Bench scale control of the crystallite size and morphology of goethite particles by different ferrous source

Control of the size and morphology of goethite (α-FeOOH) particles was attempted in a bench scale reactor of 80 dm3 in capacity. X-ray crystallite sizes (D1 0 0, D0 1 0) and their ratio (D0 1 0/D1 0 0) were examined by systematically varying the starting ferrous source, together with the relative amount of alkali to initial ferrous ion. By starting from Fe(OH)2 or the mixture of Fe(OH)2 and FeCO3, we obtained particles with large anisotropy, judged from the ratio, D0 1 0/D1 0 0, and the electron micrographs. With Green Rust (II), in contrast, lateral growth of (1 1 0) was prevented by the presence of sulfuric groups to give less anisotropic particles. Further advantage of using Fe(OH)2–FeCO3 mixture as a ferrous source is discussed in terms of possible higher crystallinity of the products.