Ash removal from inferior coal via ammonium fluoride roasting and simultaneous yield of white carbon black

The quality upgrading and deashing of inferior coal by chemical method still faces great challenges.The dangers of strong acid,strong alkali,waste water and exhaust gas as well as high cost limit its industrial production.This paper systematically investigates the ash reduction and desilicification of two typical inferior coal utilizing ammonium fluoride roasting method.Under the optimal conditions,for fat coal and gas coal,the deashing rates are 69.02%and 54.13%,and the desilicification rates are 92.64%and 90.27%,respectively.The molar dosage of ammonium fluoride remains consistent for both coals;however,the gas coal,characterized by a lower ash and silica content(less than half that of the fat coal),achieves optimum deashing effect at a reduced time and temperature.The majority of silicon in coal transforms into gaseous ammonium fluorosilicate,subsequently preparing nanoscale amorphous silica with a purity of 99.90%through ammonia precipitation.Most of the fluorine in deashed coal are assigned in inorganic minerals,suggesting the possibility of further fluorine and ash removal via flotation.This research provides a green and facile route to deash inferior coal and produce nano-scale white carbon black simultaneously.

A novel nanofluid of modified carbon black nanoparticles for enhanced oil recovery in low permeability reservoirs

A novel nanofluid of modified carbon black(MCB)nanoparticles was initially developed for enhanced oil recovery(EOR)in low permeability reservoirs.The MCB nanoparticles were obtained via a three-step reaction involving modification by oxidation,acyl chlorination,and activated grafting.MCB nano-particles were spherically dispersed,with an average size of 72.3 nm.Compared with carbon black(CB)nanoparticles,dispersed MCB nanoparticles can effectively reduce the oil-water interfacial tension(IFT)to 10^(-2)mN/m and change the surface wettability of sand particles.Based on the results of core flooding experiments,the MCB nanoparticles exhibited a better EOR capacity than surfactants and CB nano-particles,and the final oil recovery was significantly increased by 27.27%.The core scanning test showed that the MCB nanoparticles could plug high permeability channels by adsorbing onto the surfaces of sand particles and forming larger aggregates that bridge across pores or throats,resulting in a higher swept volume.The synergistic effects of improved swept volume and oil displacement efficiency were the EOR mechanisms of the MCB nanoparticles.The studies indicate that these MCB nanoparticles have excellent potential for EOR in low permeability reservoirs.

Effects of Conductive Carbon Black on Thermal and Electrical Properties of Barium Titanate/Polyvinylidene Fluoride Composites for Road Application

In the field of roads,due to the effect of vehicle loads,piezoelectric materials under the road surface can convert mechanical vibration into electrical energy,which can be further used in road facilities such as traffic signals and street lamps.The barium titanate/polyvinylidene fluoride(BaTiO_(3)/PVDF)composite,the most common hybrid ceramic-polymer system,was widely used in various fields because the composite combines the good dielectric property of ceramic materials with the good flexibility of PVDF material.Previous studies have found that conductive particles can further improve the dielectric and piezoelectric properties of other composites.However,few studies have investigated the effect of conductive carbon black on the dielectric and piezoelectric properties of BaTiO_(3)/PVDF composites.In this study,BaTiO_(3)/PVDF/conductive carbon black composites were prepared with various conductive carbon black contents based on the optimum ratio of BaTiO_(3)to PVDF.The effects of conductive carbon black content on the morphologies,thermal performance,conductivities,dielectric properties,and piezoelectric properties of the BaTiO_(3)/PVDF/conductive carbon black composites were then investigated.The addition of conductive carbon black greatly enhances the conductivities,dielectric properties,and piezoelectric properties of the BaTiO_(3)/PVDF/conductive carbon black composites,especially when the carbon black content is 0.8%by weight of PVDF.Additionally,the conductive carbon black does not have an obvious effect on the morphologies and thermal stabilities of BaTiO_(3)/PVDF/conductive carbon black composites.

Highly Sensitive Electrochemical Detection of Nitrite Based on Cationic Surfactant Modification of Conductive Carbon Black

Nitrite is a commonly used additive in cured foods and its sensitive detection is important to human health.In this work,a simple but sensitive electrochemical sensor for nitrite was developed.Conductive carbon black(VXC-72R)functionalized with a cationic surfactant cetyltrimethylammonium bromide(CTAB)was used as an electrode material,and was coated on a glassy carbon electrode(GCE)to fabricate the electrochemical sensor(CTAB/VXC-72R/GCE)for nitrite.Zeta potential characterization and a series of electrochemical tests were carried out on several materials.It was found that the present sensor showed an enhanced sensitivity towards nitrite detection due to the enhanced surface positive charge revealed by the Zeta potential.Under optimal conditions,the ranges of good linear relationship between the peak current and the nitrite concentration were obtained to be 0.5-5.0μmol/L and 5.0-1087.0μmol/L with a lower detection limit of 0.30μmol/L.It was also successfully used for the determination of nitrite in cured food samples with excellent reproducibility,stability and selectivity.

Understanding the Effect of Zinc Oxide(ZnO)With Carbon Black Coupling Agent on Physico-Mechanical Properties in Natural Rubber Matrix

Natural rubber(NR)is not only the main compounding ingredient used to make the majority of components of tires as well as other rubber products,as it plays a significant role in ensuring that they operate well and complies with environmental standards.The applications of NR products are lim-ited to high temperatures due to the revision tendency of NR vulcanizate.To address these issues,the potential engagement of a carbon black(CB)coupling agent(CA)in the presence of metal oxide i.e.Zinc Oxide(ZnO)was investigated in an NR-based system.This CA has dual functionality on physicomechanical properties.CA has the ability to reduce hysteresis loss as well as improve anti-reversion properties and these properties thorough-ly depend on the presence of ZnO.While ZnO was added to the master formulation,a 65%improvement in reversion properties was observed.On the other hand,while ZnO fully transferred to the final formulation,bound rubber(BR)content increased by 19%,the difference in storage modulus(ΔG’)is reduced by 22%,cure rate index(CRI)improved by 14%,loss tangent(tanδ)reduced by 18%and slightly improve in elongation at break compared to control compound.Thermo-gravimetric analysis(TGA)was engaged to understand the thermal stability and degree of purity of CA.A differential Scanning Calorimeter(DSC)was used to detect the phase tran-sition of CA.Fourier Transform Infrared Spectrum(FTIR)was adopted to detect the presence of carboxyl and amine groups in the CA moiety.Payne effect,BR content and Transmission Electron Microscope(TEM)were em-ployed to investigate the micro-level dispersion of CB in the natural rubber(NR)matrix.

Silver Supported on White Carbon Black Containing Rare Earths as Antibacterial Material

The antimicrobial effect of the Ag-White Carbon Black containing rare earth was investigated. Inorganic antibiotic materials consist of the antibacterial ion, the additive and the carrier. The sol-gel method was used to prepare the white carbon black carrier. Ag+ was selected to be the antibacterial ion, and cerous nitrate was selected to be the additive. They were synthesized on the white carbon black carrier. The structures and properties of antibacterial material were characterized by inductively coupled plasma, particle size measurement instrument, fourier transform infrared and enumeration tests (Escherichia coli as experimental bacterium). Results showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the general Ag-antibacterial white carbon black (without containing rare earth). Ag+ was bound to white carbon black by ion exchange process and adsorption process. Bacteriostasis rate is over 99%, and the particle size can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are good thermal and light stability. Furthermore, from the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.

Investigation of reinforcement of the modified carbon black from wasted tires by nuclear magnetic resonance

Pyrolysis has the potential of transforming waste into recyclable products. Pyrolytic carbon black (PCB) is one of the most important products from the pyrolysis of used tires. Techniques for surface modifications of PCB have been developed. One of the most significant applications for modified PCB is to reinforce the rubber matrix to obtain high added values. The transverse relaxation and the chain dynamics of vulcanized rubber networks with PCB and modified PCB were studied and compared with those of the commercial carbon blacks using selective 1H transverse relaxation (T2) experiments and dipolar correlation effect (DCE) experiments on the stimulated echo. Demineralization and coupling agent modification not only intensified the interactions between the modified PCB and the neighboring polyisoprene chains, but also increased the chemical cross-link density of the vulcanized rubber with modified PCB. The mechanical testing of the rubbers with different kinds of carbon blacks showed that the maximum strain of the rubber with modified PCB was improved greatly. The mechanical testing results confirmed the conclusion obtained by nuclear magnetic resonance (NMR). PCB modified by the demineralization and NDZ-105 titanate coupling agent could be used to replace the commercial semi-reinforcing carbon black.

INFLUENCES OF MODIFIERS ON SURFACE PROPERTIES OF WHITE CARBON BLACK AND MECHANICAL PROPERTIES OF SILICONE RUBBER

Various of modifiers were used to modify the surface activity of white carbon black. The oil absorption, viscosity, hydrophobic rate and burning loss of white carbon black and the mechanical propertiess of silicone rubber were measured. The influences of the modifiers on the properties of white carbon black and the mechanical properties of silicone rubber were discussed.

Influence of Water Content on Conductivity and Piezoresistivity of Cement-based Material with both Carbon Fiber and Carbon Black

The influence of water content on the conductivity and piezoresistivity of cement-based material with carbon fiber （CF） and carbon black （CB） was investigated. The piezoresistivity of cement-based material with both CF and CB was compared with that of cement-based material with CF only, and the changes in electrical resistivity of cement-based material with both CF and CB under static and loading conditions in different drying and soaking time were studied. It is found that the piezoresistivity of cement-based material with both CF and CB has better repeatability and linearity than that of cement-based material with CF only. The conductivity and the sensitivity of piezoresistive cement-based material with both CF and CB are enhanced as the water content in piezoresistive cement-based material increases.

Preparation and Properties of Rare Earth Modified Carbon Black/Natural Rubber Composites

The oxides Eu, Ho, Er and Dy were used to prepare the hydroxides of rare earth modified carbon black. Then natural rubber latex （NRL） was added into the reactor. The system reacted at 85 ℃ with stirring for 1 h to prepare powdered HAF-Ln（OH）3/NR composites. The effects of the kind and content of Ln on the particle size distribution of P [ NR/HAF-Ln （OH）3 ] and mechanical properties of its vulcanizate were studied respectively. It is found that rare earth can help to get the powder of the composite, the product particle with a diameter less than 0.9mm will be get when the composites containing the compound of Ho, Er and Dy with dosage of 1.0, 1.0, O. 5 percent, respectively. The adding of Ln can improve the tensile strength and tear strength of the vulcanizate effectively, what＇s more, Er and Dy can decrease the permanent set of vulcanizate significantly. The SEM studies shows that P[ NR/HAF-Dy （OH）3 ] vulcanizate shows superior mechanical properties that depend primarily on the absence of free carbon black, the fine dispersion of carbon black in the rubber matrix and better polymer-filler interaction.

Enhancement of the formic acid electrooxidation activity of palladium using graphene/carbon black binary carbon supports

Combinations of graphene(Gr)and carbon black(C)were employed as binary carbon supports to fabricate Pd‐based electrocatalysts via one‐pot co‐reduction with Pd2+.The electrocatalytic performance of the resulting Pd/Gr‐C catalysts during the electrooxidation of formic acid was assessed.A Pd/Gr0.3C0.7(Gr oxide:C=3:7,based on the precursor mass ratio)electrocatalyst exhibited better catalytic performance than both Pd/C and Pd/Gr catalysts.The current density generated by the Pd/Gr0.3C0.7catalyst was as high as102.14mA mgPd?1,a value that is approximately3times that obtained from the Pd/C(34.40mA mgPd?1)and2.6times that of the Pd/Gr material(38.50mA mgPd?1).The anodic peak potential of the Pd/Gr0.3C0.7was120mV more negative than that of the Pd/C and70mV more negative than that of the Pd/Gr.Scanning electron microscopy images indicated that the spherical C particles accumulated on the wrinkled graphene surfaces to form C cluster/Gr hybrids having three‐dimensional nanostructures.X‐ray photoelectron spectroscopy data confirmed the interaction between the Pd metal and the binary Gr‐C support.The Pd/Gr0.3C0.7also exhibited high stability,and so is a promising candidate for the fabrication of anodes for direct formic acid fuel cells.This work demonstrates a simple and cost‐effective method for improving the performance of Pd‐based electrocatalysts,which should have potential industrial applications.

Pseudo-capacitance of ruthenium oxide/carbon black composites for electrochemical capacitors

Hydrous ruthenium oxide was formed by a new process. The precursor was obtained by mixing the aqueous solutions of RuCl3xH2O and NaHCO3. The addition of NaHCO3 led to the formation of an oxide with extremely fine RuO2 particles forming a porous network structure in the oxide electrode. Polyethylene glycol was added as a controller to partly inhibit the sol-gel reaction. The rate capacitance of 530 F·g^-1 was measured for the powder formed at an optimal annealing temperature of 210℃. Several details concerning this new material, including crystal structure, particle size as a function of temperature, and electrochemical properties, were also reported. In addition, the rate capacitance of the composite electrode reached 800 F·g^-1 after carbon black was added. By using the modified electrode of a RuO2/carbon black composite electrode, the electrochemical capacitor exhibits high energy density and stable power characteristics. The values of specific energy and maximum specific power of 24 Wh·kg^-1 and 4 kW·kg^-1, respectively, are demonstrated for a cell voltage between 0 and 1 V.

Microstructure and tensile properties of magnesium nanocomposites fabricated using magnesium chips and carbon black

In this study,carbon black(0,0.01,0.03 and 0.08 wt%)and AZ31(Mg-3Al-lZn)magnesium chips were used to fabricate carbon black-reinforced magnesium matrix composites with extrusion or a combination of extrusion and high-ratio differential speed rolling.After hot pressing at 693 K and extrusion at 623 K with an extrusion ratio of 22,the magnesium chips coated with carbon black were soundly bonded into a bulk composite material.The grain sizes of the extruded materials were similar with a size of 48.2-51.5|im despite the difference in the amount of carbon black.The yield strength and ultimate tensile strength increased from 177 to 191 MPa and from 240 to 265 MPa,respectively,as a result of the addition of 0.01%carbon black;however,a further increase in the strength was marginal with additional carbon black.The same trend was observed in the strain hardening behavior.The tensile elongation increased by to the addition of 0.01%carbon black(from 15.8%to 17.4%)due to the increased work hardening effect,but decreased with additional carbon black due to its agglomeration and poor dispersion at higher concentration.After high-ratio differential speed rolling(HRDSR)on the extruded materials and subsequent annealing,the AZ31 and AZ31 composites had a similar fine grain size of 16.3-17.9 p.m.The annealed HRDSR composites showed the best mechanical properties at a higher content of carbon black(0.03%)compared to that(0.01%)for the extruded composites.This resulted from the enhanced dispersion effect of the carbon black due to the high shear flow induced during the HRDSR process.The extruded composites exhibited the three distinct hardening stages(stage II,stage III and stage IV),while the annealed HRDSR composites mainly displayed the stage III hardening.The addition of carbon black increased the strain hardening rate at all the strain hardening stages in both of the extruded and annealed HRDSR materials.At the initial hardening stage,the strain hardening rates of the extruded composites were higher than those of the annealed HRDSR composites,but this became reversed at the later stage of hardening.Possible explanations for this observation were discussed.The strength analysis suggests that dislocation-carbon black interaction by Orowan strengthening and dislocation generation due to a difference in thermal expansion between matrix and carbon black are the major strengthening mechanisms.

Study on the optical limiting properties of the mixed liquid of carbon black suspensions and green tea solution by multi-pulse laser

The optical limiting properties of the mixed liquid of carbon black suspensions （CBS） and green tea solution were studied by using an 8 ns laser pulse at 532 nm. The optical limiting effects of the CBS and mixed liquid have been compared between 5 and 10 Hz repetition frequencies with nanosecond laser pulse. The experimental results indicate that the optical limiting threshold of the sample with the incidence laser at 10 Hz repetition frequency is lower than at 5 Hz repetition frequency. The possible reasons for the influence of the repetition frequency on the samples are discussed. And by observing the optical radiant distributions when the laser pulse passing through different samples, a possible mechanism for the observed effects is suggested. At the same time, the result shows that the optical limiting of CBS is the dominant factor to optical limiting of the mixed liquid.

Improved visible-light photocatalytic H_2 generation over CdS nanosheets decorated by NiS_2 and metallic carbon black as dual earth-abundant cocatalysts

CdS nanosheets(NSs)photocatalysts modified with dual earth‐abundant co‐catalysts of metallic carbon black(CB)and NiS2were synthesized by a two‐step solvothermal/impregnation method.Allthe experiment results demonstrated that the co‐loading of CB and NiS2could significantly enhance the photocatalytic H2‐evolution activity of CdS NSs.The photocatalytic performance of the as‐prepared CdS/CB/NiS2samples was tested under visible light(λ≥420nm)by using an aqueous solution containing0.25mol L–1Na2S‐Na2SO3as the sacrifice agent.The CdS‐0.5%CB‐1.0%NiS2composite photocatalysts exhibited the highest H2‐evolution rate of166.7μmol h?1,which was approximately5.16and1.87times higher than those of pure CdS NSs and CdS‐1.0%NiS2,respectively.The possible mechanism for the enhanced H2‐evolution activity of CdS/CB/NiS2composite photocatalysts was proposed.The results showed that the enhanced photocatalytic H2‐evolution activities could be ascribed to the co‐loading of metallic CB and NiS2as co‐catalysts onto the surface of CdS NSs.The excellent synergetic effect between the CB and NiS2could obviously improve visible light absorption,promote separation of photogenerated electron‐hole pairs and boost the H2‐evolution kinetics,thus leading to an enhanced activity for H2evolution.More interestingly,the metallic CB could not only act as a cocatalyst for H2evolution,but also serve as a conductive electron bridge to promote the charge migration.This work not only demonstrates that loading CB as a co‐catalyst is a promising strategy to further boost the photocatalytic activity of CdS/NiS2composites,but also offers a new mechanistic insight into the construction of highly efficient and stable CdS NSs‐based hybrid photocatalysts with dual earth‐abundant co‐catalysts for photocatalytic applications.

Effect of Nano Carbon Black and Graphite Flake on Properties of Low Carbon Al2O3-C Refractories

Low carbon Al2O3 - C refractories specimens were prepared with tabular alumina （3. 0 - 1.0, 1.0 - 0. 5, 0.6-0.2, ≤0.3, ≤0. 045 and ≤0. 02 mm）, active alumina micropowder （≤2 μm ） and silicon （ 〈≤0. 045 mm ） as main raw materials. Nano carbon black （N220） and natural graphite flake （ 〈≤0. 074 mm ） were adopted as the carbon sources. The specimens were treated at 800, 1 000, 1 200 and 1 400 ℃ under coke embedded atmosphere. The effects of additions of nano carbon black and graphite flake on mechanical properties and thermal shock resistance of the specimens were stud- ied. Their mechanical properties were measured by three- point bending test and thermal shock resistance was de- termined by water quenching method. The phase compo- sition of the specimens was analyzed with X-ray diffrac- tion and microstruetures were observed through FESEM. The results reveal that： （1） the strengths of A1203 - C refractories with these two carbon sources show no big differences when coked at lower than 1 000 ℃ ; when coked at over 1 200 ℃ , the strengths of the specimens with graphite added are much higher than those of the specimens containing carbon black due to much more sil- icon carbide whiskers formed; （2） since the nano carbon black has small particle size, they can be filled into in- terstice of Al2O3 particles to form the nano carbon net- work structure, absorbing and relieving the thermal stressgenerated from expansion and contraction and reducing the thermal expansion coefficient of the specimens, thus their thermal shock resistance is better than that of the specimens containing graphite ; （ 3 ） low carbon Al2 O3 - C refractories with good mechanical properties and excellent thermal shock resistance can be prepared with combi- nation of nano carbon black and graphite flake.

Synthesis of Cordierite by Decomposition of Metal Nitrates on the Surface of Carbon Black Powder

Cordierite precursor was obtained through a process, which involved the decomposition of metal nitrates on the surface of ultrafine carbon black powder between 100-300℃ and the gasification of the carbon black at higher temperature in air. The average size of the particles, which were heat-treated at 700℃ for 10h, is about 1020nm, and the specific surface area is about 129m 2/g. The experimental results show that the ultrafine particles of cordierite precursor can be produced by this process. The precursor powder was calcined at different temperatures. X-ray diffraction examination indicates that β-quartz is crystallized from the amorphous matrix around 850℃ firstly and then MgO-Al 2O 3 spinel and α-cordierite appears. Above 1000℃, MgO-Al 2O 3 spinel and cristobalite disappear gradually and form an intermediate phase (sapphirine). At around 1300℃, the main phase is α-cordierite, and no other phase is detected.

NANOMECHANICAL MAPPING OF CARBON BLACK REINFORCED NATURAL RUBBER BY ATOMIC FORCE MICROSCOPY

Atomic force microscopy （AFM） has the advantage of obtaining mechanical properties as well as topographic information at the same time. By analyzing force-distance curves measured over two-dimensional area using Hertzian contact mechanics, Young＇s modulus mapping was obtained with nanometer-scale resolution. Furthermore, the sample deformation by the force exerted was also estimated from the force-distance curve analyses. We could thus reconstruct a real topographic image by incorporating apparent topographic image with deformation image. We applied this method to carbon black reinforced natural rubber to obtain Young＇s modulus distribution image together with reconstructed real topographic image. Then we were able to recognize three regions; rubber matrix, carbon black （or bound rubber） and intermediate regions. Though the existence of these regions had been investigated by pulsed nuclear magnetic resonance, this paper would be the first to report on the quantitative evaluation of the interfacial region in real space.

The Influence of Unidirectional Pressure on Electrical Conductivity of Carbon Black Filled Polyethylene

High density polyethylene filled with condutuctive carbon black was prepared by conventional meltmixing method. The effect of unidirectional pressure on the conductivity was studied. Wide angle X-ray diffraction （ WAXD ） was used to slum： the influence of pressure on the aggregate structure of the polymer filled with carbon black （CB） fillers. A model on the basis of the formation and destruction of conductive networks was proposed to explain the change in the conductivity with the application of pressure.

A New Grade Carbon Black Produced by Thermal Plasma Process

This paper presents a new route about producing carbon black, by which the natural gas cracking is carried out in the absence of oxygen thanks to an electric energy supply externally given by a plasma jet. The carbon black produced by this process has a narrow size distribution and a small average diameter of 38 nm as well as a highly branched aggregate. The higher DBP value of 1.40 ml/g shows it should be a high structure carbon black. The FTIR spectra shows that there are lots of aromatic c-c bonds and a large amount of nitrogen-containing functional groups on the carbon blacks surface, such as -NH, -CN as well as -CH, -OH, -COOH groups.