Mill Scale Waste Research Articles

Reuse of mill scale waste from the steel industry as raw material in the production of red ceramics

Reuse of mill scale waste from the steel industry as raw material in the production of red ceramics

Application of Mill Scale Waste for Geoecological Protection of Aquatic Medium

The potential for use of mill scale (metallurgical production waste) as an affordable sorption-filtration material for aqueous medium protection from phosphates and heavy metals is considered. The results of X-ray phase studies of mill scale prototypes, as well as extraction of dissolved components from them into bidistilled water at long-term contact, which revealed insignificant emission of harmful substances indicating safety of the mill scale application as a sorbent, are given. It is proposed to use industrial cartridges (filter cartridges) loaded from rolled scale to purify large volumes of surface wastewater in real conditions.

Upcycling process of mill scale waste into high-value ceramic products

Ceramic industry consumes large amounts of raw materials, including costly and environmental impact iron based-pigments. Steel rolling (SR) and wire drawing (WD) waste, rich in iron (>67 wt %), present a viable alternative. This study aims to develop high value stoneware pastes for tableware products by substituting commercial pigments with SR and WD. The influence of incorporation content (3, 5 and 10 wt %) and pre-treatments (sieving at 250, 150 and 63 μm, and grinding followed by sieving at 63 μm) on the samples properties was assessed including weight loss, firing shrinkage, apparent density, flexural resistance, and water absorption. The laboratory scale results revealed that darker hues, ranging from grey to reddish, were obtained when SR and WD were incorporated in the stoneware paste (beige colour). The smaller the particle size, more homogeneous is the developed colour, which is intensified as higher is the incorporation level.The prototypes (plates) were characterized in terms of thermal shock, edge impact, cracking and microwaves resistance, water absorption, and leaching behaviour, demonstrating that they met the industrial requirements. Thermal shock resistance was enhanced and the levels of leached Fe, Pb, Cd, Ni, Cr, Mo, V, Zn, and Cu, were below permissible limits (EU Ceramic Directive 84/500/EEC, Decree-Law n°152/2017, Decree-Law n°236/98 and WHO Guidelines for Drinking-Water Quality) confirming their effective immobilization. Concluding, this work shows the viability of using mill scale waste as a valuable secondary raw material in stoneware pastes acting as a chromophore agent. Dark colours are obtained while preserving the product technical characteristics, promoting sustainable production and reducing landfilled waste.

Innovative Transformation and Valorisation of Red Mill Scale Waste into Ferroalloys: Carbothermic Reduction in the Presence of Alumina

Primary and secondary mill scales (MSs) are waste products produced by the surface oxidation of steel during the hot (800 to 1200 °C) rolling process in downstream steelmaking. While the primary MS is comprised of FeO, Fe3O4, and Fe2O3 in a range of proportions, the secondary MS primarily contain red ferric oxide (Fe2O3) (red MS). We report a novel route for extracting iron from red MS and transforming it into ferro-aluminium alloys using carbothermic reduction in the presence of alumina. The red MS powder was blended with high-purity alumina (Al2O3) and synthetic graphite (C) in a range of proportions. The carbothermic reduction of red MS-Al2O3-C blends was carried out at 1450 °C and 1550 °C under an argon atmosphere for 30 min and then furnace-cooled. The red MS was completely reduced to iron at these temperatures with reduced iron distributed around the matrix as small droplets. However, the addition of alumina unexpectedly resulted in a significant increase in the number and sizes of iron droplets generated, much higher reactivity, and the formation of ferrous alloys. A small amount of alumina reduction into metallic aluminium was also observed at 1450 °C. There is an urgent need to identify the true potential of industrial waste and the materials within it. This study showed that red MS is a valuable material source that could be transformed into ferro-aluminium alloys. These alloys find application in a range of industrial sectors such as construction, automotive, infrastructure, etc.

Production of reduced iron from mill scale waste using tilting rotary furnace

The production of steel in steel mills generates undesired scales of oxidized iron on the surface of the hot steel. Although several attempts have been made to transform mill scale into valuable products, the low porosity of the oxides and the presence of oil contamination have been the main limitations in pelletizing the scales. In our recent research, we were able to produce reduced iron in the form of spheres with a 93% metallization degree using only mill scale as a source of iron without the need for any agglomeration or cleaning steps. The main equipment used in the production process was a tilting rotary furnace. We also examined the relationship between fuel consumption and the metallization degree of the reduced iron, as well as the effect of furnace RPM on the cross-sectional diameter of the produced spheres. By adjusting the process parameters, we were able to produce spheroidal iron with a cross-sectional diameter ranging from 10 mm to 400 mm. This high-quality reduced iron can be directly used as a replacement for DRI or scrap in traditional steel production methods.

Forming of Briquettes from Iron and Plastic Waste

This research provides the analysis of the mill scale and plastic waste properties, as well as ways of their complex recycling. Preliminary experiments on the formation of briquettes were made. The results of preliminary experiments on mill scale grinding in a cone inertial crusher and the formation of briquettes together with plastic are presented. This research has revealed the possibility of creating a briquette charge material for further processing in steelmaking processes. The addition of a plasticizer is necessary to improve the formability of the samples during pressing.

Investigation of nano-crystaline strontium hexaferrite magnet powder from mill scale waste by the mechanochemical synthesis: Effect of the annealing temperature

Today, waste management and recycling have critical importance given the dwindling natural resources and to create powerful technologies for a green future. One of these strontium hexaferrite powders were produced by mechanochemical process using mill-scale and strontium carbonate from obtained celestite ore. The strontium carbonate and the mill scale were prepared in stoichiometric ratio, and mechanochemical process was applied for 16 h to produce hard-ferrite powders. Following the mechanochemical synthesis process, powder mixture was annealed at 850–1000 °C temperatures. The morphology, crystal structure and phase composition of strontium hexaferrite powders caused the magnetic properties to change according to the annealing temperature. As a result of the studies, the most suitable annealing temperature was determined as 975 °C. The Hc, Br and (BH)max of produced powders correspond to 5505Oe, 347 mT and 5.77MGOe at 975 °C, respectively. The Curie temperature of the annealed powders was determined as 474 °C.

A STUDY OF CONCRETE INCORPORATING STEEL MILL SCALE WASTE

This paper presents the effective utilization of industrial waste steel mill scale in concrete. Tests were performed on concrete specimens incorporating 10%, 20%, 30%, and 40% steel mill scale by weight of sand and a control specimen. Results were assessed in terms of workability, compressive strength, flexural strength, and durability. The compressive and flexural strength of concrete incorporating a 20% steel mill scale was recorded higher as opposed to control and other percent replacement specimens. It was also observed that the durability and resistance against sulphate attack of concrete enhanced as the replacement proportion of mill scale were increased. Furthermore, the higher specific gravity of mill scale waste makes it a suitable material for heavyweight concrete members and radiation shield structures.

Zero-valent iron-copper bimetallic catalyst supported on graphite from spent lithium-ion battery anodes and mill scale waste for the degradation of 4-chlorophenol in aqueous phase

Graphite supported zero-valent iron-copper bimetallic catalysts (ZVI-Cu/C) were successfully prepared from mill scale (MS) waste and spent lithium-ion battery (LIB) anode using carbothermic reduction as a new approach for the recycling and revalorization of these waste. Cu and graphite were obtained from the LIB anodes, while ZVI was provided by MS waste. ZVI-Cu/C were synthesized with different MS to LIB anode powers mass ratios (1 to 4) and used as catalysts for the degradation of 4-chlorophenol (4-CP) in water by both reduction and heterogeneous Fenton reactions. ZVI-Cu/C-2 showed the highest removal percentage of 4-CP in both reactions. The degradation rates fitted well to a pseudo first-order model for both reactions. Moreover, ZVI-Cu/C-2 catalyst showed a relatively low lixiviation of iron and copper ions and a high activity in the 4-CP removal even in the fourth reuse cycle, which supports the high stability of the synthesized catalyst. Hydroquinone and 4-chlorocatechol were identified as the main intermediate by-products of 4-CP degradation. The results of this study support the possibility of synthesizing high active and stable ZVI-Cu/C catalysts using graphite and copper from spent LIB anode and iron oxide from MS waste. These catalysts show promising prospective for the removal of 4-CP in water, with comparable activities to others previously reported. This study reports, for the first time, the combined recycling of MS waste and spent LIB anodes to synthesize ZVI-Cu/C catalysts for water treatment by both oxidation and reduction reactions.

Structural, Electromagnetic and Microwave Properties of Magnetite Extracted from Mill Scale Waste via Conventional Ball Milling and Mechanical Alloying Techniques.

This study presents the utilization of mill scale waste, which has attracted much attention due to its high content of magnetite (Fe3O4). This work focuses on the extraction of Fe3O4 from mill scale waste via magnetic separation, and ball milling was used to fabricate a microwave absorber. The extracted magnetic powder was ground-milled using two different techniques: (i) a conventional milling technique (CM) and (ii) mechanical alloying (MM) process. The Fe3O4/CM samples were prepared by a conventional milling process using steel pot ball milling, while the Fe3O4/MM samples were prepared using a high-energy ball milling (HEBM) method. The effect of milling time on the structural, phase composition, and electromagnetic properties were examined using X-ray diffraction (XRD) and a vector network analyzer (VNA). XRD confirmed the formation of magnetite after both the magnetic separation and milling processes. The results revealed that Fe3O4 exhibited excellent microwave absorption properties because of the synergistic characteristics of its dielectric and magnetic loss. The results showed that the Fe3O4/CM particle powder had a greater absorption power (reflection loss: <−10 dB) with 99.9% absorption, a minimum reflection loss of −30.83 dB, and an effective bandwidth of 2.30 GHz for 2 mm thick samples. The results revealed the Fe3O4/MM powders had higher absorption properties, including a higher RL of −20.59 dB and a broader bandwidth of 2.43 GHz at a matching thickness of only 1 mm. The higher microwave absorption performance was attributed to the better impedance matching property caused by the porous microstructure. Furthermore, the magnetite, Fe3O4 showed superior microwave absorption characteristics because of the lower value of permittivity, which resulted in better impedance matching. This study presents a low-cost approach method by reutilizing mill scale waste to fabricate a high purity crystalline Fe3O4 with the best potential for designing magnetic nano-sized based microwave absorbers.

Influence of Different Waste Materials on Resistance of Cement Mortars against Carbonation and Chloride Ingress

This work is an extensive experimental study on the corrosion behavior of reinforced cementitious mortars containing industrial byproducts and waste materials. In particular, calcareous (C-class) fly ashes, iron mill scale and Electrolytic Manganese Dioxide (E.M.D.) waste were used as additives in mortars production. The abovementioned materials were used without any prior treatment or management and replaced the cement in concrete mixing by 10% wt. of cement weight. For the experimental set-up, reinforced mortars were prepared and exposed to coastal area for 12 months, while some of them were remained in a salt spray cabin for 60 days. The corrosion monitoring was performed by electrochemical and mass loss measurements, while chloride content, porosity, carbonation and mineralogy of mortars were also estimated. The results indicate, that there is a development in durability and chloride penetration resistance of composites comparing with the conventional mortars at late ages. At the same time, it was also observed that their chemical composition and fineness, control the diffusion of CO2 into the pore system and lead to increased carbonation of composite mortars. The challenge of this work is the production of eco-friendly composites with high chloride and carbon dioxide penetration resistance.

Effects of Recycled Fe2O3 Nanofiller on the Structural, Thermal, Mechanical, Dielectric, and Magnetic Properties of PTFE Matrix.

The purpose of this study was to improve the dielectric, magnetic, and thermal properties of polytetrafluoroethylene (PTFE) composites using recycled Fe2O3 (rFe2O3) nanofiller. Hematite (Fe2O3) was recycled from mill scale waste and the particle size was reduced to 11.3 nm after 6 h of high-energy ball milling. Different compositions (5–25 wt %) of rFe2O3 nanoparticles were incorporated as a filler in the PTFE matrix through a hydraulic pressing and sintering method in order to fabricate rFe2O3–PTFE nanocomposites. The microstructure properties of rFe2O3 nanoparticles and the nanocomposites were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The thermal expansion coefficients (CTEs) of the PTFE matrix and nanocomposites were determined using a dilatometer apparatus. The complex permittivity and permeability were measured using rectangular waveguide connected to vector network analyzer (VNA) in the frequency range 8.2–12.4 GHz. The CTE of PTFE matrix decreased from to when the filler loading increased to 25 wt %. The real (ε′) and imaginary (ε″) parts of permittivity increased with the rFe2O3 loading and reached maximum values of 3.1 and 0.23 at 8 GHz when the filler loading was increased from 5 to 25 wt %. A maximum complex permeability of was also achieved by 25 wt % nanocomposite at 10 GHz.

An Innovative Method of Converting Ferrous Mill Scale Wastes into Superparamagnetic Nanoadsorbents for Water Decontamination.

The need to recycle and develop nanomaterials from waste, and use them in environmental applications has become increasingly imperative in recent decades. A new method to convert the mill scale, a waste of the steel industry that contains large quantity of iron and low impurities into a nanoadsorbent that has the necessary properties to be used for water purification is presented. The mill scale waste was used as raw material for iron oxide nanopowder. A thorough characterization was performed in each stage of the conversion process from the mill scale powder to magnetic nanopowder including XRD (X-ray diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy), BET (Brunauer, Emmett and Teller) and magnetization properties. Iron oxide nanoparticles were approximately 5–6 nm with high specific surface area and good magnetic properties. These are the necessary properties that a magnetic nanopowder must have in order to be used as nanoadsorbents in the heavy metal removal from waters. The iron oxide nanoparticles were evaluated as adsorbents for the removal of Cu, Cd and Ni ions.

Rapid Adsorption of Magnetite Nanoparticles from Recycled Mill Scale Waste as Potential Adsorbent for Removal of Cu(II) Ions

The present study was conducted to establish adsorbent potential of magnetite nanoparticle ferrous ferric oxide (Fe3O4) for removal of Cu(ll) ions in wastewater. In the study, Fe3O4 was prepared by synthesizing low-cost recycled mill scale waste in an aqueous solution. Samples of scale wastes were milled and ground using high-energy ball milling (HEBM) at three milling times of 5, 7 and 9 hours. Extraction of Fe3O4 was accomplished by magnetic separation technique (MST) and Curie temperature separation technique (CTST). The morphologies and structural properties of Fe3O4 were characterized by using X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier-transform infrared spectroscopy (FTIR). HRTEM yielded images in the range of 10-22 nm. Maximum adsorption capacity, qe,and percentage removal of Cu(II) ions were achieved at 4.45 mg/g and 62.61% respectively after 7 hours of milling time. The present study recorded the smallest particle size of Fe3O4 imparting high qe, and percentage removal of Cu (II) ion in an aqueous solution, suggesting its high adsorbent potential.

A New Added-Value Application for Steel Wire Drawing Mill Scale Waste in Stoneware Ceramic Products

Mill scale (MS) is a iron-rich waste generated in the wire drawing process with high iron content and is still mainly disposed in landfills. The scientific community has been studied its use in other applications such as pigments, concretes, among others. This work aims to study a new added-value application for MS—the development of coloured ceramic pastes. For this purpose, the influence of the added amount (0, 1, 3, 5 and 10 wt.%), the pre-treatment (milling + sieving at 212 μμm), the maximum firing temperature (from 1043 to 1165 °C) and the type of furnace (laboratory/industrial) were analysed on the sample’s characteristics. A dark grey stoneware product was obtained through the incorporation of 10 wt.% of MS and leaching tests conducted at pilot scale with cups confirmed its immobilization in the ceramic matrix. Furthermore, it was proved that the firing temperature can be reduced by about 100 °C without affecting the specimen’s characteristics. This reduction leads to a considerable decrease in the energy consumption upon firing, inducing economic and environmental advantages. Therefore, this work provides a new added-value application for MS and contributes to the reduction of virgin raw materials consumption and development of more sustainable stoneware products.

Recycled Strontium Hexaferrite Permanent Magnet from Mill Scale Waste to Improve Energy Efficiency in Synchronous Electric Motors

Recycled Strontium Hexaferrite Permanent Magnet from Mill Scale Waste to Improve Energy Efficiency in Synchronous Electric Motors

Overview on production of reduced iron powder from mill scale waste

Abstract Mill scale is the metallurgical waste produced by the rolling mill in the steel hot rolling process. It contains a substantial percent of iron, including traces of other elements. The oxide of mill scale and reduced Iron powder have their scope of application in numerous segments. However, the accumulation and disposal of mill scale as a waste product has become an increasingly important issue. It must be dealt with appropriately to meet the inevitably strict environment and ecological necessities to understand its financial benefit. To build up recycling technology, no systematic effort has been put to take advantage of this resource at a higher degree commercially. A standout amongst the references many researcher, attempts to work on its process and design variable to obtain a higher degree of reduction of mill scale. However, there is still a considerable knowledge gap in developing and optimizing the process condition and design variable, incorporating simulation and modeling techniques to produce high purity reduced iron from mill scale waste. To tackle this, there is a need to devise technology that puts this waste product to appropriate use and adds significant value to tackle this. This overview brings a close summary of work done on mill scale reduction techniques in the past few decades. Also, it highlights current trends underway in the production of high purity iron powder.

Influence of Process Parameters on Countercurrent Reactor Reduction of Oxidized Mill Scale Waste and Its Co-relationship with Mathematical Model

Mill scale is treated as a waste product by the steel industry, so it is essential to recycle and reuse this waste for recovery of metallic iron and its single oxide derivative. Most of the study in the field of mill scale reduction focuses on the static mill scale reduction. Optimizing the process in dynamic conditions becomes more difficult because of the complexity involved inside the process. In the present method, mill scale having particle size ranges from 106 to 53 µm was converted to single-phase oxide Fe2O3 by blowing pure oxygen at 1100 °C and then it was subjected to a reducing atmosphere of 50% H2 and 50% N2 (1:1) at 875 ± 5 °C at a varying reactor angle from 2° to 5° and different mass flow rates varying from 0.037 to 0.148 kg/min. A generalized experimental model (GEM) has been formulated for the degree of reduction of oxide, which encompasses twelve parameters consisting of reactor design and process parameters. A Buckingham theorem was used to obtain dimensionless parameter for the degree of reduction, and a logical correlation using the proposed model has been established.

Steel mill scale waste and granite powder waste in concrete production -An experimental study

Fine aggregate is one of the large scale consuming materials in the construction industry. In general, river sand has been used as a fine aggregate for making concrete, mortar, etc. This river sand becoming one of the expensive materials due to its transportation from the source point and rapid consumption in the construction sector. Owing to the above circumstances, the concrete and construction industry needs a substitute for fine aggregate to be found. In this investigation, M20 grade concrete with the replacement of sand by steel mill scale waste and granite powder waste from 10% to 100% with the increments of 10%. This paper presents a detailed experimental study on compressive strength, bulk density, and water absorption of the M20 grade concrete containing steel mill scale and granite powder. The experimental outcomes indicate that the use of steel mill scale and granite powder in concrete showed improvement in the performance of concrete in strength and as well as in durability aspects.

Adsorption Potential of Magnetite Nanoparticles for Copper Removal From Aqueous Solution

In this study, the magnetite nanoparticles (MNP) was successfully synthesized from mill scale waste to analyze the removal of Cu (II) ions from the aqueous solution. The micron-sized magnetite was milled using the high energy ball mills (HEBM with the variation of milling hours 3,5 and 7 to produce nano-sized particles. The MNP were measured by X-Rays Diffraction (XRD), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET) and Atomic Absorption Spectroscopy (AAS). Studied parameters are contact time, the initial concentration and particle size. The adsorption kinetics was relatively quick and equilibrium is reached at about 30 minutes. In kinetic studies, the pseudo-second-order model was employed. Langmuir model (R2 &gt;0.9987) corresponded with the adsorption isotherm data of Cu (II) ions. The adsorption capacity of Cu (II) ions onto magnetite nanoparticles (MNP) is 11.36 mgg -1 at 7 hours milling hours. Pseudo-second-order model and Langmuir isotherm were obeyed with experimental results.