Coupled Modeling of Temperature Distribution and Evolution in Cemented Tailings Backfill Structures that Contain Mineral Admixtures

Abstract

Cemented paste backfill (CPB, a mixture of tailings, water and binder) is widely utilized to fill underground mine voids. To achieve a good, economical performance, one approach is to proportionally use mineral admixtures such as fly ash and slag as partial substitutes for Portland cement. Binder hydration is one of the most significant factors that can generate heat within hydrating CPB structures, which in turn, influences the mechanical and hydraulic properties of CPB, as well as the pore structure within CPB. However, the temperature evolution due to the hydration of Portland cement that contains fly ash or slag is different from that of hydration with solely Portland cement. Hence, in consideration of the heat generated by both binder hydration and transferred between CPB and its surrounding media, a numerical model is developed to predict and determine the temperature development within CPB that contains mineral admixtures. After that, data from field and laboratory studies are employed to validate the developed model. The validation results demonstrate a good consistency between the model and the field and laboratory studies. Consequently, the proposed model is applied to simulate and determine the temperature evolution with time via mineral admixtures, binder content, initial rock and CPB temperatures, stope geometry, backfilling rate, curing time and backfilling strategy. The obtained results will contribute to better designs and preparation of CPB mixtures, as well as predict the temperature distribution within CPB structures.

Paste backfill of high-sulphide mill tailings using alkali-activated blast furnace slag: Effect of activator nature, concentration and slag properties

“…Earlier studies have pointed out that ordinary Portland cement (OPC), which is widely used as binder in CPB, is not particularly suitable for paste backfill (PB) of sulphide-rich tailings due to its vulnerability to acid and sulphate attack (Benzaazoua et al, 2002;Wu and Fall, 2012;Cihangir et al, 2013;Ercikdi et al, 2010a,b;Malviya and Chaudhary, 2006;Tariq and Nehdi, 2007).…”

Cemented Backfilling Technology of Paste-Like Based on Aeolian Sand and Tailings

“…Rheological tests are used to determine the transportation pipeline parameters, and guide the design of the backfilling system [21].…”

Transportability and pressure drop of fresh cemented coal gangue-fly ash backfill (CGFB) slurry in pipe loop

“…According to the data in Table 1 the chemical reaction (i.e., cement hydration) contributes to the generation of ettringite and C-S-H [23][24][25]. These hydration products that have cementing properties precipitate among the coal gangue particles and integrate them together.…”