Grade Manganese Research Articles

Evaluation of pyrolusite flotation behavior using a cationic collector

Floatability of pyrolusite from an Iranian low grade manganese ore (13.6% MnO) containing calcite as the main gangue mineral was investigated with Armac C as a cationic collector. In the single mineral flotation experiments, the maximum recovery of pyrolusite is obtained at 82.2%, using 2000 g/t Armac C at a pH of 9, while at these conditions the flotation recovery of calcite is almost 78%. Quebracho and sodium hexa methaphosphate (SH) depress both minerals strongly at a wide range of dosages while low dosages of sodium silicate and zinc oxide depress the calcite mineral more than pyrolusite. Ca2+ ions affect the flotation recovery of pyrolusite negatively. The effective depression of calcite occurs using 1000–2000 g/t sodium silicate. However, in the ore flotation experiments, the favorable selective flotation of pyrolusite does not occur but the optimal concentrate containing 21.5% MnO with 51% recovery is obtained using 2000 g/t collector and 1000 g/t sodium silicate. A concentrate containing 37% MnO is achieved by carrying out flotation experiments on the jigging pre-concentrate under optimal conditions including pH = 9, 1000 g/t Armac C, 1000 g/t sodium silicate and 120 g/t pin oil.

Reducing UT Rejections in Cr-Mo and High Mn Steels by Controlling Hydrogen and Optimising Superheat

JSW Steel Limited, Salem Works (JSWSL), is an integrated steel plant, having a production capacity of 1.0 mtpa (million tons per annum) of high-grade automotive special steels. At JSWSL, hydrogen induced cracks and center unsoundness contribute more to UT (Ultrasonic testing) rejections in chrome-molybdenum (Cr-Mo) and high manganese grade steels. Hydrogen induced cracks was controlled by increasing argon flow rate from 3-4 Nm3 to 7-9 Nm3 during vacuum degassing. Vigorous purging led to a reduction in hydrogen levels from around 2 ppm (parts per million) to less than 1.5 ppm. Center unsoundness was controlled through optimising superheats in tundish. Data of trial heats revealed that, UT rejections were more in heats cast with superheat levels more than 35°C. Based on the data obtained from trial heats superheat was optimised to 25-35°C for both Cr-Mo and high manganese steels. The present paper discusses the measures taken to reduce UT rejections in these grades.KeywordsJSWSL, Cr-Mo, High Mn steels, UT rejections, superheat, hydrogen induced cracks, center unsoundness, vacuum degassing, continuous casting.

Surface Characteristics and Flotation Behaviour of Low-Grade Manganese Ore

Evaluation possibility of low grade manganese mineral from Hunan by froth flotation technique was investigated. Manganese mineral sample was characterized with mineralogical analysis, XRD, and SEM studies for its mineral content and surface characteristics. XRD analysis showed that the gangue contents of manganese minerals are constituted mainly by dolomite as a carbonate mineral, quartz and feldspar. SEM indicated that existence of rhodochrosite, which mainly fills in the dolomite minerals. The influences of important factors on manganese mineral flotation are investigated. The size of grind, pulp pH, dosages of depressant and collector are essential to the effective recovery of rhodochrosite in manganese mineral flotation.

Tertiary enrichment of a manganese oxide tailings material using heavy medium separation (HMS)

A study was conducted on the enrichment of manganese oxide tailings material generated from sorting spiral concentration at Ghana Manganese Company (GMC) Limited, Nsuta. The investigation explored mineralogical and particle size characterisation and heavy medium separation technique. Analytical methods used include; X-Ray Fluorescence and Atomic Absorption Spectrometry (AAS). The material contained 9.01% Al2O3, 27.43 % SiO2, 23.64% MnO2 and 9.86% Fe2O3, the other oxides range between 0.04 to 1.55 %. By treating the individual size fractions at a bath density of 2.96, the highest ratio of concentration of 3.56 was obtained at 180 ?m, while the highest enrichment ratio of 1.84 and manganese grade of 38.25% were obtained at 1180?m respectively. These qualify the enriched material as suitable for Ferro-alloy industry. DOI: http://dx.doi.org/10.3329/bjsir.v49i1.18852 Bangladesh J. Sci. Ind. Res. 49(1), 35-40, 2014

Reduction of Low Grade Egyptian Manganese Ore via Hydrogen at 800℃ - 950℃

Low grade manganese ore fine was briquetted with different amounts of molasses under different pressure was studied in this investigation. In this study, the characterizations of raw materials were studied by different methods of analyses such as X-ray and chemical analyses. The results of briquetting show that as the pressing pressure load increased both the drop damage resistance and crushing strength increased and the optimum amount of molasses added was 2% and the pressing pressure was 216.7745 MPa. The produced briquettes were reduced by different flow rate of hydrogen at different temperatures, and the reduction kinetics was determined. The results indicated that: 1) The reduction rates by hydrogen increased with increasing temperature of the reduction; 2) Increase hydrogen flow rate at constant temperature of reduction leads to increase rate of reduction; 3) The zero order is control step at time 0 - 5 min and from 5 to 20 min the gaseous diffusion in case of cylindrical products and from 20 to 60 min the reaction controlled by nucleation and growth.

下雷锰矿床三维可视化建模及矿化空间结构分布规律分析

本文采用矿区二维剖面线串模型重构三维地质体表面模型的基本思路，构建了矿区地质体三维结构模型，并分析矿体与地层的空间分布关系，以及从二维、三维角度论证矿体受褶皱作用的影响；以地质数据库为基础，应用地质统计学理论方法建立锰品位实验半变异函数模型，进行矿化空间变化结构分析，获得锰品位在主轴、次轴、短轴方向的分布形态和品位变化规律，为深部找矿提供依据和技术支持。This paper is based on the basic ideas that refactored 3D geologic body surface model form 2D geological line string model and the geologic body 3D structure model was built, which was helpful to analyze the spatial distribution relationship between the formation and ore bodies. The pers-pective of ore bodies influenced by folding was proved from 2D and 3D. On the basis of the geolog-ical database, the manganese grade test half variation model was built in geostatistics method. Analyzing the mineralization space structure, the distribution form and grade change rule of spin-dle, secondary axial and short shaft were finished, which provides the basis and technological sup-porting for prospecting the rationality.

Preparation of chemical manganese dioxide from low-grade rhodochrosite ore

The preparation of chemical manganese dioxide (CMD) from low-grade rhodochrosite ore (LGRO) in Xiushan, Chongqing, was studied and improved, including leaching with sulfuric acid, purifying, crystallizing and decomposing of MnCO3, and refining of primary MnO2. The product was characterized by X-ray diffraction. The results showed that the extraction ratio, the manganese recovery ratio of purifying, crystallization and refining reached 96.8%, 93.9%, 97.7% and 85.4%, respectively. The optimum conditions of refining were described as follows: liquid (H2SO4)/solid (primary MnO2) ratio was 3 L/g, the concentrations of NaClO exceeded 20%, and reaction time was 3 hours. Under the above conditions, the contents of MnO2 and Mn in the obtained manganese dioxide were respectively 85.1% and 53.9%. The refined MnO2 can be used as the super grade manganese dioxide mine powder in chemical industry. The XRD indicated that the structure of the product was γ-MnO2.

Smelting of ferrosilicon manganese from unconventional silicate-oxide manganese raw material

Research is performed for preparation of ore concentrates of unconventional silicate-oxide manganese ore preparation by an x-radiometric method. Study is performed in a SRF-2-100/20 separator with a size class −100+20 mm on a sample of silicate-oxide manganese ore of Ir-Nimiisk plateau. Standard ferrosilicate manganese grade MnS17 according to GOST 4756-91 is smelted from the concentrates obtained. The possibility is demonstrated of involving this form of raw material for smelting manganese alloys.

Characterization and beneficiation of iranian low-grade manganese ore

The mineralogical studies indicated that Charagah ore deposit contains approximately 17% pyrolusite, 78% calcite and 3-4% quartz. Pyrolusite as a main valuable mineral is found in the forms of coarse and fine pyrolusites. The coarse grains pyrolusite with simple texture is liberated at 180 microns. Another kind of pyrolusite with particle size finer than 10 m is disseminated inside gangue phases. This kind of pyrolusite has important effect in beneficiation processes and can affect the manganese grade of the concentrate and its recovery negatively. By jigging machine a pre-concentrate with 20% MnO and a final tailing with about 13% manganese loss are obtained. Using tabling technique or wet high intensity magnetic separation (WHIMS) and also their combination with jigging machine, production of a final pyrolusite concentrate with suitable grade but average recovery is possible. By jigging-tabling a concentrate with -500+45 m size fraction, 44.3% MnO and 61.3% recovery is obtained while jigging- WHIMS produces a concentrate containing 52.6% MnO with a recovery up to 56.6% and d80 = 180 m.

Photocatalytic Degradation of Rhodamine B Using MnO<sub>2</sub> and ZnO Nanoparticles

The oxide semiconductor with different band gap energy i.e. manganese dioxide (MnO2) (Eg: 1.30eV) and zinc oxide (ZnO) (Eg: 3.37 eV) nanoparticles were used to degrade RhodamineB (RhB) under irradiation of UV light (254 nm).The MnO2nanoparticles were synthesized by hydrothermal method (160 °C, 4 h) using analytical grade manganese sulfate hydrate and potassium permanganate (VII) as precursors. The XRD analysis reveals that the nanoparticles were d-MnO2.The photocatalytic study shows that degradation of RhB solution by ZnO nanoparticles (rate constant: 0.02749 min-1) was approximately four times faster than the d-MnO2nanoparticles (rate constant:0.0067 min-1). This observation could be attributed to the higher reducing and oxidizing power of ZnO in producing free radicals for photodegradation of RhB solution.

Microbial Recovery of Manganese using <i>Staphylococcus Epidermidis</i>

Manganese minerals are widely distributed throughout the globe. The most important industrial uses of Mn are in the manufacture of steel, non-ferrous alloys, carbon-zinc batteries and some chemical reagents. Microbial recovery of manganese from low grade manganese ores using bioleaching was investigated in this paper. A bacterial strain, Staphylococcus epidermidis (MTCC-435) was collected from microbial type culture collection, IMTECH Chandigarh and used for the experiment. The experimental results for bioleaching with S. epidermidis showed that under pH 5.5, particle size –150 μm, pulp density 10%, temperature 35℃ and agitation 200 rpm, about 80% of Mn was recovered within 20 days of incubation.

Reductive Acid Leaching of Low Grade Manganese Ores

Manganese recoveries from low-grade ores using organic acids as reducing agents were investigated in the present work. The acid leaching potential of both oxalic acid and citric acid were estimated. Manganese leaching amount were measured by using standard manganese curve and estimated by titration method. Effects of various acid concentrations on leaching efficiency were studied. The observed result suggested prominent manganese recovery of 66% by oxalic acid at 2 M concentration whereas citric acid had less effect on leaching showing leaching percentage upto 40% in 6 days. Acid leaching of manganese ore with both the acids gave a comparative data stating that oxalic acid leached better than citric acid.

Data-Driven Multiobjective Analysis of Manganese Leaching from Low Grade Sources Using Genetic Algorithms, Genetic Programming, and Other Allied Strategies

Data-driven models are constructed for leaching processes of various low grade manganese resources using various nature inspired strategies based upon genetic algorithms, neural networks, and genetic programming and subjected to a bi-objective Pareto optimization, once again using several evolutionary approaches. Both commercially available software and in-house codes were used for this purpose and were pitted against each other. The results led to an optimum trade-off between maximizing the recovery, which is a profit oriented requirement, along with a minimization of the acid consumption, which addresses the environmental concerns. The results led to a very complex scenario, often with different trends shown by the different methods, which were systematically analyzed.

Beneficiation and agglomeration process to utilize low-grade ferruginous manganese ore fines

Characterisation, beneficiation and agglomeration studies were carried out to develop a utilization strategy for typical Indian low grade manganese ore fines. The major mineral phases found are pyrolusite, hematite, goethite, clay, feldspar and quartz. QEMSCAN and Sink–Float studies suggested that 40% of manganese minerals are in liberated form, whereas 30% are locked with iron minerals. Classification followed by two-stage high intensity magnetic separation (1.7 & 1.1 Tesla) process can recover 35–40% material of ferromanganese grade with 47–49% Mn recovery. The recovered material was briquetted adding molasses (7%), cement (3%) and bentonite (1%) to use in the submerged arc furnace for metallurgical applications. A cost effective process flow sheet has been developed to utilize these fines.

Pb(II), Cd(II) and Zn(II) adsorption on low grade manganese ore

Low grade manganese ore (LMO) of Orissa containing 58.37% SiO2, 25.05% MnO2, 8.8% Al2O3, and 5.03% Fe2O3 as the main constituents was taken to study its adsorption behaviour for Pb(II), Cd(II) and Zn(II) from aqueous solutions. The XRD studies showed the crystalline phases to be quartz, ß-MnO2, d-MnO2 and Fe2O3. Batch adsorption studies were carried out by varying the experimental parameters which included contact time, pH, adsorbate and adsorbent concentrations and temperature. The time data fitted well to pseudo second order kinetics for Pb(II), Cd(II) and Zn(II) adsorption. With the increase in adsorbent dose, loading capacities decreased. With the increase in pH from 2.0 to 5.5, Pb(II) adsorption increased while Cd(II) and Zn(II) adsorption increased till an initial pH of 3.0. Positive ?H° values confirmed the adsorption process to be endothermic and positive ?S° values suggest the increased randomness at the solid-solution interface during the adsorption of cations on the sample. The adsorption data showed good fit to both Langmuir and Freundlich isotherm models for the three cations. The Langmuir monolayer capacities for Pb(II), Cd(II) and Zn(II) were estimated to be ~142.85, 59.17 and 98.0 mg per gram of LMO sample respectively. From the XRD studies of loaded samples, it was observed that Pb((II) adsorption affects silica phase whereas Cd(II) adsorption affects both silica and ß-MnO2 phases. With Zn(II) adsorption both the intensity and peak position of silica phase were disturbed. From the electron probe micro analysis (EPMA) it was observed that Pb(II), Cd(II) and Zn(II) adsorption are more prone to silica, iron oxide and ß-MnO2 phase respectively though their distribution in other phases was also marked but to a lesser extent. Due to high loading capacities obtained for Pb(II) and Zn(II), low grade manganese ore can be regarded as a potential adsorbent for these metals. Keywords: Low grade manganese ore, adsorption, Pb(II), Cd(II), Zn(II), EPMA

Globally sustainable manganese metal production and use

The “cradle to grave” concept of managing chemicals and wastes has been a descriptive analogy of proper environmental stewardship since the 1970s. The concept incorporates environmentally sustainable product choices—such as metal alloys utilized steel products which civilization is dependent upon. Manganese consumption is related to the increasing production of raw steel and upgrading ferroalloys. Nonferrous applications of manganese include production of dry-cell batteries, plant fertilizer components, animal feed and colorant for bricks. The manganese ore (high grade 35% manganese) production world wide is about 6 million ton/year and electrolytic manganese metal demand is about 0.7 million ton/year. The total manganese demand is consumed globally by industries including construction (23%), machinery (14%), and transportation (11%). Manganese is recycled within scrap of iron and steel, a small amount is recycled within aluminum used beverage cans. Recycling rate is 37% and efficiency is estimated as 53% [Roskill Metals and Minerals Reports, January 13, 2005. Manganese Report: rapid rise in output caused by Chinese crude steel production. Available from: http://www.roskill.com/reports/manganese.]. Environmentally sustainable management choices include identifying raw material chemistry, utilizing clean production processes, minimizing waste generation, recycling materials, controlling occupational exposures, and collecting representative environmental data. This paper will discuss two electrolytically produced manganese metals, the metal production differences, and environmental impacts cited to date. The two electrolytic manganese processes differ due to the addition of sulfur dioxide or selenium dioxide. Adverse environmental impacts due to use of selenium dioxide methodology include increased water consumption and order of magnitude greater solid waste generation per ton of metal processed. The use of high grade manganese ores in the electrolytic process also reduces the quantity of solid wastes generated during processing. Secondary aluminum facilities have reported hazardous waste generation management issues due to baghouse dusts from rotary furnaces processing selenium contaminated manganese alloys. Environmental impacts resulting from industry are represented by emission inventories of chemical releases to the air, water, and soil. The U.S. metals industry releases reported to EPA Toxic Release Inventory indicate the primary metals industry is the major source of metal air toxic emissions, exceeding electric utility air toxic emissions. The nonferrous metals industry is reported to be the Organization for Economic Co-operation and Development (OECD) most intensive airborne and land pollution source of bioaccumulative metals. However, total waste emissions from industries in the OECD countries have declined due to improving energy consumption. Emission registers and access are improving around the world. However, environmental databases for metal particulates have low confidence ratings since the majority of air toxic emissions are not reported, not monitored, or are estimated based on worst-case emission factors. Environmental assessments including biological monitoring are necessary to validate mandated particulate metal emission reductions and control technologies during metal processing.

Kinetics of reductive leaching of manganese oxide ore with molasses in nitric acid solution

The kinetics of reductive leaching of manganese from a low grade manganese ore in dilute nitric acid in the presence of molasses is examined. The rate is controlled by diffusion through the “product” layer composed of the associated minerals. The leaching process follows the kinetic model 1 − 2/3 X − (1 − X) 2/3 = kt with an apparent activation energy of 25.7 kJ/mole. It is concluded that the concentration of HNO 3 and molasses as well as temperature are the main factors influencing the leaching rate. The results indicate a reaction order of 1.2 for HNO 3 concentration and 1.9 for molasses concentration.

Multiobjective Optimization of Manganese Recovery from Sea Nodules Using Genetic Algorithms

Treatment of low grade manganese ores is receiving widespread attention due to major use of manganese (85–90%) as ferromanganese alloy in the rapidly growing iron and steel sector and also in other important industrial products like electrolytic manganese dioxide (EMD) used in the energy sector. Manganese bearing polymetallic sea nodules containing less than 40% Mn fall in the category of lean grade ores and besides manganese these nodules are the reserve for other metals like copper, nickel, and cobalt. In this present work, treatment of these polymetallic sea nodules in an acid-based hydrometallurgical route has been proposed using two different schemes, batch and parallel in nature. Both processes have been optimized using multiobjective genetic algorithms.

Reducing acid leaching of manganiferous ore: Effect of the iron removal operation on solid waste disposal

The process of reducing acid leaching of manganiferous ore is aimed at the extraction of manganese from low grade manganese ores. This work is focused on the iron removal operation. The following items have been considered in order to investigate the effect of the main operating conditions on solid waste disposal and on the process costs: (i) type and quantity of the base agent used for iron precipitation, (ii) effective need of leaching waste separation prior to the iron removal operation, (iii) presence of a second leaching stage with the roasted ore, which might also act as a preliminary iron removal step, and (iv) effect of tailings washing on the solid waste classification. Different base compounds have been tested, including CaO, CaCO3, NaOH, and Na2CO3. The latter gave the best results concerning both the precipitation process kinetics and the reagent consumption. The filtration of the liquor leach prior to iron removal was not necessary, implying significant savings in capital costs. A reduction of chemical consumption and an increase of manganese concentration in the solution were obtained by introducing secondary leaching tests with the previously roasted ore; this additional step was introduced without a significant decrease of global manganese extraction yield. Finally, toxicity characteristic leaching procedure (TCLP) tests carried out on the leaching solid waste showed: (i) a reduction of arsenic mobility in the presence of iron precipitates, and (ii) the need for a washing step in order to produce a waste that is classifiable as not dangerous, taking into consideration the existing Environmental National Laws.

Leaching of manganese ores using sawdust as a reductant

In this study sawdust was used as reductant for sulphuric acid leaching of manganese ore. Effects of pulp density, amount of acid, temperature, particle size of ore and amount of sawdust were studied. Manganese extraction of ∼98% was achieved under the conditions: leaching time 8 h, 5% H 2SO 4 (v/v), 10% pulp density, 90 °C and 5% sawdust (w/w), i.e. 0.5 g/g ore. Other Mn containing materials like low grade manganese ore, manganese nodule and Mn-nodule leach residues were tested and all these materials responded well giving more than 98% Mn extraction.