Crushed product

In fact, this qQ ( ) corresponds to the original PSD of the droplets, bubbles, crystals, crushed products, and so on. The limiting values of Eq. (5.8) are expressed as... 

Recently, crushing has been widely used in chemical industries. Although the crushed product size distribution in the operation has been expressed by various PSD functions, the most utilized PSD function is the log-normal PSD function. However, there is no physical background for applying the log-normal PSD function to the crushed product size distribution. Additionally, when the crushed product size distribution is expressed by various PSD functions, it becomes difficult to discuss the relationship between the parameters in the PSD and the operation condition. This fact is one of the obstacles in the development of particle technology. 

To examine whether the new PSD defined by Eq. (5.18) can sufficiently express the crushed product size distribution in the grinder. 

A fixed weight feed is fed in the ball mill and the ball mill is rotated at a fixed rotational speed. After the rotation has begun, the crushed product is removed at constant time interval, and the crushed product size distribution is measured by using a Tyler standard sieve. 

Figure 5.6 (A part of the result of new PSD versus crushed product size PSD).

Figure 5.6 Data of crushed product size probability density distribution and fitted PSD curve based on new PSD function.

For recrystallization, 10 ml. of glacial acetic acid is used for each gram of dried product. It is important that the dissolution be carried out rapidly otherwise some decomposition may occur, producing anthraquinone as a contaminant. A satisfactory technique is to add the crude, dried, and crushed product rapidly in small portions to the total amount of boiling acetic acid. The solution should then be filtered through a steam-heated funnel. 

Year Country Crushed Production Hand Imports Supply Food Total Exports Distribution... 

Year Country Crushed Production Imports Exports Food Feed Waste Total ... 

The application of ram extrusion presses overcomes the problems of roller presses. Machines with multiple (up to four for example Fig. 6.10-25, bottom) extrusion channels can produce high capacities per unit and, if this is desired or required, comparatively small amounts of binders will produce, for example, water repellant compacts. Since it is preferable to produce a crushed product (below), initial briquette shape is of no concern and can be optimized for capacity. 

Pure and Ce-doped alumina samples were prepared starting from water dispersions (10%) of (pseudo)-boelimite (Disperal Alumina, Condea Chemie). Under continuous stirring, controlled amounts of Ce nitrate solution were added in order to obtain Ce02 Al203 ratios of 3 100 (2.5 % wt) and 20 100 (16.6 % wt) in the final calcined material. The pH was adjusted with HNO3 to a final value of 3. The suspensions were dried at 353 K (24 h), and then the crushed products underwent a first oven treatment at 773 K (3 h) to convert -AlOOH into -AI2O3. 

Rolls crushers consist of two counter-rotating rolls, one of which is fixed and the other is spring-loaded. They draw feed material into a nip point , where it is crushed (Fig. 5.5). The rolls may be smooth, or profiled, which helps to draw the rock through the crusher and to reduce the slabbiness of the crushed product. Reduction ratios of only 4 1 are achievable, but the production of fines is low. The head-room requirement is lower than for impactors, but the capital cost is higher. 

Crushing Rolls. A unit frequently used for the size reduction of brick clays, etc. Two steel rolls are arranged horizontally and adjacent, with a gap between them of a uniform width equivalent to the maximum size of particle allowable in the crushed product the rolls are rotated in opposition, and sometimes at different speeds, so that the clay is carried downwards and nipped between the approaching surfaces of the rolls (cf. EXPRESSION rolls). 

In the load and carry method the wheel loader scoops up its bucket-load of fragmented rock at the quarry face and directly transports itto the crusher, which is equipped with a special receiving hopper to accept the material discharged from the bucket. With some types of crusher the loader travels up onto a kind of ramp and deposits the load into the crusher opening. The crushed product is conveyed to the cement works by overland belt conveyor. 

A swivelling conveyor may be used to receive the crushed product and provide an adaptable connecting link between the mobile crusher and the overland belt conveyor system. This intermediate conveyor is usually a belt conveyor (in 74% of the cases), or else an apron conveyor (24%) or a chain conveyor (2%). 

In present-day cement manufacture, with due regard to the possibilities of the reduction machinery employed, crushing is taken to mean reducing the particle size to between about 80 and 20 mm. This crushed product is further reduced by grinding to a fineness below about 0.2 mm size, in which condition it is called raw meal and is ready for feeding to the kiln. 

The throughput rate and fineness of the product are affected by the state of wear of the comminuting components of the crusher. Hammers have to be reversed, resurfaced with hard steel (by welding), or entirely renewed, before their size reduction effect decreases too much. The bottom grid bars, too, must be resurfaced or renewed before they let through an unacceptably high proportion of oversize particles in the crushed product. 

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