Iron Slag Research Articles

Effect of Ferronickel Slag Powder on Strength of Soil in Marine Environment

Over the past few years, soil‐cement has been widely used in marine geotechnical engineering; meanwhile, the safety of soil‐cement in marine environment has attracted wide attention. In order to study the influence of composite ferronickel slag powder on the strength and micro morphology of soil‐cement in marine environment, the composite nickel iron slag powder was added into the soil‐cement in this paper. The unconfined compressive strength test, erosion resistance coefficient analysis, SEM, and EDS test analysis of soil‐cement were carried out.. Results showed that the marine environment had great influences on the strength of soil‐cement, and the addition of compound nickel‐iron slag powder can enhance the strength of soil‐cement, and the deterioration of the strength of soil‐cement is reduced. In addition, the compound ferronickel slag powder has microaggregate effect, morphological effect, and activation effect, which not only improves compaction rate of soil‐cement and prevents invasion of erosive ions in marine environment but also has positive effects on the performance of soil‐cement.

Removal of dissolved benzaldehyde from contaminated water stream using granular iron slag by-product in the permeable reactive barrier technology

Removal of dissolved benzaldehyde from contaminated water stream using granular iron slag by-product in the permeable reactive barrier technology

Influence of GGBS on the Properties of Charge Chrome Based Geopolymer Concrete in Ambient Temperature

One of the most widely used materials in construction worldwide is concrete. Due to its cheap manufacturing and high strength it has been extensively used, leading to environmental problems. Thus, various alternatives have been suggested to concrete made from Ordinary Portland Cement (OPC), one among them being Geopolymer Concrete. Geopolymers are inorganic alumino-silicate polymers synthesised from materials of geological origin or by-product materials such as fly ash which are rich in silicon and aluminium. Fly ash is available abundantly worldwide from thermal power plants whereas Ground Granulated Blast furnace Slag(GGBS) is obtained by quenching iron slag from a blast furnace in water or steam. Ferrochrome slag or charge chrome is a major solid waste generated from submerged electric arc furnaces during manufacturing of ferrochrome alloy. A major drawback of using fly ash based GPC is its requirement of high temperature for curing. The main purpose of this study was to evaluate the mechanical properties of ambiently cured fly ash based geopolymer concrete with ferrochrome slag partially replacing coarse natural aggregate and GGBS partially replacing fly ash. Present study indicates that the compressive strength increased with the increase in proportion of GGBS with respect to fly ash from 25 MPa at 10% replacement to 50MPa at 40% replacement.

Strusky a železo z experimentální tavby železa realizované na hradě Buchlově (jv. Chřiby) v roce 2018

During experimental smelting of iron in a replica of historical shaft furnace, which was held at the Buchlov Castle in 2018, charcoal and Mn-enriched pelosiderite-limonite iron ore from the locality Strážovice near Kyjov were used. The obtained furnace slag is practically completely formed by glass phase; only rare small domains also contain olivine. The glass phase is compositionally heterogeneous and contains 0.7 - 10.7 wt. % MnO, whereas olivine corresponds to fayalite with elevated contents of tephroite (ca. 12 mol. %), forsterite (ca. 4 mol. %) and dicalciumsilicate (1 mol. %) components. The produced metallic iron is also compositionally heterogeneous, rich in phosphorus and in places it contains small spherical inclusions of pyrrhotite. The phase composition of slag differs significantly from those of typical iron slags. The reason can be seen either in anomalous chemical composition of used ore (the elevated contents of Mn could potentially act as an inhibitor of crystallization), or in too high temperatures during smelting (the phase relations in metallic iron suggest temperatures exceeding 1500 °C) in combination with rapid cooling of the furnace content after finishing of smelting. Both phase composition of slag as well as chemical composition of individual slag phases and metallic iron are significantly different from those of local historical artefacts from the period of usage of technology of direct production of iron. These findings do not support the idea that local pelosiderite iron ores were used for production of iron already during this early period.

Assessing the Quality of Iron Ores for Bloomery Smelting: Laboratory Experiments

There is fragmentary knowledge of iron ore sources exploited in the past for many regions including the Southern Levant. This missing information has the potential to shed light on political, economic, craft-production, and trading patterns of past societies. This paper presents the results of smelting experiments performed in graphite crucibles and a muffle furnace, using 14 iron ore samples from the Southern Levant, in an attempt to determine their suitability for smelting using ancient techniques. A range of analytical techniques, including optical and electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, and portable X-ray fluorescence were used to comparatively investigate the mineralogy and composition of the precursor iron ores and their smelting products: Iron bloom and slag. Several parameters attesting to the ability of a given ore to be successfully reduced and consolidated into a solid metal mass were quantified. The generated results highlight the significance of a ‘correct balance’ between iron oxides and other major elements in the smelting system in order to form fluid slag and a well-consolidated bloom. These data contribute to the understanding of factors, potentially influencing choices of iron ore exploitation by past human societies in the Southern Levant.

Predominant Mechanisms in the Treatment of Wastewater Due to Interaction of Benzaldehyde and Iron Slag Byproduct

Iron slag is a byproduct generated in huge quantities from recycled remnants of iron and steel factories; therefore, the possibility of using this waste in the removal of benzaldehyde from contaminated water offers an excellent topic in sustainability field. Results reveal that the removal efficiency was equal to 85% for the interaction of slag and water contaminated with benzaldehyde at the best operational conditions of 0.3 g/100 mL, 6, 180 min, and 250 rpm for the sorbent dosage, initial pH, agitation time, and speed, respectively with 300 mg/L initial concentration. The maximum uptake capacity of iron slag was 118.25 mg/g which was calculated by the Langmuir model. Physical sorption may be the major mechanism for the removal of benzaldehyde onto iron slag based on the analysis of isotherm and kinetic sorption data and thermodynamically, the process was spontaneous and endothermic. Finally, the X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscope (SEM) and energy-dispersive spectroscope (EDS) tests for reactive material certified that the dissolution of calcium oxide can enhance the removal of benzaldehyde by the formation of bridge cations.

An Innovative Technique for Comprehensive Utilization of High Aluminum Iron Ore via Pre-Reduced-Smelting Separation-Alkaline Leaching Process: Part I: Pre-Reduced-Smelting Separation to Recover Iron

In this study, a novel process was established for extraction of Fe and Al from a complex high aluminum iron ore (33.43% Fetotal and 19.09% Al2O3). The main steps in the proposed process included pre-reducing high alumina iron ore and subsequent smelting to produce pig iron and rich-alumina slag, followed by alkaline leaching of the slag to obtain sodium aluminate solution and a clean slag. When smelting the pre-reduced high alumina iron ore pellets at 1625 °C for 30 min with a slag basicity of 0.40, the pig iron yielded 97.08% Fe and extracted 0.13% Al2O3, together with an iron recovery of 94.54%. In addition, more than 68.93% Al2O3 was recovered by leaching the slag, which was achieved by firstly roasted the slag at 900 °C for 2 h and then alkaline leaching at 95 °C for 2 h with a liquid-to-solid ratio of 10 mL/g. In addition, the alkaline leaching slag could potentially be used as raw material for construction purpose, which mainly consisted of SiO2 and CaO.

Evidence for the formation of bog iron ore in soils of the Podravina region, NE Croatia: Geochemical and mineralogical study

This study brings evidence for possible bog iron ore formation in soils of the Podravina region, NE Croatia. During decades of archaeological investigations in the region, numerous sites with iron smelting workshops, furnaces and iron slag materials were found in the region. As archaeological evidence indicates the presence of near-by bog iron excavation sites, a total of 44 soil profiles were drilled in the vicinity of the archaeological sites. Six soil profiles, consisting of five Gleysols and one Fluvisol, were selected for further mineralogical, geochemical and textural analyses due to their visible redoximorphic features. The X-ray diffraction (XRD) analyses confirmed goethite, quartz, clay minerals, plagioclase, feldspars and dolomite. Chemical analyses indicate Fe content above median values for the Podravina region. The Kalinovac-Hrastova Greda profile showed the highest content of Fe2O3, (31.52 wt. %) at 60–80 cm depth, while the other investigated profiles show Fe2O3 contents between 3.97 and 10.90 wt. %. Contents of As (1.8–563.6 ppm) and P (484–4513 ppm) indicate high accumulations of these elements in the soils. Textural analyses indicate a high amount of silt and, sporadically, sand in all profiles, while showing a relatively small amount of clay. The enrichment factor of Fe2O3 shows significant enrichment in the Kalinovac-Hrastova Greda profile, indicating a possible ore formation. Based on the microelement distribution of Ce, Cs, Hf, La, P and Zr, all soils show a common parent material, but significant differences in contents of Fe and other major oxides indicate different formation processes. This is attributed to differences in the soil texture of the selected soil profiles, oscillations of the groundwater table and changes between oxidative and reductive conditions. The results of this study indicate that the Podravina region is a suitable area for the formation of bog iron ore, although recent conditions inhibit the formation of bog iron ore due to changes in agriculture and melioration which are altering groundwater levels.

Geophysical and Archaeological Survey in Igbo Oritaa (Iwo), Southwest Nigeria

An integrated geophysical survey was carried out in Igbo Oritaa, a suburb of Iwo town (southwest Nigeria). The study was part of an archaeological investigation initiated by the Iwo community to identify and preserve the town’s ancient sites. The geophysical investigations involved ground magnetic profiling, 1D vertical electrical sounding (VES), and 2D electrical resistivity imaging. The magnetic survey revealed anomalies of dyke-like features (central magnetic low [negative] flanked by low amplitude positive shoulders), linear depressions with prominent negative amplitude magnetic lows, and a moderately high amplitude magnetic anomaly coinciding with an old trench and several anthropogenic mounds. The resistivity survey also indicates the presence of subsurface archaeological features, including ditches and walls. Excavation units were selected based on these geophysical attributes. The excavations uncovered dense deposits of potsherds, animal bones, shells, beads, iron slag fragments, a human premolar, metallic objects, a flute, and an architectural feature, possibly the foundation of a house. The geophysical survey and the test excavations confirm that Igbo Oritaa was an ancient settlement, consistent with the oral traditions. This paper presents the geophysical methods and results, the relationships between geophysical prospecting and test excavations, as well as the implications for community-focused archaeological research design, and site interpretation and preservation.

Iron slag as fine aggregate replacement and nanosilica particles in self-compacting concrete mixtures

A study of the mechanical behavior of self-compacting concrete mixtures under sand replacement (as fine aggregate) by iron slag (residue from industrial machining) from 0.0% to 50.0% of mass, variations of water/cementitious material ratio between 0.3 and 0.5 and nano SiO2 incorporation between 0.0% and 2.0% by mass of cementitious materials is presented. Fresh state tests of slump flow were performed, and the main rheological parameters: static yield stress and plastic viscosity were determined from a rheometer. For the hardened state, compressive strength tests were performed. The study of iron slag incorporation and water/cementitious materials ratio variation was developed based on a statistical methodology of central composite design from axial points based on a 2k factorial with central points, besides a posterior analysis of variance and Tukey’s multiple comparison tests. The optimization of these variables was developed using response surface methodology on 7 days compressive strength results, from the statistical design, besides the posterior determination of nano SiO2 effects on the optimized proportions. Among the most relevant results regarding the presence of iron slag, an increase in the early age compressive strength was found, with the optimized mixture strength being more than 100% higher than mixtures without iron slag at 7 days of curing. Regarding the effect of nano SiO2 addition to the optimized mixture, a detriment of the rheological parameters and a consequent reduction of the workability were the most remarkable findings. With the obtained results, iron slag proves to be a feasible sand replacement in self-compacting concrete mixtures.

Utilization of Iron Slag as Partially Replacement with Fine Aggrgate in High Strength Self-Compacting Concrete (HSSCC)

lot of work within the field of normal mix concrete and Scc has been done in the last two decades. Utilization of different waste material from the different industries as the partial replacement of cement as well as aggregates both fine and coarse has been considered in the research work by different researchers as per their area of interest. No doubt use of Iron Slag has been in trend but only cement replacement is done with it. Research work in the replacing of Fine aggregate with iron slag in SCC has not been studied in detail. An aim was set to study the hardened properties and fresh properties of iron slag based HSSCC. Mix design of M60 grade of high strength self-compacting concrete is done as per EFNARC guidelines. Testing of rheological properties of HSSCC with U- Box, Slump Flow, L- Funnel, V- Box, apparatus were done. Testing of hardened properties of HSSCC for Split Tensile Strength, flexural strength, compressive strengthas per Indian standard guidelines. Replacement of Fine aggregate (20, 30, and 40%) was done with iron slag and further addition of Alccofine and super plasticizer was done.

Study on Mechanism of Oxidation Modification of Copper Slag

The pyrometallurgical processing of copper concentrates generates large amounts of iron and copper-containing slag. It is an available way to separate and recover iron and copper by oxidative modification slag. The copper slag used in this experiment is water-quenched copper slag tailings. The method of the experiment is to separate copper and iron in the copper slag by oxidation-magnetic separation method, and the amount of copper and iron recovered in the later stage is also greatly reduced. Mineralogical phase transform of copper slag during oxidation modification process has been investigated with the goal to provide valuable information for the recovery of copper and iron. The influence of temperature and time on the mineral phase transformation has mainly been studied during the oxidation modification. XRD combined with FT-IR has been used to characterise the mineral phase change. The experimental results showed that the oxidation temperature and time were favorable for modification of copper slag under medium- and low-temperature conditions. When the oxidation temperature was 950 °C, fayalite was transformed to hematite and quartz, which provided the necessary conditions for separating iron and silicon, and copper embedded in fayalite was also released. In addition, the copper slag particles were significantly grown under the action of oxidation reaction which was also beneficial to subsequent selection and treatment.

Equilibrium distribution of Mg in manganese electrolysis system

Aiming at the common problems of magnesium ion concentration being higher than manganese ion concentration in the electrolytic manganese industry, the equilibrium distribution of Mg in manganese electrolysis system was studied. It mainly included four main steps: the rhodochrosite was leached under acidic conditions, the Fe2+ was removed by precipitation after MnO2 oxidation, the heavy metals ware removed by SDD. Finally, the manganese metal was produced in the cathode by electrolysis of manganese sulfate solution. The morphology and phase composition of magnesium in the whole system were obtained by SEM and XRD. Under leaching conditions for industrial production, the temperature was 85 °C, liquid-solid ratio was 8:1, the excess coefficient of acid was 1.3, and the reaction time was 3 h, leaching rate of Mg was 38.19%, and the corresponding concentration of Mg2+ was 2.96 g l−1 in the solution. The effect of Mg2+ concentration on manganese leaching rate was done, the result showed that the leaching rate of manganese decreased with the increasing of magnesium ion. When the Mg2+ was increased from 0% to 50%, the leaching rate of manganese decreased from 83.12% to 76.39%. At pH 5.5 and 85 °C, Fe2+ could be completely removed by using MnO2 as oxidant and 22.44% magnesium would be taken away with iron slag. The removing of heavy metals could be achieved under the condition of 60 ± 5 °C, SDD dosage 3‰ (according solution quantity) and 1 h, 0.4% magnesium would be taken away with heavy metal slag. The electrolysis experiments were carried out under the conditions, (NH4)2SO4 content was 100 g l−1, pH was 7.2, reaction temperature was 45 °C and current density was 350 A m−2. The results showed that 88.18% of magnesium was distributed in the anode solution and 11.4% in the cathode solution, and there was 0.08% and 0.34% of magnesium in the cathode manganese sheet and the anode slag, respectively.

Geochemical Characterization of Iron and Steel Slag and Its Potential to Remove Phosphate and Neutralize Acid

Iron and steel slags from legacy and modern operations in the Chicago-Gary area of Illinois and Indiana, USA, are predominantly composed of Ca (10–44 wt. % CaO), Fe (0.3–28 wt. % FeO), and Si (10–44 wt. % SiO2), with generally lesser amounts of Al (<1–15 wt. % Al2O3), Mg (2–11 wt. % MgO), and Mn (0.3–9 wt. % MnO). Mineralogy is dominated by Ca ± Mg ± Al silicates, Fe ± Ca oxides, Ca-carbonates, and high-temperature SiO2 phases. Chromium and Mn concentrations in most samples may be environmentally significant based on comparison with generic soil contaminant guidelines. However, simulated weathering tests suggest these elements are present in generally insoluble phases making their use in water treatment applications possible; however, the generation of high pH and alkaline solutions may be an issue. As for possible water treatment applications, batch and flow-through experiments document effective removal of phosphate from synthetic solutions for nearly all slag samples. Air-cooled fine fractions (<10 mm) of modern slag were most effective; other types, including modern granulated, modern air-cooled coarse fractions (>10 mm), and legacy slag removed phosphate, but to a lesser degree. An additional water treatment application is the use of slag to neutralize acidic waters. Most slag samples are extremely alkaline and have high net neutralization potentials (NNP) (400–830 kg CaCO3/t), with the highest approximately equivalent to 80% of the neutralization potential of calcite. Overall, phosphate removal capacity and NNP correlate positively with total Ca content and the dissolution of Ca minerals facilitates secondary Ca phosphate formation and consumes acid during hydrolysis. Utilizing locally available slag to treat waste or agricultural waters in this region may be a higher value alternative than use in construction, potentially offsetting restoration costs to degraded legacy areas and decreasing steel manufacturers’ current waste footprint.

Performance of cement-slag-titanate nanofibers composite immobilized radioactive waste solution through frost and flooding events

Innovation of cement-based composites is a recently strongly emerging technology. Nanotechnology is one of the potential alternatives to improve cement characteristics and to decrease the amount of cement used in various applications, which consequently reduces the energy required for cement production and carbon dioxide emission caused by cement industry. The improvement of cementitious materials is still an important target to produce modified compounds of valuable mechanical, chemical and physical characterizations. In this paper, Portland cement mixed with iron slag was hydrated with an aqueous titanate nanofibers suspension to create cement nanocomposites as environmentally friendly material with novel properties. In this sense, nanoparticles as additive material allow for improving the mechanical durability of cement and retard the permeability of cement-based materials. SEM, FT-IR and X-ray diffraction analyses confirmed the Ca(OH)2 conversion towards calcium silicate hydrate. Porosity and compressive strength measurements were also performed through variable parameters and under different conditions. Durability tests and chemical stabilization were carried out at freezing/thawing condition during extended cycles of up to 6 months. The effect of flooding in various aqueous media including acidic and alkaline ones was evaluated during extended periods of immersion. Moreover, the radioactive contaminant 137Cs was immobilized by the novel cement nanocomposite to test the nanocomposite’s chemical stability by monitoring the leaching of 137Cs. Resulting data were used to positively assess the feasibility of this compound to be used for immobilization of radioactive and other hazardous wastes. The produced composite attained proper consistency when exposed to frost attack or flooding in various media up to 180 days.

The effect of iron slag enriched cow manure, zeolite and pumice on the sunflower Pb uptake in a soil irrigated with wastewater of battery factory

The effect of iron slag enriched cow manure, zeolite and pumice on the sunflower Pb uptake in a soil irrigated with wastewater of battery factory

Experimental studies of slag filter for drinking water treatment

Abstract The study examined the use of granulated blast furnace slag, an industrial by-product from ferrous industries for drinking water treatment. A laboratory scale filter, 9 cm diameter and 40 cm with iron slag media supported on a gravel bed could completely remove turbidity, total suspended solids and colour for an average influent loading of 28.26 NTU, 128.85 mg/L and 177.05 PCU respectively at a filtration rate of 0.32 m3hr−1m−2. The average removal of hardness, sulphate, nitrate, chloride and iron were 35%, 83%, 71%, 28% and 94% for an average influent loading of 579.79 mgL−1, 367.72 mgL−1, 120.52 mgL−1, 355.67 mgL−1 and 1.49 mgL−1respectively. Doubling the filtration rate with slight increase in loading rate showed 100% removal for turbidity, suspended solids and colour whereas hardness, sulphate, nitrate, chloride and iron removals were 27%, 73%, 86%, 28% and 95% respectively. The maximum head loss for continuous operation without backwash was only 75 mm. Intermittent washing helped to improve the filtered water quality for various filtration and loading rates. An increase in the rate of filtration up to 1.28 m3hr−1m−2 did not have any impact on the quality of treated water except sulphate and nitrate. After backwashing, there was considerable improvement in chloride removal. The removal of physicochemical parameters was due to precipitation, adsorption and ion exchange with the formation of products both at the surface and within the slag media. FTIR and XRD results also confirmed the behaviour of slag as an anion exchange resin. The maximum head loss observed in slag filter was 190 mm at the highest loading level and filtration rate.

Chemical Compositional Signatures of Constituent Minerals of Iron Slags and Ores from the Khmer Monuments

Iron slags and ores were collected from 22 sites (A to V) in Preah Khan of Kompong Svay, the area surrounding Phnom Daek, and the Angkor monuments. Iron ores were taken from two outcrops in Phnom Daek. The chemical compositions of fayalite and wüstite in the iron slags and magnetite in the iron ores were determined using a scanning electron microscope equipped with an energy dispersive spectrometer. Cluster analysis and principal component analysis using averaged chemical compositional data for fayalite allowed for the investigated slag dumps to be classified into two main groups: Groups 1 and 2. The slag dumps in the area surrounding Phnom Daek and those in the Angkor monuments were classified as Group 1, and those in Preah Khan of Kompong Svay were classified as Group 2, except for sites C and U, which were classified as Group 1. Radiocarbon dating was carried out on 10 charcoal fragments from slag dumps outside the Angkor area. The dating results indicate that iron making in Preah Khan of Kompong Svay was conducted in and after the 13th century except for sites C and U, where iron ores may have been supplied from Phnom Daek before the 13th century.

Influence of severe climatic variability on the structural, mechanical and chemical stability of cement kiln dust-slag-nanosilica composite used for radwaste solidification

Cement production and its wide applications in construction and stabilization are among the oldest technologies. Cement kiln dust is a by-product generated by cement industry with unpleasant features. Its weak integrity can be improved by mixing it with 20% of iron slag, another industrial waste generated during steel production, and a small amount of nano-additive, namely 0.1% nanosilica. This way, modified cementitious composites of improved characteristic were developed, which performed suitable for construction and waste stabilization applications.In the present study, the novel composite material has been thoroughly examined to critically assess its performance and resistance under drastic environmental conditions that are likely to occur especially in areas exposed to severe climatic variability. The impact of flooding in water of various compositions and in strongly acidic and alkaline media was investigated. Leachability of the new composite specimens in these aqueous media and when subjected towards freezing/thawing cycles was evaluated during 90 days; especially the mechanical and chemical stability of the new composite as safe containment for radioactive 137Cs waste was studied. Compressive strength, porosity, mass change and spectroscopic investigations are the tools used in this study to check the performance of the modified cementitious composite at each condition. Although prone to deterioration after drastic freezing-thawing cycles, the new composite material displayed excellent stability under excessive flooding, and holds promise as future material of choice to immobilize and finally dispose radioactive waste in a safe and sustainable fashion.

Homogeneous Photocatalytic Iron Slag Reduction Cr6+ from Chromium Wastewater Containing High-Salt in Constructed Wetland

Homogeneous Photocatalytic Iron Slag Reduction Cr6+ from Chromium Wastewater Containing High-Salt in Constructed Wetland