Analysis of key mixing parameters in industrial Wemco mechanical flotation cells

Pinto, T.C. Souza; Braga, André Soares; Filho, Laurindo de Salles Leal; Deglon, D.A.

doi:10.1016/j.mineng.2018.03.046

Cited by 7 publications

(2 citation statements)

References 26 publications

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“…Wemco 1+1™ scale-up procedure consists on keeping the Air Flow Number (N a ) constant (Arbiter et al, 1976;Weber et al, 1999;Souza Pinto et al, 2017). This parameter, also called Air Capacity Number (C a ) (Nelson & Lelinski, 2000;Gorain et al, 2007), is defined in Equation (26).…”

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confidence: 99%

Scale-up in froth flotation: A state-of-the-art review

Mesa

Brito-Parada

2019

Separation and Purification Technology

102

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Froth flotation has been one of the most important and widely used methods to concentrate minerals since its introduction over a hundred years ago. Over the last few decades, in order to process more mineral while reducing capital costs, flotation equipment has become exponentially larger. The increase in tank volume, however, has brought new challenges in the operation and design of industrial flotation tanks. This review analyses the literature on flotation tank scale-up for the first time, contrasting several techniques and approaches used in both historical and state-ofthe-art research. The study of flotation scale-up is crucial for the optimisation of industrial plant performance and the maximisation of laboratory-scale research impact. While important advances in our understanding of flotation have been achieved, large flotation tank design and scale-up has, to a large extent, remained in-house know-how of manufacturing companies. This review of the literature relevant to flotation tank scale-up has resulted in a new classification, dividing the scale-up literature into two main areas of study, namely "Kinetic scale-up" and "Machine design scale-up".This review indicates that current scale-up rules governing the design of flotation tanks focus mainly on pulp zone kinetic parameters and neglect the effects on the froth zone, despite the importance of froth stability and mobility in determining flotation performance. Froth stability and mobility are closely linked to the distance the froth needs to travel, which increases with tank diameter. Although including internal elements, such as launders and crowders, has been the industrial solution for enhancing froth transport and recovery in larger tanks, the design and scale-up of these elements have not been thoroughly studied. Gaps in our knowledge of flotation are discussed in the context of addressing the scale-up problem, considering froth transport and froth stability. Addressing these gaps will pave the way for the design and operation of large flotation tanks of enhanced performance.

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confidence: 99%

Scale-up in froth flotation: A state-of-the-art review

Mesa

Brito-Parada

2019

Separation and Purification Technology

102

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“…In the API tanks, the oily fraction is separated from water for gravimetric decantation. Separation is not complete, and therefore the water streams from the API tanks, after being mixed in an equalization tank acting as a buffer, are treated in a flotation system, 29 providing further oil‐water separation. Downstream, an active carbon filtration unit removes residual HCs and phenols.…”

Section: Refinery Descriptionmentioning

confidence: 99%

Experimental study of a reverse osmosis pilot plant for reuse of refinery wastewater

Costamagna

Rosellini

Lavarone

et al. 2021

J of Chemical Tech & Biotech

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BACKGROUND The possibility of reusing treated refinery wastewater in the cooling water system (CWS) of the refinery itself is investigated. The contaminant levels in the treated wastewater typically fluctuate around or slightly above the threshold values for recycling to the CWS and this motivates the need for an additional purification unit. To this end, the performance of reverse osmosis (RO) is experimentally investigated through a flat‐sheet RO pilot plant installed directly in the refinery (on the treated wastewater streamline). RESULTS In the pilot plant, two different RO membranes are tested: seawater (SWM) and brackish water (BWM) membranes. In both cases, the permeate water at the outlet of the RO pilot plant had conductivity below 100 μS cm–1, total hardness (TH) below 8 ppm, chemical oxygen demand (COD) below 45 ppm, Fe below 0.04 ppm, and total ammonia nitrogen (TAN) below 1.1 ppm. The concentration of hydrocarbons (HCs) is a few ppm in the treated wastewater both at the inlet of the RO pilot plant and in the RO permeate. All these data are well below the thresholds for reuse in the CWS. The results were stable and no evidence of degradation was found over the experimentation period (3 days and 6 days, respectively, for the SWMs and the BWMs). CONCLUSION The RO permeate water can be reused in the CWS of the refinery. The proposed reuse strategy is expected to make a significant reduction (20–25 t h–1) in refinery primary water withdrawal possible. © 2021 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

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