News

Mettler Toledo publishes fine tailings dewatering study

Posted on 7 Jun 2013

Mettler Toledo has announced the publication of a new white paper entitled “Optimising Thickeners, Flotation and Mature Fine Tailings (MFT) Dewatering.” The paper details common challenges mining engineers and scientists encounter when working to maximise solid-liquid separation and enhance throughput. It also explores how current state-of-the-art in situ particle characterization technologies can help meet these production challenges, enabling lowered processing costs and better production outcomes.

Flocculation is a common separation improvement technique used to enhance water recycle and control fines accumulation for mining, oil sands, pulp/paper, and biotech dewatering applications. In all cases, efficiency is proportional to incoming particle size distribution and population, as well as applied polymer type, polymer dosage and shear. Choosing the correct polymer type, polymer dosage and shear based on real-time analysis of the incoming particle stream can maximise dewatering efficiency by improving polymer dispersion and increasing initial particle aggregate size distribution.

Flocculant strength and shear intensity can result in an undesirable shift to smaller particle counts over time, however. In-process particle size and structure measurements eliminate the need for offline sampling and dilution of the particle system which can alter fragile structures and prompt unnecessary corrective action. This enhanced observational accuracy enables improved real-time control decisions so desired particle sizes and counts are achieved.

The paper goes on to review how measurement of real-time flocculation kinetics can enable creation of a population balance model. These models can then be applied using hydrodynamic modelling to help optimise operating conditions in pipes, channels or thickener feed wells to encourage processing consistency and enhance throughput/system stability. The paper can be downloaded at www.mt.com/wp-mining-separation