Abrasion ratio

The effect of Fe +/Fe + on the abrasion ratio of reduced catalysts and the stack crush strength is shown in Table 8.36 and Fig. 8.42. 

Table 8.35 Effect of Pe2+ / e + on the abrasion ratio of unreduced catalysts...

Sample No. Fe2+/Fe3+ Phase composition (By XRD) Main phase Minor phase Abrasion ratio/wt%... 

Note The particle size of catalyst is 2.2-3.3 mm the abrasion ratio is measured in accordance with the standards of HG/T2782-1996. 

Note The abrasion ratio is measured by China standard of HG/T2782-1996. 

The highest G-ratios are obtained when grinding with straight oil coolants. Such oils reduce power, increase maximum depth of cut, and produce smoother finishes. Disadvantages include inabiUty to remove heat from the work, oil mist in the work area, fire hazard, and tendency to hold grinding swarf (fine metal chips and abrasive particles produced in the grinding process) in suspension. Reference 51 is an excellent survey article for grinding fluids. 

In addition to chemical analysis a number of physical and mechanical properties are employed to determine cemented carbide quaUty. Standard test methods employed by the iadustry for abrasive wear resistance, apparent grain size, apparent porosity, coercive force, compressive strength, density, fracture toughness, hardness, linear thermal expansion, magnetic permeabiUty, microstmcture, Poisson s ratio, transverse mpture strength, and Young s modulus are set forth by ASTM/ANSI and the ISO. 

Specific Toothpaste Formulations. Two types of toothpaste formulation predominate. Type 1 is alow abrasive—high solvent toothpaste (Table 1) type 2 is a high abrasive—low solvent toothpaste (Table 2). The most important differences are the ratio of humectant to abrasive and the nature of the abrasive. Type 1 dentifrices were introduced nationally to the U.S. market in 1970 and now constitute the predominant type. Type 2 dentifrices represent a popular earlier formulation, in which economic and scientific considerations related to the abrasive and humectant favored use of a maximum amount of the abrasive component. AH type 1 dentifrices of the early 1990s contain an amorphous hydrated siUca powder as the abrasive. Type 2 dentifrices may contain one or more of many insoluble minerals. 

If the rock is abrasive, the first stage of crushing may use gyratory or jaw crushers, otherwise a rotor-impact mill. Their reduction ratio is only 1 12 to 1 18, so they often must be followed by a hammer mill, or they can feed a roll press. Rotor crushers have become the dominant primaiy crusher for cement plants because of the characteristics. All of these types of crushers may be installed in moveable crusher plants. 

Small roller-chain wheels should be hardened when used on moderate and highspeed drives, very low-speed heavily loaded drives, and when operating under abrasive conditions or when the drive ratio is greater than 4 1. Steel silent chain pinions should be hardened. 

Sundararajan et al. [131] in 1999 calculated the slurry film thickness and hydrodynamic pressure in CMP by solving the Re5molds equation. The abrasive particles undergo rotational and linear motion in the shear flow. This motion of the abrasive particles enhances the dissolution rate of the surface by facilitating the liquid phase convective mass transfer of the dissolved copper species away from the wafer surface. It is proposed that the enhancement in the polish rate is directly proportional to the product of abrasive concentration and the shear stress on the wafer surface. Hence, the ratio of the polish rate with abrasive to the polish rate without abrasive can be written as... 

Figure 7.7 Abrasion resistance (haze) dependence on GPS A1(OBu)3 molar ratio for hybrid-coated PMMA surfaces compared to uncoated PMMA. PMMA substrate is corona treated followed by a 2.5% 3-aminopropyl-triethoxysilane treatment prior to the application of GPS Al(OBu)3 hybrid solutions. Coating thickness 4 mm coatings were cured at 80 °C for 4 h. (Reproduced from ref. 5, with permission.)...

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