An Investigation on Linear Combined Comminution Law Bian Hanmin Liao Zhengguang Zhu KunquanThe paper presents a study of energy-size reduction relationship in crushing by means of a specially designed pendulum impact crushing device, which can give an accurate measurement of net energy consumptio as rock specimen is crushed. A novel linear combined form of energy-size reduction equation is proposed and well proved by the developed tests. The majorpoints concluded from the work are as follows: a) A duality of energy consumption exists in most comminution, which verifies in a unique way the ordinarily recognized saying "most comminution behaviors exist between the three well-known theories", b) The criterion of suitability of a certain comminution law is tied in more with input energy density than particle size. Different energy density imposed on rock particle will lead to inclining or approaching to the two extreme laws (Kick-type and Rit-tinger-type).comminution; duality; energy consumption; linear combined equation; energy density