Co and Ni extraction and separation in segmented micro-flow using a coiled flow inverter

Abstract

The segmented micro-flow extraction and separation of the adjacent elements of Co from Ni sulphate solution with Cyanex 272 was developed using a micro-scale coiled flow inverter (CFI). This was compared with the conventional batch extraction at comparable conditions. Continuous operation of a process involving liquid-liquid extraction and then two-phase separation was achieved. For the latter a micro-scale separator was used. Compared with batch extraction, the segmented micro-flow extraction process showed by order-of-magnitude faster extraction times, higher extraction ability for Co, lower extraction for Ni, and then a better selectivity between Co and Ni for industrial-matching sulfate solutions with high Co and Ni ions concentration. In addition, flow patterns were recorded in the CFI by a high speed camera. Regular columnar slug flow was formed at low flow rates, and the length of the inlet slug was found to be a Gaussian function of the flow rates. In-and outlet flows matched, i.e. there was no change in the flow pattern when passing the CFI. At higher flow rates, deviations from the ideal pattern were found and in-and outlet flow did not match. Finally, the mass transfer coefficient in the range of 0.014 to 0.24 mm•s -1 was obtained.

Kinetic Study of Leuco‐Indigo Carmine Oxidation and Investigation of Taylor and Dean Flow Superposition in a Coiled Flow Inverter

“…In the last years, CFIs have been characterized in terms of mixing and residence time distribution [3][4][5][6][7][8][9] and were applied for various processes such as liquid-liquid extraction [10][11][12], precipitation [13], crystallization [14][15][16], and gas-liquid reactions [17][18][19]. Here, increased mass transfer in a CFI was observed compared to straight and helically coiled capillaries as well as a more narrow residence time distribution.…”

Micro Droplet Formation towards Continuous Nanoparticles Synthesis

“…There is a large number of reports showing potential application of micro flow systems for continuous nanoparticles synthesis [ 6 , 21 , 22 , 23 , 24 ], composite materials [ 25 , 26 , 27 , 28 , 29 , 30 ], as well as for metal ion extraction and separation [ 31 ].…”

Modular Coiled Flow Inverter with Narrow Residence Time Distribution for Process Development and Production

“…For chemical reactions the flow profile is an important aspect, since it provides good radial mixing and a narrow residence time distribution. Coiled tubes and CFIs have been applied for various unit operations such as liquid‐liquid extraction , , precipitation , crystallization , , and gas‐liquid reactions , , underpinning its flexibility and potential for process development.…”