Crushing, definition

To the cold acid chloride add 175 ml. of pure carbon disulphide, cool in ice, add 30 g, of powdered anhydrous aluminium chloride in one lot, and immediately attach a reflux condenser. When the evolution of hydrogen chloride ceases (about 5 minutes), slowly warm the mixture to the boiling point on a water bath. Reflux for 10 minutes with frequent shaking the reaction is then complete. Cool the reaction mixture to 0°, and decompose the aluminium complex by the cautious addition, with shaking, of 100 g. of crushed ice. Then add 25 ml. of concentrated hydrochloric acid, transfer to a 2 htre round-bottomed flask and steam distil, preferably in the apparatus, depicted in Fig. II, 41, 3 since the a-tetralone is only moderately volatile in steam. The carbon disulphide passes over first, then there is a definite break in the distillation, after whieh the a-tetralone distils completely in about 2 htres of distillate. 

Sphere> pellet > trilobe > hollow extrudate > wagon wheel/ minilith The definitive catalyst size selection will be a compromise between high reaction rate (small partiele, exotic shape), low pressure drop (large particle, exotic shape), large crushing strength... 

If you mix sulfur and iron filings in a certain proportion and then heat the mixture, you can see a red glow spread through the mixture. After it cools, the black solid lump which has been produced, even if crushed into a powder, does not dissolve in carbon disulfide and is not attracted by a magnet. The material has a new set of properties it is a compound, called iron(II) sulfide. It has a definite composition, and if, for example, you had mixed more iron with the sulfur originally, some iron(II) sulfide and some leftover iron would have resulted. The extra iron would not have become part of the compound. 

In this experiment, a solid material, such as pecan hulls, are crushed, ground, and separated into various sizes to observe the effects of the variation of size distribution with screening time and the variation of size distribution on rate of vibration. The size and distribution of particles may be determined by several methods. Screening is commonly used for this purpose. In this method a known mass of material of various sizes is passed over a series of standard screens and the amount of material collected on each screen is determined. The rate of vibrating the screen and the time allowed for vibrating have definite effects on the distribution of particles. 

Chemically bound water is most reasonably defined as including that present in interlayer spaces, or more firmly bound, but not that present in pores larger than interlayer spaces. As will be seen in Chapter 8, the distinction between interlayer space and micropores is not sharp water adsorbed on surfaces of pores further blurs the definition. From the experimental standpoint, the determination is complicated by the fact that the amount of water retained at a given RH depends on the previous drying history of the sample and on the rate at which water is removed. An approximate estimate is obtained by equilibrating a sample, not previously dried below saturation, with an atmosphere of 11% RH (F12,F13,F14). Saturated aqueous LiCl HjO gives the required RH (partial pressure of water vapour = 2,7 torr at 25°C). To achieve apparent equilibrium in a reasonable time (several days), the sample must be crushed and the system evacuated the salt solution should be stirred, at least intermittently. Young and Hansen (Y5) found the composition of the C-S-H in C3S paste thus... 

A Solid Cube of material—weights of broken or crushed material decrease, for example, see figures given for coal and for limestone. Figures listed are for best conditions (dry, sized and without dust)—The minimum angle will increase as size of particles decrease and with higher moisture content. For other conditions refer to S-A Engineers for definite recommendations. 

Crushing rolls are very widely used for such work and are usually very satisfactory. The distance between the roll faces can be definitely set to the size of particle desired and there can be no oversize. There will be, however, a large percentage of underside because roll crushing is the result of direct compression, and consequently a good deal of fine dust is produced. Another objection to the use of rolls is that the crushing... 

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