The stone aggregates constitute over 90% of the mass of a pavement and hence its properties play a very vital role in design of satisfactory unbound as well as bituminous mixes. Also since the aggregates availability ...The stone aggregates constitute over 90% of the mass of a pavement and hence its properties play a very vital role in design of satisfactory unbound as well as bituminous mixes. Also since the aggregates availability is continuously becoming scarce, attempts have to be made to identify use of some marginal as well as inferior aggregates without sacrificing the desirable qualities of resulting mixes. One of the most important properties therefore is the combined index of aggregates which deals with aggregates shape and is the sum of flakiness and elongation indices of aggregates measured related to their thickness and length respectively. The Ministry of Road Transport and Highways （MoRTH） specifies an upper limit of 30% combined index for different types of bituminous mixes. In the field, many times the aggregates supplied have combined index of more than 30%. A pre determined mix such as bituminous concrete, dense or semi dense bituminous macadam etc. has to be designed using such aggregates. It may be easy to design the mix but to get the aggregates with desirable combined index is often very difficult. In order to overcome this, in many projects, secondary crushers are used to crush the aggregates for the second time just to bring down the combined index. This obviously increases the project cost. It is quite possible that the aggregates with higher combined index may be suitable for a particular type of mix. It is therefore appropriate to study what type of a bituminous mix can be satisfactorily prepared depending on the availability of aggregates with generally higher values of combined index. Hence, it was attempted to determine the usual Marshall test properties of two most commonly used types of bituminous mixes namely bituminous concrete and dense bituminous macadam using aggregates with combined index 30%, 40% and 50%. It was found that aggregates with higher combined index are more suitable to design dense bituminous macadam mix than bituminous concrete.展开更多
An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature wa...An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature was over a range of 550–650℃ under 1.0 MPa pressure with different atmospheres.On the basis of the individual pyrolysis behavior of bituminous coal and biomass,the influences of the biomass blending ratio,temperature,pressure and atmosphere on the product distribution were investigated.The results indicated that there existed a synergetic effect in the co-pyrolysis of bituminous coal and biomass in this pressured fluidized bed reactor,especially when the condition of bituminous coal and biomass blend ratio of 70:30(w/w),600℃,and 0.3 MPa was applied.The addition of biomass influenced the tar and char yields and gas and tar composition during co-pyrolysis.The tar yields were higher than the calculated values from individual pyrolysis of each fuel,and consequently the char yields were lower.The experimental results showed that the composition of the gaseous products was not in accordance with those of their individual fuel.The improvement of composition in tar also indicated synergistic effect in the co-pyrolysis.展开更多
High volatile bituminous coal .was demineralized by a chemical method. The vibrations of the ＂aromatics＂ structure of graphite, crystalline or non-crystalline, were observed in the spectra at the 1600 cm-1 region. T...High volatile bituminous coal .was demineralized by a chemical method. The vibrations of the ＂aromatics＂ structure of graphite, crystalline or non-crystalline, were observed in the spectra at the 1600 cm-1 region. The band at 1477 cm-1 is assigned as VR band, the band at 1392 cm-1 as VL band and the band at 1540 cm-1 as GR band. Graphite structure remains after chemical leaching liberates oxygenated functional groups and mineral groups. The silicate bands between 1010 and 1100 cm-1 are active in the infrared （IR） spec^urn but inactive in the Raman spectrum. Absorption arising from C-H stretching in alkenes occurs in the region of 3000 to 2840 cm-~. Raman bands because of symmetric stretch of water molecules were also observed in the spectrum at 3250 cm-1 and 3450 cm-1. Scanning electron microscopy analy- sis revealed the presence of a graphite layer on the surface. Leaching of the sample with hydrofluoric acid decreases the mineral phase and increases the carbon content. The ash content is reduced by 84.5wt% with leaching from its initial value by mainly removing aluminum and silicate containing minerals.展开更多
The Silurian bituminous sandstones（SBS） in the Tarim Basin, China are important basinwide reservoirs with an estimated area of approximately 249000 km^2. We investigated the ages of authigenic illites in the SBS res...The Silurian bituminous sandstones（SBS） in the Tarim Basin, China are important basinwide reservoirs with an estimated area of approximately 249000 km^2. We investigated the ages of authigenic illites in the SBS reservoirs and constrained their formation timing by using the 40^Ar/39^Ar step wise heating method. The age spectra, 39^Ar recoil loss and their controlling factors were investigated systematically. The 40^Ar/39^Ar ages were compared with the conventional K/Ar ages of identical clay fractions. The clay in the SBS reservoirs is dominated by orderly mixed-layer illite/smectite（I/S） with 5%–30% smectite layers. The I/S minerals morphology comprises primarily honeycomb, short filamentous and curved-lath particles, characteristic of authigenic illites. The unencapsulated 40^Ar/39^Ar total gas ages（UTGA） of the authigenic illites range from 188.56 ± 6.20 Ma to 491.86 ± 27.68 Ma, which are 7% to 103% older than the corresponding K/Ar ages of 124.87 ± 1.11 Ma to 383.45 ± 2.80 Ma, respectively. The K-Ar ages indicate multistage accumulations with distinct distribution patterns in the Tarim Basin： older（late Caledonian-early Hercynian） around the basin margin, younger（late Hercynian） in the basin centre, and the youngest（middle to late Yanshanian） in the Ha-6 well-block, central area of the North Uplift. The age difference is believed to have been caused by the 39^Ar recoil loss during the irradiation process. Compared with the K/Ar ages, the estimated 39^Ar recoil losses in this study are in the range from 7% to 51%. The 39^Ar recoil loss appears to increase not only with the decreasing particle sizes of the I/S, but also with increasing percentage of smectite layers（IR） of the I/S, and smectite layer content（SLC） of the samples. We conclude that due to significant 39^Ar recoil losses, UTGA may not offer any meaningful geological ages of the authigenic illite formation in the SBS and thus can not be used to represent the hydrocarbon charge timing. 39^Ar recoil losses during 40^Ar/39^Ar dating can not be neglected when dating fine authigenic illite, especially when the ordered mixed-layer I/S containing small amount of smectite layers（IR30%） in the reservoir formations. Compared with the unencapsulated Ar-Ar method, the conventional K-Ar method is less complicated, more accurate and reliable in dating authigenic illites in petroleum reservoirs.展开更多
The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to b...The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo(GCMC)simulations were then carried out to investigate the single and binary component adsorption of CO_2 and CH_4with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO_2 adsorption is greater than that of CH_4 adsorption. CO_2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH_4, which can account for the larger adsorption capacity of CO_2 in the bituminous coal model. In the case of binary adsorption of CO_2 and CH_4mixtures, CO_2 exhibits the preferential adsorption compared with CH_4 under the studied conditions. The adsorption selectivity of CO_2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO_2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO_2 decreases gradually with the increase of the bulk CO_2 mole fraction and the depth of CO_2 injection site.展开更多
Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]p...Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion.展开更多
In Greece more than 60,000 tn End of Life Tires are stockpiled every year often uncontrollable, causing severe environmental and other socio-economic negative impacts. Studies up to date are focused mainly on mechanic...In Greece more than 60,000 tn End of Life Tires are stockpiled every year often uncontrollable, causing severe environmental and other socio-economic negative impacts. Studies up to date are focused mainly on mechanical and physical characteristics of rubberized mixtures (based on cement, asphalt or soil) in which tire rubber is used either as alternative to natural aggregates or as additive. However, effect of tire rubber on noise reduction in rubberized bituminous layers, which is the main topic of present paper, has not been widely studied. In particular, this research paper is dealing with a sustainable use of tire rubber in asphalt pavement, leading to its generated noise reduction. An experimental pilot application has been conducted in the frame of a European Research Project, which has been implemented in a heavy traffic road section, cited outside Lamia city of Greece, (Vasilikon Street). The upper surface layer of the pavement has been made of rubberized bituminous mixture, produced by the wet process. Rheological characteristics of rubberized bitumen as well as basic properties of the implemented, rubberized bituminous mixture are presented. Moreover, measurements of noise level, deriving from vehicles’ motion, under operational conditions took place at the road section right after its implementation as well as after 8 months of its operation, while all data are presented in details. Results of the measurements on conventional and modified pavement sections are compared, certifying that rubberized asphalt layers can be not only environmentally friendly—since a category of solid wastes (worn automobile tires) is utilized—but also, addition of tire rubber particles in bituminous binder provides up to 3dB noise reducing bituminous mixtures and pavements, noise reduction that remains even after 8 months of road section’s operation.展开更多
The influence of a pre-oxidation process on the chemical properties of crushed bituminous coal and on adsorption properties of the subsequently formed char and activated carbon is discussed in this paper. Datong bitum...The influence of a pre-oxidation process on the chemical properties of crushed bituminous coal and on adsorption properties of the subsequently formed char and activated carbon is discussed in this paper. Datong bituminous coal samples sized 6 mm were oxidized at different temperatures and for different times and then carbonized and activated by steam to obtain activated carbons. A Uniform Design method was used to arrange the experiments,IR and adsorption experiments were used to characterize these oxidized coals,chars and activated carbon samples. The results show that the carboxyl group disappeared and α-CH2 groups joined to alkenes decreased dramatically but the carbonyl group clearly increased in the coal sample oxidized at 543 K; The chemical composition of coal samples oxidized at lower temperature is different from that of coal oxidized at 543 K. Oxidizing coal samples at higher temperatures for a short time or at lower temperatures for a longer time resulted in activated carbon samples that tended toward the same adsorption properties: Iodine number 1100 mg/g and Methylene blue value 252 mg/g. The yield of activated carbon obtained from the pre-oxidized coal is 10% higher than the yield from parent coal but the activated carbons have the same adsorption properties.展开更多
Influence of co-firing rate on SO 2 emission from co-firing municipal solid waste(MSW) and bituminous containing high amount of sulfur(1.79%) was studied in a 0.15 MWt circulating fluidized bed(CFB). The temperature ...Influence of co-firing rate on SO 2 emission from co-firing municipal solid waste(MSW) and bituminous containing high amount of sulfur(1.79%) was studied in a 0.15 MWt circulating fluidized bed(CFB). The temperature selected is 1123 K, typical for MSW incineration using CFB. The particle concentration in the dilution zone of the furnace, the alkali metal concentration and sulfate concentration in the recirculating ash and fly ash, and flue gas composition were determined. The results showed that the addition of MSW leads to a significant decrease in SO 2 emission. Concentration of SO 2 in flue gas decreased to 0 with the co-firing rate greater than 51%. This reduction in SO 2 emission is attributed both to the high particle concentration in the dilution zone of the furnace, the high content of alkali metals in the bed material, and to the comparatively high concentration of HCl in flue gas during co-firing of MSW and bituminous.展开更多
In this study uranium and thorium contents and depositional characteristics of ay rhan bituminous shales（ BS）, west of Ankara（central Anatolia）, are investigated. Samples used were collected from boreholes opened ...In this study uranium and thorium contents and depositional characteristics of ay rhan bituminous shales（ BS）, west of Ankara（central Anatolia）, are investigated. Samples used were collected from boreholes opened by Park Holding Ltd. A total of 25 samples were taken from bituminous shale levels in boreholes drilled at 6 different locations in the study area. The H rka formation which hosts bituminous shale deposits is a volcanosedimentary sequence and all lithofacies indicate that a lacustrine environment where the water level was continuously changed. In addition to hydrocarbon generation potential, bituminous shales also accumulate significant amount of radioactive elements such as uranium and thorium. The average uranium and thorium concentrations of BS（1.83/2.62 ppm） are much lower than averages of UC, NASK and PAAS（uranium： 2.70/2.66/3.10 ppm; thorium： 8.50/12.30/14.60 ppm）. Low uranium contents in comparison to those of similar lacustrine environments might be attributed to that waters of depositional environment of BS contain low concentration of dissolved uranium and redox conditions were of oxic and dioxic character. Correlation data indicate that U and Th have a similar source and are associated predominantly with clays and phosphates and dominantly with organic material. Radioactive elements in the basin might be derived from Paleozoic granites and metamorphites（e.g. gneiss, schist） which comprise the basement and volcanism which was active in the region throughout the Miocene period. These elements are probably associated with uraniferous phosphate minerals（e.g. autunite, torbernite） which occur in granite, gneiss and schist. BS with average TOC content of 10.96 % shows very good/perfect source rock potential. Positive correlations between Gamma-Ray values and U, Th and K concentrations imply that radioactivity might be originated from these three elements.展开更多
A high volatile bituminous coal was subjected to a series of organic acid treatment in steps using citric acid (1 hr and 2 hr) and buffered EDTA with acetic acid (1 to 3 hr) at room temperature. Leaching was performed...A high volatile bituminous coal was subjected to a series of organic acid treatment in steps using citric acid (1 hr and 2 hr) and buffered EDTA with acetic acid (1 to 3 hr) at room temperature. Leaching was performed with acetic acid (2N) also for 1 hr. Citric acid procedure reduced the mineral matter below 1.94%. Calcites and aluminates are completely removed along with substantial quantity of silicates by citric acid leaching. The change in absorption of organic functional groups and mineral matter in coal samples were studied using Fourier transform infrared spectroscopy (FTIR). Analysis indicated that oxygen containing species were decreased in the coal structure during acetic acid and citric acid (40%) procedure and buffered EDTA 3 hours leaching. As the period of leaching with buffered EDTA increased from 1 hr to 3 hr, organic functional groups and mineral functional groups decreased its intensity. The results indicated that the described acid treatment procedures with citric acid have measurable effects on the coal structure.展开更多
In order to reduce the hazard of coal spontaneous combustion,the cross-linking reaction between O-containing functional groups of coal should be inhibited.So the inhibitory effect of an ionic liquid(IL) on the cross-l...In order to reduce the hazard of coal spontaneous combustion,the cross-linking reaction between O-containing functional groups of coal should be inhibited.So the inhibitory effect of an ionic liquid(IL) on the cross-linking reaction was studied.The O-containing functional groups change the weight loss and H_2O,CO_2,CO yields of bituminous coal before and after[H0Emim][BF_4]and[Amim]Cl pre-treatment and were detected by Fourier Transform Infrared spectroscopy(FT1R) and Thermo Gravimetric(TC) analysis.The results show that | AmimjCI has a weaker ability to inhibit the cross-linking reaction of bituminous coal compared to[HOEmim][BF_4].Besides,based on Quantum Chemistry calculation,it was found that the different inhibiting effects of |H0Emim][BF_4]and[Amim]Cl are greatly related to their anions and the H linked with C2 atom on the imidazole ring.The H-donor ability of coal will be enhanced by[HOEmim][BF_4]leading to a weaker cross-linking reaction of coal.展开更多
The historical development of mining industry in Czech Republic, mining industry in new economical conditions, damping program of hituminous coal mining and the damping of mining activity are mentioned in this paper, ...The historical development of mining industry in Czech Republic, mining industry in new economical conditions, damping program of hituminous coal mining and the damping of mining activity are mentioned in this paper, and some important and detail data are given. This paper is not only concerned to mining, but also to social society, so it is of significance to mining industry and otber enterprises.展开更多
Bituminous rocks in the Ozankoey （Ankara） field are different from those of the Paleocene- Eocene Mengen and Giineytepe （Bolu） regions in metal enrichment levels. Organic carbon （Corg） content of organic materia...Bituminous rocks in the Ozankoey （Ankara） field are different from those of the Paleocene- Eocene Mengen and Giineytepe （Bolu） regions in metal enrichment levels. Organic carbon （Corg） content of organic material-rich rocks in the Ozankoey （Ankara） field is 3.66-40.72% wt averaging 14.34%. The dominant organic materials are algae/amorphous accompanied by minor amount of herbaceous material （The dominant kerogen type is Type-I with a limited amount of Type-Ⅱ kerogen.）. The bituminous rocks in the Ozankoey field are enriched in heavy metals such as Ni, Mn, As and Cr. In comparison with the average enrichment values of dements, Ni, Mn, As and Cr in bituminous shales of the Ozankoey field are as about 4.38, 14.93, 10.90 and 5.58 times as average values. The average concentrations of these heavy metals are also as high as 215× 10^-6, 828 × 10^-6, 58.54 × 10^-6, and 148 × 10^-6 respectively. In addition, sorption properties of day and organic materials are also important for metal enrichments in the bituminous shales.展开更多
Based oil the fundamental principles of meteorology and thermodynamics, the calculation theory of the nonlinear unstable pavement temperature fields of two-dimension layered system by analytic theory is established an...Based oil the fundamental principles of meteorology and thermodynamics, the calculation theory of the nonlinear unstable pavement temperature fields of two-dimension layered system by analytic theory is established and the calculation methods of surface temperature, ground temperature distribution along the thickness under different climate conditions are put forward respectively.展开更多
The thermogravimetry analyzer coupled with the pyrolysis gas chromatography/time-of-flight mass spectrometry technology was used in this study to investigate the mass loss behavior and volatile release characteristics...The thermogravimetry analyzer coupled with the pyrolysis gas chromatography/time-of-flight mass spectrometry technology was used in this study to investigate the mass loss behavior and volatile release characteristics of a bituminous coal. The results showed that with an increasing heating rate, the characteristic parameters and TG/DTG curves shifted obviously to the higher temperature region. The pyrolysis of a bituminous coal at different heating rates can be divided into two stages according to the Coats-Redfern(C-R) plots. The activation energy obtained from the C-R method is 50.21—85.14 kJ/mol and 5.14—7.24 kJ/mol at a heating rate range of 8—300 °C/min for the first and second pyrolysis stages, respectively. Aromatic hydrocarbons were dominant in the volatile products during fast pyrolysis of the coal, followed by the olefins, whereas the phenols were the third major components. With the increase of pyrolysis temperature, the heavy components in the volatile species increased; meanwhile the phenol cracking reactions were intensified. The carbon number of olefins was mainly concentrated in 3—9, and the aromatics were mainly composed of the compounds of C_6—C_(13).This study can provide a basic reference for fast pyrolysis of coal and other thermal chemical conversion processes.展开更多
Through a lot of experiments, a new kind of stove using horizontal combustion tech-nique for bituminous coal briquet has been developed. Making use of this stove, studies have been made on burning process of bituminou...Through a lot of experiments, a new kind of stove using horizontal combustion tech-nique for bituminous coal briquet has been developed. Making use of this stove, studies have been made on burning process of bituminous coal briquet, distribution of temperature field in the stove, the regularities of evolution and combustion of volatile matter, the burning rate and edi-ciency of bituminous coal briquet, characteristics of fire-sealing and sulfur-retention. The results show that, with the technique, some achievements can be obtained in combustion of bituminous coal briquet, such as lower pollution that the flue gas black degree is below 0. 5R and dust con-centration is below 90 mg/m3. The stove’s combustion efficiency reaches 90%, sulfur fixing effi-ciency is 60%, and oO concentration is decreased by 40% compared with other traditional stoves. With so many advantages, the stove can be used extensively in civil stoves and smaller industrial boilers.展开更多
The results of studies of radiation chemical transformations of Balakhani bituminous oil of Azerbaijan are adduced. The IR （infrared） spectra of initial and irradiated samples of tar fractions of bituminous oil are ...The results of studies of radiation chemical transformations of Balakhani bituminous oil of Azerbaijan are adduced. The IR （infrared） spectra of initial and irradiated samples of tar fractions of bituminous oil are compared. The kinetics of radiation chemical yields of gas products at the irradiation of bituminous oil and its tar fraction have been investigated. Irradiation is conducted in the gamma-ray source of isotope 60Co at the dose rate of P = 0.27 Gy/s and absorbed doses D = 5-163 kGy. It is found that in comparison with oil faction, tar fraction of bituminous oil has a high resistance to radiation.展开更多
Uneven roads surface can be observed on bituminous pavements. This is due to moving loads and climate conditions. If the observed deformations exceed the elastic limit, important damages can occur, so new materials ar...Uneven roads surface can be observed on bituminous pavements. This is due to moving loads and climate conditions. If the observed deformations exceed the elastic limit, important damages can occur, so new materials are used to improve the stiffness modulus of bituminous mixtures. To achieve this, a modified bituminous concrete by addition of the PR PLAST Sahara （produced by PR industries and PLAST for Plastic） mainly used in arid region has been studied. The use of this additive at various percentages 0.1, 0.3, 0.6 and 0.9 by weight of bituminous concrete has been investigated to determine its stiffness modulus. An experimental design using the Taguchi tables has been elaborated to reduce the number of tests. Marshall and NAT （Nottingham asphalt tester） tests have been carried out, and a mathematical model of the stiffness modulus has been proposed.展开更多
Various studies have been conducted in the past by researchers who have proposed diverse solutions to control the premature degradation noted on flexible pavements. It turns out that the binder content remains a param...Various studies have been conducted in the past by researchers who have proposed diverse solutions to control the premature degradation noted on flexible pavements. It turns out that the binder content remains a parameter so far not mastered and its optimization remains an imperative to produce a quality mix capable of meeting the technical and economic requirements sought in a formulation study. This article mainly aimed to optimize the hydrocarbon binder content of a 0/14 granular class semi-granular bituminous concrete using the Marshall and Duriez method. In the first part of the study, the different constituents were characterized according to the standards in force. The second allowed to describe the methodology used to determine the mixture and calculated the theoretical binder content. A theoretical mixture, entering the reference zone was defined at first. Following the characterization of the mixture in the laboratory, the granulometry curve of the mixture was inserted into the reference zone. This mixture was then preserved for the rest of the study. Then, it was theoretically determined bitumen contents ranging from 5.13% to 5.75% for wealth modules ranging from 3.3% to 3.7%. Thus, the Marshall method was used to characterize the performance of the mixture as a function of the binder content. The results obtained led to the selection of two grades of binders 5.13% and 5.28% for the study of water resistance using the Duriez method. On the basis of the results obtained on the Duriez test, the mixture with a binder content of 5.28% satisfies a good part of the criteria selected. This content corresponds to a wealth module of 3.4%.展开更多
文摘The stone aggregates constitute over 90% of the mass of a pavement and hence its properties play a very vital role in design of satisfactory unbound as well as bituminous mixes. Also since the aggregates availability is continuously becoming scarce, attempts have to be made to identify use of some marginal as well as inferior aggregates without sacrificing the desirable qualities of resulting mixes. One of the most important properties therefore is the combined index of aggregates which deals with aggregates shape and is the sum of flakiness and elongation indices of aggregates measured related to their thickness and length respectively. The Ministry of Road Transport and Highways （MoRTH） specifies an upper limit of 30% combined index for different types of bituminous mixes. In the field, many times the aggregates supplied have combined index of more than 30%. A pre determined mix such as bituminous concrete, dense or semi dense bituminous macadam etc. has to be designed using such aggregates. It may be easy to design the mix but to get the aggregates with desirable combined index is often very difficult. In order to overcome this, in many projects, secondary crushers are used to crush the aggregates for the second time just to bring down the combined index. This obviously increases the project cost. It is quite possible that the aggregates with higher combined index may be suitable for a particular type of mix. It is therefore appropriate to study what type of a bituminous mix can be satisfactorily prepared depending on the availability of aggregates with generally higher values of combined index. Hence, it was attempted to determine the usual Marshall test properties of two most commonly used types of bituminous mixes namely bituminous concrete and dense bituminous macadam using aggregates with combined index 30%, 40% and 50%. It was found that aggregates with higher combined index are more suitable to design dense bituminous macadam mix than bituminous concrete.
基金Supported by Hydrocarbon High-efficiency Utilization Technology Research Center of Yanchang Petroleum(Group)Co.Ltd.,China(ycsy2013ky-A-30)
文摘An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature was over a range of 550–650℃ under 1.0 MPa pressure with different atmospheres.On the basis of the individual pyrolysis behavior of bituminous coal and biomass,the influences of the biomass blending ratio,temperature,pressure and atmosphere on the product distribution were investigated.The results indicated that there existed a synergetic effect in the co-pyrolysis of bituminous coal and biomass in this pressured fluidized bed reactor,especially when the condition of bituminous coal and biomass blend ratio of 70:30(w/w),600℃,and 0.3 MPa was applied.The addition of biomass influenced the tar and char yields and gas and tar composition during co-pyrolysis.The tar yields were higher than the calculated values from individual pyrolysis of each fuel,and consequently the char yields were lower.The experimental results showed that the composition of the gaseous products was not in accordance with those of their individual fuel.The improvement of composition in tar also indicated synergistic effect in the co-pyrolysis.
文摘High volatile bituminous coal .was demineralized by a chemical method. The vibrations of the ＂aromatics＂ structure of graphite, crystalline or non-crystalline, were observed in the spectra at the 1600 cm-1 region. The band at 1477 cm-1 is assigned as VR band, the band at 1392 cm-1 as VL band and the band at 1540 cm-1 as GR band. Graphite structure remains after chemical leaching liberates oxygenated functional groups and mineral groups. The silicate bands between 1010 and 1100 cm-1 are active in the infrared （IR） spec^urn but inactive in the Raman spectrum. Absorption arising from C-H stretching in alkenes occurs in the region of 3000 to 2840 cm-~. Raman bands because of symmetric stretch of water molecules were also observed in the spectrum at 3250 cm-1 and 3450 cm-1. Scanning electron microscopy analy- sis revealed the presence of a graphite layer on the surface. Leaching of the sample with hydrofluoric acid decreases the mineral phase and increases the carbon content. The ash content is reduced by 84.5wt% with leaching from its initial value by mainly removing aluminum and silicate containing minerals.
文摘The Silurian bituminous sandstones（SBS） in the Tarim Basin, China are important basinwide reservoirs with an estimated area of approximately 249000 km^2. We investigated the ages of authigenic illites in the SBS reservoirs and constrained their formation timing by using the 40^Ar/39^Ar step wise heating method. The age spectra, 39^Ar recoil loss and their controlling factors were investigated systematically. The 40^Ar/39^Ar ages were compared with the conventional K/Ar ages of identical clay fractions. The clay in the SBS reservoirs is dominated by orderly mixed-layer illite/smectite（I/S） with 5%–30% smectite layers. The I/S minerals morphology comprises primarily honeycomb, short filamentous and curved-lath particles, characteristic of authigenic illites. The unencapsulated 40^Ar/39^Ar total gas ages（UTGA） of the authigenic illites range from 188.56 ± 6.20 Ma to 491.86 ± 27.68 Ma, which are 7% to 103% older than the corresponding K/Ar ages of 124.87 ± 1.11 Ma to 383.45 ± 2.80 Ma, respectively. The K-Ar ages indicate multistage accumulations with distinct distribution patterns in the Tarim Basin： older（late Caledonian-early Hercynian） around the basin margin, younger（late Hercynian） in the basin centre, and the youngest（middle to late Yanshanian） in the Ha-6 well-block, central area of the North Uplift. The age difference is believed to have been caused by the 39^Ar recoil loss during the irradiation process. Compared with the K/Ar ages, the estimated 39^Ar recoil losses in this study are in the range from 7% to 51%. The 39^Ar recoil loss appears to increase not only with the decreasing particle sizes of the I/S, but also with increasing percentage of smectite layers（IR） of the I/S, and smectite layer content（SLC） of the samples. We conclude that due to significant 39^Ar recoil losses, UTGA may not offer any meaningful geological ages of the authigenic illite formation in the SBS and thus can not be used to represent the hydrocarbon charge timing. 39^Ar recoil losses during 40^Ar/39^Ar dating can not be neglected when dating fine authigenic illite, especially when the ordered mixed-layer I/S containing small amount of smectite layers（IR30%） in the reservoir formations. Compared with the unencapsulated Ar-Ar method, the conventional K-Ar method is less complicated, more accurate and reliable in dating authigenic illites in petroleum reservoirs.
基金Supported by the CNPC Huabei Oilfield Science and Technology Development Project(HBYT-CYY-2014-JS-378,HBYT-CYY-2015-JS-47)
文摘The adsorption behavior of CO_2, CH_4 and their mixtures in bituminous coal was investigated in this study. First, a bituminous coal model was built through molecular dynamic(MD) simulations, and it was confirmed to be reasonable by comparing the simulated results with the experimental data. Grand Canonical Monte Carlo(GCMC)simulations were then carried out to investigate the single and binary component adsorption of CO_2 and CH_4with the built bituminous coal model. For the single component adsorption, the isosteric heat of CO_2 adsorption is greater than that of CH_4 adsorption. CO_2 also exhibits stronger electrostatic interactions with the heteroatom groups in the bituminous coal model compared with CH_4, which can account for the larger adsorption capacity of CO_2 in the bituminous coal model. In the case of binary adsorption of CO_2 and CH_4mixtures, CO_2 exhibits the preferential adsorption compared with CH_4 under the studied conditions. The adsorption selectivity of CO_2 exhibited obvious change with increasing pressure. At lower pressure, the adsorption selectivity of CO_2 shows a rapid decrease with increasing the temperature, whereas it becomes insensitive to temperature at higher pressure. Additionally, the adsorption selectivity of CO_2 decreases gradually with the increase of the bulk CO_2 mole fraction and the depth of CO_2 injection site.
文摘Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion.
文摘In Greece more than 60,000 tn End of Life Tires are stockpiled every year often uncontrollable, causing severe environmental and other socio-economic negative impacts. Studies up to date are focused mainly on mechanical and physical characteristics of rubberized mixtures (based on cement, asphalt or soil) in which tire rubber is used either as alternative to natural aggregates or as additive. However, effect of tire rubber on noise reduction in rubberized bituminous layers, which is the main topic of present paper, has not been widely studied. In particular, this research paper is dealing with a sustainable use of tire rubber in asphalt pavement, leading to its generated noise reduction. An experimental pilot application has been conducted in the frame of a European Research Project, which has been implemented in a heavy traffic road section, cited outside Lamia city of Greece, (Vasilikon Street). The upper surface layer of the pavement has been made of rubberized bituminous mixture, produced by the wet process. Rheological characteristics of rubberized bitumen as well as basic properties of the implemented, rubberized bituminous mixture are presented. Moreover, measurements of noise level, deriving from vehicles’ motion, under operational conditions took place at the road section right after its implementation as well as after 8 months of its operation, while all data are presented in details. Results of the measurements on conventional and modified pavement sections are compared, certifying that rubberized asphalt layers can be not only environmentally friendly—since a category of solid wastes (worn automobile tires) is utilized—but also, addition of tire rubber particles in bituminous binder provides up to 3dB noise reducing bituminous mixtures and pavements, noise reduction that remains even after 8 months of road section’s operation.
基金Project 50204011 supported by the National Natural Science Foundation of China
文摘The influence of a pre-oxidation process on the chemical properties of crushed bituminous coal and on adsorption properties of the subsequently formed char and activated carbon is discussed in this paper. Datong bituminous coal samples sized 6 mm were oxidized at different temperatures and for different times and then carbonized and activated by steam to obtain activated carbons. A Uniform Design method was used to arrange the experiments,IR and adsorption experiments were used to characterize these oxidized coals,chars and activated carbon samples. The results show that the carboxyl group disappeared and α-CH2 groups joined to alkenes decreased dramatically but the carbonyl group clearly increased in the coal sample oxidized at 543 K; The chemical composition of coal samples oxidized at lower temperature is different from that of coal oxidized at 543 K. Oxidizing coal samples at higher temperatures for a short time or at lower temperatures for a longer time resulted in activated carbon samples that tended toward the same adsorption properties: Iodine number 1100 mg/g and Methylene blue value 252 mg/g. The yield of activated carbon obtained from the pre-oxidized coal is 10% higher than the yield from parent coal but the activated carbons have the same adsorption properties.
文摘Influence of co-firing rate on SO 2 emission from co-firing municipal solid waste(MSW) and bituminous containing high amount of sulfur(1.79%) was studied in a 0.15 MWt circulating fluidized bed(CFB). The temperature selected is 1123 K, typical for MSW incineration using CFB. The particle concentration in the dilution zone of the furnace, the alkali metal concentration and sulfate concentration in the recirculating ash and fly ash, and flue gas composition were determined. The results showed that the addition of MSW leads to a significant decrease in SO 2 emission. Concentration of SO 2 in flue gas decreased to 0 with the co-firing rate greater than 51%. This reduction in SO 2 emission is attributed both to the high particle concentration in the dilution zone of the furnace, the high content of alkali metals in the bed material, and to the comparatively high concentration of HCl in flue gas during co-firing of MSW and bituminous.
基金supported by Ankara University Scientific Research Projects Coordination Unit(Project No:09B4343013)
文摘In this study uranium and thorium contents and depositional characteristics of ay rhan bituminous shales（ BS）, west of Ankara（central Anatolia）, are investigated. Samples used were collected from boreholes opened by Park Holding Ltd. A total of 25 samples were taken from bituminous shale levels in boreholes drilled at 6 different locations in the study area. The H rka formation which hosts bituminous shale deposits is a volcanosedimentary sequence and all lithofacies indicate that a lacustrine environment where the water level was continuously changed. In addition to hydrocarbon generation potential, bituminous shales also accumulate significant amount of radioactive elements such as uranium and thorium. The average uranium and thorium concentrations of BS（1.83/2.62 ppm） are much lower than averages of UC, NASK and PAAS（uranium： 2.70/2.66/3.10 ppm; thorium： 8.50/12.30/14.60 ppm）. Low uranium contents in comparison to those of similar lacustrine environments might be attributed to that waters of depositional environment of BS contain low concentration of dissolved uranium and redox conditions were of oxic and dioxic character. Correlation data indicate that U and Th have a similar source and are associated predominantly with clays and phosphates and dominantly with organic material. Radioactive elements in the basin might be derived from Paleozoic granites and metamorphites（e.g. gneiss, schist） which comprise the basement and volcanism which was active in the region throughout the Miocene period. These elements are probably associated with uraniferous phosphate minerals（e.g. autunite, torbernite） which occur in granite, gneiss and schist. BS with average TOC content of 10.96 % shows very good/perfect source rock potential. Positive correlations between Gamma-Ray values and U, Th and K concentrations imply that radioactivity might be originated from these three elements.
文摘A high volatile bituminous coal was subjected to a series of organic acid treatment in steps using citric acid (1 hr and 2 hr) and buffered EDTA with acetic acid (1 to 3 hr) at room temperature. Leaching was performed with acetic acid (2N) also for 1 hr. Citric acid procedure reduced the mineral matter below 1.94%. Calcites and aluminates are completely removed along with substantial quantity of silicates by citric acid leaching. The change in absorption of organic functional groups and mineral matter in coal samples were studied using Fourier transform infrared spectroscopy (FTIR). Analysis indicated that oxygen containing species were decreased in the coal structure during acetic acid and citric acid (40%) procedure and buffered EDTA 3 hours leaching. As the period of leaching with buffered EDTA increased from 1 hr to 3 hr, organic functional groups and mineral functional groups decreased its intensity. The results indicated that the described acid treatment procedures with citric acid have measurable effects on the coal structure.
基金the support from the National Natural Science Foundation of China(Nos.51304073and 51304071)the Educational Commission of Henan Province(Nos.13A440324 and 12B440004)+1 种基金the Open Projects of State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology(No.12KF02)Henan Polytechnic University(Nos.B2012-068 and B2012-085)
文摘In order to reduce the hazard of coal spontaneous combustion,the cross-linking reaction between O-containing functional groups of coal should be inhibited.So the inhibitory effect of an ionic liquid(IL) on the cross-linking reaction was studied.The O-containing functional groups change the weight loss and H_2O,CO_2,CO yields of bituminous coal before and after[H0Emim][BF_4]and[Amim]Cl pre-treatment and were detected by Fourier Transform Infrared spectroscopy(FT1R) and Thermo Gravimetric(TC) analysis.The results show that | AmimjCI has a weaker ability to inhibit the cross-linking reaction of bituminous coal compared to[HOEmim][BF_4].Besides,based on Quantum Chemistry calculation,it was found that the different inhibiting effects of |H0Emim][BF_4]and[Amim]Cl are greatly related to their anions and the H linked with C2 atom on the imidazole ring.The H-donor ability of coal will be enhanced by[HOEmim][BF_4]leading to a weaker cross-linking reaction of coal.
文摘The historical development of mining industry in Czech Republic, mining industry in new economical conditions, damping program of hituminous coal mining and the damping of mining activity are mentioned in this paper, and some important and detail data are given. This paper is not only concerned to mining, but also to social society, so it is of significance to mining industry and otber enterprises.
文摘Bituminous rocks in the Ozankoey （Ankara） field are different from those of the Paleocene- Eocene Mengen and Giineytepe （Bolu） regions in metal enrichment levels. Organic carbon （Corg） content of organic material-rich rocks in the Ozankoey （Ankara） field is 3.66-40.72% wt averaging 14.34%. The dominant organic materials are algae/amorphous accompanied by minor amount of herbaceous material （The dominant kerogen type is Type-I with a limited amount of Type-Ⅱ kerogen.）. The bituminous rocks in the Ozankoey field are enriched in heavy metals such as Ni, Mn, As and Cr. In comparison with the average enrichment values of dements, Ni, Mn, As and Cr in bituminous shales of the Ozankoey field are as about 4.38, 14.93, 10.90 and 5.58 times as average values. The average concentrations of these heavy metals are also as high as 215× 10^-6, 828 × 10^-6, 58.54 × 10^-6, and 148 × 10^-6 respectively. In addition, sorption properties of day and organic materials are also important for metal enrichments in the bituminous shales.
文摘Based oil the fundamental principles of meteorology and thermodynamics, the calculation theory of the nonlinear unstable pavement temperature fields of two-dimension layered system by analytic theory is established and the calculation methods of surface temperature, ground temperature distribution along the thickness under different climate conditions are put forward respectively.
基金financial support from the National Natural Science Foundation of China (Grant Nos. 21576293 and 21576294)
文摘The thermogravimetry analyzer coupled with the pyrolysis gas chromatography/time-of-flight mass spectrometry technology was used in this study to investigate the mass loss behavior and volatile release characteristics of a bituminous coal. The results showed that with an increasing heating rate, the characteristic parameters and TG/DTG curves shifted obviously to the higher temperature region. The pyrolysis of a bituminous coal at different heating rates can be divided into two stages according to the Coats-Redfern(C-R) plots. The activation energy obtained from the C-R method is 50.21—85.14 kJ/mol and 5.14—7.24 kJ/mol at a heating rate range of 8—300 °C/min for the first and second pyrolysis stages, respectively. Aromatic hydrocarbons were dominant in the volatile products during fast pyrolysis of the coal, followed by the olefins, whereas the phenols were the third major components. With the increase of pyrolysis temperature, the heavy components in the volatile species increased; meanwhile the phenol cracking reactions were intensified. The carbon number of olefins was mainly concentrated in 3—9, and the aromatics were mainly composed of the compounds of C_6—C_(13).This study can provide a basic reference for fast pyrolysis of coal and other thermal chemical conversion processes.
文摘Through a lot of experiments, a new kind of stove using horizontal combustion tech-nique for bituminous coal briquet has been developed. Making use of this stove, studies have been made on burning process of bituminous coal briquet, distribution of temperature field in the stove, the regularities of evolution and combustion of volatile matter, the burning rate and edi-ciency of bituminous coal briquet, characteristics of fire-sealing and sulfur-retention. The results show that, with the technique, some achievements can be obtained in combustion of bituminous coal briquet, such as lower pollution that the flue gas black degree is below 0. 5R and dust con-centration is below 90 mg/m3. The stove’s combustion efficiency reaches 90%, sulfur fixing effi-ciency is 60%, and oO concentration is decreased by 40% compared with other traditional stoves. With so many advantages, the stove can be used extensively in civil stoves and smaller industrial boilers.
文摘The results of studies of radiation chemical transformations of Balakhani bituminous oil of Azerbaijan are adduced. The IR （infrared） spectra of initial and irradiated samples of tar fractions of bituminous oil are compared. The kinetics of radiation chemical yields of gas products at the irradiation of bituminous oil and its tar fraction have been investigated. Irradiation is conducted in the gamma-ray source of isotope 60Co at the dose rate of P = 0.27 Gy/s and absorbed doses D = 5-163 kGy. It is found that in comparison with oil faction, tar fraction of bituminous oil has a high resistance to radiation.
文摘Uneven roads surface can be observed on bituminous pavements. This is due to moving loads and climate conditions. If the observed deformations exceed the elastic limit, important damages can occur, so new materials are used to improve the stiffness modulus of bituminous mixtures. To achieve this, a modified bituminous concrete by addition of the PR PLAST Sahara （produced by PR industries and PLAST for Plastic） mainly used in arid region has been studied. The use of this additive at various percentages 0.1, 0.3, 0.6 and 0.9 by weight of bituminous concrete has been investigated to determine its stiffness modulus. An experimental design using the Taguchi tables has been elaborated to reduce the number of tests. Marshall and NAT （Nottingham asphalt tester） tests have been carried out, and a mathematical model of the stiffness modulus has been proposed.
文摘Various studies have been conducted in the past by researchers who have proposed diverse solutions to control the premature degradation noted on flexible pavements. It turns out that the binder content remains a parameter so far not mastered and its optimization remains an imperative to produce a quality mix capable of meeting the technical and economic requirements sought in a formulation study. This article mainly aimed to optimize the hydrocarbon binder content of a 0/14 granular class semi-granular bituminous concrete using the Marshall and Duriez method. In the first part of the study, the different constituents were characterized according to the standards in force. The second allowed to describe the methodology used to determine the mixture and calculated the theoretical binder content. A theoretical mixture, entering the reference zone was defined at first. Following the characterization of the mixture in the laboratory, the granulometry curve of the mixture was inserted into the reference zone. This mixture was then preserved for the rest of the study. Then, it was theoretically determined bitumen contents ranging from 5.13% to 5.75% for wealth modules ranging from 3.3% to 3.7%. Thus, the Marshall method was used to characterize the performance of the mixture as a function of the binder content. The results obtained led to the selection of two grades of binders 5.13% and 5.28% for the study of water resistance using the Duriez method. On the basis of the results obtained on the Duriez test, the mixture with a binder content of 5.28% satisfies a good part of the criteria selected. This content corresponds to a wealth module of 3.4%.
