Ravikrishna Chatti - Academia.edu (original) (raw)

Papers by Ravikrishna Chatti

New Journal of Chemistry, 2015

The present work is devoted to the characterization of gypsum synthesized on the laboratory scale... more The present work is devoted to the characterization of gypsum synthesized on the laboratory scale by the atmospheric leaching of-60 mesh LD slag fines generated from a waste recycling plant (WRP) during the Linz-Donawitz process of steel making at the Tata Steel plant, Jamshedpur, India. The main objective of the present work was to synthesize and characterize gypsum which is a value added product from LD slag which is a waste product of the steel industry. The techniques used for the characterization were X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and thermogravimetry (TG) techniques. The XRD analysis revealed the presence of the anhydrite and gypsum phases in the product material as well as the presence of silica in the form of coesite. This observation was further correlated by the TG analysis which indicated that the synthetic gypsum was a mixture of gypsum (dihydrate), hemihydrate, soluble g-anhydrite and insoluble b-anhydrite phases of gypsum. The morphology of the material was found to be like tabular crystals along with the presence of intermittent needle-like and rod like structures as observed from the SEM micrographs. The chemical composition was further confirmed by SEM-EDS analysis. The purity of the product was also estimated to be 86.12% calcium sulphate by the estimation of sulphur trioxide content. These findings have been discussed in detail in the subsequent sections of the paper.

Submit Manuscript | http://medcraveonline.com rate of about 125 kg/t of the steel produced which ... more Submit Manuscript | http://medcraveonline.com rate of about 125 kg/t of the steel produced which leads to piling of the slag in the plant. This slag is generally recycled in a waste recycling plant (WRP) so as to separate the magnetic and the nonmagnetic portions by means of mechanical crushing and magnetic separation. The magnetic portion is then recycled and used in the primary steel making process, whereas the non-magnetic portion is further processed at the WRP and stocked separately. This nonmagnetic or reject portion of the slag currently has applications in the road construction sector where it is used as a replacement for aggregate [1-4]. Carbon dioxide sequestration using LD slag has also been an area of growing research [5]. The slag is also useful as an excellent replacement of commercial lime used in fluxing of sinter. Thus, the piling of the reject slag is avoided and conservation of natural resources is also ensured [6]. However, with this high rate of generation of LD slag (about 125 kg per tonne of steel), these applications are not sufficient and further value addition of the slag needs to be explored.

Austenitic stainless steels (ASSs) are well known for their excellent mechanical properties and a... more Austenitic stainless steels (ASSs) are well known for their excellent mechanical properties and are the most corrosion resistant among the stainless steel group.1–3 However, they are susceptible to pitting corrosion in presence of chloride ions. Pitting corrosion or pitting is a localized type of corrosion which leads to the development of small holes in the metal. This form of corrosion is dependent upon the various alloying elements in the stainless steel, microstructure, heat treatment and overall environmental conditions where the material is being used. The corrosion can be prevented by using niobium and titanium as alloying elements in the stainless steel, by a process known as ‘stabilization’ and the material is described as stabilized stainless steel. In this process, Nb plays the role of an inhibitor and prevents the formation of chromium enriched M23C6 carbides at the grain boundaries, thus increasing the intergranular corrosion resistance and pitting resistance of the ASSs during the process of ageing.4 Different studies have also revealed that as an alloying element, niobium can promote passivation by virtue of incorporation of Nb5+ in the passive film, thus retarding global or localized corrosion in ferritic stainless steel.5 low alloy steel.6 and Ti‒based alloy.7 Therefore, it can be well understood that Nb is a very important alloying element in stainless steel.

The process of sintering is one of the important processes in the integrated steel plant. In this... more The process of sintering is one of the important processes in the integrated steel plant. In this process, fine particles of iron ore, secondary iron oxide wastes such as mill scale, collected dusts, coke breeze, water treatment plant sludge and fluxes are agglomerated by combustion. This agglomeration is essential to enable the passage of hot gases during operation of blast furnace.1 Sintering involves the heating of iron ore, fluxes, coal and coke leading to a semi-molten mass which solidifies into porous pieces of sinter with the size and strength that is appropriate for use in the blast furnace. Sintering plant thus help in reduction of the solid waste of the steel plant by combusting the waste products and capturing the trace iron present in the mixture.2 However, during this process, there can be a possibility that the sinter may get contaminated with some traces of lead, zinc and cadmium which are toxic in nature. One of the major sources of lead, zinc and cadmium is the dust from electric arc furnace (EAF) processes in steelmaking plants. The dust is identified as a potential hazardous waste by USEPA if it contains lead or cadmium or zinc.3

2017-Sustainable Industrial Processing Summit, May 22, 2017

LD slag (Linz Donawitz slag) is one of the major industrial by-products generated during steel ma... more LD slag (Linz Donawitz slag) is one of the major industrial by-products generated during steel making in the integrated Tata Steel plant at Jamshedpur, Jharkhand, India. The plant uses approximately 25 million tons of iron ore and coal/coke blend every year to produce about 10 million tons of steel. Hot metal or molten iron from the blast furnace is transferred into vessels called torpedoes and transported on rail tracks to the LD shops. Here, the molten iron is refined into steel using the ‘basic oxygen furnace’ (BOF) method. In a steel industry, all the three types of waste materials (gaseous, liquid and solid) are generated. The generation of gaseous waste material is the highest, but the management of solid waste material is the most intricate. The steel slag generated from LD converter (steel making) is dumped in pits and allowed to cool by sprinkling water. The solidified steel slag is then sent to a waste recycling plant (WRP) for recovery of the metallic and non-metallic portions. The quantity of non-metallic portion of (-6.0mm) LD Slag fines after the recovery of metallic portion is around 40000MT/Month, which is close to 5 Lakh tons per annum. The present study aims at value addition of this enormous amount of non-metallic slag by a chemical process to obtain “yellow gypsum”, which has a wide range of industrial and agricultural applications. The authors have characterized this material using techniques such as x-ray diffraction (XRD), chemical analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared analysis (FTIR), and Raman spectroscopy. The authors have also discussed the applicability of this material for different applications. An Indian patent application (572/KOL/2014) has been filed for this material.

Current Science, Aug 1, 2015

We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz... more We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz-Donawitz slag (LD slag), which is an industrial waste product of the steel industry. XRD analysis of the product confirmed the presence of anhydrite and gypsum phases as well as the presence of iron, silica and titanium in the form of fayalite and illmenite phases. A weight loss of 17.26% was observed from the TG analysis, indicating the presence of mixture of the dihydrate, hemihydrate, soluble -anhydrite and insoluble -anhydrite phases of gypsum in the product.

Current Science, Jan 10, 2020

In the present study, ICP-AES and ICP-MS techniques were used to analyse and validate the content... more In the present study, ICP-AES and ICP-MS techniques were used to analyse and validate the content of heavy and trace elements in yellow gypsum samples produced by a chemical process from a solid waste generated at an integrated steel plant. The present study tries to demonstrate that the content of heavy metals like lead, mercury and arsenic in yellow gypsum is less than the toxicity characteristic leaching procedure (TCLP) norms set for a comparable industrial by-product phospho-gypsum. This study also concludes that yellow gypsum contains some elements (copper, boron, etc.) in traces, apart from heavy metals which are beneficial to plants as micronutrients.

Zenodo (CERN European Organization for Nuclear Research), Nov 30, 2013

The estimation of sulfur in coal by combustion followed by iodometric titration is discussed in t... more The estimation of sulfur in coal by combustion followed by iodometric titration is discussed in the present study. The inherent advantage of this method is a rapid aud accurate analysis of sulfur content iu coal, when compared to the conventional techniques like the wet chemical method using Eschka mixture and followed by precipitation by BaC1 2 solution as barium sulfate and Eschka mixture method combined with Inductively Coupled Plasma Emission (ICP) Spectrometric analysis. The present work describes the use of a combustion-iodometric titration method in the subsequent sections of the paper. The method has been validated by measuring sulfur content in different certified reference materials and it was found that the values of sulfur measured by this method are in agreement with the certified values. The present method is also environment friendly due to avoidance of use of chromic oxide as the oxidant and perchloric acid as part of the absorption solution.

Zenodo (CERN European Organization for Nuclear Research), Nov 30, 2013

The importance of nickel in the steel industry is significant due to a wide variety of applicatio... more The importance of nickel in the steel industry is significant due to a wide variety of applications as an alloying component in stainless steel. In this context, the present paper endeavors to determine the nickel content of different blast furnace (BF) inputs such as iron ore, coal, coke and sinter. This has been done by analyzing the different raw materials using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) technique. The ICP-AES technique was chosen because it was observed that as the content of nickel was very low in these raw materials, it would be difl'icult to analyze the same using classical methods such as the dimethylglyoxime (gravimetric) method. The major objective of the present study was to deliver an accurate and less-time consuming method based on an instrumental technique, namely, the ICP-AES technique for analysis of nickel (low content) in different blast furnace inputs. In this context, the established method was validated by the evaluation of certified reference materials (CRMs) namely ECRM 681-1 and ECRM 679-1 and thus, it was felt that the present method was very much appropriate for determination of nickel content below 0.01 %.

Metallurgical Research & Technology, 2018

The thermogravimetric (TG) method offers a new approach to the study of the thermal degradation o... more The thermogravimetric (TG) method offers a new approach to the study of the thermal degradation of LD Slag fines, which is a by-product produced in the Tata Steel plant, Jamshedpur during the steel making process. TG curves for LD Slag fines of different particle sizes in oxygen and nitrogen atmosphere from 100 to 900 °C were compared to each other to find the variation in the weight loss. Effect of FeO and free lime on weight loss of LD Slag fines was also discussed. Weight loss in the temperature range of 450–550 °C and then up to 700 °C confirmed the presence of calcium hydroxide, magnesium hydroxide, calcium silicate hydrate and calcite in LD Slag fines. Except −6.0 + 2.0 mm LD Slag fines, the weight loss in oxygen atmosphere is more than nitrogen atmosphere for other size fractions. The higher weight loss in nitrogen atmosphere than the oxygen atmosphere was attributed to the decomposition of calcium silicate hydrate and hydrated aluminate phases. Higher free lime values in finer LD Slag fractions than the coarser LD Slag fractions confirmed more volumetric stability of coarser LD Slag size fractions than the finer fractions due to powdering in the cooling process.

Current Science

In the present study, ICP-AES and ICP-MS techniques were used to analyse and validate the content... more In the present study, ICP-AES and ICP-MS techniques were used to analyse and validate the content of heavy and trace elements in yellow gypsum samples produced by a chemical process from a solid waste generated at an integrated steel plant. The present study tries to demonstrate that the content of heavy metals like lead, mercury and arsenic in yellow gypsum is less than the toxicity characteristic leaching procedure (TCLP) norms set for a comparable industrial by-product phospho-gypsum. This study also concludes that yellow gypsum contains some elements (copper, boron, etc.) in traces, apart from heavy metals which are beneficial to plants as micronutrients.

Chemical Laboratory, R & D and Scientific Services, Tata Steel Limited, Jamshedpur-831 001, Jhark... more Chemical Laboratory, R & D and Scientific Services, Tata Steel Limited, Jamshedpur-831 001, Jharkhand, India <em>E-mail</em> : r.chatti@tatasteel.com, shrenivas@tatasteel.com, k.udpa@tatasteel.com The importance of nickel in the steel industry is significant due to a wide variety of applications as an alloying component in stainless steel. In this context, the present paper endeavors to determine the nickel content of different blast furnace (BF) inputs such as iron ore, coal, coke and sinter. This has been done by analyzing the different raw materials using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) technique. The ICP-AES technique was chosen because it was observed that as the content of nickel was very low in these raw materials, it would be difficult to analyze the same using classical methods such as the dimethylglyoxime (gravimetric) method. The major objective of the present study was to deliver an accurate and less-time consuming method bas...

Chemical Laboratory, R&D and Scientific Services, Tata Steel Limited, Jamshedpur-831 001, Jharkha... more Chemical Laboratory, R&D and Scientific Services, Tata Steel Limited, Jamshedpur-831 001, Jharkhand, India <em>E-mail</em> : shrenivas@tatasteel.com, r.chatti@tatasteel.com The estimation of sulfur in coal by combustion followed by iodometric titration is discussed in the present study. The inherent advantage of this method is a rapid and accurate analysis of sulfur content iu coal, when compared to the conventional techniques like the wet chemical method using Eschka mixture and followed by precipitation by BaC1₂solution as barium sulfate and Eschka mixture method combined with Inductively Coupled Plasma Emission (ICP) Spectrometric analysis. The present work describes the use of a combustion-iodometric titration method in the subsequent sections of the paper. The method has been validated by measuring sulfur content in different certified reference materials and it was found that the values of sulfur measured by this method are in agreement with...

LD slag (Linz Donawitz slag) is one of the major industrial by-products generated during steel ma... more LD slag (Linz Donawitz slag) is one of the major industrial by-products generated during steel making in the integrated Tata Steel plant at Jamshedpur, Jharkhand, India. The plant uses approximately 25 million tons of iron ore and coal/coke blend every year to produce about 10 million tons of steel. Hot metal or molten iron from the blast furnace is transferred into vessels called torpedoes and transported on rail tracks to the LD shops. Here, the molten iron is refined into steel using the ‘basic oxygen furnace’ (BOF) method. In a steel industry, all the three types of waste materials (gaseous, liquid and solid) are generated. The generation of gaseous waste material is the highest, but the management of solid waste material is the most intricate. The steel slag generated from LD converter (steel making) is dumped in pits and allowed to cool by sprinkling water. The solidified steel slag is then sent to a waste recycling plant (WRP) for recovery of the metallic and non-metallic por...

Current Science, 2015

We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz... more We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz-Donawitz slag (LD slag), which is an industrial waste product of the steel industry. XRD analysis of the product confirmed the presence of anhydrite and gypsum phases as well as the presence of iron, silica and titanium in the form of fayalite and illmenite phases. A weight loss of 17.26% was observed from the TG analysis, indicating the presence of mixture of the dihydrate, hemihydrate, soluble γ-anhydrite and insoluble β-anhydrite phases of gypsum in the product.

Submit Manuscript | http://medcraveonline.com rate of about 125 kg/t of the steel produced which ... more Submit Manuscript | http://medcraveonline.com rate of about 125 kg/t of the steel produced which leads to piling of the slag in the plant. This slag is generally recycled in a waste recycling plant (WRP) so as to separate the magnetic and the nonmagnetic portions by means of mechanical crushing and magnetic separation. The magnetic portion is then recycled and used in the primary steel making process, whereas the non-magnetic portion is further processed at the WRP and stocked separately. This nonmagnetic or reject portion of the slag currently has applications in the road construction sector where it is used as a replacement for aggregate [1-4]. Carbon dioxide sequestration using LD slag has also been an area of growing research [5]. The slag is also useful as an excellent replacement of commercial lime used in fluxing of sinter. Thus, the piling of the reject slag is avoided and conservation of natural resources is also ensured [6]. However, with this high rate of generation of LD...

The process of sintering is one of the important processes in the integrated steel plant. In this... more The process of sintering is one of the important processes in the integrated steel plant. In this process, fine particles of iron ore, secondary iron oxide wastes such as mill scale, collected dusts, coke breeze, water treatment plant sludge and fluxes are agglomerated by combustion. This agglomeration is essential to enable the passage of hot gases during operation of blast furnace.1 Sintering involves the heating of iron ore, fluxes, coal and coke leading to a semi-molten mass which solidifies into porous pieces of sinter with the size and strength that is appropriate for use in the blast furnace. Sintering plant thus help in reduction of the solid waste of the steel plant by combusting the waste products and capturing the trace iron present in the mixture.2 However, during this process, there can be a possibility that the sinter may get contaminated with some traces of lead, zinc and cadmium which are toxic in nature. One of the major sources of lead, zinc and cadmium is the dust...

Metallurgical Research & Technology, 2020

The blast furnace flue dust has potential reuse application in iron making process via the sinter... more The blast furnace flue dust has potential reuse application in iron making process via the sinter making route mainly due to its high carbon content. The specific aim of this study was to use different analytical techniques like chemical analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and petrography to identify the different phases present in the blast furnace flue dust of Tata Steel Limited, Jamshedpur and discuss on possible use of suitable separation techniques for economic utilization of flue dust and put those separated fractions for the innovative industrial applications.

Journal of Environmental Chemical Engineering, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Environmental Analytical Chemistry, 2019

Flue dust from blast furnace is being regularly analysed in the Chemical Laboratory at Tata Steel... more Flue dust from blast furnace is being regularly analysed in the Chemical Laboratory at Tata Steel Plant at Jamshedpur. The analysis includes determination of carbon by combustion-infrared technique, loss on ignition (LOI) at 1000°C and analysis of other constituents such as iron oxide (Fe 2 O 3), lime (CaO), silica (SiO 2), phosphorus (P), alumina (Al 2 O 3), magnesium oxide (MgO) and manganese oxide (MnO). The period for determination of carbon and other constituents is usually around 15-20 min, whereas LOI determination takes about 2 h, thus creating an unavoidable delay in reporting the results to the customer. The present study provides an interesting scientific solution to avoid this delay by establishing a strong linear correlation between carbon (≈6.96-45%) and LOI (≈ 4.0-52.0%) values. The study also indicates that the carbon in the flue dust is from the carbonaceous matter fed to the furnace and not due to the fluxes introduced in the furnace during the charging because no correlation was observed between the carbon values and CaO, MgO values of flue dust. This correlation obtained is further proved with the help of characterisation techniques such as X-ray diffraction (XRD), Fourier transform infrared analysis (FTIR) and Raman analysis.

New Journal of Chemistry, 2015

The present work is devoted to the characterization of gypsum synthesized on the laboratory scale... more The present work is devoted to the characterization of gypsum synthesized on the laboratory scale by the atmospheric leaching of-60 mesh LD slag fines generated from a waste recycling plant (WRP) during the Linz-Donawitz process of steel making at the Tata Steel plant, Jamshedpur, India. The main objective of the present work was to synthesize and characterize gypsum which is a value added product from LD slag which is a waste product of the steel industry. The techniques used for the characterization were X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and thermogravimetry (TG) techniques. The XRD analysis revealed the presence of the anhydrite and gypsum phases in the product material as well as the presence of silica in the form of coesite. This observation was further correlated by the TG analysis which indicated that the synthetic gypsum was a mixture of gypsum (dihydrate), hemihydrate, soluble g-anhydrite and insoluble b-anhydrite phases of gypsum. The morphology of the material was found to be like tabular crystals along with the presence of intermittent needle-like and rod like structures as observed from the SEM micrographs. The chemical composition was further confirmed by SEM-EDS analysis. The purity of the product was also estimated to be 86.12% calcium sulphate by the estimation of sulphur trioxide content. These findings have been discussed in detail in the subsequent sections of the paper.

Submit Manuscript | http://medcraveonline.com rate of about 125 kg/t of the steel produced which ... more Submit Manuscript | http://medcraveonline.com rate of about 125 kg/t of the steel produced which leads to piling of the slag in the plant. This slag is generally recycled in a waste recycling plant (WRP) so as to separate the magnetic and the nonmagnetic portions by means of mechanical crushing and magnetic separation. The magnetic portion is then recycled and used in the primary steel making process, whereas the non-magnetic portion is further processed at the WRP and stocked separately. This nonmagnetic or reject portion of the slag currently has applications in the road construction sector where it is used as a replacement for aggregate [1-4]. Carbon dioxide sequestration using LD slag has also been an area of growing research [5]. The slag is also useful as an excellent replacement of commercial lime used in fluxing of sinter. Thus, the piling of the reject slag is avoided and conservation of natural resources is also ensured [6]. However, with this high rate of generation of LD slag (about 125 kg per tonne of steel), these applications are not sufficient and further value addition of the slag needs to be explored.

Austenitic stainless steels (ASSs) are well known for their excellent mechanical properties and a... more Austenitic stainless steels (ASSs) are well known for their excellent mechanical properties and are the most corrosion resistant among the stainless steel group.1–3 However, they are susceptible to pitting corrosion in presence of chloride ions. Pitting corrosion or pitting is a localized type of corrosion which leads to the development of small holes in the metal. This form of corrosion is dependent upon the various alloying elements in the stainless steel, microstructure, heat treatment and overall environmental conditions where the material is being used. The corrosion can be prevented by using niobium and titanium as alloying elements in the stainless steel, by a process known as ‘stabilization’ and the material is described as stabilized stainless steel. In this process, Nb plays the role of an inhibitor and prevents the formation of chromium enriched M23C6 carbides at the grain boundaries, thus increasing the intergranular corrosion resistance and pitting resistance of the ASSs during the process of ageing.4 Different studies have also revealed that as an alloying element, niobium can promote passivation by virtue of incorporation of Nb5+ in the passive film, thus retarding global or localized corrosion in ferritic stainless steel.5 low alloy steel.6 and Ti‒based alloy.7 Therefore, it can be well understood that Nb is a very important alloying element in stainless steel.

The process of sintering is one of the important processes in the integrated steel plant. In this... more The process of sintering is one of the important processes in the integrated steel plant. In this process, fine particles of iron ore, secondary iron oxide wastes such as mill scale, collected dusts, coke breeze, water treatment plant sludge and fluxes are agglomerated by combustion. This agglomeration is essential to enable the passage of hot gases during operation of blast furnace.1 Sintering involves the heating of iron ore, fluxes, coal and coke leading to a semi-molten mass which solidifies into porous pieces of sinter with the size and strength that is appropriate for use in the blast furnace. Sintering plant thus help in reduction of the solid waste of the steel plant by combusting the waste products and capturing the trace iron present in the mixture.2 However, during this process, there can be a possibility that the sinter may get contaminated with some traces of lead, zinc and cadmium which are toxic in nature. One of the major sources of lead, zinc and cadmium is the dust from electric arc furnace (EAF) processes in steelmaking plants. The dust is identified as a potential hazardous waste by USEPA if it contains lead or cadmium or zinc.3

2017-Sustainable Industrial Processing Summit, May 22, 2017

LD slag (Linz Donawitz slag) is one of the major industrial by-products generated during steel ma... more LD slag (Linz Donawitz slag) is one of the major industrial by-products generated during steel making in the integrated Tata Steel plant at Jamshedpur, Jharkhand, India. The plant uses approximately 25 million tons of iron ore and coal/coke blend every year to produce about 10 million tons of steel. Hot metal or molten iron from the blast furnace is transferred into vessels called torpedoes and transported on rail tracks to the LD shops. Here, the molten iron is refined into steel using the ‘basic oxygen furnace’ (BOF) method. In a steel industry, all the three types of waste materials (gaseous, liquid and solid) are generated. The generation of gaseous waste material is the highest, but the management of solid waste material is the most intricate. The steel slag generated from LD converter (steel making) is dumped in pits and allowed to cool by sprinkling water. The solidified steel slag is then sent to a waste recycling plant (WRP) for recovery of the metallic and non-metallic portions. The quantity of non-metallic portion of (-6.0mm) LD Slag fines after the recovery of metallic portion is around 40000MT/Month, which is close to 5 Lakh tons per annum. The present study aims at value addition of this enormous amount of non-metallic slag by a chemical process to obtain “yellow gypsum”, which has a wide range of industrial and agricultural applications. The authors have characterized this material using techniques such as x-ray diffraction (XRD), chemical analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared analysis (FTIR), and Raman spectroscopy. The authors have also discussed the applicability of this material for different applications. An Indian patent application (572/KOL/2014) has been filed for this material.

Current Science, Aug 1, 2015

We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz... more We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz-Donawitz slag (LD slag), which is an industrial waste product of the steel industry. XRD analysis of the product confirmed the presence of anhydrite and gypsum phases as well as the presence of iron, silica and titanium in the form of fayalite and illmenite phases. A weight loss of 17.26% was observed from the TG analysis, indicating the presence of mixture of the dihydrate, hemihydrate, soluble -anhydrite and insoluble -anhydrite phases of gypsum in the product.

Current Science, Jan 10, 2020

In the present study, ICP-AES and ICP-MS techniques were used to analyse and validate the content... more In the present study, ICP-AES and ICP-MS techniques were used to analyse and validate the content of heavy and trace elements in yellow gypsum samples produced by a chemical process from a solid waste generated at an integrated steel plant. The present study tries to demonstrate that the content of heavy metals like lead, mercury and arsenic in yellow gypsum is less than the toxicity characteristic leaching procedure (TCLP) norms set for a comparable industrial by-product phospho-gypsum. This study also concludes that yellow gypsum contains some elements (copper, boron, etc.) in traces, apart from heavy metals which are beneficial to plants as micronutrients.

Zenodo (CERN European Organization for Nuclear Research), Nov 30, 2013

The estimation of sulfur in coal by combustion followed by iodometric titration is discussed in t... more The estimation of sulfur in coal by combustion followed by iodometric titration is discussed in the present study. The inherent advantage of this method is a rapid aud accurate analysis of sulfur content iu coal, when compared to the conventional techniques like the wet chemical method using Eschka mixture and followed by precipitation by BaC1 2 solution as barium sulfate and Eschka mixture method combined with Inductively Coupled Plasma Emission (ICP) Spectrometric analysis. The present work describes the use of a combustion-iodometric titration method in the subsequent sections of the paper. The method has been validated by measuring sulfur content in different certified reference materials and it was found that the values of sulfur measured by this method are in agreement with the certified values. The present method is also environment friendly due to avoidance of use of chromic oxide as the oxidant and perchloric acid as part of the absorption solution.

Zenodo (CERN European Organization for Nuclear Research), Nov 30, 2013

The importance of nickel in the steel industry is significant due to a wide variety of applicatio... more The importance of nickel in the steel industry is significant due to a wide variety of applications as an alloying component in stainless steel. In this context, the present paper endeavors to determine the nickel content of different blast furnace (BF) inputs such as iron ore, coal, coke and sinter. This has been done by analyzing the different raw materials using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) technique. The ICP-AES technique was chosen because it was observed that as the content of nickel was very low in these raw materials, it would be difl'icult to analyze the same using classical methods such as the dimethylglyoxime (gravimetric) method. The major objective of the present study was to deliver an accurate and less-time consuming method based on an instrumental technique, namely, the ICP-AES technique for analysis of nickel (low content) in different blast furnace inputs. In this context, the established method was validated by the evaluation of certified reference materials (CRMs) namely ECRM 681-1 and ECRM 679-1 and thus, it was felt that the present method was very much appropriate for determination of nickel content below 0.01 %.

Metallurgical Research & Technology, 2018

The thermogravimetric (TG) method offers a new approach to the study of the thermal degradation o... more The thermogravimetric (TG) method offers a new approach to the study of the thermal degradation of LD Slag fines, which is a by-product produced in the Tata Steel plant, Jamshedpur during the steel making process. TG curves for LD Slag fines of different particle sizes in oxygen and nitrogen atmosphere from 100 to 900 °C were compared to each other to find the variation in the weight loss. Effect of FeO and free lime on weight loss of LD Slag fines was also discussed. Weight loss in the temperature range of 450–550 °C and then up to 700 °C confirmed the presence of calcium hydroxide, magnesium hydroxide, calcium silicate hydrate and calcite in LD Slag fines. Except −6.0 + 2.0 mm LD Slag fines, the weight loss in oxygen atmosphere is more than nitrogen atmosphere for other size fractions. The higher weight loss in nitrogen atmosphere than the oxygen atmosphere was attributed to the decomposition of calcium silicate hydrate and hydrated aluminate phases. Higher free lime values in finer LD Slag fractions than the coarser LD Slag fractions confirmed more volumetric stability of coarser LD Slag size fractions than the finer fractions due to powdering in the cooling process.

Current Science

In the present study, ICP-AES and ICP-MS techniques were used to analyse and validate the content... more In the present study, ICP-AES and ICP-MS techniques were used to analyse and validate the content of heavy and trace elements in yellow gypsum samples produced by a chemical process from a solid waste generated at an integrated steel plant. The present study tries to demonstrate that the content of heavy metals like lead, mercury and arsenic in yellow gypsum is less than the toxicity characteristic leaching procedure (TCLP) norms set for a comparable industrial by-product phospho-gypsum. This study also concludes that yellow gypsum contains some elements (copper, boron, etc.) in traces, apart from heavy metals which are beneficial to plants as micronutrients.

Chemical Laboratory, R & D and Scientific Services, Tata Steel Limited, Jamshedpur-831 001, Jhark... more Chemical Laboratory, R & D and Scientific Services, Tata Steel Limited, Jamshedpur-831 001, Jharkhand, India <em>E-mail</em> : r.chatti@tatasteel.com, shrenivas@tatasteel.com, k.udpa@tatasteel.com The importance of nickel in the steel industry is significant due to a wide variety of applications as an alloying component in stainless steel. In this context, the present paper endeavors to determine the nickel content of different blast furnace (BF) inputs such as iron ore, coal, coke and sinter. This has been done by analyzing the different raw materials using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) technique. The ICP-AES technique was chosen because it was observed that as the content of nickel was very low in these raw materials, it would be difficult to analyze the same using classical methods such as the dimethylglyoxime (gravimetric) method. The major objective of the present study was to deliver an accurate and less-time consuming method bas...

Chemical Laboratory, R&D and Scientific Services, Tata Steel Limited, Jamshedpur-831 001, Jharkha... more Chemical Laboratory, R&D and Scientific Services, Tata Steel Limited, Jamshedpur-831 001, Jharkhand, India <em>E-mail</em> : shrenivas@tatasteel.com, r.chatti@tatasteel.com The estimation of sulfur in coal by combustion followed by iodometric titration is discussed in the present study. The inherent advantage of this method is a rapid and accurate analysis of sulfur content iu coal, when compared to the conventional techniques like the wet chemical method using Eschka mixture and followed by precipitation by BaC1₂solution as barium sulfate and Eschka mixture method combined with Inductively Coupled Plasma Emission (ICP) Spectrometric analysis. The present work describes the use of a combustion-iodometric titration method in the subsequent sections of the paper. The method has been validated by measuring sulfur content in different certified reference materials and it was found that the values of sulfur measured by this method are in agreement with...

LD slag (Linz Donawitz slag) is one of the major industrial by-products generated during steel ma... more LD slag (Linz Donawitz slag) is one of the major industrial by-products generated during steel making in the integrated Tata Steel plant at Jamshedpur, Jharkhand, India. The plant uses approximately 25 million tons of iron ore and coal/coke blend every year to produce about 10 million tons of steel. Hot metal or molten iron from the blast furnace is transferred into vessels called torpedoes and transported on rail tracks to the LD shops. Here, the molten iron is refined into steel using the ‘basic oxygen furnace’ (BOF) method. In a steel industry, all the three types of waste materials (gaseous, liquid and solid) are generated. The generation of gaseous waste material is the highest, but the management of solid waste material is the most intricate. The steel slag generated from LD converter (steel making) is dumped in pits and allowed to cool by sprinkling water. The solidified steel slag is then sent to a waste recycling plant (WRP) for recovery of the metallic and non-metallic por...

Current Science, 2015

We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz... more We describe here a simple method for synthesis of a value-added product (yellow gypsum) from Linz-Donawitz slag (LD slag), which is an industrial waste product of the steel industry. XRD analysis of the product confirmed the presence of anhydrite and gypsum phases as well as the presence of iron, silica and titanium in the form of fayalite and illmenite phases. A weight loss of 17.26% was observed from the TG analysis, indicating the presence of mixture of the dihydrate, hemihydrate, soluble γ-anhydrite and insoluble β-anhydrite phases of gypsum in the product.

Submit Manuscript | http://medcraveonline.com rate of about 125 kg/t of the steel produced which ... more Submit Manuscript | http://medcraveonline.com rate of about 125 kg/t of the steel produced which leads to piling of the slag in the plant. This slag is generally recycled in a waste recycling plant (WRP) so as to separate the magnetic and the nonmagnetic portions by means of mechanical crushing and magnetic separation. The magnetic portion is then recycled and used in the primary steel making process, whereas the non-magnetic portion is further processed at the WRP and stocked separately. This nonmagnetic or reject portion of the slag currently has applications in the road construction sector where it is used as a replacement for aggregate [1-4]. Carbon dioxide sequestration using LD slag has also been an area of growing research [5]. The slag is also useful as an excellent replacement of commercial lime used in fluxing of sinter. Thus, the piling of the reject slag is avoided and conservation of natural resources is also ensured [6]. However, with this high rate of generation of LD...

The process of sintering is one of the important processes in the integrated steel plant. In this... more The process of sintering is one of the important processes in the integrated steel plant. In this process, fine particles of iron ore, secondary iron oxide wastes such as mill scale, collected dusts, coke breeze, water treatment plant sludge and fluxes are agglomerated by combustion. This agglomeration is essential to enable the passage of hot gases during operation of blast furnace.1 Sintering involves the heating of iron ore, fluxes, coal and coke leading to a semi-molten mass which solidifies into porous pieces of sinter with the size and strength that is appropriate for use in the blast furnace. Sintering plant thus help in reduction of the solid waste of the steel plant by combusting the waste products and capturing the trace iron present in the mixture.2 However, during this process, there can be a possibility that the sinter may get contaminated with some traces of lead, zinc and cadmium which are toxic in nature. One of the major sources of lead, zinc and cadmium is the dust...

Metallurgical Research & Technology, 2020

The blast furnace flue dust has potential reuse application in iron making process via the sinter... more The blast furnace flue dust has potential reuse application in iron making process via the sinter making route mainly due to its high carbon content. The specific aim of this study was to use different analytical techniques like chemical analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and petrography to identify the different phases present in the blast furnace flue dust of Tata Steel Limited, Jamshedpur and discuss on possible use of suitable separation techniques for economic utilization of flue dust and put those separated fractions for the innovative industrial applications.

Journal of Environmental Chemical Engineering, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Environmental Analytical Chemistry, 2019

Flue dust from blast furnace is being regularly analysed in the Chemical Laboratory at Tata Steel... more Flue dust from blast furnace is being regularly analysed in the Chemical Laboratory at Tata Steel Plant at Jamshedpur. The analysis includes determination of carbon by combustion-infrared technique, loss on ignition (LOI) at 1000°C and analysis of other constituents such as iron oxide (Fe 2 O 3), lime (CaO), silica (SiO 2), phosphorus (P), alumina (Al 2 O 3), magnesium oxide (MgO) and manganese oxide (MnO). The period for determination of carbon and other constituents is usually around 15-20 min, whereas LOI determination takes about 2 h, thus creating an unavoidable delay in reporting the results to the customer. The present study provides an interesting scientific solution to avoid this delay by establishing a strong linear correlation between carbon (≈6.96-45%) and LOI (≈ 4.0-52.0%) values. The study also indicates that the carbon in the flue dust is from the carbonaceous matter fed to the furnace and not due to the fluxes introduced in the furnace during the charging because no correlation was observed between the carbon values and CaO, MgO values of flue dust. This correlation obtained is further proved with the help of characterisation techniques such as X-ray diffraction (XRD), Fourier transform infrared analysis (FTIR) and Raman analysis.