Sieve analysis, dry

DIN 53477, Testing of Plastics Determination of Particle Size Distribution of Moulding Materials by Dry Sieving Analysis, 1992. 

DIN 53477, Testing of plastics, determination of particle size distribution of moulding materials by dry sieving analysis, 1992. 

Dry-sieve analysis is the easiest and the most convenient method for measuring granule size. The granulation is placed on top of a stack of five to six sieves which have successively smaller-sized openings from top to bottom. The stack is vibrated, and the particles eollect on top of the sieves. The data are usually represented in terms of percentage retained on the sieve, or percentage that is undersize or oversize vs. screen-opening size (Fig. 4) (6). 

DRY SIEVING OR SCREEN ANALYSIS WOVEN WIRE SIEVES... 

Figure 4.41. Trend analysis over 12 batches of a bulk chemical. The sieve analysis shows that over time crystals larger than 250 /urn were reduced from a weight contribution in the range of a few percent of the total to about 1% in favor of smaller sizes. Impurity C appears to follow the trend given by the lead compound for the competing side reaction 1. The very low moisture found for sample 3 could be due to a laboratory error because during drying one would expect ethanol to be driven off before water. Methanol is always below the detection limit.

The classical approach for particle size determination, or more correctly for particle size selection - which is still used for solids like soils, sediments and other technical materials like coal, and also for biological materials - is sieving analysis. The raw material is milled, generally after drying, see Section 2.1, and if the required particle size is obtained, typically ranging from <0.1 to a few mm, it is allowed to pass sieves with different apertures to discard coarse particles and remaining materials. For materials consisting of numerous different particles microscopical inspection is used. 

Step 1 To an appropriate centrifuge tube add 1-g (0.001-g) of air-dry, sieved soil and 40 mL of acetic acid. The mixture is shaken overnight, centrifuged, and the supernate separated from the residue for analysis. 

The product was dried in a drier (as described for mercury fulminate) at temperatures from 65 to 70°C in batches of 1.2 kg at a time it was then sieved as described above. A sieve analysis of the product showed, for example, the following sizes of crystals ... 

Loss on drying (Mettler LP 16/PM 480 Deltarange infrared balance) Sieve analysis (Fritsch Analysette laboratory sieving machine)... 

Brunauer-Emmett-Teller (BET) analysis was carried out on the ceramic aggregate with both nitrogen and krypton as adsorbates. The sample was crushed and dry sieved, and the fraction between 74 and 589 micrometer was retained for analysis. Results were repeatable, and consistent for the two gases. Over the range of firing and proportioning conditions studied, specific surface area of the ceramic aggregate was between 0.3 and 6 m Vg, which can be compared, for example, to a non-porous... 

Moisture assessment Drying endpoint target (moisture test) Granule size Sieve analysis... 

Wanogho, S., Gettinby, G., Caddy, B., and Robertson, J. (1987a). Some factors affecting soil sieve analysis in forensic science 1 Dry sieving. Forensic Sci. Int. 33, 129-137. 

SatnpCe Preparation. Seventy grams of sample, previously calcined at 538°C, was dispersed in about 125 mL of sodium metaphosphate solution and "wet screened" using a sieve stack of 250, 270 and 325 mesh, 8-inch diameter sieves. The sieves were washed with water until the effluent was free of any particulate and then rinsed with acetone to de-water. After air drying, the contents of each sieve were transferred to a porcelain dish and the material was recalcined at 538°C. Appropriate weights taken during this procedure allowed for the determination of percent moisture in the starting material and sieve analysis relative to the appropriate sieve fractions. The total +325 mesh material was recombined and mixed for the test. 

Complete instructions and procedures on the use and calibration of testing sieves are contained in ASTM STP447B [7]. Contents include analytical methods, information relating to wire mesh, perforated plate and micromesh sieves, dry and wet testing and other methods. This publication also contains a list of all published ASTM standards on sieve analysis... 

The end-point of sieving can be determined by microscopic examination of the cleanness of the sample [97] or by adopting the same criteria as are used in conventional dry sieving. Since only one sieve is in operation at any one time, a full analysis may be unduly protracted although with sieves coarser than 30 pm the run time is less than 3 min. 

ASTM C285-88 (Re-approved 1994) Standard test method for sieve analysis of wet milled and dry milled porcelain enamel, for determination of the fineness of frit in wet-or dry-milled porcelain enamels and other ceramic coatings on metals by use of the number 200 or No 325 mesh, 212 ASTM C925-79 (Re-approved 1995) Standard test method for precision electroformed wet sieve analysis of non-plastic ceramic powders, for particle size distribution determination ofpulverized alumina and quartz for particle sizes from 45 pm to 5 pm by wet sieving, 212, 230... 

ASTM Cl 921-96 Standard test methodfor particle size (sieve analysis) of plastic materials, applicable to particle size determination of plastic materials in powdered, granular or pelleted forms by dry sieving with a lower limit of measurement of about 38 pm, 212... 

For a rapid determination of loss on drying, an IR drying balance may be used. In the matter of size distribution, effervescent granulations are controlled by sieve analysis. 

---