The setting and style of manganese mineralization in the Constantiaberg Massif, Cape Peninsula, South Africa

Manganese oxyhydroxide mineralization is widespread in the Constantiaberg Massif. It is largely hosted by west-northwest – east-southeast trending brittle structures in the competent Ordovician arenites of the Peninsula Formation of the Cape Supergroup. Manganese is also found impregnating more porous Peninsula Formation arenites and Quaternary scree. This study proposes that the more significant deposits at Hout Bay and Constantiaberg differ from most of the mineralization in that they are spatially associated with saprolithic dolerite dykes belonging to the 132 Ma False Bay dolerite dyke swarm. It is suggested that this deep weathering may be related to a Miocene palaeo-landsurface, yielding a maximum age for these more important Mn deposits. However, there is evidence for mineralization of different ages through the Quaternary Period. Apart from Mn-mineralization hosted by rare breccias containing hydrothermal quartz, most of the mineralization is supergene, having been leached and transported in reduced acidic groundwater and precipitated at or near a redox front in a near-surface environment.

Redox-assisted multicomponent deposition of ultrathin amorphous metal oxides on arbitrary substrates: highly durable cobalt manganese oxyhydroxide for efficient oxygen evolution

Large-scale amorphous metal oxide films deposited on arbitrary substrates via redox interaction exhibit greater efficiency and durability in electrocatalytic oxygen evolution than benchmark materials.

Sorption extraction of 137Cs and 90Sr radionuclides from aqueous solutions by MnO(OH) nanoparticles

In this study, nano-sized particles of manganese oxyhydroxide (MnO(OH)) are synthesized. Sorption properties of this material towards 90 Sr and 137 Cs radionuclides in the pH range from 2 to 9 at a temperature of 293.15 K solution are studied. The time of sorption achievement equilibrium in the radionuclide sorbent system depends on the nature of sorbed cation, but does not exceed 60 min.

Synthesis and Characterization of Nanosized Manganese Oxyhydroxide Compounds by Sonochemical Method

Manganese oxyhydroxide (MnOOH) nanoparticles were synthesized by the reaction of [Mn(Hsal)2] complex and NaOH in the presence of ultrasound irradiation. In this study, the effect of different reaction parameters such as type of solvent, sonication time and type of surfactant on the morphology and the particle size of product were studied. The as-synthesized nanoparticles, with an average size of 10–15 nm, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and energy dispersive spectrometry (EDS). To the best of author’s knowledge, it is the first time that [Mn(Hsal)2] complex is used as manganese source for the synthesis of MnOOH nanoparticles.