Impending catastrophic failure of granular earth slopes manifests distinct kinematic patterns in space and time. While risk assessments of slope failure hazards have routinely relied on the monitoring of ground motion, such precursory failure patterns remain poorly understood. A key challenge is the multiplicity of spatiotemporal scales and dynamical regimes. In particular, there exist a precursory failure regime where two mesoscale mechanisms coevolve, namely, the preferred transmission paths for force and damage. Despite extensive studies, a formulation which can address their coevolution not just in laboratory tests but also in large, uncontrolled field environments has proved elusive. Here we address this problem by developing a slope stability analytics framework which uses network flow theory and mesoscience to model this coevolution and predict emergent kinematic clusters solely from surface ground motion data. We test this framework on four data sets: one at the laboratory scale using individual grain displacement data; three at the field scale using line-of-sight displacement of a slope surface, from ground-based radar in two mines and from space-borne radar for the 2017 Xinmo landslide. The dynamics of the kinematic clusters deliver an early prediction of the geometry, location and time of failure.
Environmental concerns, water and energy availability and costs as well as the public's license to operate all contrive to demand more efforts targeting sustainability. In this paper we discuss the broad lessons learnt in the wider mining industry that may be relevant to the phosphate rock industry. In particular, we suggest that it is innovation, particularly in technology that holds the key to more sustainable mining. Breakthrough developments in automation, in sorting, comminution and flotation are highlighted together with some suggestions as to how a more collaborative approach is needed to bring through step changes in the industry.
Sustainability in the phosphate industryPhosphorus use in fertilizers has shown long-term growth, reflecting the essential nature of phosphorus in nutrition. It is however a non-renewable resource and this frequently raises questions as to the sustainability of the rock phosphate industry. The track record of some parts of the rock phosphate industry in the past has been far from ideal in terms of sustainability. The earlier mining techniques used on some of the Pacific Islands such as Nauru [1] and Banaba [2] are not compatible with the standards demanded today for sustainability. Reviews of current practices [3] indicate that sustainability is taken seriously and significant advances are being made. The relative size of the rock phosphate industry (198 Mt/y in 2011 [4]) against the shear size of the rest of the mining industry suggests that there are many more opportunities for sustainability practice to develop in the wider mining industry. For every tonne of phosphate rock mined, there are over 50 tonnes mined, just in coal (7678 Mt/y in 2011) and iron ore (2940 Mt/y in 2011) alone. This is not to imply that transfer is only in one direction; there are good examples of the rock phosphate industry being quick to adopt leading edge innovations, eg the use of thickened slurries to minimize water usage in placement of slimes from wet screening [4,p45], much like tailings disposal in hard rock mining.In many countries, mining and sustainability are considered to be incompatible because of the obvious depletion that inevitably occurs with any particular mine. The confusion arises from two directions: firstly from a fundamental misunderstanding that sustainability requires or implies that something is endlessly available, like sunshine. The original Bruntland definition [5] however is quite clear -sustainability is about needs, in particular "development that meets the needs of the present without compromising the ability of future generations to meet their own needs". In the case of phosphorus, the key is whether the known and likely resources are adequate for the forseeable future to meet the needs of future generation. The price hike in 2008 caused by shortages
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