Magnetic separation: its application in mining, waste purification, medicine, biochemistry and chemistry

Abstract

The use of strong magnetic field gradients and high magnetic fields generated by permanent magnets or superconducting coils has found applications in many fields such as mining, solid state chemistry, biochemistry and medical research. Lab scale or industrial implementations involve separation of macro- and nanoparticles, cells, proteins, and macromolecules down to small molecules and ions. Most promising are those attempts where the object to be separated is attached to a strong magnetic nanoparticle. Here, all kinds of specific affinity interactions are used to attach magnetic carrier particles to mainly objects of biological interest. Other attempts use a strong paramagnetic suspension for the separation of purely diamagnetic objects, such as bio-macromolecules or heavy metals. The application of magnetic separation to superconducting inorganic phases is of particular interest in combination with ceramic combinatorial chemistry to generate a library of e.g. cuprate superconductors.

Continuous‐Flow Synthesis of Supported Magnetic Iron Oxide Nanoparticles for Efficient Isoeugenol Conversion into Vanillin

“…In this context,n anocatalyst recovery by magnetic fields could enablem ore efficient separation compared with conventional decantation and filtration,e specially when nanocatalysts are expensive (i.e.,n oble metals) and difficultt os eparate. [4,5] The incorporation of an iron oxide core in the nanocatalyst increasesi ts density and thus also its recovery efficiency by conventional separation methods. The synthesis of magnetic nanoparticles (MNPs) was proposed fors everala pplications and is currentlyahot topic in future catalystd esign practices.…”

Unknotting of quasi-two-dimensional ferrogranular networks by in-plane homogeneous magnetic fields

“…Whereas large aggregation of magnetic nanoparticles in ferrofluids (10 −8 m) is usually undesirable [1], it plays a decisive role in magnetorheological fluids (10 −5 m) [2,3] as well as in purification techniques for water [4] or air [5]. On a macroscopic level (10 −3 m) it is important for ore separation [6] and may even be an important mechanism in the formation of iron-rich planetesimals, precursors of rocky planets in protoplanetary discs [7,8,9,10].…”

Preparation and characterization of manganese, cobalt and zinc DNA nanoflowers with tuneable morphology, DNA content and size

“…For example, hybrid materials that combine magnetic materials with biological components have found a wide range of biomedical applications (3,4). They can be directed to a particular location using an external magnetic field to deliver therapeutics (5,6), used to generate heat locally (7) or combined with biological molecules such as antibodies, enabling magnetic capture and isolation of materials (8). Alternatively, magnetic materials can be combined with enzymes to produce enzyme nanogels which are stable, catalytically active, and can be readily recovered and reused (9).…”