The study of geotechnical parameters for paste technologies: a general review.

The disposal of process wastes in paste form is an attractive option for waste management as it eliminates or reduces the risks associated with conventional methods. The geotechnical characteristics of the paste are very similar to soil materials, and the determination of geotechnical properties and the relationships between them is essential in relation to the durability of the paste. The ultimate compressive strength (UCS) is an important parameter, particularly in backfill applications. Parameters which affect the UCS are binder type and content, admixtures, water/solid ratio and curing time and temperature. Thickened tailings are usually mixed with the appropriate amounts of a binder such as Portland cement to improve UCS development. Porosity affects the mechanical and geochemical behaviour of paste tailings and grain size distribution has a strong effect on porosity. There is no significant correlation between total porosity, curing time and binder type, but the binder affects the porosity of the paste. The mechanical properties of the paste material itself and the interface shear strength between the material and the surrounding or adjacent rock mass plays a substantial role in the stability of paste tailings. The shear stress is important in relation to surface disposal methods and pumpability. Water content directly affects the strength of the paste. The volumetric water content begins to decrease with an increase in matric suction, and the evolution of the water content during the drying phases is different for cemented and uncemented layers. Yield stress and viscosity increase with a decrease in water content, and the water content is strongly correlated with the mechanical properties of the paste. Hydraulic conductivity decreases as the water content increases, and the water content also affects geochemical reactions such as sulphide oxidation. The hydraulic conductivity of cemented paste backfill (CPB) is significantly affected by binder type and conten
The disposal of process wastes in paste form is an attractive option for waste management as it eliminates or reduces the risks associated with conventional methods. The geotechnical characteristics of the paste are very similar to soil materials, and the determination of geotechnical properties and the relationships between them is essential in relation to the durability of the paste. The ultimate compressive strength (UCS) is an important parameter, particularly in backfill applications. Parameters which affect the UCS are binder type and content, admixtures, water/solid ratio and curing time and temperature. Thickened tailings are usually mixed with the appropriate amounts of a binder such as Portland cement to improve UCS development. Porosity affects the mechanical and geochemical behaviour of paste tailings and grain size distribution has a strong effect on porosity. There is no significant correlation between total porosity, curing time and binder type, but the binder affects the porosity of the paste. The mechanical properties of the paste material itself and the interface shear strength between the material and the surrounding or adjacent rock mass plays a substantial role in the stability of paste tailings. The shear stress is important in relation to surface disposal methods and pumpability. Water content directly affects the strength of the paste. The volumetric water content begins to decrease with an increase in matric suction, and the evolution of the water content during the drying phases is different for cemented and uncemented layers. Yield stress and viscosity increase with a decrease in water content, and the water content is strongly correlated with the mechanical properties of the paste. Hydraulic conductivity decreases as the water content increases, and the water content also affects geochemical reactions such as sulphide oxidation. The hydraulic conductivity of cemented paste backfill (CPB) is significantly affected by binder type and conten