Influence of Morphology and Particle Size of Powdered Rubber on Mill Processing

1975 ◽  
Vol 48 (2) ◽  
pp. 254-262 ◽  
Author(s):  
P. L. Bleyie
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Granular Material ◽  
Specific Energy ◽  
Mixing Time ◽  
Considerable Effect ◽  
Area Increase ◽  
Surface Area Increase ◽  
Powdered Rubber ◽  
Carbon Black Dispersion

Abstract The powdered rubber method leads to a considerable shortening of mill mixing time and hence to a reduction of the specific energy required. While the transition from granular material to powder (from above 1 mm to below 1 mm particle size) has considerable effect both on mixing time and on specific energy, the effect of size reduction on specific energy for sizes below 1 mm is substantially smaller than expected from the surface area increase, probably, because a large part of the energy is used for carbon black dispersion. No effect of specific surface on specific energy and mixing time was found.

A Comparison of Methods for Determining Surface Areas of Carbon Black

1973 ◽  
Vol 46 (1) ◽  
pp. 192-203 ◽  
Author(s):  
R. A. Klyne ◽  
B. D. Simpson ◽  
M. L. Studebaker
Keyword(s):  
Carbon Black ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Surface Areas ◽  
Furnace Black ◽  
Area Increase ◽  
Experimental Errors ◽  
Specific Surface Areas ◽  
Surface Area Increase

Abstract 1. The various tint tests correlate with each other—it does not make much difference which of the three procedures is used. The discrimination between similar blacks is comparable. Specific surface areas obtained by the three methods are comparable and differences appear to be due to experimental errors. (Compare Figures 5–7). 2. Surface areas larger than some 90 to 100 m2/g cannot be reliably determined from tint strength measurements alone. 3. Structure exerts a pronounced effect on tint strength of furnace blacks, especially above 90 to 100 m2/g. Porosity and/or composition are apparently also variables which affect tinting strength. 4. Densichron reflectance on the dry carbon black can be used to estimate specific surface areas up to about 140 m2/g; but, since theabsoluteerrorincreases as the specific surface area increases, this method loses some of its reliability at values above about 110 m2/g. The relative error in reflectance determinations does not vary greatly over the furnace-black range. Densichron reflectance is influenced by composition, evidently due to composition-related differences in optical properties of the carbons. 5. In CTAB adsorption measurements, titration errors and handling errors tend to be rather constant for blacks of different surface area. Hence, CTAB permits better discrimination among blacks of small particle size. 6. The errors in Densichron reflectance surface area increase with specific surface area. Hence, the deviations between CTAB and reflectance surface area which are due to experimental error increase with the surface area of the sample.

Research on Mechanochemical of Silica and its Composite Powders

2014 ◽  
Vol 881-883 ◽  
pp. 1487-1491 ◽  
Author(s):  
Jing Jing Zhu ◽  
Hua Zhi Gu ◽  
Tian Xing Peng ◽  
Bao Hua Sun
Keyword(s):  
Particle Size ◽  
Crystal Size ◽  
Lattice Distortion ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
X Ray ◽  
Peak Intensity ◽  
Area Increase ◽  
Surface Area Increase ◽  
Grinding Time

Silca and its composite powders added different amount of microsilica were ground in a planetary ball mill (QM-3SP4) at various grinding period with addition of a certain number of grinding aid. The effects of mechano-chemical on particle size, crystal size and lattice deformation in grinding process were analyzed. The phase compositions and size compositions of the treated powders were investigated by X-ray Diffraction (XRD) and Laser Particle Size Analyzers. With the increase of grinding time, the particle size decrease, the specific surface area increase, and the more amount of microsilica added, the smaller particle size the powders had after grinding. The XRD results showed that the diffraction peak intensity of powders weaken and gradually widen. The surface of the particle happened to amorphization, and occurred grain refinement and lattice distortion. Comparing with other treated powders, the change of the powders with the microsilica addition of 5% was larger. Even though the grinding time reached to 30h, the crystal transformation of SiO2has not been detected.

The Dispersion of Carbon Black in Rubber Part I. Rapid Method for Assessing Quality of Dispersion

1992 ◽  
Vol 65 (5) ◽  
pp. 973-997 ◽  
Author(s):  
A. Y. Coran ◽  
J-B. Donnet
Keyword(s):  
Carbon Black ◽  
Mixing Time ◽  
Poor Performance ◽  
Raw Material ◽  
Rubber Part ◽  
Reproducible Method ◽  
Internal Mixer ◽  
Kinetics Of ◽  
Carbon Black Dispersion

Abstract Carbon black is the most important reinforcing filler for rubbers. The incorporation of carbon black into rubber vulcanizates generally gives improved strength, extensibility, fatigue resistance, abrasion resistance, etc. In order to exert its beneficial influence on the properties of rubber vulcanizates, the carbon black must be sufficiently dispersed therein. Indeed, poor dispersion can, in itself, give rise to detrimental effects (e.g. reduced product life, poor performance in service, poor product appearance, poor processing characteristics, poor product uniformity, raw-material waste, high finished-product rejection rates, and excessive energy usage). These inadequacies are generally the result of the presence of rather large, undispersed agglomerates. The present work was initiated in order to develop an improved understanding of the carbon-black dispersion process including the understanding of factors which affect the kinetics of dispersion. The work described here is focused on methodology for reproducibly mixing carbon black with rubber in the laboratory, and reproducibility, but rapidly and easily estimating the degree of dispersion of the carbon black into the rubber as a function of mixing time. Procedures were developed for introducing rubber, filler, and other ingredients into a small, laboratory internal mixer and for mixing the batches for various periods of time. Also, an improved, simple-to-use, reproducible method for determining the degree of carbon black dispersion in rubber has been adapted. The extent of dispersion was correlated with various measures of tensile strength and with other performance-related properties.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

scholarly journals The Study of Carbon Recovery from Electrolysis Aluminum Carbon Dust by Froth Flotation

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 145
Author(s):  
Hesong Li ◽  
Jiaoru Wang ◽  
Wenyuan Hou ◽  
Mao Li ◽  
Benjun Cheng ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Mixing Time ◽  
Froth Flotation ◽  
Aluminum Electrolysis ◽  
Carbon Powder ◽  
Molten Salt Electrolysis ◽  
Carbon Recovery ◽  
Aluminum Smelting

A large amount of carbon dust is generated in the process of aluminum smelting by molten salt electrolysis. The carbon dust is solid hazardous waste but contains a large quantity of recyclable components such as carbon and fluoride. How to recycle carbon dust more effectively is a challenge in the aluminum electrolysis field. In this study, X-ray diffraction, scanning electron microscope, and other methods were used to analyze the phase composition of electrolytic aluminum carbon dust. The effects of particle size distribution of carbon dust, impeller speed, reagent addition, mixing time, and flotation time on the flotation recovery of carbon dust were studied. The optimal flotation conditions were obtained and the flotation products were analyzed. The results show that the optimal particle size distribution is 70% of particles below 200 mesh, corresponding to a grinding time of 11 min. The optimum speed of the flotation machine was to be between 1600 and 1800 r/min with the best slurry concentration of 20–30% and 5 min mixing time, and the collector kerosene was suitable for adding in batches. Under the above conditions, the recovered carbon powder with a carbon content of 75.6% was obtained, and the carbon recovery rate was 86.9%.

States of Carbon Black Dispersion and Extensibility of Rubbers

1993 ◽  
Vol 66 (2) ◽  
pp. 317-328 ◽  
Author(s):  
Asahiro Ahagon
Keyword(s):  
Carbon Black ◽  
Tensile Property ◽  
Crosslink Density ◽  
Hydrodynamic Effect ◽  
Property Variation ◽  
Agglomerate Size ◽  
Filled Rubber ◽  
Two Temperatures ◽  
Confined Polymer ◽  
Carbon Black Dispersion

Abstract Analysis is made for the origin of the mixing-induced tensile property variation of a filled rubber. Attention is paid to the hydrodynamic effect f(ϕe) of the filler, defined here as the factor to adjust the deviation of 100% modulus from the theory of rubber elasticity. For the rubbers mixed under variety of conditions, the f(ϕe)'s are calculated from the observed values of the modulus, at 25°C and 100°C, and the crosslink density. The variation of the f(ϕe) is considered to be governed by the mobility of the polymer confined in agglomerates of the filler. The mobility variation due to mixing seems to be mainly influenced by agglomerate size at 25°C, and by agglomerate size and chemical constraints at 100°C. Therefore, the f(ϕe)'s at the two temperatures are suggested to be useful measures of the state of carbon-black micro-dispersion. The extensibility of the rubbers is closely related f(ϕe). This indicates that the failure property is also governed by the mobility of the confined polymer.

Effect of Diameter and Surface Area of Carbon Black Particles on Certain Properties of Rubber Compounds

1944 ◽  
Vol 17 (2) ◽  
pp. 451-474
Author(s):  
D. Parkinson
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Carbon Black ◽  
Abrasion Resistance ◽  
Particle Diameter ◽  
Stiffness Modulus ◽  
Carbon Structures ◽  
Rubber Compounds ◽  
Regular Manner ◽  
Tear Resistance

Abstract Carbon blacks can be grouped into different classes according to the way in which their fineness of division relates to different properties in rubber. Within any one class the principal properties vary in a regular manner with particle size. The normal class consists of the furnace carbons, Kosmos (Dixie)-40, Statex, the rubber-grade impingement carbons, and possibly, the color-grade impingement carbons. The subnormal classes consist of thermal carbons and acetylene and lamp blacks. Irrespective of the above classification, the properties which depend more on fineness of division than on other factors are rebound resilience, abrasion resistance, tensile strength and tear resistance. The lower limit of particle diameter for best tensile strength and tear resistance appears to be higher than that for abrasion resistance. B.S.I, hardness and electrical conductivity are properties which depend at least as much on other factors as on particle size. Stiffness (modulus) depends more on other factors than on particle size. Factors modifying the effects of particle size (or specific surface) include the presence of carbon-carbon structures and a reduction in strength of bond in rubber-carbon structures. Carbon black is thought to exist in rubber in four states: agglomerated, flocculated, dispersed, and bonded to the rubber molecules (the reënforcing fraction). Abrasion resistance is regarded as providing the only reliable measure of reënforcement.

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