Recent Patents on Roll Crushing Mills for Selective Crushing of Coal and Gangue

Background: Gangue is the concomitant product of coal mining. The traditional approach for gangue treatment is to transport it from underground to ground level to accumulate and form gangue hills. Objective: On the basis of summarizing previous research results, this paper introduces the hydraulic roller crusher and the electric machine built-in coal gangue roller crusher, which avoids the complex transmission problems caused by the movement of the central axis when the roller crusher is allowed to roll. Methods: The hydraulic counter-roll crusher directly separates large pieces of coal and underground gangue such that large pieces of coal gangue do not escape from the well. The electric machine built-in roller crusher is an explosion-proof electric machine used in the crushing roller. Results: Both of these crushers can be used in the selective crushing technology of coal gangue in a coal mine and can meet the requirements of crushing different material sizes and generally avoid the centre of the roller crusher. Conclusion: Both of these crushers reduce transportation costs, minimise land occupation, prevent surface subsidence, decrease environmental treatment costs, reduce environmental pollution, and decrease the transport volume of gangue underground. Various patents have been discussed in this article.