Soft Pitch Research Articles

Synthesis of needle coke by co-carbonization of coal liquefaction pitch and refined soft pitch

ABSTRACT Needle coke was a type of engineering material and function artificial carbon material that was extensively utilized as a raw material for the synthesis of ultra-high power electrodes and nuclear graphite. The characteristics of the pitch have a considerable influence on the generation of needle coke of high quality. To study the potential of coal liquefaction pitch (CLP) for the synthesis of high-quality needle coke, refined soft pitch was utilized as an additive to generate needle coke via the co-carbonization method. The optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction, Raman spectrum, and curve-fitted method were used to analyze the microstructure, true density, carbon crystalline distribution, and micro-strength of the generated needle coke, respectively. Factually, the blending of CLP and refined soft pitch was an essential method to adjust the thermal stability of the pitch mixtures. In addition, co-carbonization of CLP and refined soft pitch was an effective technique for preparing needle coke of high quality with a true density of 2.206 g/cm−3 and a fibrous structure and leaflet structure content of 94.44%.

Characterization approach to develop distillation process for production of anode-grade coal tar pitch

Many efforts have been spent to make a trade-off between designing an efficient distillation system and meeting very strict requirements of pitch product. The design of coal tar distillation for pitch production should be able not only energetically efficient but also to meet the physicochemical requirements of pitch. This paper presents a practical approach and a systematic method of material characterizations to evaluate appropriate distillation operating conditions. The purpose of this study was to develop a simple coal tar distillation process that focused on obtaining anode-grade binder having certain specifications. The distillation process was carried out in two stages. The first stage occurred up to 360-370°C at atmospheric pressure to separate all volatile fractions. The second stage distillation involves vacuum pressure with 4 conditions in which A<B<C<D ranging from -4 to -35 cmHg and varying soaking time to convert soft pitch into hard pitch. Higher vacuum pressure of distillation is not necessarily high to meet specifications. Our finding shows that B is the most favourable vacuum pressure and can be further heat treated for specific requirements of pitch.

Preparation and characterization of high-spinnability isotropic pitch from 1-methylnaphthalene-extracted low-rank coal by co-carbonization with petroleum residue

Coal extract produced by solvent extraction of low-rank coal is not suitable for spinning due to its high oxygen content. In order to effectively overcome this limitation, soft pitch was produced by co-carbonization of coal extract and petroleum residues. The decrease in oxygen content was confirmed by physical property analyses of the soft pitches blended at different mixing ratios. A bridge/hydroaromatic structure of the soft pitch was observed during the co-carbonization. The produced spinnable pitch had a high spinnability and a softening point of 230 °C. This spinnable pitch, prepared by solvent extraction of low-rank coal, showed excellent spinnability and was heat-treated at 800 °C for 5 min to produce isotropic carbon fibers having diameters of 7 μm and a tensile strength of 1189 MPa. Thus, the co-carbonization of coal extract and petroleum residue is an effective method for the production of inexpensive spinnable pitch for isotropic carbon-fiber manufacture.

Development of Coal Chemistry at PAO Koks

At PAO Koks, in view of the small quantity of available coal tar, it is preferable to construct a system for processing heavy tar by atmospheric–vacuum distillation, with collection of the following products: soft coal pitch, vacuum-treated binding pitch, raw materials for carbon black (anthracene fractions 1 and 2), adsorbing oil, and a broad fraction (phenol + naphthalene).

Hierarchical porous carbon sheets derived from biomass containing an activation agent and in-built template for lithium ion batteries

We report a new strategy for synthesizing two-dimensional (2D) hierarchically porous carbon (HPC) based on soft pitch as the carbon source and oyster shell as both the template and activation agent precursor. The confined space of the sheet-like CaCO3 in oyster shell allows the soft pitch to diffuse and coat the in-built template, and the resultant 2D carbon derived from pyrolysis of the pitch inherited the sheet-like morphology of the template. Furthermore, CaCO3 can be easily converted into CaO, which acts as the self-activation agent to produce interconnected micro-, meso-, and macroporous carbon networks. The specific surface area of the resultant HPC was tuned from 612 to 1258 m2 g−1 by varying the pyrolysis time at 900 °C, and the resulting micro/meso-pore sizes were in the range of 0.7–9.5 nm. When used as the electrode of a lithium ion battery (LIB), the HPC exhibited a high reversible capacity of 1251 mAh g−1 at 0.1 A g−1 with excellent cycle stability. These results indicate that the 2D layered structure might effectively shorten the solid-state diffusion distance for Li ions in a LIB during the charging and discharging process. The interconnected hierarchical porous structure also improved the capacitance.

Thermal Conversion Characteristics of Coal Tar Soft Pitch at Atmospheric and Elevated Pressures

Coal tar soft pitch (CTSP) used as raw material of preparing needle coke was heat-treated at 460, 480 and 500 °C for different holding time under the pressure of 0 MPa and 0.25 MPa. The changes of group compositions such as toluene solubles (TS), toluene insolubles-quinoline solubles (TI-QS) and quinoline insolubles (QI) were mainly studies during the thermal conversion of the CTSP. The microstructure morphologies of some calcined cokes were characterized by scanning electron microscope (SEM). The results showed that the thermal conversion of the CTSP had the features of consecutive reaction, and the pressure could accelerate the conversion rate of TS and TI-QS and the formation rate of QI. The calcined coke derived from the semi-coke obtained at atmospheric pressure exhibited better and longer streamlined fiber structures than that of the semi-coke obtained at elevated pressure, while the latter possessed more compact carbon structures than the former.

Reducing the Effects of Game Day Pressures through Stress Exposure Training

There is a truism that “you play the way you train,” and like most bits of folk wisdom, this has an element of truth. When most baseball batters train, they hit soft pitches, work in a batting cage, and hit during batting practice, typically in a controlled setting with little to no stress. The problem is that most training takes place without systematic attention to preparing for game day demands, such as the heightened demands of actual competition, game day distractions, and other stressors present in the game day context. The purpose of this article is to describe a stress exposure training approach to prepare players to maintain effective performance under high demands. We discuss the implications of this approach for sports training.

Carbonization Regime Process of Coal Tar Refined Soft Pitch

The thermal behavior of coal tar refined soft pitch (CTRSP) was investigated by using polarizing microscope with heating stage and thermogravimetric analyzer. The phenomena of carbonization regime process of CTRSP were observed directly in the micro-picture taken online. The results showed that the carbonization thermal dynamic process of CTRSP is divided into several typical stages. At 30-250°C,there is small molecular evaporation; at 250-390 °C,there is thermal decomposition and small molecular evaporation; at 390-480°C,there is the condensation of small molecules and radicals into macromolecules and directional arrangement generating small spheres; at 480-520°C,there is the coking stage; at 520-560°C, there is the semicokes dehydrogenation and shrinkage. The spherules are formed at about 390°C. The growth process of the spherules is divided into several stages: absorption optical isotropic matrix asphalt to grow, two spherule collision fusion and growth, finally (at 480-520°C) due to gravity is greater than surface tension small spheroid disintegration deformation and became fibrillar semicoke (at 520-560 °C). Thermogravimetric (TG) - differential thermogravimetry (DTG) curve are treated by Freeman-Carrolls non isothermal differential method, coal tar soft pitchs first-order reaction is from 253°C to 325°C, from 370 °C to 413°C two temperature stages, activation energy is 28.575 kJ/mol and 60.210 kJ/mol, pre-exponential factor is 2.328×106 and 1.4833×107, respectively. The microscopic picture recording was consistent with thermal heavy kinetic equation and the results confirmed that the chief of thermal decomposition reaction is operated from 253 °C to 325 °C, the most of condensation polymerization reaction is operated from 370 °C to 413 °C.

Study on Carbonization Thermal Dynamic Process of Coal Tar Refined Soft Pitch

The carbonization thermal dynamic process of coal tar refined soft pitch(CTRSP) is studied by using a polarizing microscope with a heat stage. The pitch is preprated and it’s characteristics are that the soft point of 30°C, group compositions consist of 54.80% heptane soluble, 48.77% heptane insoluble but toluene soluble, 5.95% toluene insoluble but quinoline soluble and 0.08% quinoline insoluble, relative average molecular weight of about 292, average molecular structure of five- rings linear arrangement and cata-condensed structure. The polarizing microphotographs show that temperature of mesophase spherules beginning formation in the pitch is 440°C. To avoid speed of spherules generated is too fast, the temperature is decreased to 420°C at a rate of 10°C/min, and these spherules grow slowly at 420°C for 5 min. Then during temperature is raised to 500°C at rate of 3°C/min, these spherules change into bigger mesophase spheres because of absorbing matrix or colliding and coalescence between spherules. These bigger mesophase spheres absorb matrix or colliding and combine between bigger spherule again, finally because of gravity at 500°C, big mesophase spheres deform gradually, and develop into the semi-coke with streamline or clipper-built and/or coarse- fibrotic modality.

Wind Tunnel Testing of a Swashplateless Rotor with Compact Brushless Motor Actuated Flaps for Primary Control

A swashplateless rotor trim using brushless DC motor actuated trailing edge flaps was achieved in the Glenn L. Martin wind tunnel. A 6-ft-diameter, four-bladed articulated rotor with motor–flap system integrated into the NACA 0012 airfoil section was fabricated. A Maxon EC-10 brushless DC motor as an on-blade actuator and a lightweight mechanism were incorporated to actuate the trailing edge flap. The rotor torsion frequency was lowered to 2/rev using soft pitch links, allowing the blade pitch response to a trailing edge flap input. A closed-loop controller was employed to ensure trailing edge flap operation at desired amplitude with correct phase difference and in sync with the rotor azimuth. A trim methodology was implemented, and wind tunnel trim was achieved at 900 and 1200 RPM for a number of advance ratios. Results show that the brushless DC motors can provide sufficient primary control authority and have structural strength to withstand centrifugal loads, while fitting within airfoil profile and incurring minimal weight penalty.

Multi-salt coagulation of soft pitch colloids

The dynamic coagulation of colloidal pitch was quantified under orthokinetic conditions. The effects of single salt, multiple salt and cation valency on the stability of the colloidal pitch were investigated as a function of salt concentration. Critical coagulation concentrations (CCCs) were determined for a range of individual cations. The CCC in the presence of a number of divalent or trivalent cations was investigated to gain an understanding of the effect of multiple salts normally found in industrial systems.Electrostatic destabilisation of wood resin colloids by a single salt is strongly influenced by salt valency (z) and mostly independent of the individual cation (at constant z). Addition of a second cation to solution resulted in a decrease in the CCC for both calcium and aluminium ions in the presence of sodium ions. The decrease in the CCC for the wood resin colloids was non-linear and showed restabilisation of the colloids above the CCC, unlike the effects observed for a single salt. Comparison of the experimental CCC results with the DVLO theory indicates that a higher Hamaker constant than reported for the interaction of abietic acid with talc in water (used here as a model interaction) is needed. This suggests that the aggregation process of the wood resin colloids involves a stronger interaction than abietic acid with talc. Experimental CCC values for divalent and trivalent ions were also lower than those predicted theoretically. To obtain agreement between theory and experimental results, reduced Stern potentials and higher Hamaker constants were required, suggesting specific ion adsorption of the multivalent cations is occurring to reduce surface charge of the colloid.

Rubrics in Education: Old Term, New Meanings

The term is used widely in education. In classroom, rubric may mean set of categories, criteria for assessment, and gradients for presenting and evaluating learning. grading student's essay, for example, teacher may apply rubric for its quality of organization, giving 3 for Advanced Proficient, 2 for Proficient, and 1 for Partially Proficient. Other criteria that could be rubrics include use of examples, paragraph structure, grammar, and overall quality. Yet, like many terms in education, meaning of rubric is confusing. For example, Wiggins defines rubric of basic tools in assessor's kit ... telling us what elements matter most (1998, p. 153). Schmoker states that rubric simply means rule or guide ... by which students' performance or product is judged. It nails down criteria, making them available to schools, teachers, parents, and students and providing clear direction and focus (2006, pp. 70-71). And Guskey explains that rubrics specific guidelines that can be used to describe students' work in reading, writing, mathematics, and other content areas (1994, p. 25). The term, apparently, can refer to almost anything: rule, guide, criterion, or description that is used to assess progress of students in their academic subjects, well grading system for assessing each criterion. The term rubric has been used in English since 1400s, making it old it is interesting. The root of rubric refers to color red or red earth. The Oxford English Dictionary gives an example of term used in 1607: marrow of deer in sheep's milk with rubric and soft pitch, drunk every day, helps digestion and obstructions. Another meaning, closer to how it is currently used in education, is heading of chapter or division of book, written or printed in red ink or underlined in red for emphasis. In 1658, Phillips stated that rubric is a noted Sentence of any Book marked with red Letters. The Catholic Church has long employed term for directions for conducting Mass, which are printed in red and inserted into liturgical books. Foxe in 1583 explained that rubric is part of the whole Canon of Masse, with Rubricke thereof, it standeth in Masse/booke. John Wesley, founder of Methodist church, stated that as Minister, I teach her Doctrines. I use her Offices. I conform to her Rubricks. And in law, rubric is heading or title of statute or section of legal code (again, originally printed in red ink). In 1634, Kirk explained that When this Act came to be heard in open Parliament, his Majestie gave orders to read only rubricks of it. Red delineations, headings, and divisions--the term rubric has long and interesting history. APPLYING RUBRICS Educators today use rubric to refer to category of behavior that can be used to evaluate performance. The term is currently so popular that no one writing funding proposal would ignore laying out rubric for evaluating program's success. Today's rubrics involve creating standard and descriptive statement that illustrates how standard is to be achieved. For example, rubric for judging an essay would list everything student needs to include to receive certain grade on that essay. Generally, rubric also would specify what is needed to achieve different levels of performance, such what is needed for an A, B, etc. In addition to helping students know what they need to do to achieve certain grade, rubrics have other benefits: 1. A rubric can help teachers think carefully and critically about what they are teaching and what students need to learn. The rubric is predetermined set of categories. Whatever subject or project for which it's used, rubric will help teachers consider what's important for them to teach and how to determine level at which students have learned what's been taught. …

The dynamic behaviour of cricket balls during impact and variations due to grass and soil type

Stroboscopic photography was used to analyse the impact of cricket balls on experimental plots constructed using different soil and grass types. All impacts were carried out using the same initial dynamic conditions, designed to simulate fast–medium bowling. Significant differences in the impact behaviour were found between both the grasses and soils and simulated trajectory analysis showed that soil choice (within the set of seven soils used) had a greater overall effect than grass choice (within the set of 10 perennial ryegrass cultivars used). Correlations between the dynamic data, pitch measurements and soil characteristics were examined and it was found that a damp, soft pitch (such as Mendip Loam, with a high organic matter content) leads to a low rebound velocity with high top spin, whereas a firm, dry pitch (such as Kaloam, with a low organic matter content) leads to a high rebound velocity with low top spin. The factors concerning rebound angle were found to be more complicated. A hypothesis was made that this was due to the combined effect of restitution and deformation on the rebound angle.

Process Development for Production of Hard Pitch from Coal Tar for Electrode Industries.

Coal tar pitch is a residue of coal tar distillation and can be processed suitably to produce hard pitch of desired quality in terms of softening point (SP), benzene insoluble (Bl), quinoline insoluble (Ql), β-resin and coking value (CV). As per customer requirement, these properties could be achieved by controlling coal tar quality, different parameters during distillation of tar and processing of soft and medium pitch. Coal tar pitch with CV in the range of 55–58%, Bl content of 30–32%, Ql content of 13–16% and SP of 95–105°C, finds its use as a binder for manufacture of electrodes. During 1993, Bokaro Steel Plant (BSL), SAIL produced poor quality coal tar with high Bl and Ql content in it due to poor health of coke oven batteries. The by product plant, found it difficult to produce hard pitch to the specification of aluminium and electrode industries. The R&D Centre at SAIL in association with BSL undertook a project of process development for converting high Bl and Ql content tar to hard pitch by blending it with low Bl and Ql tar from other plants in an appropriate ratio, modifying operating procedure (tar flow rate to pipestill, second stage evaporator temperature, air flow rate & temp. of soft pitch in a batch reactor) to the customer's requirements. Bokaro Steel Plant produces and sells about 3000t/year of hard pitch to electrode industries.

小口径ガラスロッド端面の球面加工基礎理論と加工装置構想

This paper proposes a new convex spherical finishing method for end of small diameter glass rods, and also describes the kinematical basic theory and the newly designed polishing machine for obtaining spherical surface on them. The distinctive feature of this method is to use the lip type finishing tool whose form is hollow and a cone shape. The inner cone surface is used for tool surface. The spherical surface on end of glass rods is able to be formed by pushing the end of them perpendicu-larly against the inner cone surface of the tool, rotating the glass rods at low speed and the tool at high speed. The experiments are performed for optical small diameter glass rod works (φ2.0×L110 mm), using lip type grinding tool filled up with 7 μm diamonds uniformly to the inner cone surface and lip type polishing tool coated with soft pitch under supplying CeO2 powders slurry. Following conclusions are obtained : (1) Spherical radius R of the work can be changed continuously with adjustment of the work position against the tool. (2) Surface roughness and form accuracy values of spherical surface reach approximately 2 nm Rmax and 0.1 μm P-V, and R is 2.5 mm in agreement with the calculated value on the experiments.

乾式脱硫脱硝用活性コークスの製造に関する研究

Since the dry process for the simultaneous removal of SOx and NOx in the flue gas requires the coke of high mechanical strength, catalytic and adsorption abilities, its preparative procedure was studied . Such a coke has been successfully prepared through the consecutive steps which are fluidized coking of coal into semi-coke, formed coking of semi-coke with coal and soft pitch, and the activation with steam. The optimum conditions for the respective steps were studied to reveal the following conclusions.1) The optimum temperature of fluidized coking was between 480-500 t, semi-coke of highest surface area being obtained.2) Control of the mechanical strength of the active coke can be carried out using the Roga index of the blends.3) The carbonization temperature influenced the strength and reactivity of the coke in a contrary manner, 800°C appearing optimum.4) The activation increased to surface area but reduced the strength of the active coke. The treatment at 900°C for 40 min gave temporarily the best result.SOx adsorption and the catalytic activity for NOx reduction.

Improvements in Production Technique for Pitch-Coke

Nittetsu Chemical considered the use of coal tar soft pitch as raw material for coke production because of relatively abundant supply, relatively low cost, and the need for coke in Japan. Although pitch coke has been produced commercially coking at high temperature in coke ovens, Nittetsu was looking for a quicker and economical process to produce pitch coke. The expansion of alminum industry greatly increases the demand for coke especially coke with low sulfur, ash, and metal contents.Thus the world's first coking plant using coal tar sofe pitch was built in Tobata, Kita-Kyushu city, Japan. Delayed coking plant was designed to produce 75000 metric tons per year of green coke and calcining plant was designed to produce 60000 metric tons per year of calcined pitch coke.The basic design and engineering of Delayed Coking Plant was prepared by The Lummus Company in United States. The detailed engineering and construction of the plant were carried out by Toyo Engineering Corporation. The basic design and engine-ering of Calcining Plant was prepared by Petrocarb Incorporated in the United States.The detailed engineering and construction of the plant were carried out by Nissho-Iwai Co., Ltd.(Iwai & Co., Ltd. before merger) and Ishikawajima-Harima Heavy Industries Co., Ldt.Nittetsu Plant has been in continuous good operation from start up (August 26. 1968) except for the scheduled shut-down.The quality ofpitch coke by a new process is higher than petroleum coke and is now used for electrodes and anodes in the aluminum industry in Japan.

Water‐soluble polycarboxylic acids from the oxidation of coal‐tar pitch

AbstractA medium soft pitch has been oxidized in oxygen at elevated temperature and pressure in the presence of strong alkali to yield a complex mixture of water‐soluble aliphatic acids and aromatic polycarboxylic acids in about 30% yield based on carbon. By chromatography of the methylated hydrocarbons obtained from the acids and from infra‐red spectra, it is concluded that these acids have mainly polynuclear structures.

The chemical composition of high‐boiling fractions of coal tar. I. A steam distillate from a vertical‐retort soft pitch

AbstractA neutral oil boiling above 380°/760 mm., obtained from a soft vertical‐retort coal‐tar pitch, has been separated by chromatography into paraffin waxes, fluorescent oils, solids and brown residual oils.The fluorescent oils, which cannot be induced to crystallize, consist mainly of non‐picrate‐forming components, which have average molecular weights of about 250 and average hydrogen: carbon ratios of about 1·1:1. These oils are resistant to dehydrogenation.The chief components of the solids are: fluoranthene, pyrene, brazan, 2:3‐benzofluorene, 5:12‐dihydronaphthacene, chrysene and 1:2‐benzanthracene. Minor components that have been identified are: 4‐methylpyrene, 1:2:8‐trimethylphenanthrene, triphenylene, 2:3‐benzocarbazole, 1:2‐benzofluorene, an alkylbrazan and an unidentified compound, C16H10OS.1:2‐Benzocarbazole has been separated from the brown residual oils.Of these substances, 5:12‐dihydronaphthacene, 4‐methylpyrene and 1:2:8‐trimethylphenanthrene have not previously been isolated from coal tar.

ON THE PITCH TROUBLES AT PAPER MILLS AND PRESENT CONDITIONS OF CURING METHODS

After having given the causes and aspects of pitch trouble in various spots at Takasago mill of the Mitsubishi Seishi Co. the writer remarks that the extent of trouble may depend upon the kinds of pulp and paper made from, and suggests such curable methods as seen below : 1.Adding 24% of bleaching powder in beater and after treating for 2 hours, to make paper without washing.2.To blend both clay and size in beater after light beating.On judging from the results of his testing, he says that the chief cause of pitch troubles will lie rather in quality, but not in quantity, and it is judged by the degree of stickiness of pitches in pulp, for which test its tackiness ought to be measured.He suggests the following temporary methods as being effective for mill practices : 1.For the separation or isolated pitches washing out; dispersing and washing ;saponification ; salting out in beater ; Having on dandy roll sticked, etc.2.Hardening of soft pitches.3.Setting pitches on fiber.4.Co-operation with pulp makers.