A Semi-Empirical Water and Energy Analysis of Industrial Production of Nickel From Mineral Ores: Comparative Analysis Between Two Different Technologies of Calcination

Author(s):  
Janneth Ruiz ◽  
Antonio Ardila ◽  
Bernardo Rueda ◽  
Jorge Echeverri ◽  
Daniel Quintero ◽  
...  

Abstract In the ferronickel production process, mineral calcination is one of the most energy-intensive stages. In a typical rotary kiln calciner, particulate solids and combustions gases move counter currently, while solids undergo drying, pre-reduction, and partial reduction reactions. The combustion of natural gas provides the thermal energy for drying and reduction reactions. About 80 to 85% of the incoming laterite ore leaves the reactor as calcined ore, while the flue gases entrain part of the solids as dust. This work presents a theoretical analysis contrasted with experimental results to evaluate the partial reduction of laterite ores in two rotary kilns of 185 m and 135 m length. The study focused on the water formed in the process, including a comparative analysis of water consumption by two different solids recovery technologies, a gas scrubber and an electrostatic precipitator. Simulations allowed evaluating the water and greenhouse gas formation in the main streams of the process. Among the tested operation conditions, the moisture content in the pellets, consisting of agglomerated dust, strongly influenced the amount of water released in the process and the energy consumption. Furnace RK-2 needs approximately 56% more energy to evaporate the moisture content in the feedstock. Furthermore, furnace RK-2 released 55.4 m3h−1 of water into the atmosphere, which represented two times the amount released by furnace RK-1. Gas scrubber analysis showed that as the liquid water increased, more H2O in the gases was condensed; however, the destroyed exergy also increased. Electrostatic precipitators appear as an adequate technology for reducing water and energy consumption in the ferronickel industry.

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1999
Author(s):  
Guanyong Sun ◽  
Bin Li ◽  
Hanjie Guo ◽  
Wensheng Yang ◽  
Shaoying Li ◽  
...  

Carbon included in coke and coal was used as a reduction agent and fuel in blast furnace (BF) ironmaking processes, which released large quantities of carbon dioxide (CO2). Minimizing the carbon consumption and CO2 output has always the goal of ironmaking research. In this paper, the reduction reactions of iron oxides by carbon, the gasification reaction of carbon by CO2, and the coupling reactions were studied by thermodynamic functions, which were derived from isobaric specific heat capacity. The reaction enthalpy at 298 K could not represent the heat value at the other reaction temperature, so the certain temperature should be confirmed by Gibbs frees energy and gas partial pressure. Based on Hess’ law, the energy consumption of the ironmaking process by carbon was calculated in detail. The decrease in the reduction temperature of solid metal iron has been beneficial in reducing the sensible heat required. When the volume ratio of CO to CO2 in the top gas of the furnace was given as 1.1–1.5, the coupling parameters of carbon gasification were 1.06–1.28 for Fe2O3, 0.71–0.85 for Fe3O4, 0.35–0.43 for FeO, respectively. With the increase in the coupling parameters, the volume fraction of CO2 decreased, and energy consumption and CO2 output increased. The minimum energy consumption and CO2 output of liquid iron production were in the reduction reactions with only CO2 generated, which were 9.952 GJ/t and 1265.854 kg/t from Fe2O3, 9.761 GJ/t and 1226.799 kg/t from Fe3O4, 9.007 GJ/t and 1107.368 kg/t from FeO, respectively. Compared with the current energy consumption of 11.65 GJ/t hot metal (HM) and CO2 output of 1650 kg/tHM of BF, the energy consumption and CO2 of ironmaking by carbon could reach lower levels by decreasing the coupled gasification reactions, lowering the temperature needed to generate solid Fe and adjusting the iron oxides to improve the iron content in the raw material. This article provides a simplified calculation method to understand the limit of energy consumption and CO2 output of ironmaking by carbon reduction iron oxides.


2014 ◽  
Vol 631-632 ◽  
pp. 362-366
Author(s):  
Ning Ling Wang ◽  
Yong Zhang ◽  
Long Fei Zhu ◽  
Zhi Ping Yang

An accurate and reliable energy-consumption model is the key to operation optimization and energy-saving diagnosis of thermal power units especially under different operation conditions and boundaries. Conventional mathematical and data-driven modeling methods were overviewed and compared in this paper. A hybrid modeling based on thermodynamic theory and fuzzy rough set (FRS) method was proposed to process the great volume of operation data and describe the energy-consumption behavior of thermal power units. On this basis, the operation optimization was performed with intelligent computation methods to derive the realizable benchmark state with the whole set of operation parameters. The resultant optimum operation state reflects the exterior factors and system behavior, taking practical guidelines for the modeling and optimization of large thermal power units.


2012 ◽  
Vol 209-211 ◽  
pp. 1068-1072
Author(s):  
Ming Liu ◽  
Bao Gang Zhang ◽  
Liu Wen ◽  
Zhong Zhi Huang

To ensure passengers can have a comfortable thermal environment in the subway waiting room is one of the main targets in subway environment control. By using the CFD software, this paper takes an island platform with double-layer of Shenyang as the object to simulate the thermal environment of platform screen door and ventilation in the open system, then detailed analysis on the variation of the temperature field, airflow velocity field in the typical position. The results indicated that average temperature of no-PSD system platform is 2.5 ~3 °C higher than that of PSD system, standing room is 1.5 °C higher than that of PSD system , but these also meet the requirement of the standards of the environmental control and passengers’ thermal comfort. Meanwhile, through the comparative analysis to the energy consumption of the two systems, we find ventilating condition has superior to PSD system in energy saving, and it is more suitable for the local climate in the northeast.


2012 ◽  
Vol 524-527 ◽  
pp. 3079-3082
Author(s):  
Di Ping Zhang ◽  
Shuang Shuang He ◽  
Gao Qing Li

Taking Zhejiang province as an example, this paper conducted a comparative analysis on the current situation of the energy consumption structure from the vertical and horizontal using the descriptive statistical method. By calculating some indexes such as energy consumption per unit GDP, energy consumption elasticity coefficient, and so on, the study analyzes and evaluates the present situation, trend and influence factors of energy efficiency. Finally, it puts forward some policy suggestions about the optimization of energy consumption structure and energy efficiency.


2021 ◽  
Author(s):  
Dil Rowshan

This study aimed to explore the impact of the Places to Grow Plan 2006 on travel behavior of the work commuters living in GTHA. A comparative analysis was done between the year 2001 and 2011 which represent the situations five year before and after the implementation of the Plan. Data were collected from Transportation Tomorrow Survey. The study revealed that in 2011, energy consumption by motorized vehicles increased in the Traffic Assessment Zones of GTHA around the Growth Centres designated by the Places to Grow Plan. Active transportation increased mainly in Toronto in 2011. It is apprehended that the intensification strategy of the Places to Grow Plan contributed in increasing the energy consumption of work commuters either by increasing the number of trips or length of trips made by motorized vehicles (including cars and different forms of transit) which also affect the Greenhouse Gas emissions in the atmosphere.


Author(s):  
Sahar Safarianbana ◽  
Runar Unnthorsson ◽  
Christiaan Richter

Abstract Wood and paper residues are usually processed as wastes, but they can also be used to produce electrical and thermal energy through processes of thermochemical conversion of gasification. This study proposes a new steady state simulation model for down draft waste biomass gasification developed using the commercial software Aspen Plus for optimization of the gasifier performance. The model was validated by comparison with experimental data obtained from six different operation conditions. This model is used for analysis of gasification performance of wood chips and mixed paper wastes. The operating parameters of temperature and moisture content (MC) have been varied over wide range and their effect on the high heating value (HHV) of syngas and cold gas efficiency (CGE) were investigated. The results show that increasing the temperature improves the gasifier performance and it increases the production of CO and H2 which leads to higher LHV and CGE. However, an increase in moisture content reduces gasifier performance and results in low CGE.


2020 ◽  
Vol 67 (2) ◽  
pp. 73-77
Author(s):  
Zarife Bajraktari-Gashi ◽  
Muharrem Zabeli ◽  
Behram Halilaj

AbstractDuring 1984–1997, the ferronickel plant in Drenas used iron-nickel ore from the mines of the Republic of Kosovo: Glavica and Çikatove (Dushkaje and Suke) mines. However, during the years 2007–2017, when the plant started operating from the cessation of production, which was from 1998 to 2007, some types of iron-nickel ores from different countries began to be used, starting from iron-nickel ores from Kosovo, iron-nickel ores from Albania, ores from Indonesia, ores from the Philippines, ores from Guatemala, ores from Turkey and ores from Macedonia. The ore composition, however, is mainly oxide-laterite ore. Iron-nickel ores in the plant are characterised by high moisture content, a very important factor influencing the process of scraping the charge in rotary kilns and presenting in general. Among the iron-nickel ore used in the ferronickel plant, the ores from Albania are characterised due to their low moisture content when compared with the other ores as well as the high content of iron oxides, which affect the temperature rise inside the furnaces, as the iron ores play an important role in the pre-casting process in rotary kilns.


2019 ◽  
Vol 10 (4) ◽  
pp. 627-647 ◽  
Author(s):  
Izabela Jonek-Kowalska

Research background: Energy policy is closely linked to economic development. Therefore, its optimization is an important issue especially in the contemporary European environmental conditions.  EU regulations enforce a reduction of carbon dioxide emissions and the abandonment of non-renewable energy resources. Instead, they promote renewable energy sources. In this way, new legal and environmental circumstances are becoming the main reason for the transformation of energy balances, which is a real economic and technological challenge. This transformation requires a strategic and effective approach, especially in those countries which until now have used mainly hard coal in the energy sector. Purpose of the article: According to above justification, the main purpose of the article is to identify the strategies for the transformation of energy balances that were implemented in the years 1990–2017 by chosen European countries and Turkey. Methods: The study period covers the years 1990–2017, and the subject of the research at first applies to all European countries, and then to 7 countries selected due to their high share of bituminous coal in energy balance in the first year of the analysis, treated as the initial point of transformation (1990). As a result of this selection, 6 EU members and Turkey with the largest share of coal in energy production in the year 1990 are examined. Particularly, an analysis of the trends in their energy balances in the years 1990–2017 is conducted. The research uses data on non-renewable energy consumption and renewable energy resources and the total energy consumption. The research methodology includes: analysis of the structure and dynamics, evaluation of trends and comparative analysis and presentation of development strategies. At the end of the article, a comparative analysis is carried out, the economic consequences of identified changes are assessed, and recommendations are formulated aimed at optimizing the structure of the energy balance in the future. Findings & Value added: Generally, there are four theoretical and empirical patterns of transformation strategies of energy balances with dominant coal consumption: 1) using other non-renewable energy resources; 2) replacing non-renewable energy resources with renewable ones; 3) using nuclear energy instead of coal; 4) increasing coal consumption as available and efficient energy resource. It was found that the examined countries implement mainly the strategy in which the decreasing share of coal is made up for by an increasing share of gas. Additionally, we can observe an increase in the share of nuclear energy in France, the Czech Republic and the United Kingdom. In Spain and Germany, despite the use of nuclear power plants for the production of energy, the share of nuclear energy in the energy balances has systematically decreased in time. In all analyzed countries, we can also observe an increasing share of renewable sources in energy balances, however, this growth is very slow.


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