Measurement of solids concentration in aqueous slurries for monitoring the solids recovery in solid bowl centrifugation

Solid bowl centrifugation (SBC) is widely used for various solid-liquid separation tasks in mineral and coal processing. The SBC often suffers from a relatively high solids loss during the separation process, mainly owing to lack of an effective tool that can monitor the solids recovery. Despite its importance, the information on monitoring the solids recovery in the solid bowl centrifugation is scarce. In the present study, a strong correlation between an index (defined as the ratio of the solids concentration of the effluent by weight to the solids concentration of the feed by weight) and the solids recovery in solid bowl centrifugation was identified based on analysis of the data available in the literature. In an attempt to use this correlation for monitoring the solids recovery, a novel solids concentration measuring tool was developed to measure the solids concentration of a slurry. The tool consists of a slurry image acquisition apparatus and the backend interpolation algorithm to retrieve the concentration information from the recorded slurry images. A hybrid of the convolutional neural network and the long short-term memory network, coined as SConcNet, was built and trained with a newly created database. The SConcNet achieved a high level of accuracy and reliability in measuring the solids concentration by weight. The potential of using the index and the developed solids concentration measurement method to monitor the solids recovery of the SBC in real-time was also discussed.

Automated summary

A strong correlation between an index and the solids recovery in solid bowl centrifugation was identified based on analysis of literature data. A new solids concentration measuring tool was developed to measure the solids concentration of a slurry, showing high accuracy and reliability.