Magnetite coagulation

Holding of the temperature between 400 and 575°C causes the iron particles to coagulate and the scale becomes further enriched in oxygen. Since wiistite is unstable below 575°C, scales produced at temperatures lower than this contain magnetite and haematite only. In addition, the scales are often cracked and porous. This is due to the difference in contraction... 

Figure 18. Relationship between magnetic coagulation force and concentration of magnetite particles in a suspension. Parameter particle size...

Some of the available options are powdered activated carbon, UV/o2one, magnetite, lime softening, ion exchange, conventional media filtration, and coagulation with inorganic and polymeric coagulants. 

The adsorption measurements show that at conditions of monolayer formation 0.5 mMol perfluoropolyether-surfactant can be fixed on 1 g magnetite, and that it is possible to nearly totally eliminate the surfactant from the water carrier. During the adsorption process the modified particles coagulate and can be separated by a simple laboratory magnet. 

Rudolph M, Peuker UA (2011) Coagulation and stabiUzation of sterically functioneiUzed magnetite nanoparticles in an organic solvent with different techniceil polymers. J Colloid Interface Sd 357 292-299... 

---