Binding Properties of Mechanically Activated Nepheline Containing Mining Waste

Abstract

The development of apatite and rare-metal deposits of the Khibiny and Lovozero—the world’s largest ultrabasic massifs located in the Kola Alkaline Province—is accompanied by accumulation of huge amounts of sandy tailings dumps, about half consisting of nepheline. These tailings, on the one hand, pose a real threat of environmental pollution. On the other hand, they are “technogenic deposits” that contain reserves of valuable components (Na2O, K2O, Al2O3, etc.). In this paper, methods of processing of the nepheline-containing mining waste using mechanical activation to produce binding materials—geopolymers and blended cements—are observed. The advantages of combining the nepheline containing tailings dumps with other mining wastes accumulated in the region, such as Cu–Ni slag, are presented.

Tailings Utilization and Zinc Extraction Based on Mechanochemical Activation

“…The transition to the development of copper and impregnated ores due to the development of rich ore-bearing horizons is determined by the growth of preparatory work, the volume of geomaterials lifted to the surface per unit of finished product, as well as the problems of the rock pressure control during the development of reserves in deep horizons [ 11 ]. The growth of the global economy and the consumption of rare-earth metals has caused the need to increase the extraction of georesources during the ecological modernization of underground geotechnologies with the widespread use of filling [ 12 , 13 ]. For example, Hua Na proved the possibility of using copper-nickel slag to form expanding filling mixtures with the addition of hexadecyltrimethyl ammonium bromide and Sodium silicate [ 14 ].…”

Improvement of Strength and Strain Characteristics of Lightweight Fiber Concrete by Electromagnetic Activation in a Vortex Layer Apparatus

“…The essence of activation is to increase the specific surface area of materials with a simultaneous increase in surface energy, which increases the reactivity of the cement binder. The disadvantages of the dry method of activating cement include the processing time, which can reach several hours, the high energy consumption of the equipment and its low productivity, and the short terms and complexity of the activated cement storage [10,[19][20][21][22][23][24][25][26][27][28][29][30].…”