Prepared by K. G. Tsakalakis, Professor NTUA

Bond work index tables (wi) from various sources

Material Number Tested Specific Gravity Ειδικό βάρος Work Index (kWh/t)

Andesite 6 2.84 20.12 Barite 7 4.50 6.32 Basalt 3 2.91 18.85

Bauxite 4 2.20 9.68 Cement clinker 14 3.15 14.95 Cement (raw) 19 2.67 11.59

Coke 7 1.31 16.73 Copper ore 204 3.02 14.03

Diorite 4 2.82 23.04 Dolomite 5 2.74 12.42

Emery 4 3.48 62.50 Feldspar 8 2.59 11.90

Ferro-chrome 9 6.66 8.42 Ferro-manganese 5 6.32 9.15

Table of Materials Reported by Fred Bond1

1 adjusted from short tons to metric tonnes 2

Material Number Tested Specific Gravity Ειδικό βάρος

Work Index (kWh/t)

Ferro-silicon 13 4.41 11.03 Flint 5 2.65 28.84

Fluorspar 5 3.01 9.82 Gabbro 4 2.83 20.34 Glass 4 2.58 13.57 Glass 4 2.58 13.57

Gneiss 3 2.71 22.19 Gold ore 197 2.81 16.46 Granite 36 2.66 16.59 Graphite 6 1.75 48.02 Gravel 15 2.66 17.70

Gypsum rock 4 2.69 7.42 Iron ore – hematite 56 3.55 14.25

Hematite-specularite 3 3.28 15.26

Table of Materials Reported by Fred Bond1

1 adjusted from short tons to metric tonnes 3

Material Number Tested Specific Gravity Ειδικό βάρος

Work Index (kWh/t)

Hematite – Oolitic 6 3.52 12.49 Magnetite 58 3.88 10.99 Taconite 55 3.54 16.09 Lead ore 8 3.45 12.93

Lead-zinc ore 12 3.54 11.65 Limestone 72 2.65 13.82

Manganese ore 12 3.53 13.45 Magnesite 9 3.06 12.27

Molybdenum ore 6 2.70 14.11 Nickel ore 8 3.28 15.05 Oilshale 9 1.84 17.46

Phosphate rock 17 2.74 10.93 Potash ore 8 2.40 8.87 Pyrite ore 6 4.06 9.84

Pyrrhotite ore 3 4.04 10.55

Table of Materials Reported by Fred Bond1

1 adjusted from short tons to metric tonnes 4

Material Number Tested Specific Gravity Ειδικό βάρος Work Index (kWh/t)

Quartzite 8 2.68 10.56 Quartz 13 2.65 14.96

Rutile ore 4 2.80 13.98 Shale 9 2.63 17.49

Silica sand 5 2.67 15.54 Silicon carbide 3 2.75 28.52

Slag 12 2.83 10.35 Slate 2 2.57 15.76

Sodium silicate 3 2.10 14.88 Spodumene ore 3 2.79 11.43

Syenite 3 2.73 14.47 Tin ore 8 3.95 12.02

Titanium ore 14 4.01 13.59 Trap rock 17 2.87 21.30 Zinc ore 12 3.64 12.74

Table of Materials Reported by Fred Bond1

1 adjusted from short tons to metric tonnes 5

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7

8

9

From: SME Handbook of Mineral Processing, N.L. Weiss Editor, NY 1985., “Page 30-71 , Sampling and Testing -Characterization of Test Samples”

From the: G.C. Lowrison, “Crushing and Grinding” in Chapter 4 Energy Consumed in the Comminution Process, page 53, Butterworths, 1974, London

Approximate energy consumption in comminution, kWh/t (after Bond)