ABSTRACT
The long-term integrity of residue deposits is central to sustainable closure. Integrity is in turn a function of overall structural stability, erosional stability and hydraulic integrity. These three aspects of integrity, although inter-related, depend on different parameters.
This paper deals specifically with loss of integrity through cracking. Piping and the erosional damage, which may follow, is a function of the properties of the tailings, depositional methods and stress history. The paper examines the parameters which influence integrity from the perspective of shrinkage and cracking of the outer walls of residue deposits. The influence of slurry density, grading, mineralogy and chemical additives are examined in relation to stress history and rate-of-rise. The influence of each parameter is discussed and the conclusions are backed up with empirical test results, which provide a basis for the assessment of the potential for post-depositional and long-term cracking and the associated loss of integrity.
