Iron Ore Waste Research Articles

A Novel Technique for Making Cold Briquettes for Charging in Blast Furnace

Different metallurgical wastes are generated during pyro processing of iron ore, which is used for making sponge iron or hot metal and for producing steel. Apart from these wastes, coke fines are generated during the coke making, and iron ore fines are generated during mining of iron ore. Although iron ore fines are used for making pellet after beneficiation still, it generates a huge quantity of iron ore waste during beneficiation with comparatively lower iron content. In the present study, briquettes are made by a stiff extrusion process from metallurgical waste like iron ore fines and coke fines with the addition of Portland cement as a binder and clay as a rheology modifier. Physical properties of the briquettes are evaluated, and reducibility of the briquettes is studied in comparison to lumpy iron ore. Phase analysis and microstructural analysis of the briquettes and lumpy iron ore are carried out after firing at different temperatures in the simulated blast furnace condition. Physical and mineralogical properties are correlated with the reducibility of the briquettes and lumpy iron ore. Briquettes made by a stiff extrusion process show a better mechanical strength fired at a different temperature to take the load of burden and better reducibility than lumpy iron ore. The briquettes after self-curing are charged to a 23 mt3 blast furnace which shows encouraging results.

Enhancing adsorptive removal of sulfate by metal layered double hydroxide functionalized Quartz-Albitophire iron ore waste: preparation, characterization and properties

In this study, the seemingly worthless Quartz-Albitophire iron ore mineral waste has been modified with metal double hydroxides (Mg–Al, Ni–Fe, Ni–Al and Mg–Fe) and utilized as a sulfate adsorbent which is characterized by XRD, XRF, FTIR and SEM analysis.

Fabrication and characterization of magnetite/reduced graphene oxide composite incurred from iron ore tailings for high performance application

A feasible approach to synthesis iron oxide (Fe3O4) from waste iron ore tailings (IOTs) to synthesis magnetic graphene (Fe3O4/rGO) is demonstrated in the present study. Plain Fe3O4 was prepared by acid leaching of IOTs with hydrochloric acid followed by co precipitation. The anchoring of Fe3O4 onto the graphene template was done by hydrothermal method involving polyvinylpyrollidone (PVP) as a surface directing agent. The samples were characterized by FTIR, XRD, SEM, TEM, Nitrogen adsorption–desorption studies, XPS and Raman spectroscopic analysis. The electrochemical performances of the material were evaluated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge techniques. The synergistic effect between the rGO matrix and Fe3O4 directs to increased conductivity and ionic diffusion, leading to a material with superior electrochemical performance. Thus the synthesis of magnetic graphene composite from IOTs was technically feasible, providing additional opportunities for future application of these composites in environmental management.

Ecological and biochemical aspects of parasite-host interactions in transformed aquatic bodies: A case study of the cestode Triaenophorus nodulosus and its host, the northern pike Esox lucius

The lysosomal enzyme activities of the cestode Triaenophorus nodulosus and its host, the pike, in-aquatic bodies with different degrees of technogenic transformation (Northern Karelia, Russia) have been studied. As has been shown, iron-ore waste causes an increase in the acid phosphatase, nuclease, and beta-galactosidase activities of the host and a decrease in its beta-glucosidase and cathepsin D activities. As a rule, the changes in the same cestode enzyme activities are the opposite. With a decrease in the technogenic load, most of the studied characteristics display the trend of approaching the corresponding values observed in a clean lake. It is assumed that the host plays a leading role in the biochemical adaptation of the parasite and its host to mineral environmental pollution.

Study on the Modification of Blast Furnace Smelt Slag and Crystallization Behavior in the Solidification Process

The direct fibrillation of blast furnace slag can solve these problems, such as having not been recycled of sensible heat, the consumption of water resources, environmental pollution and the low additional value of product, which are caused by the traditional water quenching method. The modification is the key problem of fiber forming. The thesis mainly aims at the study of viscosity of slag, the ability of crystallization and mineral phase structure after the modified process of blast furnace slag and confined the relevance of the three to optimize the appropriate texturizer and adding ratio. The results are as following: Iron ore waste rock, fly-ash and compounded texturizer can improve the high temperature viscosity of the slag respectively, while it has different effect on landing gradient of viscosity and temperature (Fly-ash occupies first place, compounded texturizer comes second and iron ore and waste rock comes the minimum). By analyzing the crystallization behavior of the slag in the solidification process, when the proportion of iron ore waste rock is more than 9%, the fly-ash is equal or greater than 8% and the compounded texturizer is more than 9%, the solidification slag will appear amorphous. The mineral composition of the slag transforms gradually from melilite to vitreous body, which will make the air hole of the vitreous body increased and aperture decreased. When the iron ore waste rock is added, the homogeneity of the air hole will deteriorate, while adding the fly-ash and compounded texturizer will strengthen the homogeneity of the air hole and make the mineral structure intensive gradually.

Visible light induced photocatalytic decolourisation of rhodamine B by magnetite nanoparticles synthesised using recovered iron from waste iron ore tailing

The photocatalytic activity of highly dispersed magnetite nanoparticles (MNP), synthesised using ferric iron recovered from waste iron ore tailing and reagent grade ferrous chloride by coprecipitation, for the decolourisation of rhodamine B (RhB) under visible light (VL)/sunlight was evaluated. The effects of different reaction parameters such as pH, dye concentration, catalyst dose and externally added H2O2 were also investigated. MNP with sizes in the range 8–23nm and relatively low band gap (1.67 eV) showed good photocatalytic activity, magnetic separability and stability for repeated use. More than 85% of RhB (10 mg/l) is found to be decolourised within 2 h under VL with a MNP dose of 0.51 g/l. Suitable mechanisms have been proposed to account the photocatalytic activities in the presence and absence of H2O2. Results obtained in the current study may be useful to prepare suitable photocatalyst combinations with other semiconducting materials for photocatalytic remediation of different water contaminants including organic dyes.

Thermal, electrical and tensile properties of synthesized magnetite/polyurethane nanocomposites using magnetite nanoparticles derived from waste iron ore tailing

The synthesis of magnetite nanoparticles (MNP) using waste iron tailing as one of the starting materials and its use in preparation of MNP/polyurethane (MNP/PU) nanocomposites with bio-based PU were described. A comparison of XRD patterns, FT-IR and UV–vis diffuse reflectance spectra of neat MNP, neat PU and MNP/PU nanocomposites indicated the incorporation of MNP in PU resin. The SEM and TEM micrographs showed nearly uniform dispersion of MNP in MNP/PU nanocomposites. Both thermal stability and electrical conductivity of MNP/PU nanocomposites were increased with increase of MNP loading while MNP addition significantly improved the tensile properties of PU. The magnetic measurements revealed a transition from superparamagnetic behaviour of neat MNP to ferromagnetic in MNP/PU at lower MNP content. The MNP/PU nanocomposites may be exploited further for electronic and optoelectronic applications.

SEM Investigation of the Structure of Ceramic Matrix Composite Produced from Iron-Ore Waste

The article gives the results of scanning electron microscopy (SEM) studies of the structure of ceramic matrix composite materials produced from iron ore waste. It is established that inside the matrix and the granules during the firing the processes of solid-phase and liquid-phase sintering with formation of new mineral phases take place. It is shown that in the matrix a liquid phase is formed, which fills intergranular cells and binds the particles of minerals together.

Magnetite powder and kaolinite derived from waste iron ore tailings for environmental applications

The present study demonstrated a feasible approach of utilizing waste iron ore tailings in synthesis of value added products for environmental applications. The ferric iron recovered from waste iron ore tailings via acid leaching followed by precipitation as ferric (hydr)oxide was used as feed stock to synthesis magnetite powder by its reductive-roasting with charcoal. Physicochemical characterizations revealed the formation of sufficiently pure magnetite powder with ferric (hydr)oxide to charcoal ratio 1:2 and calcined at 1200°C for 4h. The magnetic powder as such or coated with polyacrylic acid, was found efficient for removal of a model dye, methylene blue from its solution within 2min. The acid insoluble residue, generated after iron recovery from iron ore tailings, was characterized as kaolinite. The residue with reasonably good surface area (119m2g−1) was also found effective for adsorptive removal of dyes including methylene blue and can find large scale applications in wastewater treatment. Moreover the present study provided further inputs for possible alternative uses of waste iron ore tailings to partly reduce its associated disposal problems.

Synthesis and characterization of magnetite nanoparticles using waste iron ore tailings for adsorptive removal of dyes from aqueous solution

The ferric iron recovered from waste iron ore tailings (IOTs) via acid leaching and precipitation to iron (hydr)oxide was used to synthesize magnetite nanoparticles (MNPs) by coprecipitation of its aqueous acidic solution along with ferrous iron under inert atmosphere. The electrostatically stabilized MNPs showed super paramagnetic behavior and good dispersibility in aqueous medium with high stability. Powder XRD, UV–Vis and FT-IR spectra confirmed the formation of single phase magnetite. The scanning and transmission electron micrographs revealed that the MNPs were spheroidal or cubic in shape with size ranging from 8.3 to 23.0 nm. The MNPs were found effective for fast adsorptive removal of both cationic (methylene blue) and anionic (Congo red) dyes from their aqueous solutions. Under optimized condition, the maximum monolayer adsorption capacities were found to be 70.4 mg g −1 and 172.4 mg g −1 for methylene blue and Congo red, respectively. Moreover, the present study addressed a feasible alternative use of waste IOT to synthesize a value added product for its possible large scale application in treatment of wastewaters.

Alterações microestruturais de cerâmica argilosa incorporada com rejeito de minério de ferro

Este trabalho tem por objetivo avaliar o efeito da incorporação de rejeito de minério de ferro na microestrutura de uma cerâmica argilosa. Foram preparadas formulações, com percentuais de rejeito de até 30% em peso, usadas na confecção de corpos-de-prova por prensagem uniaxial para queima nas temperaturas de 700, 900 e 1100ºC. A microestrutura da região de fratura das cerâmicas foi avaliada por microscopia eletrônica de varredura, difração de raios-X e porosimetria de mercúrio. Os resultados mostraram que a adição do rejeito à massa argilosa altera significativamente a microestrutura da cerâmica. Incorporações de até 10% em peso do rejeito são benéficas para a qualidade da cerâmica por meio da redução da porosidade aberta.

SELF-REDUCING PELLETS FOR IRONMAKING: REACTION RATE AND PROCESSING

Self-reducing pellets bearing iron oxides and carbonaceous material are considered as an efficient way of promoting the carbothermic reduction of iron ore or iron-containing wastes, as several processes already employ this technology. This paper discusses the reaction rates obtained when this kind of agglomerate is heated at different temperatures. To take advantage of the kinetic features presented by self-reducing pellets, any process has to solve the problem of furnishing a high heat load to the charge without compromising its physical integrity. This paper also presents a discussion on how the different existing or proposed processes tackle this problem.

Raw Materials Analysis by XRF in the Cement Industry

AbstractThe sources of raw materials used in the manufacture of Portland cement include pure to argillaceous limestones, shale and clay, plus minor quantities of sand, iron ore, fly ash, coal ash and suitable industrial wastes. To ensure a high quality product, rapid - precise - reproducible and practical analytical techniques are required. Quantitative XRF analysis techniques meet those demands.For this comparative technique, the instrument used is a wavelength dispersive sequential spectrometer. The advantages and the drawbacks of the technique are discussed, along with the procedure of the specimen fused bead preparation. The importance of calibration standards and unknown samples being prepared in an identical manner, and being presented to the instrument under similar conditions, is stressed. International and synthetic standards, concentration ranges for the five major elements, mathematically generated coefficients to correct absorption and enhancement effects, and a summary of the standard error of estimates are examined and discussed.The accuracy of the method is verified by the analysis of known standard reference materials such as obsidian rock, coal fly ash, argillaceous limestone and blastfurnace slag. The values are compared with the known certified values.

Properties of stone castings made from iron-ore waste

Properties of stone castings made from iron-ore waste