Bond working index

E Bond work index kWh/Mg (hp-hyton u Settling velocity of particles cm/s ft/s... 

W1 is Bond work index based on 100 percent passing a 200-mesh sieve, is the sohds feed rate in kg/min, and S is weight percent solids in the feed. This represents experimental data for limestone, feldspar, sulfide ore, and quartz. The influence of Wl is believed to be due to its effect on amount of fines present in the mill. Parameters that did not affect are specific gravity of feed material, and feed size over the narrow range studied. 

Bond work index -particle size reduction [SIZE REDUCTION] (Vol 22)... 

The Bond working index W, is the most common description for comminution tasks, and is measured routinely in small-scale laboratory mills ... 

The Bond work index for a mesh-of-grind of 200 mesh for a rock consisting mainly of quartz is 17.5 kWh/ton. How much power is needed to reduce the material in a wetgrinding ball mill from an 80 percent passing size of 1100 gm to an 80 percent passing size of 80 gm ... 

Abrasion resistance. The resistance of aggregates to abrasion is measured in terms of the aggregate abrasion value and the polished stone value (see section 6.4.3). An alternative measure is the Bond Work Index [3.3], which ranges from 4 kW-hr/t for soft limestones, to about 10 for typical dense limestones. 

As the limestone must be ground to about 90 % less than 40 pm, it is important that the operating and capital costs of the grinding equipment should not be excessive. The Bond Work Index test [12.7] was developed as a measure of the ease with which a substance can be ground. The value of the index for many limestones is between 8 and 10 kW hr/short ton. 

Test Method for Limestone Grindability and Calculation of Bond Work Index", Method 7. In FGD Chemistry and Analytical Methods Handbook , Vol. 2, EPRI Report CS 3612, July 1984. 

When Xi and X2 are measured in micrometers and E in kWh/ton, K = 5Ei, where E is the Bond Work Index, defined as the energy required to reduce a unit mass of material from an infinite particle size to a size such that 80% passes a 100 pm sieve. The Bond s work index is obtained from laboratory crushing tests on the feed material. Bond s law holds reasonably well for a variety of materials undergoing coarse, medium, and fine size reduction. 

Both Eb and Wj have the dimensions of energy per unit mass and commonly expressed in the units kilowatt-hour per short ton (2000 lb) (1 kWh/short ton 4000 J/kg). The Bond work index, Wi, must be determined empirically. Some common examples are bauxite, 9.45 kWh/short ton coke from coal, 20.7 kWh/ short ton gypsum rock, 8.16 kWh/short ton. 

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