Waste Iron Research Articles

Enhancing of Concrete Properties by Using Aluminium and Iron Residues as a Partial Replacement of Fine Aggregate

According to the growing of the world's population, the necessitate for using different building materials such as cement, steel, admixtures, wood and aluminium increased. The main problem faces the world with the increasing need for building materials is the construction wastes, which are a type of environmental pollution that must be reduced. This study focused on aluminium and iron wastes resulted from factories and the possibility to reuse these wastes again like partial replacement from sand with proportions (0.25, 0.5, 0.75 and 1%) in concrete mixtures for both types of residues at ages (7, 14, and 28) days. It had studied the effect of the using of aluminium residues (AR) and iron residues (IR) especially on the mechanical characteristics of concrete. These mechanical characteristics were the compression strength (CS) and tensile strength (TS). The achieved results were compared between the residues concrete specimens and those of reference concrete. Also, the effect of age and replacement percentage for samples which they contain AR and IR had been discussed. The results had shown that the (CS) of iron residues concrete samples (IRC) was increasing with increasing of the iron residues percentage till (0.5%) (IR) in opposite of the observed values of aluminium residues concrete (ARC), as well as for the results of the (TS) of concrete samples which containing the mineral residues at all ages. Where it was observed that the using of aluminium residues (AR) showed a decreasing in the values of (TS) and (CS) compare with reference concrete, but with the use of iron residues (IR) both of (TS) and (CS) results were more than their counterparts of reference concrete at all ages for the first two percentages of replacement.

A new concept of waste iron recycling for the enhancement of the anammox process

As a by-product of industry, waste iron scraps (WIS) are low-cost and widely available, which was potential for the development of iron-assisted anammox. In this study, the feasibility of adding WIS to enhance the nitrogen removal of the anammox process (also called WIS-assisted anammox) was demonstrated. Results indicated that the WIS-assisted anammox reactors performed a 15–35% higher nitrogen removal efficiency than that of the control. Compared to the sludge from the control, the sludge from the WIS-assisted anammox reactors had a higher iron content (78–113 g kg−1 SS) and a better specific anammox activity (10.8–15.5 mg N g−1 VSS h−1). The enhanced growth of the anammox bacteria (related to Ca. Kuenenia stuttgartiensis with 99% similarity) in the WIS-assisted anammox reactors was also confirmed by high-throughput sequencing and qPCR. Furthermore, the functional genes predicted by PICRUSt2 revealed a higher level of hydroxylamine oxidoreductase (hao)-like proteins expression of the biomass from the WIS-assisted anammox reactors, implying that the hydroxylamine-related anammox pathway was promoted. Additionally, the observation of cytoplasmic nitrate reductase (narG), copper-containing nitrite reductase (nirK), and nitric oxide reductase (norB) suggested that the introduction of WIS might promote the denitrification ability. This was correlated to the lower ΔNO3-/ΔNH4+ ratio observed in these WIS-assisted anammox reactors. Overall, the WIS-assisted anammox offers a sustainable nitrogen removal process for wastewater treatment with waste iron recycling.

Modification of Iron-Tailings Concrete with Biochar and Basalt Fiber for Sustainability

Currently, less than 15% of waste iron tailings are utilized. Iron tailings can be used as fine aggregate in concrete, but this kind of concrete has no coarse aggregate, resulting in low strength. Additionally, iron tailings contain some heavy metals, which will cause environmental pollution if improperly treated. In this study, the mechanical properties, sulfate resistance, and pore structure distribution of basalt fiber-biochar-concrete (PFB) were studied. Where basalt is to enhance the mechanical properties of samples, and biochar is to adsorb heavy metals in iron tailings, to prepare environmentally friendly materials. Unconfined compressive strength (UCS) test, flexural strength (FS), sulfate immersion test, leaching behavior, and mercury intrusion porosimetry (MIP) test were used to study the performance of the samples, and X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), and scanning electron microscope (SEM) was used to characterize the samples, explaining the change mechanism of the macroscopic test. The results show that the compressive strength of PFB increased by 2.5% but the flexural strength increased by 12%. The basalt and biochar improve the pore size distribution of samples, that is, the pore size greater than 10 nm is reduced while the pore size between 2 and 6 nm is increased. Biochar can effectively adsorb heavy metals of Cu, Zn, Pb, and Cd, and their leaching concentration is reduced by 50–70%. Basalt fiber improves the mixing performance of concrete, while biochar with a small particle size fills the micro pores in concrete; this paper provides a new idea of sustainability for the preparation of environmentally friendly materials and the utilization of waste iron tailings.

Promoted degradation of ofloxacin by ozone integrated with Fenton-like process using iron-containing waste mineral enriched by magnetic composite as heterogeneous catalyst

In this study, a heterogeneous catalyst derived from iron-containing waste mineral was enriched by magnetic composite (Fe3+/Fe2+) at modification ratio of 5 % for the highest mineralization of ofloxacin (OFL) by ozone/Fenton system. A comparative study between O3, perozone (H2O2) and O3/Fenton systems in mineralization of ofloxacin (OFL) under various solution pH, H2O2 dosages, initial OFL concentrations and catalyst (MFS-5) dosages was performed. Adding Fenton reagent (H2O2/MFS-5) into ozonation system gave the highest OFL removal efficiency of 70 % at optimal operational conditions of pH 9, catalyst dosage of 1.5 g/L, H2O2 dosage of 100 mg/L with initial OFL concentration of 100 mg/L due to synergistic effect of O3 and Fenton reagent. The catalyst's properties were evaluated through BET, SEM image, EDS and mapping data, FTIR and XRD. The main mineralization mechanism of OFL was through hydroxyl radicals (⁎OH) which were formed during ozonation process because FeO, Fe3O4 and SiO2 in the MFS-5's constituent accelerated decomposition of O3 and promoted reaction rate with H2O2. The catalyst exhibited a good reusability and stability after five consecutive runs with negligible change in mineralization efficiency of OFL and a very low leached iron amount into solution. Besides, there was an efficient improvement of biodegradability of real pharmaceutical wastewater after treatment by O3/Fenton with 71 % and 62 % removal of COD and TOC, respectively. These findings indicated utilizing magnetic-modified waste iron mineral as heterogeneous catalyst in combination with H2O2 and O3 achieved high efficiency and feasibility in removal of OFL antibiotic from real pharmaceutical wastewater.

Fe3O4-Fused Magnetic Air Stone Prepared From Wasted Iron Slag Enhances Denitrification in a Biofilm Reactor by Increasing Electron Transfer Flow.

nFe3O4 was prepared from waste iron slag and loaded onto air stone (named magnetic air stone or MAS in the following text). The main component of air stone is carborundum. To study the magnetic effects of MAS on denitrification, a biofilm reactor was built, and its microbial community structure and electron transfer in denitrification were analyzed. The results showed that MAS improved the performance of the reactor in both carbon and nitrogen removal compared with air stone (AS) control, and the average removal efficiencies of COD, TN, and NH4 +-N increased by 17.15, 16.1, and 11.58%, respectively. High-throughput sequencing revealed that magnetism of MAS had a significant effect on the diversity and richness of microorganisms in the biofilm. The MAS also reduced the inhibition of rotenone, mipalene dihydrochloride (QDH), and sodium azide on the respiratory chain in denitrification and enhanced the accumulation of nitrite, in order to provide sufficient substrate for the following denitrification process. Therefore, the denitrification process is accelerated by the MAS. The results allowed us to deduce the acceleration sites of MAS in the denitrification electron transport chain.The existence of MAS provides a new rapid method for the denitrifying electron transport process. Even in the presence of respiratory inhibitors of denitrifying enzymes, the electron transfer acceleration provided by MAS still exists objectively. This is the mechanism through which MAS can restore the denitrification process inhibited by respiratory inhibitors to a certain extent.

THE ECOLOGICAL CONDITIONALITY OF TREE VITALITY INDICATORS AND DENDROMETRIC PARAMETERS OF THE WOODY PLANTS COMMUNITY GROWING NATURALLY ON THE DEVASTATED LANDS IN IRON WASTE ROCK DUMP

Introduction. Numerous researchers have сonvincingly proven that iron waste rock dumps have a strong and negative impact on the environment in industrial areas. While the tree revegetation is the most efficient, effective and widely accepted way for environmental stabilization of the said post-mining landforms. That’s why the knowledge on relationships between the current state of woody plants community and the harsh environmental conditions on iron waste rock dumps play an important role in pollution control, ecological protection, and safe-guarding human health. Aim. The object of this study was to analyze from the standpoint of an ecosystem approach the ecological conditionality of the current state, tree vitality and dendrometric parameters) of the community of woody plants growing naturally on the devastated lands in iron waste rock dump. Material and Methods. Petrovsky waste rock dump areas at Kryvyi Rih Iron Ore Mining & Metallurgical District (central part of Ukraine) were chosen for the present research. During 2017–2021, the 5 research plots (40*50 m) were established in the dump’s ecosystems and the field data (tree species, tree vitality, mean diameter and height of trees, volume, basal area) were collected through direct enumeration and measurement of all trees in each plot. Pearson and Spearman correlative analysisbetween the indices of the current state of the woody plants community and the parameters of the dump’s environmental conditions (the content of heavy metals in the soil, the time of the community formation, air temperature and soil moisture)was applied. Results. It is shown that in Petrovsky waste rock dump the woody plant species are usually affected by adverse environmental factors and are in the state of stress. Therefore, they lose their ecological stability and phytomeliorative (reclamative/restorative) efficiency. Our calculations confirm that there is a correlation between the content of heavy metals in the dump’s initial soil and indicators of the currentstate of the woody plants community. In this case, 45.5–92.7% Pearson correlation coefficients are significant p < 0.05 (from the theoretically possible ones). The feedback has a slight prevalence – 54.9–66.7% from the number of significant coefficients. The weak and medium relationship prevails – 70–100% from the number of significant coefficients. It is established that there is a correlation between the ecological conditions of the devastated land on the dump and characteristics of the current state of the woody plants community. It should also be noted that 66.7–83.3% Spearman correlation coefficients are significant p < 0.05 (from the theoretically possible ones). The feedback also has a slight prevalence – 55.6–80.0% from the number of significant coefficients. As in the previous case the weak and medium relationship predomanated – 30–70% from the number of significant coefficients. Conclusion. The taxonomic structure, tree vitality and dendrometric parameters of the community of woody plants that grow naturally on in iron waste rock dump have a clear ecological determinism. The most strong correlations were observed betweenthe concentrations of Pb, Zn, Cd, Fe in the dump’s soils, as well as the duration of vegetation formation, the additional soil moisture and indicators of the current state of the woody plants community.

Novel electromagnetic induction heat curing process of fly ash geopolymer using waste iron powder as a conductive material

Geopolymer (GP) was invented to replace concrete, but its heat curing requirement hinders extensive use in real-world construction. Past studies have tested several methods of heat curing. However, the conventional heat curing process (using an oven) is still required for GP to develop good strength on the laboratory scale. This study introduces a new heat curing method for GP based on an electromagnetic field (EMF)generator and a ferromagnetic material. Waste iron powder (WIP) was used as the ferromagnetic material mixed with the fly ash-based GP to generate heat through induction. The sample was cured at 1.18 kW with 150–200 kHz of EMF generator for 15 min. The results showed that 5% of the WIP mixed sample gained compressive and flexural strength at 28 days more than the control (oven-cured). Compressive and flexural strengths of 76.8 MPa and 11.3 MPa were obtained, respectively. In addition, heat induction enhanced the densification and geopolymerization in the GP matrix following SEM and XRD results. This alternative method of heat curing accelerated the formation of the GP matrix, reduced curing time, and increased strength. Moreover, this EMF curing method can save 99.70% of the energy consumed compared to the conventional heat curing method.

Adding waste iron shavings in a pilot-scale two-stage SBRs to develop aerobic granular sludge treating real wastewater

A pilot-scale two-stage SBRs added waste iron shavings was proposed and established to develop aerobic granular sludge for real wastewater treatment based on a previous lab-scale study. The results showed that aerobic granular sludge was successfully cultivated, and the treatment performance was satisfactory. The sludge volume index at 30 min (SVI30) was approximately 25.0 mL/g and the mean particle size reached approximately 0.8 mm. The mixed liquor suspended solids (MLSS) exceeded 14 g/L and 10 g/L in the two SBRs. The average removal rates of chemical oxygen demand (COD), total phosphorus (TP), ammonia nitrogen (NH4+-N), total nitrogen (TN), and suspended solids (SS) were 95.2%, 99.2%, 96.1%, 82.9%, and 95.0%, respectively. In addition, low total iron (TFe) concentrations were unlikely to impact the effluent. Two-stage SBRs can efficiently reduce the effluent SS concentration during early in the operation process, and improve the utilisation of carbon source from raw wastewater for denitrification. Overall, the coupling of iron shavings micro-electrolysis and biological processes promoted aerobic sludge granulation and pollutant removal.

Utilization of iron waste from steel industries in persulfate activation for effective degradation of dye solutions

The performance of three solid iron wastes (SIW-1, SIW-2 and SIW-3) was evaluated as an activator of persulfate (PS) for the degradation of methylene blue (MB). SIW-3 showed the highest performance among the three catalysts. The morphology, chemical composition and chemical structure of the three SIW were investigated using various analyses. Complete degradation of methylene blue (MB) in neutral pH was achieved after 60 min at PS concentration of 4 mM, initial MB concentration of 10 mg/L and catalyst dose of 1.0 g/100 mL using light. The degradation efficiency of MB decreased from 100% to 34.6% by increasing the initial MB concentration from 10 mg/L to 100 mg/L. The degradation of MB followed the second-order model. Scavenging experiments showed the major role of hydroxyl and sulfate radicals in the MB degradation. The performance of iron waste in the retained form was investigated and the degradation efficiencies were 96%, 91.2%, 91%, 89% and 86% in five succeeding cycles at pH 7, catalyst dose of 1 g/100 mL, initial MB concentration of 10 mg/L and PS concentration of 4 mM. Moreover, the reusability of suspended iron waste was investigated. The degradation efficiencies of methylene blue, methyl red, Congo red and acid blue-25 were 100%, 97%, 96% and 97.3%, respectively after 60 min. The degradation pathways of MB were proposed after the identification of intermediates using liquid chromatography-mass spectroscopy analysis. This study revealed that the iron waste can be efficiently employed for PS activation in the suspended and immobilized modes which reduces the total cost of the Fenton process paving the way for the large-scale application of this technique.

Synthesis of Iron-Based Carbon Microspheres with Tobacco Waste Liquid and Waste Iron Residue for Cd(II) Removal from Water and Soil.

Herein, a novel magnetic iron-based carbon microsphere was prepared by cohydrothermal treatment of tobacco waste liquid (TWL) and waste iron residue (WIR) to form WIR@TWL. After that, WIR@TWL was coated with sodium polyacrylate (S.P.) to fabricate WIR@TWL@SP, whose removal efficiency for bivalent cadmium (Cd(II)) was studied in water and soil. As a result, WIR@TWL@SP possessed a high Cd(II) removal efficiency, which could reach 98.5% within 2 h. The adsorption process was consistent with the pseudo-second-order kinetic model because of the higher value of adjusted R2 (0.99). The thermodynamic data showed that the adsorption process was spontaneous (ΔG° < 0) and exothermic (ΔH° = 32.42 KJ·mol-1 > 0). Cd(II) removal mechanisms also include cation exchange, electrostatic attraction, hydrogen-bond interaction, and cation-π interaction. Notably, pot experiments demonstrated that WIR@TWL@SP could effectively reduce Cd absorption by plants in water and soil. Thus, this study offers an effective method for remediating Cd(II)-contaminated water and soil and may have a practical application value.

Fenton like oxidative degradation of toxic water pollutants by iron nanoparticles synthesized via facile green route using waste iron rust as the iron precursor

Corrosion of iron by oxidation is a global problem that affects the economy and gives rise to environmental pollution. Iron rust is oxide or hydroxide of iron, it can be used as a secondary iron source which will lead to its management as well as reduce the pressure on primary iron sources. In the present study, waste iron rust was used as the precursor of iron for the synthesis of iron nanoparticles via the green route using extract of dried Jatropha leaf. Synthesized nanoparticles were characterized using different instrumental techniques. Synthesized iron nanoparticles bear an extremely large specific surface area of 190.2 m2/g. The catalytic potential of synthesized nanoparticles was tested for the degradation of toxic organic pollutants phenol and p-nitrophenol (PNP) in an aqueous solution. Both the pollutants were removed rapidly in the initial 30 minutes of the reaction time. Optimization of the removal process was done by varying different variables. Maximum removal of phenol (~98%) and PNP (~95%) was achieved at 0.1 g/L concentration of nanoparticles. The degradation reaction rate was determined by pseudo-first-order and pseudo-second-order kinetics and the data was found to be followed best by the pseudo-first-order kinetics.

A Magic Filter Filled with Waste Plastic Shavings, Loofah, and Iron Shavings for Wastewater Treatment.

Integrated sewage treatment equipment has been widely used, but the commonly used fillers for wastewater treatment are not suitable in rural areas due to their price and performance issues. In this study, an integrated magic filter filled with waste fillers was proposed and established for wastewater treatment. The filter was composed of functional modules and an equipment room, and the fillers in each module can be taken out separately and changed arbitrarily according to the needs of specific treatment conditions. The fillers used include waste plastic shavings, loofah, and waste iron shavings, generated during the processing of plastic, crop, and steel. At the same time, a 91 d experiment was performed for real wastewater treatment, and a satisfactory removal performance was obtained, with average removal rates of COD, TP, NH4+-N, TN, and SS being 83.3%, 89.6%, 93.8%, 74.7%, and 94.0%, respectively. Through microscope observation, a large number of microorganisms were attached to the surface of the fillers, which was conducive to the simultaneous removal of nitrogen and phosphorus. The micro-electrolysis of waste iron shavings can produce Fe2+ and Fe3+, which would combine with PO43− to form Fe3(PO4)2 and FePO4 precipitates, enhancing the removal of phosphorus. In addition, the filled fillers have an excellent physical filtering effect, which can reduce the effluent SS. The magic filter achieves both the recycling of wastes and the treatment of wastewater.

Flexural behavior evaluation and energy dissipation mechanisms of modified iron tailings powder incorporating cement and fibers subjected to freeze-thaw cycles

Waste iron tailings with cement-based inorganic binder is an economical and sustainable highway engineering base material, which is an effective way to reduce iron tailings inventory and affinity for engineering promotion. The flexural behavior considering the freeze-thaw action plays a crucial role for highway engineering base material. In this study, two types of fibers including polypropylene (PP) fiber and glass fiber were used to modify cement iron tailings powder (CITP), i.e., PPCITP or GCITP. Based on flexural tests, the influences of fiber length and freeze-thaw cycles on flexural behavior of modified CITPs were discussed. The results showed that the failure flexural strength of PPCITP reached the highest value at PP fiber length of 12 mm, while the flexural strength of GCITP presented a wavy downward trend with the increase of glass fiber length. The freeze-thaw cycle test results showed that the flexural strength of both PPCITP and GCITP decreased with the increase of freeze-thaw cycles, and the frost resistance of GCITP was better than that of PPCITP under the condition of the same volume of fibers. Then the single fiber pull-out test results implied that the interface action between glass fiber and CITP (G-CITP) was higher than that between PP fiber and CITP (PP-CITP) considering various curing ages and freeze-thaw cycles. Moreover, it is corroborated that PP fiber and glass fiber with length of 12 mm have the better reinforcement role in CITP specimens from the perspective of dissipative energy of fiber failure. Meanwhile, the dissipative energy results of both modified CITPs with fibers showed a downward trend with freeze-thaw cycles as a whole, and the dissipative energy of GCITP was higher than PPCITP at the specimen broken, which is consistent with the conclusion drawn in the single fiber pull-out test. The quantitative relationship models among dissipative energy, effective fiber length and freeze-thaw cycles of PPCITP and GCITP were further established, which could provide a reference for the large-scale production of waste iron tailings in highway engineering base materials.

Experimental and material characterization of composites, including waste iron and marble powder.

Due to its fine particle size, waste marble slurry originating in cutting and processing units mixes into the air after drying, causing environmental and health problems in nearby areas. On the other hand, large amounts of iron particles are generated as metalworking industry waste, affecting the environmental system. In this study, 0%, 10%, and 20% marble powder (instead of cement) and iron particles (instead of fine aggregate) were used in mixtures, and the composites produced were subjected to two different curing periods: 7 and 28days. The physical, mechanical, microstructural, and thermal properties of the fresh and hardened composites were ascertained via bulk density, consistency, porosity, water absorption, capillary water absorption, strength tests, particle size distribution, X-ray diffraction (XRF), X-ray fluorescence (XRF), scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS), and thermogravimetric analyses (TGA). The results revealed that minimum water absorption (8.5%) and porosity (19.8%) values were achieved in 28-day composites produced with 10% marble-20% iron wastes among all composites. Thus, iron particles substituted for natural aggregates were mainly responsible for the increase in mechanical performance. A maximum flexural strength of 5.9MPa and a compressive strength of 26.7MPa were observed in 28-day composites containing 0% marble-20% iron wastes. Furthermore, capillary water absorption tended to decrease with the substitution of 10% marble powder.

Changes in soil properties during iron mining and in rehabilitating minelands in the Eastern Amazon.

Open-cast iron mining causes drastic disturbances in soil properties. Recovery of soil chemical and physical properties is essential for successful revegetation and landscape rehabilitation. To identify changes in soil properties during the mining and revegetation process, soil samples were collected from undisturbed sites represented by forestand ferriferous savannas stocking above iron outcrops, called "cangas," in open-pit benches, and in rehabilitation chronosequences of iron waste piles in the Carajás Mineral Province (CMP), Eastern Amazon, Brazil. The samples wereanalyzed for chemical and physical properties. Our results showed that iron mining operations resulted in significant alteration of the chemical soil properties when forest and canga vegetation are suppressed to form open-pit benches or waste piles in the CMP. Mining substrates showed lower contents of soil organic matter (SOM) and nutrients than undisturbed areas of forests and cangas. In order to achieve the success of revegetation, nutrients have been added prior to plant establishment. We have demonstrated how soil fertility changes along with mineland rehabilitation, and the variation among chronosequence was attributable mainly due to contents of SOM, K, and B in the soil. The slight improvement of SOM found in rehabilitated waste piles reinforces the notion that recovery of soil quality can be a slow process in iron minelands in the CMP.

Alkali-activated bricks made with mining waste iron ore tailings

In India, the enormous growth in the housing sector has put tremendous pressure on construction materials such as bricks. Conventional brick production methods include fired bricks and cement blocks. However, conventional methods significantly contribute to environmental carbon emissions and therefore alternative brick production methods have caught the attention of several researchers. Furthermore, the waste generated in various industries can be a useful resource for the construction industry, and in particular, voluminous waste is generated during the beneficiation stage of iron ore concentrate, which can be integrated into the construction industry to achieve sustainable practice. With this quest in mind, this study proposes the utilization of mining waste iron ore tailing (IOT) in alkali-activated bricks. For this purpose, six different brick compositions were synthesized with fly ash, GGBS, and IOT along with Na2SiO3 sol. The raw materials were characterized using various techniques such as X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscope (SEM), and particle size analysis (PSA). Furthermore, a series of standard tests were conducted on the developed bricks to evaluate their strength and durability properties. The developed bricks have presented a maximum compressive strength of 18.45 MPa and minimum water absorption of 12.6%. Besides, the alkali-activated bricks have shown excellent resistance to brick ageing which was attributed to improvement in the microstructure of bricks due to the filling up of voids with products of the polymeric reaction. Finally, it was interesting to notice that with 8% Na2SiO3 as an alkaline activator and with the combination of fly ash and GGBS more than 50% IOT can be utilized to produce good quality bricks at ambient curing conditions.

Magnetization roasting of waste iron ore beneficiation plant tailings using sawdust biomass; A novel approach to produce metallurgical grade pellets

Minerals recovery and recycling of valuables from industrial waste using biomass (renewable energy resource) is the need of the hour for mineral-rich countries worldwide. Moreover, growing steel demand and fossil fuel consumption led civilization to ponder the alternative raw materials and energy sources apart from conventional coal/coke as an appropriate reductant for the iron and steelmaking process. Therefore, the generated waste iron ore beneficiation plant tailings (IOBPT) containing 56.96% Fe(T), 4.07% Al2O3, 7.23% SiO2 and 4.38% of LOI (contributed mainly from clay and goethite) can be considered a potential secondary mineral resource consumed in the downstream iron making processes. In the current investigation, a novel approach of magnetization roasting of the IOBPT using sawdust biomass (SDB) (generated from the sawmill) as a carbonaceous solid reductant is used to recover the pellet grade magnetite concentrate. On the other hand, the IOBPT was directly subjected to a wet high-intensity magnetic separator (WHIMS) to compare the generated pellet grade concentrate in both methods. In this regard, the quality of the concentrate and indurated pellets obtained from both processes was characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), wet chemical analysis, and X-ray microtomography (X-ray microCT), respectively. Altogether, the innovative way of utilizing SDB as a suitable reductant in magnetization roasting at 950 °C to produce metallurgical grade pellets (CCS:258 kg/pellet, Porosity:25.68%, RI:0.71%/min at Rt = 60, RDI-2:RDI]-2.8 = 2.61%, FSI:19.05%) indicates towards a fossil fuel-free industrialization.

The Influence of Iron Lathe Waste Addition to the Flexural Strength of Galvanized Fiber Concrete

Galvanized wire and iron lathe are alternative fiber types in fiber concrete mixes. Galvanized wire has flexural properties, no corrosion it is relatively inexpensive, while iron lathe waste is known to increase the flexural strength of beams. The study uses 5 cm long galvanized wire with 2% cement by weight and uses iron lathe waste. The purpose of this study is to obtain the value of the flexural strength of the beam.The test specimens used were 12 samples with a variation of 3 pieces each, with the code for normal concrete specimens (NA-NB-NC), 2% galvanized fiber concrete (2A-2B-2C), galvanized fiber concrete with iron lathe variation 10% (10A-10B-10C), galvanized fiber concrete with iron lathe variation 14% (14A-14B-14C). The test was carried out when the concrete was 28 days old with a plan of 22.5 MPa concrete quality.The test results are the average value of the flexural strength of normal concrete is 0.900 MPa, the flexural strength of galvanized fiber concrete is 0.975 MPa, the flexural strength of galvanized fiber concrete with the addition of waste iron lathe with a variation of 10% is 1.425 MPa, variations 14% is 1,125 MPa. The highest percentage of flexural strength increase ratio for normal concrete is 10% variation of 58.333% and for galvanized fiber concrete is 10% variation of 46.154%.

Highly Efficient Photocatalyst Fabricated from the Chemical Recycling of Iron Waste and Natural Zeolite for Super Dye Degradation.

In this paper, Fe2O3 and Fe2O3-zeolite nanopowders are prepared by chemical precipitation utilizing the rusted iron waste and natural zeolite. In addition to the nanomorphologies; the chemical composition, structural parameters, and optical properties are examined using many techniques. The Fe2O3-zeolite photocatalyst showed smaller sizes and higher light absorption in visible light than Fe2O3. Both Fe2O3 and Fe2O3-zeolite are used as photocatalysts for methylene blue (MB) photodegradation under solar light. The effects of the contact time, starting MB concentration, Fe2O3-zeolite dose, and pH value on photocatalytic performance are investigated. The full photocatalytic degradation of MB dye (10 mg/L) is achieved using 75 mg of Fe2O3-zeolite under visible light after 30 s, which, to the best of our knowledge, is the highest performance yet for Fe2O3-based photocatalysts. This photocatalyst has also shown remarkable stability and recyclability. The kinetics and mechanisms of the photocatalytic process are studied. Therefore, the current work can be applied industrially as a cost-effective method for eliminating the harmful MB dye from wastewater and recycling the rusted iron wires.

Reutilizing Waste Iron Tailing Powders as Filler in Mortar to Realize Cement Reduction and Strength Enhancement.

Recently, the massive accumulation of waste iron tailings powder (WITP) has resulted in significant environmental pollution. To solve this problem, this paper proposes an original mortar replacement (M) method to reuse waste solids and reduce cement consumption. In the experiment, the author employed an M method which replaces water, cement, and sand with WITP under constant water/cement and found that the strength development can be significantly improved. Specifically, a mortar with 20% WITP replacement can obtain a 30.95% improvement in strength development. To study the internal mechanism, we performed experiments such as thermogravimetric analysis (TGA), mercury intrusion porosimetry (MIP), and SEM. The results demonstrate that the nucleation effect and pozzolanic effect of WITP can help promote cement hydration, and MIP reveals that WITP can effectively optimize pore structure. In addition, 1 kg 20% WITP mortar reduced cement consumption by 20%, which saves 19.98% of the economic cost. Comprehensively, our approach achieves the effective utilization of WITP and provides a favorable reference for practical engineering.