Semantic Scholar extracted view of "The Determination of Available Oxygen in Pyrolusite." by O. Barnebey
Kinetics and determination of the rate controlling step. Based on the optimized condition determined for the maximum manganese recovery ... There are certain consecutive steps in the leaching of solids (pyrolusite in the present research) according to this model: (i) the reagents (organic acids) diffuse through a liquid film around the ...
The pyrolusite was reduction roasted under the conditions: a mass ratio (carbonaceous gold ore to pyrolusite) at 1:3, 1:2, 2:3, 5:6, and 1:1, a temperature at 1073.15 K, a roasting time at 50 min. The roasting product of pyrolusite was leached for 120 min by 1.75 mol/dm 3 sulfuric acid to evaluate the effect of mass ratio on the …
A sensitive method for simultaneous determination of dithionate (S2O62-) and sulfate (SO42-) using ion chromatography (IC) equipped with suppressed conductivity detector was developed.
Pyrolusite and ramsdellite exhibit either simultaneous growth or partial transformation from one into the other. Both polymorphs appear opaque or silver-black, …
A procedure is described for the determination of total manganese in pyrolusite. The sample is decomposed with hydroxylamine hydrochloride solution. The residue left after filtration is fused with sodium carbonate and extracted again with hydroxylamine hydrochloride solution. A suitable aliquot is t …
In this study, several machine learning models were used to analyze the process variables of electric-field-enhanced pyrolusite leaching and predict the leaching rate of manganese, and the applicability of those models in …
pyrolusite, common manganese mineral, manganese dioxide (MnO 2), that constitutes an important ore.Always formed under highly oxidizing conditions, it forms light-gray to black, metallic, moderately heavy coatings, crusts, or fibres that are alteration products of other manganese ores (e.g., rhodochrosite); bog, lake, or shallow marine products; or …
The optimum condition for low-grade pyrolusite sample JM-2 was achieved as 0.5 MPa of the oxygen partial pressure, 55% of KOH, 14 of the initial alkali-manganese ratio, and ≤ 48 μm of the mineral granularity at 260 °C within 150 min of leaching time and 500 rpm. In alkaline leaching of low-grade pyrolusite, Mn(IV) was oxidized into Mn(VI). ...
Manganese in pyrolusite ores from various regions of Myanmar was determined by thermal neutron activation analysis using an Am(Be) neutron source. ... U., Swe, M.T. Determination of manganese in some pyrolusite ores of Myanmar by neutron activation analysis. Journal of Radioanalytical and Nuclear Chemistry Letters 187, 113–116 …
First-derivative XANES finger allows the unique identification of pyrolusite, ramsdellite, and potentially lithiophorite within the manganate group. However, XANES spectra of individual Mn compounds can vary significantly depending on chemical composition and/or crystallinity, which limits the accuracy of XANES-based speciation …
pyrolusite; only on the y-axis is a contraction required. This modification implies the formation of lamellae and cavities (cracks) parallel to (010), whose existence causes the reflectivity of the basal sections (parallel to x and y) to present great variations. In the same way, cracks cause huge variations in hardness, which can
With the shortage of high-quality raw materials and increasingly strict environmental regulations, the recovery of metals from copper slag and pyrolusite has become a research hotspot. A novel method for simultaneously extracting Mn and Fe from pyrolusite and copper slag has been proposed. Under the optimal conditions (Copper …
A new method was studied for extracting manganese from low-grade pyrolusite with H2SO4 roasting and subsequent water leaching. The mechanism of roasting and optimal conditions for roasting, including the amounts of H2SO4 and H2O addition and the roasting temperature and time, were discussed. The results indicated …
3.9 Determination of the rate of reaction and activation energy . ... In this work, the behavior of low-grade pyrolusite during microwave-assisted heating was systematically investigated, and the ...
Determination of viscosity of sample oil by Oswald's viscometer III Conductometric titration of strong acid vs. strong base IV Conductometric titration of mixture of acid vs. strong base V Potentiometric titration of strong acid vs. strong base VI Estimation of manganese dioxide in pyrolusite VII
Determination of manganese dioxide in pyrolusite by iodometric method. C. Ming. Published 2012. Chemistry. Uranium Mining and Metallurgy. Under the conditions of …
Pyrolusite was chosen as a model Mn-oxide for this study because it is the most thermodynamically stable Mn mineral phase, and therefore represents the end-member case for Mn(IV) reduction by Fe(II). ... Yotsuyanagi T, Nagayama M. Spectrophotometric determination of iron(II) with 1, 10-phenanthroline in the presence …
This paper deals with the determination of the adsorption capacities of various organic compounds in water suspension on MnO 2 pyrolusite which can be present in the natural environment and in potabilisation treatment. The adsorption was linearised according to Langmuir and Freundlich models.
A highly-sensitive, accurate method for SAC determination is an important prerequisite for carrying out detailed investigation into the fate of SAC at trace levels from ng/L to μg/L in the aqueous environment. Most recent studies of water and wastewater quality have placed emphasis on physicochemical indicators (such as pH, ...
A common Mn mineral, although difficult to distinguish from similar Mn minerals, pyrolusite forms under oxidizing conditions and high pH. Mainly a mineral of lacustrine, shallow …
Pyrolusite crystal diminishes fear and aligns the chakras as well as auric body. Derived from the Greek " fire wash", the pyrolusite is a stone of purification. It offers support during emotional healing, and also releases blockage and stabilized relationships. The stone promotes confidence, optimism, and determination.
Request PDF | On Sep 29, 2011, T. Jeevananda published A novel Iodo-Potentiometric method for estimation of percentage of MnO2 in Pyrolusite | Find, read and cite all the research you need on ...
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The schematic diagram of the preparation procedure of MnO 2 from low-grade pyrolusite is presented in Scheme 1.First, water, sulfuric acid and the pyrolusite sample were mixed and then roasted under the following conditions: H 2 O to H 2 SO 4 volume ratio of 0.2:1, H 2 SO 4 to pyrolusite mass ratio of 2:1, roasting time of 4 h and …
other metal ions on the exactitude of the results has been studied. And the method can be used for the determination of Manganese in alloys. Keywords: Manganese determination, EDTA titration, Introduction Manganese is a silvery grey metal and exists in three allotropic forms which are stable over various temperature ranges. It is
Thermodynamic calculations, X-ray photoelectron spectroscopy, and X-ray diffractometry analyses determined that the phase transformation of pyrolusite followed …