Blaine method

The specific surface area of eement is eommonly determined directly by air. permeability methods. In the Lea and Nurse method (LI 5). a bed of cement / of porosity 0.475 is eontained in a cell through which a stream of air is f passed, and steady flow established. The specific surface area is caleulated ( from the density of the eement, the porosity and dimensions of the bed of j powder, the pressure differenee aeross the bed, and the rate of flow and ] kinematie viscosity of the air. In the Blaine method (B36), a fixed volume of I air passes through the bed at a steadily deereasing rate, whieh is controlled / and measured by the movement of oil in a manometer, the time required i being measured. The apparatus is ealibrated empirically, most obviously / using a cement that has also been examined by the Lea and Nurse method. The two methods gave elosely similar results. The Blaine method, though not absolute, is simpler to operate and automated variants of it have been devised. 

FIG. 12. External surface area of calcined AI2O3 calculated from particle-size distribution (/) and determined by the Blaine method... 

The optimmn gypsum content is influenced also by the fineness of cement and the content of alkali. The gypsum addition increases with the specific surface area of cement S (by Blaine method, in m /kg) and with the Na O, content. The following correlation has been proposed by Ost [40] ... 

The fineness of cement may be conveniently characterized by the Blaine method, even though the values obtained by this procedure are systematically lower than those found by the more accurate, but also more complicated, BET method. The specific surface area of ordinary Portland cement typically ranges between 280 and 350 m /kg (Blaine), whereas high early strength cement may be groimd up to a specific surface area of 450-500 m /kg (Blaine). This higher smface area contributes to an accelerated hydration of the cement, but also increases its water requirement. 

Cement by Air Flow. Blaine Method. Ditto Federal Test Method... 

The fineness of grinding of cements may be determined by sieving or a separation method (the fineness being expressed as a certain percentage by weight above a certain size, e. g., as residue retained on a standard sieve), but is more usually based on the specific surface determined by the Blaine method (air permeability of a bed of cement, the result being expressed in cm /g the finer the cement, the higher the specific surface) (see also Section X.1). 

One of the industries where there is continuous research for automatic on-line control of the fineness of a product is the cement industry. For many years they have used the Blaine fineness number deduced from the data obtained using the simple permeameter discussed in the previous section. A problem with the classical Blaine method is the fact that it is labour intensive and, to some extent, operator dependent. The type of variation that is encountered in cement producdon is shown in the Figure 9.5. In this diagram the Blaine fineness tester data for a production run is compared to information generated by a diffractometer known as the Microtrac [24,25, see also Chapter 7]. 

Specific Surface Area Sneeifie surface area of iron ore is measured by Blaine method (GB8074-87), the test is done in Blaine breathable instrument [7, 8]. 

GB/T 8074-1987.Testing Method for Specific Surface of Cement—Blaine Method. 

The Blaine method [2S] is the standard for the cement industry in the United States and, although based on the Carman-Kozeny equation, it is normally used as a comparison method using a powder of known Surface area as a standard reference. 

Uagner turbidimeter Dito AASHTO T 98, ANSI A 1.7 Standard for the determination of the fineness of Portland cement by air flou Blaine method ... 

There are several methods to determine the SSA of cement powder. The method most widely used by the cement industry is the Blaine air permeability as it is a simple and quick method. The SSA determined by the Blaine method is referred to as Blaine fineness and it is expressed as total surface... 

The Blaine method suffers from various weaknesses and limitations that can compromise the reliability of the results. The empirical calibration and its poor reproducibility (the value of SSA obtained is clearly influenced by the person who runs the test) are examples of the weakness of this test. In addition, cement particles are not mono-sized and spherical as the calculation of the Blaine fineness assumes. 

Unlike the Blaine method, the LD method does not require calibration, but it involves the assumption of the spherical particle geometry. As in the case of the Blaine method, SSAs calculated by LD are significantly lower than the true value as surface roughness and porosity of the particles are not considered. In addition, as explained above, the refractive index of the powder in the dispersive media must be known. The value of refractive index of cement is agreed upon but this value has not been determined accurately for certain supplementary cementitious materials. In some cases, the SSA from LD can give a reasonable assessment (e.g. fly ash in Table 10.1), in other cases it can be very low such as for heavily agglomerated powder (e.g. clays in Table 10.1). 

In contrast with the air permeability test and LD techniques, nitrogen adsorption does not postulate the particle shape and size or include semi-empirical equations. Nitrogen adsorption also considers the irregularities and porosity of the particles and that is why it is considered a more reliable technique for the scientific community. In addition, the Blaine method or LD techniques are not suitable to determine the SSA of hydrated cement as they are not able to measure correctly fine agglomerated particles as found in most hydrates (Yamada 2011). 

R. L. Blaine and C. K. Schoff, Purity Determinations by Thermal Methods, ASTM Press, Philadelphia, 1984. 

Blaine (1941) used the Carman method, modified by Lea and Nurse (1939), to determine the specific surface of cement and developed a con-... 

Sarthou G, Baker AR, Blain S, Achterberg EP, Boye M, Bowie AR, Croot P, Laan P, de Baar HJW, Jickells TD, Worsfold PJ (2003) Atmospheric iron deposition and sea-surface dissolved iron concentrations in the eastern Atlantic Ocean. Deep-Sea Res 50 1339-1352 Schafer H, Muyzer G (2001) Denaturing gradient gel electrophoresis in marine microbial ecology. In Paul J (ed) Methods in microbiology, vol 30. Academic Press, London, pp 425-468... 

Weiland [42] used a similar idea but based on the Blaine permeability method. An automatic weigher produced a packed bed of powder, of known voidage, in a standard cell. Air was drawn through the bed by the passage of water from one reservoir to another. After a certain volume of air had passed through the bed, measured by a certain volume of water flowing, the time required was converted to an electrical proportionality... 

Permeabilimetry (Blaine Fisher) Gas adsorption (BET method) Porous volume obtained by MIP PSD obtained by laser light scattering... 

Figure 5 comparison between SSA values obtained by Blaine Fisher and BET methods... 

The methods used to prepare solid supported macrocyclic ligands are not difficult. These materials have been used to remove cations from water and other solvents. This is an exciting new area of research that can lead to important new methods to remove, concentrate, and recover toxic heavy metals and the precious metals from industrial waste streams (Blain et al., 1990, 1991 Bradshaw et al., 1988a, 1989a, 1989b Izatt et al., 1988 1990 Porath, 1991). 

Blaine and Fair (55) determined new estimates for the true magnetic transition temperatures of the ICTA Certified Magnetic Reference Materials GM761, using a six-point calibration method. The results of the magnetic transition temperatures obtained are presented in Table 3.2. Experimental measurement precision varied from 0.81°C for nickel to 3.2°C for Permanorm 3. The narrowest magnetic transition temperature was 3.0°C for nickel, whereas the widest was 13.1°C for Permanorm 3. A pooled standard deviation of 2.0°C could be calculated from these data. The experi-... 

Physically, cement kiln dust (CKD) and lime kiln dust (LKD) are fine, powdery materials of relatively uniform size. Approximately 75% of the kiln dust particles are finer than 0.030 mm. The fineness of kiln dust, as Portland cement, can be determined using the Blaine air permeabihty apparatus in accordance with ASTM method C204 [88-98]. 

Materials and Methods. The Portland cement used was ternary blend cement, Cemento 5-5 , from Cemento Loma Negra, Argentina, with 300 m /kg of blaine surface. PVA was provided by Quimica Oeste, Buenos Aires, Argentina, and the hydrolysis degree is 88%. The clay was provided by Minarmco, Argentina. It was a sodic bentonite and it was used as received. 

R.L. Blaine ud C.K. Schoff(Edx). Parity Dctermiiutioax by Theniul Methods" ASTM Special Technical Pablication 108. Amencan Society for Testing and Materials. Philadelphia. 1984. 

S. A Morus, in "Purity Dcicrminaiions hy Thermal Methods". (Eds R L, Blaine iiod C.K. Seboff). ASTM S]X ia) Tovhnicul Publication 838, Ameitcan Sociely forTcMing and Materials. Philadelphia, 1984, p.22. 

J.E- Hunter III and R-U Blaine, in "Purity DcKtmmatioos by Thennal Methods" (Eds R.L. Blaine and C.K. Schoff), ASTM Special Technical Publication 838. Ameticaa Socteiy for Testing and Matenals. Philadelphia. I9S4. p39. 

J.P. Eldef. tn Purity Deieiniinuloih by Thermal Methods", (E3ck R.I.. Blaine and C.K SebofT). ASTM Special Technical Publication 838, American Sociely for Testing and MateriaK. PfeiLtdelpbia, 1984, p.S0,... 

A.R. MeOhie. in "Purity Deicrminotions by Thermal Methods", i Eds R.L. Blaine and C.K. SchofO. ASTM Special Technicnl Publicaiion 8.38, American Sociely for Tesliitg and Materials. Philadelphia, 1984, p,6l. 

C.K. Schorr, in Puniy Dctcraiinaliom by ThcrmaJ Method. tEdi ILL. Blaine... 

R.L. Blaine and C.K. SchofftEds). Purity Dcteraiinatioiui b) Thermal. Methods,... 

The Ono parameters were found to be the dominant variables (above chemical composition, including the normal moduli and porosity) in an experiment to explain problems of grindability (Kawamura and others, 1982). These authors gave the following equation to predict the Blaine surface area (BL) with the Ono method, stating the microscopical factors in the arbitrary scale of 4, 3, 2, and 1 as given previously ... 

The onset of oxidation is taken as the endpoint for the OIT measurement. Two means of determining the oxidation onset are in use (Blaine et al. 1997). The most common is the extrapolated miset in which the tangents are drawn at the point of maximum rate of oxidation and the baseline prior to oxidation (say 0.05 W/g). The endpoint for the OIT determination is taken at the point where the exothermic event crosses that threshold. If the oxidation exotherm is sharp, these two endpoint indicators produce similar results as seen in Fig. 10.56. However, some materials seem to have a multistaged oxidation, and the endpoint established by the two experimental procedures may be quite different as shown in Fig. 10.57 (Blaine et al. 1997). The selection of the method of determination of the OIT endpoint is the first parameter affecting the comparison of results from one laboratory to another. Apart from this, OIT values are influenced by temperature, oxygen flow rate, oxygen pressure, catalysts (sample pan materials), sample mass and form, and time, which will be discussed below. 

The large specific surface area of TLC-cellulose powder (about 15000 cm /g for MN 300 according to Blaine s method) means that more substance can be taken up in a smaller space this leads to compact spots. 

Important methods for the determination of the specific surface area and of the pore size distribution are based on the measurement of the gas adsorption isotherm [1,2]. The gas adsorption method and the evaluation according to Brunauer, Emmett and Teller using the two-parameter BET equation has been standardized in several countries for a number of years and an ISO standard just appeared. To establish the pore size distribution the method of Barrett, Joyner and Halenda (BJH) is generally accepted. Other methods for this purpose make use of the flow resistance of air through the compressed sample. The Blaine test and other flow tests used to characterize building materials are standardized world-wide. 

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