Crushing references

Chemi- concen- T reatment Tough- Bend- Crushing Refer-... 

Temperature (°C) Electrolyte T Method Instrument Crushed Reference... 

Plutonium is transported by the groundwater in fractures in the rock (usually <1 mm wide). A typical groundwater velocity (vw) at >100 m depth in Swedish bedrock is 0.1 tn/y. The fractures are filled with crushed, weathered, clayish minerals, which have a high capacity to sorb the plutonium. Assuming instantaneous and reversible reactions, the sorption will cause the plutonium to move considerably slower (with velocity vn) than the groundwater. The ratio between these two velocities is referred to as the retention factor (RF), defined by... 

In the preparation of many solid state reference materials, reduction of the grain size plays an important role. Usually this reduction is required because of the measurement methods to be used both in the projects and later by the users of the reference material, as well as to come to an acceptable minimum sample intake. The minimum sample intake can be defined as the minimum amount of material needed, so that the heterogeneity of the material does not affect the repeatability of the measurement method. The reduction of the grain size is usually implemented by crushing and/or grinding techniques. The techniques employed and the equipment used must be suitable for the purpose of processing the material. Potential problems of contamination, loss of volatile components, and/or other physical and... 

Some mineral products are employed essentially in the form in which they are mined, with only shaping, crushing, cleaning or other treatments that do not change their compositions. Coal, in most of its uses, is a typical example. Most minerals are processed, however, to yield usable products - metals, chemicals or other materials from which most of the items of utility are derived. As regards coal, it may be pointed out that it is often referred to as a mineral, but unlike a true mineral, it has no fixed chemical formula. 

Separation processes, as could be seen from Figure 2.1, position themselves at the back end of the sequence in operations in the mineral processing flowsheet. The front-end operations has been found virtually to terminate with the liberation or the size-reduction processes involving crushing and grinding. It is important to limit the amount of size reduction to that at which adequate liberation is accomplished. The term adequacy is related to the cost involved in comminution and to performance of the concentration methods that follows. The concentration is obtained by separation processes which rely on differences in the properties of the particles, the physical and physico-chemical characteristics of minerals. In this context, it will only be relevant to refer to Table 2.5 which presents a summary of the processes along with the properties of the minerals that are exploited. 

An embankment refers to a volume of longitudinal earthen material that is placed and compacted for the purpose of raising the level of a roadway (or railway) above the level of the existing ground surface. A fill refers to a volume of earthen material that is placed and compacted for the purpose of filling in a hole, cavity, or excavation. Embankments or fills are constructed of materials that usually consist of soil, but may also include aggregate, rock, or crushed paving material. 

Alkylation of benzene with propylene was carried out with the acid zeolites, pelletized, crushed, and sieved at 0.25-0.42 mm diameter. The reaction was performed in an automated high pressure stainless steel reactor, at 3.5 MPa, temperatures ranging from 125 to 200°C, WF1SV from 12 to 18 h"1 referred to the olefin, and benzene to propylene (B/P) molar ratio of 3.5. More details can be found in [7]. 

Owens, J. S. Trans. Inst. Min. Met. 42 (1933) 407. Notes on power used in crushing ore, with special reference to rolls and their behaviour. 

The aluminium content of the two samples is comparable, when referred to the silica content of the original clay, and the two PILC have comparable surface areas after calcination at 300°C. The ACH bentonite was formed into small extrudates and flash-dried, whereas sample G5 was dried in a thin cake. In both cases, crushing to a fine powder was easy. Sample G5 retains a higher surface area at 800°C in spite of a higher potassium content. Therefore the K O content of the PILC is not the predominant factor for the thermal stability. 

The reaction mixture is dehydrated at temperatures as high as 160°C (higher temperatures can be tolerated than with resoles). The prepolymer is cooled, crushed, blended with 5-15% hexamethylenetetramine, (CH2)6N4, and sold to the fabricator. Hexamethylenetetramine, referred to as hexa, is the product of the reaction of 6 mol of formaldehyde and 4 mol of ammonia. Curring occurs rapidly on heating with the formation of both methylene and ben-zylamine crosslinking bridges between benzene rings. The crosslinked network is pictured as... 

The same laboratory describes a group of complexes with a unique property among metal complexes, referred to as luminescence tribochromism [39], which is a substantial change in the emission of the solid upon application of pressure. This phenomenon contrasts with the more common triboluminescence, which refers to the transient emission seen upon sample grinding or crushing. In this case, the effect was observed in a set of complexes of formula [Au2( J.-TU)((j,-dppm)]Y and [Au2( i-MeTU)( i-dppm)]Y (TU = 2-thiouracyl MeTU = 6-methyl-2-thiouracyl Y = CF3COOT NCV, CKV, Au(CN)2 ). 

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