Veerendra Singh | Tata Steel (original) (raw)

Papers by Veerendra Singh

Journal of the Southern African Institute of Mining and Metallurgy, 2017

Comminution is a critical process in mineral processing which strongly influences the economics o... more Comminution is a critical process in mineral processing which strongly influences the economics of production. In mineral processing, particles containing valuable minerals must be disintegrated at a sufficiently fine size to liberate valuable minerals from waste constituents, so that they can be easily separated by an appropriate beneficiation method. The Sukinda chrome ore beneficiation plant utilizes different types of run-of-mine (ROM) ore with different physical properties (viz. grindability characteristics, work index, mineral composition, liberation, chemical composition, etc. for the production of chrome concentrate. In the feed preparation circuit, the ROM ore is crushed and ground to below 1 mm. Grinding in the chromite beneficiation plant is a critical unit operation to achieve the desired product size of below 1 mm and to control the generation of the ultrafine particles. Furthermore, about 40% of total power consumption in the beneficiation plant is accounted for by the grinding of the ore. This implies that any improvement of the circuit performance will lead to an overall increase in productivity.

Journal of Minerals and Materials Characterization and Engineering, 2011

Large tonnages of chromite tailing were discarded during processing of chromite ore in the conven... more Large tonnages of chromite tailing were discarded during processing of chromite ore in the conventional circuit. A typical chromite plant tailing was treated in wilfley table for the recovery of chromite values. Optimisation study was carried out for the process parameters of wilfley table using empirical models, developed from the experimental data. It was found that grade and recovery (% Cr 2 O 3) in the concentrate fraction majorly depended on the variation of deck tilt angle. To achieve high grade (>45%) with acceptable recovery (>40%), set of optimisation condition of parameters have derived which resulted large quantity of wash water (>5lpm of flow rate) is necessary. Validation of the empirical models were done with set of tests which resulted good agreement with the predict values (R 2 is 0.96 and 0.99 for the grade and recovery respectively).

Geotechnical and Geological Engineering, 2005

Drilling and Blasting are still considered to be the most economical method for rock excavation e... more Drilling and Blasting are still considered to be the most economical method for rock excavation either on surface or underground. The explosive energy, which breaks the rockmass, is not fully utilized for this purpose. Only 20-30% of explosive energy is utilized for fragmenting the rockmass and the rest wasted away in the form of ground vibration, air blast, noise, fly rock, back breaks, etc. Among them, ground vibration is considered to have the most damaging effect. A number of predictor equations have been proposed by various researchers to predict ground vibration prior to blasting. Still, it is difficult to recommend any one predictor for a particular ground condition because ground vibration is influenced by a number of parameters. These parameters are either controllable or non-controllable like blast geometry, explosive types, rock strength properties, joints patterns, etc. In the present paper, an attempt has been made to predict the ground vibration using an Artificial Neural Network incorporating large number of parameters, which affect the ground vibration. Results are also compared with the values obtained from regression analysis and observed field data sets. Finally, it is found that the neural network approach is more accurate and able to predict the value of blast vibration without increasing error with increasing number of inputs and non-linearity among these.

Conventional chromite beneficiation plants of India discards large tonnage of chromite values as ... more Conventional chromite beneficiation plants of India discards large tonnage of chromite values as plant tailing. In the present investigation, a typical chromite beneficiation plant tailing of Sukinda region has investigated by using wet shaking table for the effective utilisation of the natural resource. In this context, the effect of different process variables such as wash water flow rate, deck tilt angle and feed flow rate has analysed. The interactional effects between different process variables has analysed in terms of 3D response surface plots. It was found that the Cr 2 O 3 content has improved to 61.37% from a feed assaying 24.26%. It was envisaged that deck tilt angle has influence major on both grade and recovery of concentrate fraction of shaking table and in case of interactional effects, the interaction between deck tilt angle and feed flow rate has major influence compared to the others. Second order quadratic equations have developed for the prediction of grade and recovery of concentrate fraction of shaking table.

About 40% of the Indian chromite ore reserves are suitable for metallurgical purpose due to highe... more About 40% of the Indian chromite ore reserves are suitable for metallurgical purpose due to higher Cr:Fe rat io. The present investigation emphasized on the liberation and beneficiation characteristics of Indian chromite oreto improve the Cr: Fe ratio . The off grade chro mite samp le ofSukinda region, India analysed 40.8% of Cr 2 O 3 with Cr:Fe rat io of 1.7 and 5.8% of SiO 2 which was not suitable for metallu rgical industry. Detailed characterisation studies were carried out to predict the theoretical limits to improve the Cr/Fe rat io. Mineralogical investigation by using QEMSCAN studies revealed that chromite, hematite, goethite, Fe Silicates and kaolin ite are do minating phases in the ore.Half of the Fe was present in the chromite spinel, whereas other 30% and 20% werereported fro m silicates and iron minerals, respectively. It was predicted fro m characterisation that, product can be enriched to 2.48 Cr:Fe ratio by discarding the silicate/locked silicate, Fe silicate gangue ...

Journal of Nepal Paediatric Society, 2018

Introduction: Severe anaemia is a leading cause of paediatric morbidity, hospitalization, and mor... more Introduction: Severe anaemia is a leading cause of paediatric morbidity, hospitalization, and mortality and it is very important co morbidity in children with severe acute malnutrition. Severe Acute Malnutrition (SAM) with anaemia has been shown to have 2.62 times higher mortality as compared to SAM with no anaemia. So this study was done to evaluate this co-morbidity further. The aim of present study was to determine the prevalence and type of anaemia and to evaluate the possible aetiologies of anaemia in severe acute malnourished (SAM) children.Material and Methods: In tertiary care hospital a cross sectional study was conducted over a period of 8 month with 100 cases of SAM children and 101 cases of normal children. In both cases disorders of primary haematological problem were excluded. Auto analysers were used to measure blood counts. Blood smear was analysed by pathology consultant of institute and recorded for all patients with anaemia. Grade of anaemia and morphologic type o...

Indian Journal of Animal Research, 2017

The present investigation was undertaken to study the management practices and socio-economic fac... more The present investigation was undertaken to study the management practices and socio-economic factors affecting the farming of Jaunpuri goat in two districts of its native tracts in eastern Uttar Pradesh. viz., Allahabad and Jaunpur. Ten villages from Jaunpur and fifteen villages from Allahabad district were randomly selected for the present investigation. The findings revealed that most of the goat farmers in Jaunpur and Allahabad district were of marginal type in their land holding capacity with 47.61 and 68.18% respectively and they earned more than Rs.5000 per annum from goatery. Besides the goatery, the other professions of goat rearers are 60% farming, 33.33% labor, 6.67% small business in Jaunpur and 58.82% labour, 41.18% farming in Allahabad district. The literacy of the head of the Jaunpuri goat rearing family was 66.67 and 68.18 % respectively in the Jaunpur and Allahabad district and most of farmers have 6-8 members per family. The farmers of both districts used to house ...

Ironmaking & Steelmaking, 2016

This study is carried out to develop a smart ore blending methodology for high carbon ferromangan... more This study is carried out to develop a smart ore blending methodology for high carbon ferromanganese production units. Geometallurgical characterisation of the ores collected from 10 different mines has been carried out to estimate variation in their aptness for the alloy production process. An evolutionary algorithm-based methodology has been adopted for ore blending to maximise the total manganese content of the ore blend under applied physico-chemical constraints. Analysis provides various blends of the same chemical composition but of different geometallurgical ranks. An artificial neural network model has been developed to predict the operational parameters such as slag and metal composition. This method allows the operator to visualise the impact of combinations of different ore blends on slag–metal composition as well as on electric power and coke required for smelting reduction of ores in the submerged arc furnace. It was observed that best blends could reduce power and coke consumption by 100 kWh ton−1 and 30 kg ton−1, respectively, but optimum values can be established in long run considering conservation of natural resources.

Journal of The Institution of Engineers (India): Series D, 2015

Minerals

The ferromanganese (FeMn) alloy is produced through the smelting-reduction of manganese ores in s... more The ferromanganese (FeMn) alloy is produced through the smelting-reduction of manganese ores in submerged arc furnaces. This process generates large amounts of furnace dust that is environmentally problematic for storage. Due to its fineness and high volatile content, this furnace dust cannot be recirculated through the process, either. Conventional MnO2 production requires the pre-reduction of low-grade ores at around 900 °C to convert the manganese oxides present in the ore into their respective acid-soluble forms; however, the furnace dust is a partly reduced by-product. In this study, a hydrometallurgical route is proposed to valorize the waste dust for the production of battery-grade MnO2. By using dextrin, a cheap organic reductant, the direct and complete dissolution of the manganese in the furnace dust is possible without any need for high-temperature pre-reduction. The leachate is then purified through pH adjustment followed by direct electrowinning for electrolytic mangane...

Journal of Cleaner Production

Mining, Metallurgy & Exploration

Mineral Processing and Extractive Metallurgy

Minerals

The low chromium‐to‐iron ratio of chromite ores is an important issue in some chromite deposits. ... more The low chromium‐to‐iron ratio of chromite ores is an important issue in some chromite deposits. The value of the chromite ore is indeed dictated in the market by its iron, as well as its chromium content. In the present study, a chromite concentrate was reprocessed by gravity (spiral concentrator) and magnetic separation to enhance the chromium‐to‐iron ratio. Also, detailed characterization studies including automated mineralogy were carried out to better understand the nature of the samples. Enhancing the chromium‐to‐iron ratio was achieved by using advanced spiral separators which will be discussed in this paper.

Aspects in Mining & Mineral Science

These studies have been carried out to compare the grinding characteristics of different morpholo... more These studies have been carried out to compare the grinding characteristics of different morphological mineral matters. Coal, dolomite, manganese and iron ores samples were ground using a ball mill in different grinding conditions (dry and wet) and at different critical speed (R 45% , R 70% and R 90%) during wet grinding. Results are compared considering the relative impact on particle size and shape. Materials were ground in a lab scale ball mill for 2hours with steel balls and size analysis of products were carried out using different size sieves (1, 0.5, 0.25, 0.15, 0.106 and 0.053mm). Microscopic studies were carried out to know the effect of different grinding conditions on particle properties. Light, fine grain and soft dolomite shows only 8% reduction in D 80 whereas heavy, friable and hard manganese ore shows a 29% reduction in D 80 for similar dry and wet grinding conditions. It was found that light materials are less sensitive towards mill speed (R) during wet grinding. Energy calculations indicated that wet grinding is less efficient for low density and soft materials than high density and hard materials. The relative increase in the fineness (D 80) for coal, dolomite, manganese ores and iron ores were 8.9, 6.5, 25, and 15.8%, respectively for wet and dry grinding. Variation in D/L indicates that abrasion is a prominent phenomenon in dry grinding and chipping is more prominent in wet grinding especially for material with bedded structures.

Mining, Metallurgy & Exploration

Mineral Processing and Extractive Metallurgy Review

Mineral Processing and Extractive Metallurgy

Mineral Processing and Extractive Metallurgy Review

Journal of the Southern African Institute of Mining and Metallurgy, 2017

Comminution is a critical process in mineral processing which strongly influences the economics o... more Comminution is a critical process in mineral processing which strongly influences the economics of production. In mineral processing, particles containing valuable minerals must be disintegrated at a sufficiently fine size to liberate valuable minerals from waste constituents, so that they can be easily separated by an appropriate beneficiation method. The Sukinda chrome ore beneficiation plant utilizes different types of run-of-mine (ROM) ore with different physical properties (viz. grindability characteristics, work index, mineral composition, liberation, chemical composition, etc. for the production of chrome concentrate. In the feed preparation circuit, the ROM ore is crushed and ground to below 1 mm. Grinding in the chromite beneficiation plant is a critical unit operation to achieve the desired product size of below 1 mm and to control the generation of the ultrafine particles. Furthermore, about 40% of total power consumption in the beneficiation plant is accounted for by the grinding of the ore. This implies that any improvement of the circuit performance will lead to an overall increase in productivity.

Journal of Minerals and Materials Characterization and Engineering, 2011

Large tonnages of chromite tailing were discarded during processing of chromite ore in the conven... more Large tonnages of chromite tailing were discarded during processing of chromite ore in the conventional circuit. A typical chromite plant tailing was treated in wilfley table for the recovery of chromite values. Optimisation study was carried out for the process parameters of wilfley table using empirical models, developed from the experimental data. It was found that grade and recovery (% Cr 2 O 3) in the concentrate fraction majorly depended on the variation of deck tilt angle. To achieve high grade (>45%) with acceptable recovery (>40%), set of optimisation condition of parameters have derived which resulted large quantity of wash water (>5lpm of flow rate) is necessary. Validation of the empirical models were done with set of tests which resulted good agreement with the predict values (R 2 is 0.96 and 0.99 for the grade and recovery respectively).

Geotechnical and Geological Engineering, 2005

Drilling and Blasting are still considered to be the most economical method for rock excavation e... more Drilling and Blasting are still considered to be the most economical method for rock excavation either on surface or underground. The explosive energy, which breaks the rockmass, is not fully utilized for this purpose. Only 20-30% of explosive energy is utilized for fragmenting the rockmass and the rest wasted away in the form of ground vibration, air blast, noise, fly rock, back breaks, etc. Among them, ground vibration is considered to have the most damaging effect. A number of predictor equations have been proposed by various researchers to predict ground vibration prior to blasting. Still, it is difficult to recommend any one predictor for a particular ground condition because ground vibration is influenced by a number of parameters. These parameters are either controllable or non-controllable like blast geometry, explosive types, rock strength properties, joints patterns, etc. In the present paper, an attempt has been made to predict the ground vibration using an Artificial Neural Network incorporating large number of parameters, which affect the ground vibration. Results are also compared with the values obtained from regression analysis and observed field data sets. Finally, it is found that the neural network approach is more accurate and able to predict the value of blast vibration without increasing error with increasing number of inputs and non-linearity among these.

Conventional chromite beneficiation plants of India discards large tonnage of chromite values as ... more Conventional chromite beneficiation plants of India discards large tonnage of chromite values as plant tailing. In the present investigation, a typical chromite beneficiation plant tailing of Sukinda region has investigated by using wet shaking table for the effective utilisation of the natural resource. In this context, the effect of different process variables such as wash water flow rate, deck tilt angle and feed flow rate has analysed. The interactional effects between different process variables has analysed in terms of 3D response surface plots. It was found that the Cr 2 O 3 content has improved to 61.37% from a feed assaying 24.26%. It was envisaged that deck tilt angle has influence major on both grade and recovery of concentrate fraction of shaking table and in case of interactional effects, the interaction between deck tilt angle and feed flow rate has major influence compared to the others. Second order quadratic equations have developed for the prediction of grade and recovery of concentrate fraction of shaking table.

About 40% of the Indian chromite ore reserves are suitable for metallurgical purpose due to highe... more About 40% of the Indian chromite ore reserves are suitable for metallurgical purpose due to higher Cr:Fe rat io. The present investigation emphasized on the liberation and beneficiation characteristics of Indian chromite oreto improve the Cr: Fe ratio . The off grade chro mite samp le ofSukinda region, India analysed 40.8% of Cr 2 O 3 with Cr:Fe rat io of 1.7 and 5.8% of SiO 2 which was not suitable for metallu rgical industry. Detailed characterisation studies were carried out to predict the theoretical limits to improve the Cr/Fe rat io. Mineralogical investigation by using QEMSCAN studies revealed that chromite, hematite, goethite, Fe Silicates and kaolin ite are do minating phases in the ore.Half of the Fe was present in the chromite spinel, whereas other 30% and 20% werereported fro m silicates and iron minerals, respectively. It was predicted fro m characterisation that, product can be enriched to 2.48 Cr:Fe ratio by discarding the silicate/locked silicate, Fe silicate gangue ...

Journal of Nepal Paediatric Society, 2018

Introduction: Severe anaemia is a leading cause of paediatric morbidity, hospitalization, and mor... more Introduction: Severe anaemia is a leading cause of paediatric morbidity, hospitalization, and mortality and it is very important co morbidity in children with severe acute malnutrition. Severe Acute Malnutrition (SAM) with anaemia has been shown to have 2.62 times higher mortality as compared to SAM with no anaemia. So this study was done to evaluate this co-morbidity further. The aim of present study was to determine the prevalence and type of anaemia and to evaluate the possible aetiologies of anaemia in severe acute malnourished (SAM) children.Material and Methods: In tertiary care hospital a cross sectional study was conducted over a period of 8 month with 100 cases of SAM children and 101 cases of normal children. In both cases disorders of primary haematological problem were excluded. Auto analysers were used to measure blood counts. Blood smear was analysed by pathology consultant of institute and recorded for all patients with anaemia. Grade of anaemia and morphologic type o...

Indian Journal of Animal Research, 2017

The present investigation was undertaken to study the management practices and socio-economic fac... more The present investigation was undertaken to study the management practices and socio-economic factors affecting the farming of Jaunpuri goat in two districts of its native tracts in eastern Uttar Pradesh. viz., Allahabad and Jaunpur. Ten villages from Jaunpur and fifteen villages from Allahabad district were randomly selected for the present investigation. The findings revealed that most of the goat farmers in Jaunpur and Allahabad district were of marginal type in their land holding capacity with 47.61 and 68.18% respectively and they earned more than Rs.5000 per annum from goatery. Besides the goatery, the other professions of goat rearers are 60% farming, 33.33% labor, 6.67% small business in Jaunpur and 58.82% labour, 41.18% farming in Allahabad district. The literacy of the head of the Jaunpuri goat rearing family was 66.67 and 68.18 % respectively in the Jaunpur and Allahabad district and most of farmers have 6-8 members per family. The farmers of both districts used to house ...

Ironmaking & Steelmaking, 2016

This study is carried out to develop a smart ore blending methodology for high carbon ferromangan... more This study is carried out to develop a smart ore blending methodology for high carbon ferromanganese production units. Geometallurgical characterisation of the ores collected from 10 different mines has been carried out to estimate variation in their aptness for the alloy production process. An evolutionary algorithm-based methodology has been adopted for ore blending to maximise the total manganese content of the ore blend under applied physico-chemical constraints. Analysis provides various blends of the same chemical composition but of different geometallurgical ranks. An artificial neural network model has been developed to predict the operational parameters such as slag and metal composition. This method allows the operator to visualise the impact of combinations of different ore blends on slag–metal composition as well as on electric power and coke required for smelting reduction of ores in the submerged arc furnace. It was observed that best blends could reduce power and coke consumption by 100 kWh ton−1 and 30 kg ton−1, respectively, but optimum values can be established in long run considering conservation of natural resources.

Journal of The Institution of Engineers (India): Series D, 2015

Minerals

The ferromanganese (FeMn) alloy is produced through the smelting-reduction of manganese ores in s... more The ferromanganese (FeMn) alloy is produced through the smelting-reduction of manganese ores in submerged arc furnaces. This process generates large amounts of furnace dust that is environmentally problematic for storage. Due to its fineness and high volatile content, this furnace dust cannot be recirculated through the process, either. Conventional MnO2 production requires the pre-reduction of low-grade ores at around 900 °C to convert the manganese oxides present in the ore into their respective acid-soluble forms; however, the furnace dust is a partly reduced by-product. In this study, a hydrometallurgical route is proposed to valorize the waste dust for the production of battery-grade MnO2. By using dextrin, a cheap organic reductant, the direct and complete dissolution of the manganese in the furnace dust is possible without any need for high-temperature pre-reduction. The leachate is then purified through pH adjustment followed by direct electrowinning for electrolytic mangane...

Journal of Cleaner Production

Mining, Metallurgy & Exploration

Mineral Processing and Extractive Metallurgy

Minerals

The low chromium‐to‐iron ratio of chromite ores is an important issue in some chromite deposits. ... more The low chromium‐to‐iron ratio of chromite ores is an important issue in some chromite deposits. The value of the chromite ore is indeed dictated in the market by its iron, as well as its chromium content. In the present study, a chromite concentrate was reprocessed by gravity (spiral concentrator) and magnetic separation to enhance the chromium‐to‐iron ratio. Also, detailed characterization studies including automated mineralogy were carried out to better understand the nature of the samples. Enhancing the chromium‐to‐iron ratio was achieved by using advanced spiral separators which will be discussed in this paper.

Aspects in Mining & Mineral Science

These studies have been carried out to compare the grinding characteristics of different morpholo... more These studies have been carried out to compare the grinding characteristics of different morphological mineral matters. Coal, dolomite, manganese and iron ores samples were ground using a ball mill in different grinding conditions (dry and wet) and at different critical speed (R 45% , R 70% and R 90%) during wet grinding. Results are compared considering the relative impact on particle size and shape. Materials were ground in a lab scale ball mill for 2hours with steel balls and size analysis of products were carried out using different size sieves (1, 0.5, 0.25, 0.15, 0.106 and 0.053mm). Microscopic studies were carried out to know the effect of different grinding conditions on particle properties. Light, fine grain and soft dolomite shows only 8% reduction in D 80 whereas heavy, friable and hard manganese ore shows a 29% reduction in D 80 for similar dry and wet grinding conditions. It was found that light materials are less sensitive towards mill speed (R) during wet grinding. Energy calculations indicated that wet grinding is less efficient for low density and soft materials than high density and hard materials. The relative increase in the fineness (D 80) for coal, dolomite, manganese ores and iron ores were 8.9, 6.5, 25, and 15.8%, respectively for wet and dry grinding. Variation in D/L indicates that abrasion is a prominent phenomenon in dry grinding and chipping is more prominent in wet grinding especially for material with bedded structures.

Mining, Metallurgy & Exploration

Mineral Processing and Extractive Metallurgy Review

Mineral Processing and Extractive Metallurgy

Mineral Processing and Extractive Metallurgy Review