Diurnal Oxidation for Manganese Minerals in the Arctic Ocean

The relative abundance of different oxidation states for this important micronutrient varies on the basis of how much available sunlight there is.

Processing and production of pellets from poor-grade manganese-containing raw materials

there is a review of current researches in the processing of poor-grade manganese raw materials. The variety of manganese minerals caused by the valent state of metal in compounds is demonstrated. Different processing methods for manganese-containing mineral and technogenic raw materials are considered. The process of extraction of manganese from ferruginous manganese ore using reduction roasting and magnetic separation, beneficiation technology of poor-grade manganese ore to improve the ratio of Mn/Fe; processes of beneficiation and sintering of fine ferruginous manganese ore with low manganese content; production of agglomerate from the concentrate of manganese poor-grade ore to produce ferrosilicon manganese are described. Results of the authors researches intended to obtain concentrate from manganese-containing sludge and to produce hardened pellets suitable for melting into ferromanganese on its basis using a new component of the binder are presented.

Hydrochemical evolution of pore water in riverbed sedimentation zone during riverbank infiltration

The riverbed sedimentation zone is an important zone of hydrochemistry, and the biogeochemical action in this zone has a significant impact on groundwater quality. As the main area where hydrochemistry occurs, studying the law of hydrochemical evolution within 1 m below the riverbed is of great significance for understanding the migration and removal of river pollutants. In this study, a combination of onsite monitoring and indoor experiments was used to analyze the variation characteristics of the hydrochemical composition of pore water during riverbank infiltration, as well as the main hydrochemical effects and influencing factors. The results show that in the process of river water infiltration, a series of redox reactions occur in the riverbed sedimentation zone, and there are differences in different infiltration depths. From 0 to 20 cm below the riverbed, strong respiration and denitrification mainly occurred. Reductive dissolution of manganese minerals mainly occurred from 20 to 60 cm, and reductive dissolution of iron minerals mainly occurred from 60 to 90 cm. River water level, dissolved organic carbon content and microbial activity had varying degrees of influence on these redox effects. The recharge of river water infiltration ensures the exploitation amount of the pumping wells, but it also leads to the increase of some components in groundwater, and the extracted water cannot be directly drunk.

ELEMENTAL ANALYSIS OF LOCAL AND FOREIGN RAW MATERIALS FOR THE PRODUCTION OF TRIMANGANESE TETRAOXIDE PIGMENT

In the course of continuation of scientific research in the development of Kazakhstani technology for the production of trimanganese tetraoxide pigment, there have been proposed new methods of analysis which make it possible to investigate new nanostructural materials sourced from local deposits. The results obtained are of practical importance and serve as the foundation for developing new technologically advanced domestic production of a competitive product that is in demand both on the national and international markets. The available methods are not able to highlight the particularity and diversity of Kazakhstani manganese ores due to the uneven distribution of manganese minerals and host (waste) rock, the quantitative ratio of rock-forming components and their variation instability. Methods of energy-dispersive analysis of manganese ores from Kazakhstani Zhaksylyk and Bogach deposits have been put forward, electronic micrographs, spectrograms of samples, diagrams of normalized distribution of elements on the surface of samples have been obtained and a comparative analysis with raw analogue samples of some foreign manufacturers has been performed.

Ranciéit a doprovodné minerály z Rychaltic u Frýdku-Místku (Morava, Česká republika)

Recently described small outcrop of the upper part of the Barnasiówka Formation yielded several manganese oxidic minerals. Outcrop at the bank of the Krnalovice Stream (GPS N 49°38.623’ E 018°14.630’) consists of Lower Turonian greenish to grey-black laminated claystone alternating with grey chert. The whole sequence is a part of the Baška facies of the Silesian Unit, Outer Western Carpathians. In the middle part of the profile occur concretional aggregates containing manganese minerals. The central pale part of these aggregates is composed of quartz (ca. 90 wt.%), albite (ca. 9 wt.%), and muscovite, the darker rim of quartz (ca. 80 wt.%), goethite (ca. 10 wt.%), illite, todorokite, plagioclase, K-feldspar, and pyrite. Occasionally, remains of Mn-rich siderite were preserved in the cores. We suppose that they are in fact weathering products of carbonate-rich silicites. Manganese oxides also enter fissures in form of thin black coatings. Powder X-ray diffraction proved the presence of todorokite, ranciéite, pyrolusite, and possible vernadite. Todorokite forms black coatings with submetallic lustre, often associating with ranciéite. Ranciéite is dark pink to pinkish-brown, with a metallic lustre. Back-scattered electron images reveal its extremely thin tabular, sometimes undulated crystals and hexagonally oriented intergrowths. Powder diffraction data are strongly affected by preferred orientation, with dominating basal reflections of 001 plane at 7.4849 Å and plane 002 at 3.7424 Å. Its average formula from nine WDS spots (Ca0.14Mg0.01Ba0.01K0.01)Σ0.17(Mn4+0.86Si0.02Al0.03Fe0.01)Σ0.92O2.00·0.88H2O (based on 2 anions, water calculated from the ratio of cation sum / H2O in the formula according to Post et al. 2008) and CaO/MnO2 ratio 9 to 12 correspond well to the published data for this phase. Ranciéite is a rather common phyllomanganate from various geological environments, but this locality represents its first unambiguous occurrence in the Czech Republic. It closely resembles the one from Polish flysch Carpathians from Nowa Wieś near Rzesów.

Anoxic photogeochemical oxidation of manganese carbonate yields manganese oxide

The oxidation states of manganese minerals in the geological record have been interpreted as proxies for the evolution of molecular oxygen in the Archean eon. Here we report that an Archean manganese mineral, rhodochrosite (MnCO3), can be photochemically oxidized by light under anoxic, abiotic conditions. Rhodochrosite has a calculated bandgap of about 5.4 eV, corresponding to light energy centering around 230 nm. Light at that wavelength would have been present on Earth’s surface in the Archean, prior to the formation of stratospheric ozone. We show experimentally that the photooxidation of rhodochrosite in suspension with light centered at 230 nm produced H2 gas and manganite (γ-MnOOH) with an apparent quantum yield of 1.37 × 10−3 moles hydrogen per moles incident photons. Our results suggest that manganese oxides could have formed abiotically on the surface in shallow waters and on continents during the Archean eon in the absence of molecular oxygen.

Source and Mobilization Mechanism of Iron, Manganese and Arsenic in Groundwater of Shuangliao City, Northeast China

Excessive levels of Fe, Mn and As are the main factors affecting groundwater quality in Songliao plain, northeast China. However, there are few studies on the source and mobilization mechanisms of Fe, Mn and As in the groundwater of Northeastern China. This study takes Shuangliao city in the middle of Songliao plain as an example, where the source and mobilization mechanisms of iron, manganese and arsenic in groundwater in the study area were analyzed by statistical methods and spatial analysis. The results show that the source of Fe and Mn in the groundwater of the platform is the iron and manganese nodules in the clay layer, while, in the river valley plain, it originates from the soil and the whole aquifer. The TDS, fluctuation in groundwater levels and the residence time are the important factors affecting the content of Fe and Mn in groundwater. The dissolution of iron and manganese minerals causes arsenic adsorbed on them to be released into groundwater. This study provides a basis for the rational utilization of groundwater and protection of people’s health in areas with high iron, manganese and arsenic contents.

Technological study on the Gravity Processing of Manganese Ore

This study investigated the effectiveness of the gravity beneficiation method based on gravitation and centrifugal forces for manganese ore. Manganese ores from Unagad deposit, samples powders were analyzed for their element and mineralogical composition using inductively coupled plasma mass spectrometry (ICP-MS) and X-ray diffractometer (XRD). Mineralogy and petrographic analysis are presented the mineralogical compositions are hydro goethite, manganese minerals and magnetite, the gangue minerals are quartz, albite, orthoclase, microcline in manganese ore. Manganese mineral occurs white, improper shape particles, weak grained-aggregates associated in gangue minerals. The most important minerals consist of manganese minerals are hausmannite, pyrolusite, rhodochrosite, and manganosite. The composite of feed containing 17.31 % Mn and 36.3 % SiO2 was produced by a centrifugal concentrator in combination with the shaking table. In the experiment, a concentrate assaying 41.37% Mn was obtained from this composite with 11.9 % yields. In the next experiment, f80=0.074mm particle size feed ore was used in the MGS concentration test. A concentrate containing 38.33 % Mn with 26.57 % yields was produced in this experiment. The results showed that it is possible to obtain concentrate on the gravity processing of manganese ore that economically significant and meet standard requirements. Манганы хүдрийг гравитацийн аргаар баяжуулах технологийн судалгаа Хураангуй: Энэхүү судалгааны ажлаар манганы хүдрийг хүндийн хүч болон төвөөс зугтах хүчний үйлчлэл дээр үндэслэн гравитацийн аргаар баяжуулах туршилт явуулав. Унагад ордын манганы хүдрийн дээжийн элементийн найрлагыг индукцийн холбоост плазмын масс спектрометр (ICP-MS), эрдсийн найрлагыг рентген дифрактометрийн аргаар тодорхойлсон. Минералоги, петрографийн шинжилгээгээр чулуулагт гидрогётит, манганы эрдсүүд, магнетит гэсэн хүдрийн эрдсүүд, кварц, альбит, ортоклаз, микроклин зэрэг хүдрийн бус эрдсүүд тодорхойлогдлоо. Хүдрийн бус эрдэс дотор манганы эрдэс нь цагаан өнгөтэй, зөв бус хэлбэртэй мөхлөгүүд мөн сул шигтгээлэг байдлаар тааралдаж байна. Манганы эрдсүүд нь гаусманит, пиролюзит, родохрозит, манганизит хэлбэрээр агуулагдсан байна. Манганы 17.31%, цахиурын ислийн 36.3% агуулгатай анхдагч хүдрийг төвөөс зугтах хүчний сепаратор болон ширээний хосолсон аргаар баяжуулахад баяжмалын агуулга Mn-41.37%, гарц 11.9% байв. Харин -0.074 мм фракцийн агуулга 80%-тай анхдагч хүдрийг хүндийн хүчний сепаратор (MGS)–аар баяжуулж, 38.33% -ийн манган агуулсан, 26.57% -ийн гарцтай баяжмал гарган авсан. Иймд манганы хүдрийг гравитацийн аргаар баяжуулахад стандартын шаардлага хангасан эдийн засгийн ач холбогдолтой бүтээгдэхүүн гарган авах боломжтойг тогтоов. Түлхүүр үг: Манганы хүдэр, хүндийн хүчний сепаратор, төвөөс зугтах хүчний сепаратор, рентген - дифрактометр.