Specific Surface

specific surface

[spə′sif·ik ′sər·fəs]
(chemical engineering)
The surface area per unit weight or volume of a particulate solid; used in size-reduction (crushing and grinding) calculations.

Surface, Specific


an averaged characteristic of the dimensions of the internal cavities, canals, or pores of a porous body or of particles of a finely divided phase of a disperse system. The specific surface expresses the ratio of the total surface of a porous or dispersed substance in a given medium to its volume or mass. The specific surface is proportional to the dispersity; that is, it is inversely proportional to the particle size of the dispersed phase. The adsorptive capacity of adsorbents, the effectiveness of solid catalysts, and the properties of filter materials all depend on the magnitude of the specific surface.

Values of the specific surface are 500–1,500 m2/g for activated carbons, up to 800 m2/g for silica gels, not more than 70 m2/g macroporous ion-exchange resins, and less than 10 m2/g for diatomaceous carriers for gas-liquid chromatography. The specific surface characterizes the dispersity of such powdery materials as fillers, pigments, powdered fuels, and mineral binders. The values of the specific surface of these materials usually range from several tenths of 1 m2/g to several dozens m2/g.

The specific surface is usually determined by the amount of inert gas absorbed by the material or according to the air permeability of a layer of powder or porous material. The adsorption methods provide the most reliable values.


Gregg, S., and K. Sing. Adsorbtsiia, udel’naia poverkhnost’, poristost’. Moscow, 1970. (Translated from English.)
Kouzov, P. A. Osnovy analiza dispersnogo sostava promyshlennykh pylei i izmel’chennykh materialov, 2nd ed. Leningrad, 1974.


specific surface

In a unit weight of a material, the surface area of the contained particles.
References in periodicals archive ?
Objective: The overarching goal of this proposal is to develop a novel experimental framework for quantifying the total specific surface area of organic matter and the wettability of pores in shales, And interpreting the displacement mechanism between gas and water by using a selective adsorption approach coupled with independent verified electron microscope measurements.
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The aim of this research is to study the regularities of extraction process of tarry substances of manufacturing sewage of an ammonium sulphate with use of sodium and calcium bentonites, an absorbite and peat, and definition of a specific surface area of the specified adsorbents.
For the comprehensive effect of spatial structure and specific surface area, the WHC changed in a certain range when the particle size of the powder was below a certain size.
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1 to 100 nm; and a specific surface area of 1 to 4000 [m.
Specific surface area, pore volume and average pore size of the samples were determined from low temperature nitrogen adsorption isotherm by BET method on a TriStar II 3020 analyzer (Micromeritics, USA).
We took samples of undisturbed addition and defined hydro-physical properties (volume weight, particle density, volume humidity, void space, permeability coefficient, volume specific surface area, volume specific energy) on the chosen testing areas.
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