Basic Oxygen Furnace Research Articles

Economic Evaluation of Renewable Hydrogen Integration into Steelworks for the Production of Methanol and Methane

This work investigates the cost-efficient integration of renewable hydrogen into steelworks for the production of methane and methanol as an efficient way to decarbonize the steel industry. Three case studies that utilize a mixture of steelworks off-gases (blast furnace gas, coke oven gas, and basic oxygen furnace gas), which differ on the amount of used off-gases as well as on the end product (methane and/or methanol), are analyzed and evaluated in terms of their economic performance. The most influential cost factors are identified and sensitivity analyses are conducted for different operating and economic parameters. Renewable hydrogen produced by PEM electrolysis is the most expensive component in this scheme and responsible for over 80% of the total costs. Progress in the hydrogen economy (lower electrolyzer capital costs, improved electrolyzer efficiency, and lower electricity prices) is necessary to establish this technology in the future.

Global Droplet Heat Transfer in Oxygen Steelmaking Process

Generated droplets in a basic oxygen furnace (BOF) process create an interfacial area between metal and slag/emulsion that helps in heat transfer during different stages of the blowing period. Previous studies have developed extensive models to understand bloating behavior and overall refining kinetics contributed by the droplets in a BOF process. Except for the recent study on single droplet heat transfer by the current authors, no studies in the open literature have addressed the heat transfer contributed by droplets in a BOF. The present work is an extension of single droplet heat transfer, wherein a global droplet heat transfer model is developed by integrating kinetic and dynamic aspects of generated droplets during the blowing period. The model was developed based on previous chemical kinetic studies and input values from plant trials. The results from the global droplet heat transfer model are integrated into the overall zone heat balance calculations to predict the temperature evolution profile of hot spot, slag, and hot metal zones during the blowing period. The results highlight that the hot spot temperature ranges from 1900 °C to 2090 °C, with a peak value of around 2300 °C observed during the middle of the blow. Furthermore, computing the overall droplet heat transfer efficiency, it was observed that the droplets transfer 90% of the heat to the slag up to the first 10 min of the blow, and then the heat transfer efficiency drops towards the end of the blow.

Drainability and Clogging Behavior of Open-Graded Asphalt Friction Courses with Basic Oxygen Furnace Steel Slag Aggregates

Drainability of an open-graded asphalt friction course (OGAFC) is a primary functional requirement, which mainly depends on the presence of a network of interconnected air voids. These mixtures, however, are prone to clogging, which severely limits their drainability. Clogging predominantly occurs as a result of the deposition of external (sand, debris, and dust) and internal (stripped-off bitumen) materials into the pores of OGAFC, which is referred to as particle-related clogging. Another type of clogging is deformation-related clogging and it is observed mainly because of rutting along the wheel path. In this study, the drainability and clogging behavior of OGAFC mixes with basic oxygen furnace (BOF) steel slag as replacement of natural aggregates was studied. BOF steel slag was used as 0% (control mix), 25%, 50%, 75%, and 100% substitution for coarse natural aggregates in the preparation of OGAFC mixes with two types of modified binders. Three different clogging mechanisms: particle-related clogging (caused by intrusion of foreign material such as sand); stripping-related clogging (caused by the deposition of stripped-off bitumen-fines mortar), and deformation-related clogging (reduced drainability caused by permanent deformation) were considered in this study. Comparisons were made to investigate the effect of BOF steel slag on the clogging potential of OGAFC mixes. OGAFC specimens were evaluated for their drainage potential using a flexible-wall falling-head permeameter both before and after being subjected to various clogging environments. BOF-steel-slag-incorporated OGAFC mixes exhibited lower clogging potential and reported better performance in resisting clogging resulting from stripping and permanent deformation.

Physical, mechanical, and sliding wear behavior of micro‐sized Linz‐Donawintz slag filled epoxy composites

AbstractLinz‐Donawintz (LD) slag is a solid waste produced during the basic oxygen furnace process of steel making and is more often disposed of on nearby land causing a disturbance in vegetation and human health. Hence, judicial management of LD slag is a need for an hour. For this purpose, the usability of LD slags as a reinforcement material in epoxy composites was investigated in the present work. In this investigation, the physical properties (density, void content, water absorption rate), mechanical properties (tensile properties, flexural properties, compressive strength, hardness), and tribological properties (sliding wear behavior) are reported. From the experimental investigation, it is found that the density, void content, and water intake capacity increase with LD slag loading. The maximum voids present in the composite is 1.92% for epoxy/40 wt. % LD slag composite. Similarly, maximum water uptake of only 0.6% is observed for composite with maximum filler content and for maximum immersion time. Further, it is observed that the strength of composite under tensile and flexural loading was compromised slightly. At 40 wt. % of LD slag, the measured tensile and flexural strength are 20.8 MPa and 28.78 MPa respectively. The strength of composites under compressive loading increases with filler content and reaches a maximum of 108 MPa for epoxy/40 wt. % LD slag composite. The high hardness of filler assists in increasing the hardness of the composites. The hardness of neat epoxy is Shore‐D number 75 which increases to Shore‐D number 84. With increased hardness, ultimately the specific wear rate under dry sliding conditions reduces. Taguchi's L25 orthogonal array having four factors, each at five different levels is implemented to conduct the sliding wear tests. A forecast model is built on an artificial neural network (ANN) which successfully envisages the sliding wear performance of the composite under investigation inside and outside the experimental domain.

Friction Characteristics of Open Graded Asphalt Friction Courses with BOF and EAF Steel Slag Aggregates

Friction properties of open graded asphalt friction course (OGAFC) mixtures play an essential role in ensuring traffic safety, especially under wet weather conditions. This study evaluated the friction characteristics of basic oxygen furnace (BOF) and electric-arc furnace (EAF) steel slag aggregate incorporated OGAFC mixes. Nine sets of OGAFC mixes were fabricated using five percentage replacements (0%, 25%, 50%, 75%, and 100%) of the coarse natural aggregate fraction by BOF and EAF steel slags. The effect of modified binder type (polymer and crumb-rubber modified) on the frictional characteristics of OGAFC mixes was also examined. The principal friction test devices used were the British pendulum tester and dynamic friction tester. Multiple friction performance aspects were studied: (1) effect of surface condition (dry, wet, and ponding) on the measured friction coefficient; (2) separate evaluation of adhesion and hysteresis friction components; (3) variation of friction coefficient with varying slip speeds, and (4) friction performance later in the OGAFC service life using artificially polished aggregates, and comparison of the performance with unpolished aggregates. Results revealed that the use of steel slags in OGAFC mixes considerably enhanced the frictional characteristics and that the skid resistance of OGAFC-BOF mixes was better than that of OGAFC-EAF mixes. Frictional resistance of the mixes was found to increase with an increase in steel slag content. OGAFC mixes comprising polished steel slag aggregates also showed promising results with the increment in steel slag content. The findings also indicated that OGAFC-CRMB mixes perform better than OGAFC-PMB mixes.

Numerical simulation on the melting kinetics of steel scrap in iron-carbon bath

Steel scrap melting kinetics is a key factor that affects the scrap ratio and temperature trajectory of Basic Oxygen Furnace steelmaking process and the productivity and energy utilization of Electric Arc Furnace steelmaking process. In this paper, the interface between steel scrap and melt is analyzed and a novel theoretical model of steel scrap melting in iron-carbon bath is established. Moreover, the effects of bath temperature, bath carbon content, preheating temperature and characteristic length of steel scrap on the melting rate of steel scrap, mass transfer coefficient of carbon, heat transfer coefficient and interface carbon concentration were investigated. The results show that the ultimate steady melting rate increases from −2.04 × 10 −4 to −3.32 × 10 −3 m/s with the increases of bath temperature from 1793 K to 1873 K, the ultimate steady heat and mass transfer coefficient first increase and subsequently decrease, are in the range of 1.04 × 10 5 to 2.86 × 10 5 W/m 2 /K and 0 to 2.89 × 10 −4 m/s, respectively. As the bath carbon content increase from 1.0 wt% to 4.0 wt%, the ultimate steady melting rate increases from −8.85 × 10 −5 to −3.23 × 10 −4 m/s, the ultimate steady heat transfer coefficient first increases and subsequently decreases, is in the range of 7.59 × 10 4 to 1.01 × 10 5 W/m 2 /K. Furthermore, the ultimate steady mass transfer coefficient and the ultimate steady interface carbon content gradually decreases from 1.40 × 10 −4 to 5.21 × 10 −5 m/s and from 0.73 to 0.69 wt%, respectively. With the increase of preheating temperature and characteristic length of steel scrap, the ultimate steady melting rate, heat transfer coefficient between steel scrap and melt, mass transfer coefficient and interface carbon concentration remain almost constant, about −8.85 × 10 −5 m/s, 8.40 × 10 4 W/m 2 /K, 1.40 × 10 −4 m/s and 0.70 wt%, respectively.

70 Years of LD-Steelmaking—Quo Vadis?

Basic Oxygen Furnace (BOF) steelmaking is, worldwide, the most frequently applied process. According to the world steel organization statistical report, 2021, it saw a total production share of 73.2%, or 1371.2 million tons per year of the world steel production in 2020. The rest is produced in Electric Arc Furnace (EAF)-based steel mills (26.3%), and only a very few open-hearth and induction furnace-based steel mills. The BOF technology remains the leading technology applied based on its undoubted advantages in productivity and liquid steel composition control. The BOF technology started as the LD process 70 years ago, with the first heat applied in November 1952 in a steel mill in Linz, Austria. The name LD was formed from the first letters of the two sites with the first industrial scale plants, Linz and Donawitz, both in Austria. The history and development of the process have been honored in multiple anniversary publications over the last few decades. Nevertheless, the focus of the steel industry worldwide is significantly changing following a social and political trend and the requirement for fossil-free energy generation and industrial production to be in accordance with the world climate targets committed to in relation to the decades leading up to 2050. Iron and steel production is one of the major polluters of climate changing greenhouse gases; it must change to renewable primary energy sources and the use of climate-neutral reduction agents. Because it is very obvious that carbon, as the main component for steel strength properties, cannot be eliminated totally from the steel production process, the question arises of where a “zero carbon” approach can lead? This paper will review the ongoing success story of the LD-process, discuss the recent technology advancements, and give an outlook on the future role of the process in the steel industry.

Numerical Simulation of Bubble and Velocity Distribution in a Furnace

An industrial furnace, such as a blast furnace, molten salt furnace and a basic oxygen furnace, is a popular reactor, where the distribution of liquid, flow pattern of the fluid and the velocity of the fluid determine the energy distribution and chemical reaction in the reactor. Taking a furnace as the research object, this paper studies the effects of different inlet velocities, liquid densities and viscosity on bubble and velocity distribution. A three-dimensional mathematical model of the furnace is set up by a numerical simulation, and the volume-of-fluid (VOF) method is used to study the behavior of bubbles. The accuracy of the simulation parameters selected in the simulation calculation is verified by comparing the simulation with the experimental results. The findings show that an excessive or too small an inlet velocity will lead to an uneven distribution of chlorine in the furnace, therefore, an inlet velocity of about 30 m/s is more appropriate. In addition, changing the liquid density has little effect on the bubble and velocity distribution while choosing the appropriate liquid viscosity can ensure the proper gas holdup and fluidity of chlorine in the furnace.

A Static Balance Model and Analysis of 430 Stainless Steel Produced by Basic Oxygen Furnace–Argon Oxygen Decarburization Furnace Process

Herein, a static mass and energy balance model of 430 stainless steel (SS) produced by the basic oxygen furnace (BOF)–argon oxygen decarburization furnace (AOD) process is established and verified by plant data. It is found that in the AOD, the energy input is efficiently utilized, the heat available for other uses is relatively low (4.0%), and the addition of SS scrap is limited. The high carbon content of dephosphorization hot metal (DPHM) and post‐combustion ratio (PCR) in AOD are conducive to promoting the recycling of SS scrap. In contrast, when the carbon content of DPHM and PCR is low, it is necessary to add an exothermic agent to the furnace. Due to the saving of nickel‐containing raw materials and China's high proportion of thermal power, the carbon emissions and energy consumption per ton 430 SS produced by the BOF–AOD process are 3131 kg‐CO2 and 24 161 MJ, which is much lower than per ton 304 SS produced by the electric arc furnace (EAF)–AOD process. Meaning the former is more conducive to the promotion of energy conservation and emission reduction.

Hybrid Method for Endpoint Prediction in a Basic Oxygen Furnace

Strict monitoring and prediction of endpoints in a Basic Oxygen Furnace (BOF) are essential for end-product quality and overall process efficiency. Existing control models are mostly developed based on thermodynamic principles or by deploying advanced sensors. This article aims to propose a novel hybrid algorithm for endpoint temperature, carbon, and phosphorus, based on heat and mass balance and a data-driven technique. Three types of static models were established in this study: firstly, theoretical models, based on user-specified inputs, were formulated based on mass and energy balance; secondly, artificial neural networks (ANN) were developed for endpoints predictions; finally, the proposed hybrid model was established, based upon exchanging outputs among theoretical models and ANNs. Data of steelmaking production details collected from 28,000 heats from Tata Steel India were used for this article. Machine learning model validation was carried out with five-fold cross-validation to ensure generalizations in model predictions. ANNs are found to achieve better predictive accuracies than theoretical models in all three endpoints. However, they cannot be directly applied in any steelmaking plants, due to possible variations in the production setting. After applying the hybrid algorithm, normalized root mean squared errors are reduced for endpoint carbon and phosphorus by 3.7% and 9.77%.

Contribution of CO2 Emissions from Basic Oxygen Steelmaking Process

The steelmaking process is an energy-intensive multi-stage process, and the step involving the conversion of molten iron to steel, commonly performed in a basic oxygen furnace (BOF), makes an important contribution to greenhouse gas generation. The effective utilization of energy is one of the major challenges in the process, as minor variations of operational parameters can have significant negative effects on the converter in terms of CO2 emissions. A recent study published by the same authors analyzed the BOF process by developing a general mass and energy balance model. The present study utilizes these models to quantify the contribution of global warming potential (GWP) from the BOF and analyses its sensitivity with the parameters such as hot metal composition, the temperature of hot metal, tapping temperature, scrap quantity, and levels of post-combustion. The term GWP in this study refers to the quantified CO2 values obtained by summing up the carbon dioxide associated with the production of CaO associated with the mass of flux and carbon dioxide generated from the off-gas (considering C in hot metal is completely oxidized to CO2). The results from the analysis indicates that for a tapping temperature increase from 1650 °C to 1683 °C, the percentage change in the global warming potential (GWP) was found to be approximately 1%. The study identified that increasing the scrap percentage in the feed would be the most effective approach to effectively utilizing chemical energy from the process and reduce CO2 emissions. However, increasing scrap above 30% of the total feed is likely to raise issues around: (a) the presence of residual elements in scrap affecting the quality of liquid steel, (b) the effective utilization of post-combustion heat within the furnace, and (c) the recovery of off-gas heat for scrap preheating (assuming no steam recovery from the off-gas system). If these issues could be addressed at the industrial level, a significant reduction in CO2 emissions from the BOF process could be achieved.

Minimum Emissions Configuration of a Green Energy–Steel System: An Analytical Model

The need to significantly reduce emissions from the steelmaking sector requires effective and ready-to-use technical solutions. With this aim, different decarbonization strategies have been investigated by both researchers and practitioners. To this concern, the most promising pathway is represented by the replacement of natural gas with pure hydrogen in the direct reduced iron (DRI) production process to feed an electric arc furnace (EAF). This solution allows to significantly reduce direct emissions of carbon dioxide from the DRI process but requires a significant amount of electricity to power electrolyzers adopted to produce hydrogen. The adoption of renewable electricity sources (green hydrogen) would reduce emissions by 95–100% compared to the blast furnace–basic oxygen furnace (BF–BOF) route. In this work, an analytical model for the identification of the minimum emission configuration of a green energy–steel system consisting of a secondary route supported by a DRI production process and a renewable energy conversion system is proposed. In the model, both technological features of the hydrogen steel plant and renewable energy production potential of the site where it is to be located are considered. Compared to previous studies, the novelty of this work consists of the joint modeling of a renewable energy system and a steel plant. This allows to optimize the overall system from an environmental point of view, considering the availability of green hydrogen as an inherent part of the model. Numerical experiments proved the effectiveness of the model proposed in evaluating the suitability of using green hydrogen in the steelmaking process. Depending on the characteristics of the site and the renewable energy conversion system adopted, decreases in emissions ranging from 60% to 91%, compared to the BF–BOF route, were observed for the green energy–steel system considered It was found that the environmental benefit of using hydrogen in the secondary route is strictly related to the national energy mix and to the electrolyzers’ technology. Depending on the reference context, it was found that there exists a maximum value of the emission factor from the national electricity grid below which is environmentally convenient to produce DRI by using only hydrogen. It was moreover found that the lower the electricity consumption of the electrolyzer, the higher the value assumed by the emission factor from the electricity grid, which makes the use of hydrogen convenient.

Removal Arsenic(V) Efficiency and Characteristics Using Modified Basic Oxygen Furnace Slag in Aqueous Solution

Basic oxygen furnace (BOF) slag, the solid waste produced in the steelmaking process, is reused in industry, agriculture and environmental treatment. However, as an adsorbent for wastewater, the removal effect of BOF slag on anionic pollutants needs to be improved. In this study, acid and alkali were used to modify BOF slag, and the removal efficiency and mechanism of arsenic(V) with modified BOF slag in solution were studied. The effects of the As(V) initial concentration, solution pH and reaction time on the removal efficiency were determined by batch experiments, and the removal mechanism of As(V) using modified BOF slag was studied by an adsorption kinetic model and isothermal adsorption model and the Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectral analysis. The results showed that the slag modified by 15% sulfuric acid had the best removal effect on As(V), while the removal effect of As(V) by alkali-modified slag was not ideal. The removal rate of As(V) by acid-modified slag increased with the increase in the initial concentration, decreased slowly with the increase in pH and reached equilibrium in 180 min. The adsorption kinetic model and isothermal adsorption model of As(V) by acid-modified BOF slag showed that the chemical adsorption was the limiting step. The FTIR and XPS analysis results showed that the silicate and ferrite in the acid-modified slag could remove As(V) in the solution by ion exchange to form an arsenate precipitate. Therefore, modified BOF slag can be used as a potential adsorbent for large scale arsenic polluted waterbody to realize the ecological utilization of industrial solid waste.

Optimization of Iron Recovery from BOF Slag by Oxidation and Magnetic Separation

In order to solve the problem of solid waste pollution of basic oxygen furnace (BOF) slag in the metallurgical process, this paper took BOF slag as the research object, and carried out oxidation reconstruction of BOF slag and alcohol wet magnetic separation recovery of iron phase, so as to efficiently recover and utilize BOF slag. In the early stages, the research group realized the transformation from weak magnetic iron oxide to strong magnetic magnesia-iron spinel phase in BOF slag through oxidation reconstruction experiments under different technological parameters. On this basis, different conditions in the magnetic separation process were adjusted to achieve the optimal iron recovery rate and grade in this paper. The experimental results show that, under the appropriate reconstruction temperature, with the increase of reaction time, gas flow rate and magnetic field intensity, the iron recovery will increase and the iron grade will decrease. The most suitable magnetic field intensity is 75 mT, the magnetic material yield is 46.00%, the iron grade is 29.10%, and the iron recovery is 64.12%. Compared with the initial steel slag, the iron grade increased by 8.22%, and the iron recovery increased by 46.38% compared with the direct magnetic separation without oxidation.

A pilot-process for calcium hydroxide production from iron slag by low-temperature precipitation

The production of Ca(OH)2 via thermal decomposition of limestone is an energy intensive process resulting in significant CO2 emissions. However, if produced in a manner that obviates the need for the thermal decomposition of limestone, Ca(OH)2 could be a “CO2-negative” material. Herein, we design and demonstrate the operation of a continuous, low-temperature (< 100 °C), aqueous-phase pilot-process to produce Ca(OH)2 using calcium extracted from alkaline industrial wastes. The three-step process encompasses unit operations including: (i) calcium leaching from basic oxygen furnace BOF slag, (ii) leachate concentration by reverse osmosis (RO), and (iii) Ca(OH)2 precipitation by temperature swing. This process presents several advantages compared to the traditional route. First, it advances the recycling of waste from the steel industry. Second, it operates significantly below the temperature used in conventional lime production (900 °C) as it bypasses limestone calcination, responsible for ~65% of the CO2 emissions from the current process. Thus, the new process has a lower CO2 footprint and enables the use of industrial waste heat. The mass and energy balances were quantified to reveal that increasing the calcium concentration of the feed solution and the precipitation temperature, decrease the energy demands of the RO step, thereby reducing the process’s overall CO2 footprint. The pilot system operated continuously and achieved a production rate of nearly 1 kg per day of Ca(OH)2 with a purity greater than 95 wt%. The average particle size of the precipitates depended on the residence time in the precipitation reactor, demonstrating an ability to produce size-controlled particulates. Importantly, the process achieved full water recirculation/reutilization level indicative of a low-consumable water demand. The outcomes offer new insights and understanding relevant to developing and upscaling low-CO2 processes for cement, lime, and portlandite.

The effect of Basic Oxygen Furnace, Blast Furnace, and Kanbara Reactor Slag as Reinforcement to Cement Based Mortar

Slag is a waste from steelmaking industries that was released into the environment. Slag was used as reinforced material in mortar. Different types of slag, including Air Cooled Slag (ACS), Granulated Blast Furnace Slag (GBFS), Basic Oxygen Furnace Slag (BOFS), and Kanbara Reactor Slag (KRS), were used as a reinforcing material in this study. The composition of slag in the mixture on mortar was 10%, 20%, 30%, 40%, and 50%. The sample was made with a water-cement ratio (w/c) of 0.35, with the ratio of sand and cement being 1:1.5, respectively. Treatment of mortar sample at ambient temperature was applied. The mortar samples were left to cure until 3, 7, and 28 days, which performed a compression test. The results show that adding slag to the mortar enhanced the compressive strength of the pristine mortar. The highest strength was obtained by adding 10% slag at 28 days. The compressive strength of GBFS, BOFS, KRS, and ACS was 23.76 MPa, 23.28 MPa, 19.68 MPa and 17.48 MPa, respectively. Based on the XRD result, it was discovered that the mixture has more Calcium Silicate Hydrate Peak than Pristine mortar.

Contribution of Hot-Spot Zone in Decarburization of BOF Steel-Making: Fundamental Analysis Based upon the FactSage-Macro Program

An improved computational model to describe the decarburization process in basic oxygen furnaces for steel making is presented in this work. A dynamic model was thus developed to calculate the decarburization rate and its breakup as a contribution coming from the hot-spot zone (under jet impact) and emulsion zone (by droplet and slag reactions). In this work, multiple interconnected equilibrium/adiabatic stoichiometric-reactor-based approaches are used to describe the overall basic oxygen steel-making process. The macroprogramming facility of FactSage™ software was used to understand the thermodynamics and kinetics of basic oxygen steel-making processes. The temperature, compositions, and volumes of various phases are estimated with the use of this model. Hot-spot temperatures in the range from 2000 to 3000 °C as a benchmark was considered for calculations. The major contribution of decarburization was established to come from hot-spot reactions in the major part of the blow, except in the last part when emulsion phase reactions govern it. This development represents an original contribution to our understanding of the BOF steel-making process.

The Carbon Footprint of Plate Glass: The Energy Required is Not Transparent: Numbers Don't Lie

Plate glass, like steel, is all around us. It is taken for granted, and most people have no idea how it is made. Although both materials are ancient, their production was fundamentally improved only after World War II&#x2014;primary steel-making with the introduction of basic oxygen furnaces, and plate-glassmaking by the successful application of the old idea of floating molten glass on a large bath of molten tin. The tin provides a perfectly level surface.

Recycling of ironmaking and steelmaking slags in Japan and China

The mass production of steel is inevitably accompanied by large quantities of slags. The treatment of ironmaking and steelmaking slags is a great challenge in the sustainable development of the steel industry. Japan and China are two major steel producing countries that have placed a large emphasis on developing new technologies to decrease slag emission or promote slag valorization. Slags are almost completely reused or recycled in Japan. However, due to stagnant infrastructural investments, future applications of slags in conventional sectors are expected to be difficult. Exploring new functions or applications of slags has become a research priority in Japan. For example, the utilization of steelmaking slags in offshore seabeds to create marine forests is under development. China is the top steel producer in the world. The utilization ratios of ironmaking and steelmaking slags have risen steadily in recent years, driven largely by technological advances. For example, hot stage processing of slags for materials as well as heat recovery techniques has been widely applied in steel plants with good results. However, increasing the utilization ratio of basic oxygen furnace slags remains a major challenge. Technological innovations in slag recycling are crucial for the steel industries in Japan and China. Here, the current status and developing trends of utilization technologies of slags in both countries are reviewed.

Assessment of suitable dose of calcium silicate to rice and its impact on soil properties in laterite soils of Odisha

A field experiment was conducted in the central farm, Regional Research and Technology Transfer Station, Coastal Zone OUAT, Bhubaneswar during kharif 2020 using cv-Lalat variety of rice. The experiment was laid out in randomized block design (RBD) with ten treatments and three replications. In this experiment, Basic Oxygen Furnace (BOF) slag was used as a source of silica for application in rice crop. 200, 300 and 400 kg SiO2ha-1 was applied in combination with 50% Soil Test Dose (STD) and 75% STD in order to assess the efficacy of Silica with reduction in fertilizer dose by 50% and 25%. The result indicated that there was significant increase in number of effective tillers per plant and length of the panicle, but no significant increase was observed in case of 1000 grain weight over control. In case of grain yield, straw yield and harvest index, 100% STD registered maximum (36.9q/ha) grain yield which was 29.4% more than that of control. In case of 50% or 75% STD with 300kg SiO2ha-1 grain yield was at par with 100% STD, which indicated that silica application has the capability to reduce the fertilizer dose. Harvest index was not significantly affected by Si treatments. However, maximum HI (0.478) was observed in 75% STD + 300 kg SiO2ha-1. The present study showed increase in pH and organic carbon content in post-harvest soil which suggests that application of silica has the capacity to correct soil acidity and improve soil organic carbon in acidic laterite soils.