(6dg) The Role of Microfluidic Interfaces in Metals Extraction, Soil and Fertilizers

Will the Earth cope with anthropogenic pressure? Will humanity invent a truly sustainable way to develop itself? The consequences of globalization and population growth on our planet are unclear. Pressing challenges of environmental degradation, global food security and climate change require multidisciplinary and creative approaches to be solved. My research takes one step in this direction bridging chemical engineering, chemistry and materials science, with the aim to elucidate interfacial processes that are key for both the environment and the chemical industry. Such a research makes use of a broad spectrum of analytical techniques and put a special emphasis on the benefits of microfluidic technology for interface science.

A first research effort focuses on the extraction of metals. Global demand for metals continues to increase, with solvent-extraction being the elected industrial method for the production and refinement of key elements such as cobalt, nickel and copper. It is an industry that relies on old technologies and therefore in need of sustainable innovations. Particularly, mixer-settlers and contactors have been designed on the idea of chemical equilibrium, thus requiring huge amount of toxic solvents and long equilibration times. To reduce the amount of solvents and improve the efficiency of extraction, a new generation of non‑equilibrium contactors is being proposed by the industry. For such contactors, a comprehensive kinetic understanding becomes of critical importance and microfluidic devices offer an unprecedented opportunity to achieve such an understanding.

A second research effort interprets the soil as a microfluidic system. Advances in soil science are necessary to unlock the mechanisms responsible for carbon and nutrient cycling, to improve agricultural yields as well as to address land degradation, erosion and pollution.

A third research effort devises and optimizes new ecofriendly and sustainable processes for the synthesis of fertilizers. With concerns about the possibility to feed the world in the coming decades, there is a need to formulate a new generation of fertilizers, which can address both the soil and socio-economic requirements of tropical countries. Silicate minerals are a promising source of agricultural nutrients although sound economic processing to reduce their chemical stability have to be found (e.g., hydrothermal treatments).

SELECTED PUBLICATIONS:

1. Ciceri D., Allanore A. Microfluidic leaching of soil minerals: K⁺ from K‑feldspar (Submitted)

2. Ciceri D., Manning D.A.C., Allanore A. Historical and technical developments of potassium resources. Science of the Total Environment 502 590-601 (2015) DOI: 10.1016/j.scitotenv.2014.09.013

3. Ciceri D., Perera J.M., Stevens G.W. The Use of Microfluidic Devices in Solvent Extraction. Journal of Chemical Technology and Biotechnology 89(6) 771-786 (2014) DOI: 10.1002/jctb.431.

4. Ciceri D., Mason L.R., Harvie D.J.E., Perera J.M., Stevens G.W. Extraction Kinetics of Fe(III) by di (2‑ethylhexyl) phosphoric acid in a Y-Y shaped microfluidic device. Chemical Engineering Research and Design 92(3) 571-580 (2014) DOI: 10.1016/j.cherd.2013.08.033.

5. Ciceri D., Mason L.R., Harvie D.J.E., Perera J.M., Stevens G.W. Modelling of Interfacial Mass Transfer in Microfluidic Solvent-Extraction. Part II. Heterogeneous Transport with Reaction. Microfluidics Nanofluidics 14(1) 213‑224 (2013) DOI: 10.1007/s10404-012-1039-y.