxidized road bitumen and solution of styrene-butadiene-styrene (SBS) modifiers in various plasticizers. Several flaws are intrinsic to this technology
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