The results showed that (1) the highest UCS values of 14-day and 28-day cured CTB samples were 1.259 MPa and 2.429 MPa, respectively, and the effect of different activator types was in the order of SH > GM > DA > Q and SH > GM > Q > DA (2) the relationship between UCS and activator dosages followed the function y = ax3 − bx2 + cx − d. A series of uniaxial compressive strength (UCS) tests were carried out on cemented tailings backfill (CTB) samples containing different activators. With the use of glauberite mineral (GM) and sodium hydroxide (SH) alkaline catalysts to stimulate slag powder’s internal cementation activity and incorporate the two fine-grained solid wastes, such as quicklime (Q) and desulfurized ash (DA), a new cementitious material suitable for mine tailings was developed to replace traditional ordinary Portland cement (OPC) for reducing cement-related costs. Likewise, the heart of the paste backfill plant is the paste mixer, primary process parameters are monitored, trending adjustments to binder (commonly cement, fly ash, blast furnace slag or some combination) and water addition with feedback on paste backfill consistency. The thickener contents (bed level and bed pressure) and thickened tailings solids content in the underflow are observed, providing a running synopsis of the equipment. Specific parameters are measured to optimise the performance of the thickener. From an instrumentation and controls perspective, at the plant level there are two particular areas of interest, the tailings thickener and, in backfill systems, the paste mixer. The types of instruments used and conceptual control strategies are introduced. The key uses of instrumentation at the plant level, transportation system and as placed in the paste backfill are discussed. Instrumentation is widely used in paste or thickened tailings systems from controlling the production process to diversion of material to monitoring of deposited backfill. Safely disposal of mine tailings under surface conditions is of great importance in the aspect of environment. acid potential, stabilization, cost and applicability of the paste tailings etc.) should be evaluated. Also, the some parameters such as physical and chemical characterization of tailings, properties of newly formed material (e.g. In this context, tailings management are very important to selection of the optimum disposal method. The control and configuration of this kind of environmentally dangerous tailings in terms of isolation at disposal site, construction of impermeable layers, transportation from plant, stabilization, safety, their effects on water, and soil quality are the main parameters that could be considered carefully. The influence of these hazardous tailings on the environment may have multiple aspects. yield stress, viscosity) are not addressed in this chapter.Ī significant amount of tailings with a high content of cyanide or sulphur arises from the beneficiation process of metallic mines such as gold, silver, copper, and lead. However, the properties for assessing the transportability of CPB (e.g. In this chapter, a comprehensive review of the current knowledge on the physical, thermal (T), hydraulic (H), mechanical (M), microstructural and chemical properties (C) of CPB as well as the factors that affect them and their interactions is provided. Thus, an understanding of the properties of CPB and the factors that affect them is critical for the safe and cost-effective design of CPB structures. These processes and their interactions affect the behaviour and performance of CPB. temperature of the rock mass, self-heating of the rocks) on the strength development of CPB, or the effects of the pressure of the self-weight of backfill and the filling rate on its consolidation behaviour, are external factors. For example, the effects of thermal loads (e.g. They also include other processes, such as self-desiccation, cement reaction and heat generated by binder hydration, and (2) external factors or processes, which include all phenomena that take place in relation to environmental aspects. binder, tailings and water) and their changes with curing time. Each property can be affected by different parameters that are mainly classified as (1) internal factors, which include all the intrinsic and multi-physics properties, such as parameters related to the main components of CPB (e.g. The primary properties and characteristics of CPB are categorised by their physical, mechanical, hydraulic, thermal, chemical and microstructural aspects. Knowledge on the properties of cemented paste backfill (CPB) material is essential for the design of cost-effective, safe and durable cemented backfill structures.
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