Mechanical activation of power station fl y ash by grinding – A review

Abstract

Power station fly ash has good application possibilities mainly in the construction industry, nevertheless, significant amount is landfilled due to their relatively low reactivity and heterogeneity. Hydraulic properties of fly ashes can be tailored by mechanical activation achieving a higher added value product, for example supplementary cementing materials (scms). the improved properties are higher specific surface area and desired particle size distribution (containing submicron size particles) as well as higher amount of reactive components that can be optimized by grinding. the objective of this paper is to investigate the effect of mechanical activation of fly ash by grinding on physico-chemical and minerological properties. it can be established that there are numerous techniques for mechanical activation of fly ash, e.g. planetary ball mill, vibratory mill or stirred media mill. on the other hand, most of the results reported in the literature are focusing on material related investigations, but beside this, from energetic point of view the process related evaluation has even higher importance. keywords: mechanical activation, grinding, power station fly ash, reactivity, energy efficiency.Gábor Mucsi Associate Professor and Deputy Dean at the university of miskolc, Faculty of earth science and engineering, institute of raw material Preparation and environmental Processing. His main fields in education and research are mechanical processes -comminution, especially fine grinding, mechanical activation -and utilization of industrial by-products and waste materials. He has more than 100 publications.

Technology Development for Strong Reduction of Energy Consumption and Co2 Emission in Lime and Cement Manufacture

“…The mechanical activation has been applied to increase the chemical reactivity of several minerals [10] with good commercial success, especially for leaching complex sulfides [11]. In a recent paper, Mucsi [12] reports the mechanical activation of fly ash and cement [9] in order to improve their performance as hydraulic binders. On the other hand, Sekulica [13] found that cement treated mechanically reported a compression stress 58% higher than an inactivated sample of similar composition; also reported that endothermic and exothermic reactions proceed at lower temperatures as indication of increased reactivity of mechanically activated sample.…”

Effects of Wet Separated and High Speed Milling Fly Ash Added in High Volume to Cementitious Materials

“…High speed milling/grinding with pin mills or disintegrator is a type of high energy milling, which involves supply of energy in large amounts in a short duration of time with high power pulses [1]. In this way the amount of energy which is supplied to a solid material is much more than in conventional mills, with almost the same input power supplied [2].…”

Alkali-Activated Binder Based on Milled Antigorite

“…Because of the low hydraulic activity of serpentine, we employed a pre-treatment step of mechanical activation. The efficiency of mechanical activation for increasing the reactivity of solids is well established [25][26][27][28], and is a particularly effective technique for improving the mechanical properties of alkali-activated materials [29][30][31][32][33][34][35]. The term "mechanical activation" (MA) in this paper refers to the structural-chemical changes on the surface and in the bulk of minerals caused by milling.…”