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Bed permeability, rate of reductant and productivity of blast furnace (BF) performance mainly depends on both iron bearing material but also carbonaceous material. Most of the BFs have the sinter being a major burden; hence, in JSW Steel Ltd, four sinter plants are operating to fulfill the four BF's requirement. For efficient BF operations, sinter plants are key units whose proper performance is vital to produce desired sinter strength. The tumbler index of the sinter is an important property of the sinter, and sinter strength depends on the raw material composition and machine parameters. For smooth sinter plants operation, changes to the operating conditions should be few and precise. To achieve this, a much better understanding of the mechanisms relating control inputs to a sinter production rate and quality needs to be established. In the present work, a neural network based model has been developed and trained relating sinter strength with a set of nine process variables, namely, basicity, Al2O3/SiO2, MgO, MnO, FeO, moisture, coke breeze, burnthrough temperature and machine speed, to predict the tumbler index (?-?6.3?mm) of the sinter. The variables to which strength of the sinter was most sensitive were Al2O3/SiO2, basicty, machine speed, and MgO, MnO and FeO. Tumbler index of the sinter was influenced by sinter porosity, which was itself determined by the firing temperature and green sinter mix carbon content. The predicted results were in good agreement with the actual data with

From a sinter production point of view, it is important to optimise the sintering process with regard to both sinter quality and production rate. In sintering, airflow rate within the sinter bed decides the production rate and its physical and metallurgical properties. To study the influence of airflow rate (flame front speed) on sinter production and sinter quality, pot grate sintering experiments were conducted at sinter grate suction pressures ranging from 900 to 1700 mm water column over the sinter bed. During sintering, time–temperature data were recorded, and mineralogical studies were carried out. This study reveals that increase in sinter grate suction pressure through the sinter bed from 900 to 1700 mm water column significantly improved the sinter productivity from 34·37 to 48·90 t/m2/day; however, the physical and metallurgical properties of the sinter at higher suction pressure were not optimum with respect to blast furnace requirements. The maximum sinter productivity with desired physical and metallurgical properties was obtained at suction pressure 1300 mm water column. At this pressure, improvement in sinter quality was due to optimum firing temperature and enough retention time available for formation of mineral phases. At an airflow rate 1300 mm water column, sinter productivity was 41·0 t/m2/day, sinter strength (TI) was 73·10%, reduction degradation index was 25·0 and reducibility was 71·50%.

Iron ore sinter, constituting a major proportion of blast furnace burden, significantly impacts the blast furnace performance. The chemical composition of iron ore fines, particularly alumina, sinter basicity and sinter MgO together with the thermal conditions that sinter blends are subjected to play an important role in the formation of mineral phases in sinter. To increase the sinter proportion (70–80%) in blast furnace, lowering of CaO in sinter mix is a vital parameter to balance the flux supply without affecting the slag volume and productivity. At present, the alumina content in the sinter grade iron ore fines at JSW Steel varies from 4 to 6%. The quality of iron ore presently being used calls for extensive investigations to produce low basicity sinter with high alumina iron ore. Studies have been carried out on low and high alumina iron ore fines to know the influence of sinter basicity and fuel (coke breeze) addition on sinter mineralogy, properties and productivity. It is found that with increase in sinter basicity, sinter productivity and reduction degradation index (RDI) decreased and tumbler index (TI) increased for both low and high alumina sinter at coke breeze rate of 65 kg t-1of sinter. The low alumina sinter showed higher productivity and strength, and lower RDI due to the presence of higher silico ferrites of calcium and aluminium (SFCA) and magnetite phase, and lower pore phase as compared to high alumina iron ore sinter. The sinter productivity decreased and physical and metallurgical properties improved with increase in coke breeze addition by increasing the sinter basicity for high alumina sinter.

The quality of iron ore sinter mainly depends on sinter mineralogy, which in turn depends on the chemical composition of the sinter mix. The reduction properties of the mineral phases formed in the sinter influences the sinter reducibility. MgO has a varying effect on sinter reducibility at different silica contents. A recent trend in blast furnace operation shows that there is a considerable increase in usage of dolomite as a basic flux either directly or through sinter. Recently the silica levels in the sinter product of Sinter plant 1(SP1) of JSW Steel Limited have been fluctuating in the range of 5·5–9·6% due to variation in silica content of iron ore fines. At the same time, as per blast furnace requirement, the addition of dolomite has been changed from 2·4 to greater than 3·0% at SP1, and the reducibility of the sinter decreased (<60·0%). Laboratory pot grate sintering experiments have been carried out to determine the influence of MgO addition on microstructure and reducibility of low and high silica sinter. MgO additions have been varied from 1·4 to 3·2% for low silica (4·5%), and high silica (6·3%) iron ore fines.From the studies it was found that the reducibility of both sinters decreased with increase in MgO addition due to an increase in magnetite/magnesio spinel phase and silicate/slag phase. Reducibility of low silica sinter was greater with high silica sinter. High silica with high MgO sinter had lower reducibility compared to low silica with low MgO/high MgO and high silica with low MgO sinter.

The quality of iron ore sinter mainly depends on sinter mineralogy, which in turn depends on the chemical composition of the sinter mix. Dolomite is the critical additive for fluxing the sinter and controlling the sinter MgO. Recently, the silica level in the sinter product of the sinter plant 1 has been varying in the range of 5·51 to 9·58% owing to variation in silica content of iron ore fines. At the same time, as per the blast furnace requirement, the rate of addition of dolomite has been changed from 2·40 to greater than 3·00% at the sinter plant 1. In iron ore sinter, MgO plays different roles on sinter properties at different silica ranges. Because of wide range of fluctuation in iron ore silica it is essential to optimise the MgO addition in sinter mix to get desired properties. Laboratory pot grate sintering experiments have been carried out to know the influence of MgO addition on microstructure and properties of low silica and high silica sinter. MgO addition has been varied from 1·40 to 3·20% for low silica (4·47%), and high silica (6·25%) iron ore fines. High silica with high MgO sinter showed lower strength, higher reduction degradation index, and lower reducibility compared to low silica with low and high MgO and high silica with low MgO sinter. To achieve better sinter properties MgO content in the sinter should not be more than 2·80% when silica is more than 6·0%.

Coke breeze is the most common fuel used in sintering, and its usage depends on the alumina content and fineness of the sinter mix. The coke breeze consumption in the JSW Steel Limited sinter plant was high compared to many other sinter plants in the world, and as there was a local shortage, optimisation in the sinter plants was necessary. FeO is an indicator of the thermal state of the sintering process and is employed as a quality control tool at many plants. Laboratory pot sinters were made, and the variation in FeO was affected by varying the amount of coke breeze in the green mix from 55 to 85 kg t-1of sinter. The produced sinters were evaluated with respect to productivity, strength (tumbler index), reduction degradation index (RDI), reducibility and microstructural phases in the FeO range between 6·2 and 14·8%. It was found that the sinter with FeO range of 8·60–9·88% showed higher productivity and higher strength with desired RDI of ?27% and reducibility of >60%. Analysis of plant data has revealed that the sinter with FeO of 8·5–10·0% showed higher productivity, higher strength and lower RDI.

During the processing of steel in steel mills, iron oxides will form on the surface of the metal. These oxides, known as mill scale, occur during continuous casting, reheating and hot rolling operations. Mill scale is a valuable metallurgical raw material since it contains 65–70% iron. JSW Steel Ltd is a 7 Mtpa integrated steel plant and generates 270 t of mill scale per day. Most of the materials of steel plant wastes are recycled through sinter making in most of the countries. Because of its physical, chemical and mineralogical properties, it can be used as a raw material in a process like sintering. The mill scale contains high amounts of Fe and low amounts of silica and alumina. Thus, recycling it through the sintering process helps in the saving of raw materials like iron ore and limestone. This paper presents preliminary findings of a study that investigates the potential for recycling steel mill scale in the sintering process. Experiments were conducted using the mill scale in sinter making from 0 to 70 kg/t of sinter. The total Fe and FeO contents of the sinter increased with the increase in mill scale addition. The sinter productivity decreased with the increase in mill scale addition due to a decrease in sinter bed permeability. The sinter strength and sinter mean size initially increased and reaches a maximum at mill scale addition of 40–50 kg/t of sinter and afterwards declines with the increase in mill scale addition. Sinter reduction degradation index and reducibility decreased with the increase in mill scale addition due to the increase in FeO content. Except sinter productivity, other desired sinter properties can be obtained with the use of 40–50 kg mill scale per tonne of sinter.

Recently it was shown that the rectangular transform (RT), an efficient circular convolution algorithm, offers significant computational advantage over the fast Fourier transform (FFT) when used to implement a circular convolution adaptive filter. This observation as well as its potential in fixed filtering applications have motivated the present investigation of the development of an RT based linear convolution block adaptive finite impulse response (FIR) digital filter. Unlike the existing FFT and Fermat number transform (FNT) based block adaptive filter structures, which exploit their respective transform properties, the present formulation yields a more general efficient structure which does not rely on the properties of a particular circular convolution algorithm. To achieve both the computational efficiency and saving in memory, the existing RT has been modified. A condition for optimum ordering of the short RT modules which results in an overall minimum computational load is also derived. An evaluation of the computational requirements shows that for moderate order filters the proposed structure is a useful alternative to its FFT implementation. To justify the validity of the technique presented, the convergence properties of the filter for both white and correlated inputs are also studied through simulation.

Results of investigation of starting a single-phase induction motor having a single stator winding and using normal stator and rotor punchings are presented in this paper. Theoretical and experimental studies show that the motor requires less copper for its stator winding compared to a split-phase motor and the overall starting performance is very satisfactory.

Weight gain, feed efficiency and proliferation response of splenic lymphocytes were studied in mice fed either a yogurt or a milk-based diet. The yogurt contained live Lactobacillus bulgaricus and Streptococcus thermophilus. The feeding trial lasted for 10 months. Proliferation response of lymphocytes was measured by the uptake of tritiated thymidine into the cells when stimulated with the mitogens phytohaemagglutinin (PHA), concanavalin A (Con A) and Escherichia coli lipopolysaccharide (LPS). There was no significant difference between the average body weight of mice belonging to the two dietary groups. But yogurt diet showed a higher feed efficiency ratio when compared to the milk diet for the first 8 weeks of the study while the mice were growing. After the period of growth was over, yogurt-fed mice maintained a constant body weight like the milk-fed mice but on a lower energy intake. The proliferation of splenic lymphocytes, expressed as Stimulation Index, was significantly higher in response to the T-lymphocyte mitogens Con A and PHA. Results suggest that yogurt has better feed efficiency and its long term inclusion in diets primes the splenic T-lymphocytes for a higher mitogenic response.

Dynamic quadrupole polarizability of lithium atom has been calculated in its ground state using linked cluster many-body perturbation theory. Van der Waals constants have been calculated for dipole-quadrupole and quadrupole-quadrupole interactions of lithium atoms with helium and other lithium atoms. The results compare well with other available values.

The article discusses the highlights of the 2nd International Symposium on Medicinal and Nutraceutical Plants (ISMNP) organized by the Nutrition and Phytomedicine Laboratory, Department of Physiology of the All India Institute of Medical Sciences (AIIMS). Conference topics include growing medicinal and nutraceutical plants, investigation of medicinal properties in experimental models and methodologies for extracting chemical constituents. Yoga guru Swami Ramdev presented a live Yoga demonstration.