Limonite Iron Research Articles

Recentní vznik limonitové bahenní železné rudy v Hulíně (niva řeky Moravy)

There is described a new occurrence of mud limonite iron ore in this paper. Limonite originates recently in streams situated in flood plain of the Morava River near Hulín (central Moravia, Czech Republic). The chemical composition of precipitated limonite indicates that a contamination of subterranean waters by phosphorus, arsenic and some transitional metals (Cr, Zn) occurs here, very probably due to long-lasting intense agricultural usage of the surrounding fields. Based on experimental precipitation of limonite from local well water, a probable mechanism of formation of limonite was outlined. The Fe2+ ions, dissolved in the subterranean waters, are after their seepage into the stream oxidized by aerial oxygen to Fe3+, which is subsequently hydrolysed and precipitated in form of solid iron hydroxide. An important role of microorganisms and/or organic matter during precipitation of limonite is not suggested by collected data.

Enhancement of anti-corrosion and mechanical properties of alkyd-based protective paints for steel petroleum structures incorporating natural limonite pigment

In the present approach, natural limonite iron oxide samples from Baharyia Oasis areas have been collected and ground to the micro-sized scale to be used as pigment for upholding the corrosion resi...

Effect of Carbon Content in Direct Reduction Process of Limonite Iron Oxide to Produce Pig Iron Substitute for Thin Wall Ductile Iron Process

Quality molten metal needed to produce thin wall ductile iron (TWDI). Pig iron, as the major base material to produce quality molten metal, due to its high price, has been change with scraps. The use of scrap as major base material associates with more cleaning and chemical composition adjustment. The ITmk3 technology in iron making has successfully produced iron nugget. Iron nugget can be use to substitute pig iron due to its quality that is comparable to pig iron but lower in price. This research conducted to see the effects of carbon content in producing iron nugget. Limonite iron ores used in this research are part of laterite rocks taken from Sebuku Island in South Kalimantan, Indonesia. Variation made to weight of carbon mixed with laterite. Heating temperatures of direct reduction process are 700°C, 900°C, and 1000°C. The process times are 10, 20, and 30 minutes. XRF used in analysing Fe content in laterite and XRD is used in analysing result of direct reduction process. The result shows that increasing carbon content to certain condition will increase the rate of gasification process during direct reduction. The increase of gasification rate will result to higher Fe formation.

Optimization of Dolomite Usage in Iron Ore Sintering Process

To achieve the action mechanism and optimal usage of dolomite in the sintering process, solid reaction tests, fluidity tests, bonding strength tests and sinter pot tests were conducted, then microstructure and energy spectrum were analysed further. Reaction temperature of dolomite with calcium ferrite was lower than that with limonite iron ore about 155°C. Fluidity of bonding phase and strength of sinter using dolomite were lower than that using light burned dolomite and serpentine owing to the higher MgO content in the calcium ferrite and formation of secondary bonding phase. Action mechanism of dolomite in sintering process mainly included 4 steps, thermal decomposition, solid reaction, formation of primary bonding phase and formation of secondary bonding phase. Dolomite mainly played it’s role in the third step in which high viscosity CFM (calcium ferrite with MgO) and magnetite solid solution formed. Increasing the solid solubility of MgO in magnetite by mixing dolomite with magnetite concentrate before granulation, decreasing the dispersity of MgO in sinter mixture by increasing the particle size of dolomite appropriately, increasing the separation degree of MgO and CaO by light-burning the dolomite, and decreasing the reaction amount of MgO by using big particle size magnesia, all could decrease the content of MgO in calcium ferrite, thus showed good performance in sinter pot tests.

Catalytic gasification of woody biomass in an air-blown fluidized-bed reactor using Canadian limonite iron ore as the bed material

A Canadian limonite iron ore was tested for the first time as a catalytic bed material for air-blown gasification of pine sawdust at various equivalence ratios (ER, 0.20–0.35) on a pilot-scale fluidized bed gasifier, in comparison to a conventional olivine bed material. Effects of bed materials (iron ore and olivine) on tar formation and gasification efficiencies were comparatively investigated. The use of Canadian limonite iron ore as the bed material was found to be more active than olivine for tar reduction in the fluidized bed gasification of biomass at a small ER (⩽0.3), leading to a very low tar yield of 15–25g/kg biomass at ER=0.30. The yields of combustible gas (carbon monoxide hydrogen, methane and C2 hydrocarbon gases) and cold gas efficiency were generally the highest at medium values of ER (0.25–0.30) for both bed materials. The iron ore was less active than olivine for producing combustible gases, leading to a lower cold gas efficiency (50% at ER=0.30) compared to 75% for olivine. However, the use of the iron ore produced a higher yield of hydrogen than that of olivine in the gasification: 5.0mol hydrogen per kg of biomass with the iron ore at ER=0.30 which was about 25% higher than that with olivine.

Biotar Ironmaking Using Wooden Biomass and Nanoporous Iron Ore

This paper describes fundamental experiments of a new biomass ironmaking that employs low-grade iron ore and woody biomass for promoting the direct reduction, FeO + C = Fe + CO, in which dehydrated, porous limonite iron ore was filled with carbon deposited from the biomass tar, biotar. In our experiments, three types of iron ores containing different amounts of combined water (CW; 1.6, 3.8, and 9.0 mass %) were first dehydrated at 450 °C to make them porous and then heated with pine tree biomass at 500−600 °C for the gasification and the tar vapor generated was decomposed to deposit carbon within/on the porous ores. The dehydration treatment made the iron ores porous by removing CW and significantly increased their Brunauer−Emmett−Teller (BET) specific surface areas and porosities. In the second treatment of biomass gasification and decomposition of tar vapor, the biomass was changed into char, tar vapor, and reducing gas; the biotar was decomposed and carbonized within the porous ores. Interestingly, the...

Effect of Granulation Condition and Property of Raw Material on Strength of Granulated Particle by Tumbling Granulation

In order to clarify the factors on strength of granules for iron ore sinter, especially made of limonite iron ore, the effects of porosity, moisture and revolution speed of pelletizer on the strength of granules were examined with using reagent hematite. Moreover, using three kinds of commercial iron ores, the relationship between granule size and strength was examined. The strength measurement was undertaken before and after drying with a compression taster. The results obtained are follows:(1) In case of reagent hematite sample, the strength after drying became very low compared with that before drying. The compressive strength of sample just after granulation is determined by the adhesion force between hematite particles by liquid bridge of added water, but the strength after drying is maintained by the adhesion force by intertwined particles.(2) In case of commercial iron ores, the compressive strength after drying was very high compared with that in wet condition.(3) The cause for the different effect of drying on compressive strength between the commercial iron ore and reagent hematite seems to be the difference of gangue minerals that exist only in the iron ore and/or that of surface properties because the particle size distribution of reagent hematite and iron ores used is the same.

還元褐鉄鉱のCO-H<SUB>2</SUB>-H<SUB>2</SUB>S混合ガスによる流動層中での炭化挙動:還元温度と炭化温度の影響

還元褐鉄鉱のCO-H<SUB>2</SUB>-H<SUB>2</SUB>S混合ガスによる流動層中での炭化挙動:還元温度と炭化温度の影響

High‐Intensity Magnetic Separation of Limonite Iron Ores

Results of investigation into the development of HIMS technology for separation of weakly magnetic finely disseminated limonite iron ores are discussed.

Importance of sample grinding time in X‐ray emission spectrometry

AbstractThe effect of the sample grinding time on X‐ray spectrometric results was examined on real samples (limonite iron ore, sinter mixture and blast furnace slag). Comparative results were obtained for X‐ray diffraction analysis and scanning electron microscopic analysis. The optimal grinding time depended on the type of analyte and on the phase composition of the sample.