In Phase 1 the characteristics and behaviour of the tailings is determined. The results of these analysis are To understand the plume dispersion and the continuous process of settling, deposition and bed formation of mine tailings in this project, first the tailings are characterized. The analyses results enable narrowing down of uncertainties in the critical sediment parameters in the predicted behaviour of the mine tailings and are the basis of the project to select potential floculants used in Phase 2 and 3.

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2) Accurate determination of sediment settling velocities

During the mining  process a plume of material will be placed above the bed . In time the particles within the plume will settle. This hindered settling process is related to time. The higher the settling velocity, the faster the particles reach the bed, the smaller the spread of the plume and chances of spreading of the plume leading to environmental issues. The floculant will influence this hindered settling velocity. To understand the influence of the floculant, first the hindered settling of the material without floculant is tested. This experiment is carried out in 1 m settling columns. The material is posed into the columns (well mixed). Thereafter the hindered settling process is recorded with camera's. From this data set the hindered settling velocity can be determined as shown in the graph below. The higher the concentration, the lower the settling velocity because more particles hinder each other. For concentrations larger than 150 g/l, the settling velocity reseaches zero. The particles are close enough to each other to form a (gelled) bed. The maximum fall velocity is determined by the weight of the particle and the surrounding concentration. However it should be taken into account that these are controled laboratory conditions. In the field the plume be exposed to currents or storm conditions enforcing uplift conditions.

3) Settling and consolidation columns

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