Grinding Aid Additives for Dry Fine Grinding Processes

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Author Last Name: 
P. Prziwara, A. Kwade
Report Type: 
Research Area: 
Size Reduction
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t is well known that attractive particle-particle interactions become more decisive with decreasing particle size. Especially in dry fine grinding processes, where small particles are produced within a dry environment by different types of mechanical stress, these forces lead to a variety of challenges, such as a complicated control of the powder behavior, a decrease of grinding efficiencies and production rates as well as obtaining high product finenesses. In order to control these forces, chemical liquid or solid additives – so called grinding aids – are added to the process in many industrial dry fine grinding applications. Even though the benefits of grinding aids have already been shown in various experimental studies and industrial applications, their selection and application is still mostly based on empirical knowledge. As shown in this review article, the variety of applied substances, ground materials and target finenesses, but also available mill types, process designs, mill and process parameters as well as analysis methods complicate the development of a comprehensive understanding. Within this article, we present the basic mechanisms of action of various liquid, gaseous and solid grinding aids. Subsequently, it is shown how grinding aid molecules interact with the solid particle surface, leading to decisive changes of the particle and bulk behavior. Based on various scientific studies it is shown, how this may affect the micro- and macro-processes inside the mill as well as the whole grinding plan