Shrenivas Ashrit

Bio: Shrenivas Ashrit is an academic researcher from Tata Steel. The author has contributed to research in topics: Slag & Lime. The author has an hindex of 4, co-authored 21 publications receiving 61 citations.

Characterization of gypsum synthesized from LD slag fines generated at a waste recycling plant of a steel plant

Abstract: 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 γ-anhydrite and insoluble β-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.

Synthesis and Characterization of Yellow Gypsum from LD Slag Fines Generated in a Steel Plant

Abstract: 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 1726% 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

Performance of Slag-Based Gypsum on Maize Yield and Available Soil Nutrients over Commercial Gypsum under Acidic and Neutral Soil

Abstract: Effect of slag-based gypsum (SBG) and commercial gypsum (CG) on maize was investigated in acidic and neutral soils. A randomized complete block design (RCBD) with seven treatments consisting of thr...

Characterisation of LD slag fines by X-ray Diffraction

Abstract: The reject of waste recycling plant (WRP) ie LD slag fines (0–6 mm) after metal recovery does not contain much of metallic iron, but this contains substantial quantity of calcium bearing mineral phases like mono, di and tri calcium silicates along with free lime content varying in the range of 11–15% The WRP waste of − 6 mm is further subjected to sieving mainly in to three different size fractions viz +10 mesh (− 60 mm +20 mm), +60 mesh (− 20 mm +025 mm), − 60 mesh (− 025 mm) These three size fractions of WRP waste shows the free lime content varying from 34% for +10 mesh and 97% for − 60 mesh The X-ray diffraction analysis shows portlandite, merwinite, dicalcium silicate – alpha, calcium silicate – beta, and brownmillerite and di calcium diferrate as the major phases in the above said size fractions The X-ray diffraction analysis was carried out in this paper to get the deeper insight in the mineralogical constitution and behaviour of such waste which represents a valuable raw material for many infrastructure industries including the road construction industry

An infrared and Raman spectroscopic study of yellow gypsum synthesized from LD slag fines

Abstract: 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.

Biofortification—A Frontier Novel Approach to Enrich Micronutrients in Field Crops to Encounter the Nutritional Security

Abstract: Globally, many developing countries are facing silent epidemics of nutritional deficiencies in human beings and animals. The lack of diversity in diet, i.e., cereal-based crops deficient in mineral nutrients is an additional threat to nutritional quality. The present review accounts for the significance of biofortification as a process to enhance the productivity of crops and also an agricultural solution to address the issues of nutritional security. In this endeavor, different innovative and specific biofortification approaches have been discussed for nutrient enrichment of field crops including cereals, pulses, oilseeds and fodder crops. The agronomic approach increases the micronutrient density in crops with soil and foliar application of fertilizers including amendments. The biofortification through conventional breeding approach includes the selection of efficient genotypes, practicing crossing of plants with desirable nutritional traits without sacrificing agricultural and economic productivity. However, the transgenic/biotechnological approach involves the synthesis of transgenes for micronutrient re-translocation between tissues to enhance their bioavailability. Soil microorganisms enhance nutrient content in the rhizosphere through diverse mechanisms such as synthesis, mobilization, transformations and siderophore production which accumulate more minerals in plants. Different sources of micronutrients viz. mineral solutions, chelates and nanoparticles play a pivotal role in the process of biofortification as it regulates the absorption rates and mechanisms in plants. Apart from the quality parameters, biofortification also improved the crop yield to alleviate hidden hunger thus proving to be a sustainable and cost-effective approach. Thus, this review article conveys a message for researchers about the adequate potential of biofortification to increase crop productivity and nourish the crop with additional nutrient content to provide food security and nutritional quality to humans and livestock.

Inorganic Scaling in Membrane Desalination: Models, Mechanisms, and Characterization Methods.

Abstract: Inorganic scaling caused by precipitation of sparingly soluble salts at supersaturation is a common but critical issue, limiting the efficiency of membrane-based desalination and brine management technologies as well as other engineered systems. A wide range of minerals including calcium carbonate, calcium sulfate, and silica precipitate during membrane-based desalination, limiting water recovery and reducing process efficiency. The economic impact of scaling on desalination processes requires understanding of its sources, causes, effects, and control methods. In this Critical Review, we first describe nucleation mechanisms and crystal growth theories, which are fundamental to understanding inorganic scale formation during membrane desalination. We, then, discuss the key mechanisms and factors that govern membrane scaling, including membrane properties, such as surface roughness, charge, and functionality, as well as feedwater characteristics, such as pH, temperature, and ionic strength. We follow with a critical review of current characterization techniques for both homogeneous and heterogeneous nucleation, focusing on the strengths and limitations of each technique to elucidate scale-inducing mechanisms, observe actual crystal growth, and analyze the outcome of scaling behaviors of desalination membranes. We conclude with an outlook on research needs and future research directions to provide guidelines for scale mitigation in water treatment and desalination.