Traceability of raw materials in silos in an anode plant

Carbon anodes, regularly consumed in primary aluminum production, are made of calcined petroleum coke, coal tar pitch, and recycled materials. The properties of calcined coke depend on the source of crude oil and the calcination conditions. Similarly, pitch properties depend on the coal tar source and the manufacturing process. Different calcined coke and pitch mixtures are commonly used in anode manufacturing to meet various regulations and/or due to economics and availability. This makes it hard to maintain the anode quality. Calcined coke and pitch are placed in silos and used when required for production. It is hard for the industries to track the source of raw materials used in their daily recipes. This article presents an approach to trace back the details of the use of particulate raw materials with a custom-made software, which takes into account the type (mass flow or funnel flow) of silos. Such tracking can help identify the causes of problems and maintain/improve anode quality

Characterisation of bulk and shear properties of basmati and non-basmati rice flour

Background The flours are often unstable in relation to their flow performance which is evident when a free flowing material ceases to flow and the processing, handling, and production parameters depend on the inherent powder characteristics and their bulk behaviour. The present study was conducted to compare the flowability of basmati and non-basmati rice flour affecting bulk handling which could be related to its particle size, shape and surface roughness (measured by Atomic Force Microscope) as well as bulk and shear properties depending upon the processing conditions. Results Particle size (171.1-171.9 µm) of both the samples was not significantly different. However, the flowability of the non-basmati rice flour was significantly affected by its particle shape (circularity 0.487), surface roughness (124.23nm) and compressibility (25.32%) in comparison to basmati rice flour (circularity 0.653, surface roughness 113.59nm and compressibility 21.09%) making it more cohesive than basmati rice flour. Also, basic flow energy was significantly higher in non-basmati flour, thus required more energy (147.54mJ) to flow than basmati rice flour (130.15mJ). Conclusion Overall, flowability was analysed by applying three different pressures (3, 6 and 9kPa) among which non-basmati rice flour was found less flowable (flow function coefficient, FFC 2.33 at 9kPa) in comparison to basmati (FFC 3.35 at 9kPa) creating bulk handling difficult. This study could be useful in designing processing equipments, hoppers and silos for rice flour handling.by Shumaila Jan, Chinmay Ghoroi and D. C. Saxen