scholarly journals Nickel Laterite Smelting Processes and Some Examples of Recent Possible Modifications to the Conventional Route

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 974 ◽  
Author(s):  
Ender Keskinkilic
Keyword(s):  
Extractive Metallurgy ◽  
Pilot Scale ◽  
High Energy ◽  
Low Grade ◽  
New Developments ◽  
The Past ◽  
Nickel Production ◽  
Removal Of Impurities ◽  
Alternative Processes ◽  
High Energy Consumption

The treatment of laterites has been a research hotspot in extractive metallurgy over the past decades. Industrially, the pyrometallurgical treatment of laterites is mostly accomplished with a well-established method, namely, the rotary kiln–electric arc furnace (RKEF) process, which includes three main operations—calcination, prereduction, and smelting—followed by further refining for the removal of impurities from the raw ferro-nickel. As indicated in many studies of the RKEF process, the major downside of this method is its high energy consumption. Efforts have been made to lower this consumption. Furthermore, several new processes have been proposed. Among these, low-grade ferro-nickel production is regarded as the most widely and industrially used process after traditional RKEF operation. Although not widespread, other alternative processes of industrial scale have been generated since the start of the millennium. Recently, certain innovative processes have been tested either in the laboratory or at pilot-scale. In this paper, a literature review related to the smelting of laterites is made, and an emphasis on new processes and some examples of new developments in the RKEF process are presented.

scholarly journals Actuation Mechanism of Microvalves: A Review

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 172 ◽  
Author(s):  
Jin-Yuan Qian ◽  
Cong-Wei Hou ◽  
Xiao-Juan Li ◽  
Zhi-Jiang Jin
Keyword(s):  
Energy Consumption ◽  
Acoustic Wave ◽  
Chemical Engineering ◽  
Life Science ◽  
Flow Characteristics ◽  
High Energy ◽  
Comprehensive Review ◽  
Actuation Mechanism ◽  
The Past ◽  
High Energy Consumption

The microvalve is one of the most important components in microfluidics. With decades of development, the microvalve has been widely used in many industries such as life science, chemical engineering, chip, and so forth. This paper presents a comprehensive review of the progress made over the past years about microvalves based on different actuation mechanisms. According to driving sources, plenty of actuation mechanisms are developed and adopted in microvalves, including electricity, magnetism, gas, material and creature, surface acoustic wave, and so on. Although there are currently a variety of microvalves, problems such as leakage, low precision, poor reliability, high energy consumption, and high cost still exist. Problems deserving to be further addressed are suggested, aimed at materials, fabrication methods, controlling performances, flow characteristics, and applications.

scholarly journals Development of Geopolymers Formulations Based on Low-Grade Kaolins as a Potential Construction Material

2019 ◽  
Author(s):  
Cristiana Costa ◽  
Sara Fernandes ◽  
Ana Velosa ◽  
Fernando Rocha
Keyword(s):  
Energy Consumption ◽  
Mechanical Strength ◽  
Co2 Emissions ◽  
Construction Material ◽  
Construction Materials ◽  
High Energy ◽  
Low Grade ◽  
Inorganic Polymers ◽  
New Materials ◽  
High Energy Consumption

Sustainability, particularly in construction materials, has been a subject of growing interest. Civil construction is one of the industries where more materials are consumed, which leads to high energy consumption and CO2 emissions. The production of cement, especially clinker is largely responsible for these problems. As a solution, new materials emerge, which do not require much energy for their production, which are the alkaline cements, specifically the geopolymers. Geopolymers are inorganic polymers obtained by the alkaline activation of aluminosilicate precursors. In the present study geopolymers were developed with low grade kaolin (as a precursor) from a Portuguese company. The development of these geopolymers will be, due to their properties, a good solution for rehabilitation of earth buildings, especially in adobe. The development of these geopolymers is also a contribution to the sustainability of kaolin exploitations as it opens new markets for the low grade kaolins, presently not easily commercialized. As mechanical strength of adobe materials ranges in literature from 0.6 to 8.3 MPa, the values obtained for the developed geopolymers (between ~2 to 10 MPa) can be considered as totally adequate.

The Discussion on the Application of the Electrical Construction Technology of Prefabricated Buildings

2020 ◽  
Vol 9 (4) ◽  
pp. 180
Author(s):  
Guoxiu Cao
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
High Energy ◽  
Building Construction ◽  
Lightning Protection ◽  
Construction Technology ◽  
Engineering Construction ◽  
The Past ◽  
Construction Techniques ◽  
High Energy Consumption

The acceleration of the development of economy and the construction of urbanization has promoted the development of the construction industry, and the construction technology of various construction projects has been continuously innovated. In the past, the building construction often suffered from disadvantages such as high energy consumption and generating large amounts of garbage. Modern construction techniques are actively improving these problems. Prefabricated construction techniques are widely used in the building construction, such as electrical pipeline construction, which makes electrical engineering construction more convenient and environmentally friendly. This paper mainly discusses the construction application of prefabricated electricity in the construction from the aspects of pipeline embedment, lightning protection grounding, the position of electric boxes and so on.

Bioleaching Experiments on a Low-Grade Complex Zinc Ore from Inner Mongolia

2017 ◽  
Vol 262 ◽  
pp. 155-158
Author(s):  
Jia Feng Li ◽  
Lin Lin Tong ◽  
Qiao Chen ◽  
Zhe Nan Jin ◽  
Hong Ying Yang
Keyword(s):  
Inner Mongolia ◽  
High Energy ◽  
Economic Benefits ◽  
Aeration Rate ◽  
Low Grade ◽  
Leaching Rate ◽  
Initial Stage ◽  
Initial Ph ◽  
Efficient Processing ◽  
High Energy Consumption

When dealing with a low-grade complex Zinc ore from Inner Mongolia, problems of low leaching rate, high energy consumption, low economic benefits and pollution were encountered. To treat this low-grade zinc ore economically and effectively, bioleaching was used. This approach produces reliable data for an environmentally friendly and efficient processing of the zinc ore. The results indicate that Zinc occurs in the ore mainly as sphalerite, the latter also containing Indium. The experimental results demonstrated an excellent leaching performance: A leaching rate of nearly 100% is achieved at a temperature of 45°C, a pulp concentration of 10%, an initial pH of 1.8, and an aeration rate of 0.8m3/h. In the initial stage the leaching rate is higher than at the end. It starts with 85% of zinc leaching rate in three days. The Indium in the sphalerite is leached almost completely. This makes a further comprehensive use of such resources possible.

scholarly journals A Review of Exergy Based Optimization and Control

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 364 ◽  
Author(s):  
Corey James ◽  
Tae Young Kim ◽  
Robert Jane
Keyword(s):  
High Energy ◽  
Exergy Destruction ◽  
Multi Objective Optimization ◽  
First Law Of Thermodynamics ◽  
Energy Networks ◽  
The Past ◽  
Optimization And Control ◽  
And Control ◽  
Future Work ◽  
High Energy Consumption

This work presents a critical review of the use of exergy based control and optimization for efficiency improvements in energy networks, with a background of exergy based analysis given for context. Over the past three decades, a number of studies using exergy were conducted to gain a performance advantage for high energy consumption systems and networks. Due to their complexity and the increased scale of the systems, the opportunity to misuse energy inevitability leads to inefficient operations. The studies accomplished in this area are grouped into either control or optimization to highlight each method’s ability to minimize system irreversibilities that lead to exergy destruction. The exergy based optimization and control studies featured demonstrate substantial improvements (as high as 40%) over traditional methods based on the first law of thermodynamics. This paper reviews the work completed in the area of exergy based optimization and control as of the end of September 2019, outlines the progress made, and identifies specific areas where future work can advance this area of study. A relatively small amount of publications are available compared to other fields, with most work occurring in the area of exergy based multi-objective optimization.

scholarly journals The Discussion on the Application of the Electrical Construction Technology of Prefabricated Buildings

2020 ◽  
Vol 9 (5) ◽  
pp. 21
Author(s):  
Guoxiu Cao
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
High Energy ◽  
Building Construction ◽  
Lightning Protection ◽  
Construction Technology ◽  
Engineering Construction ◽  
The Past ◽  
Construction Techniques ◽  
High Energy Consumption

The acceleration of the development of economy and the construction of urbanization has promoted the development of the construction industry, and the construction technology of various construction projects has been continuously innovated. In the past, the building construction often suffered from disadvantages such as high energy consumption and generating large amounts of garbage. Modern construction techniques are actively improving these problems. Prefabricated construction techniques are widely used in the building construction, such as electrical pipeline construction, which makes electrical engineering construction more convenient and environmentally friendly. This paper mainly discusses the construction application of prefabricated electricity in the construction from the aspects of pipeline embedment, lightning protection grounding, the position of electric boxes and so on.

Pilot-scale combustion studies with kraft lignin in a powder burner and a CFB boiler

TAPPI Journal ◽  
2010 ◽  
Vol 9 (6) ◽  
pp. 24-30 ◽  
Author(s):  
NIKLAS BERGLIN ◽  
PER TOMANI ◽  
HASSAN SALMAN ◽  
SOLVIE HERSTAD SVÄRD ◽  
LARS-ERIK ÅMAND
Keyword(s):  
Circulating Fluidized Bed ◽  
Black Liquor ◽  
Chloride Content ◽  
Pilot Scale ◽  
High Energy ◽  
Kraft Lignin ◽  
High Energy Density ◽  
Alkali Chloride ◽  
Cfb Boiler ◽  
Solid Biofuel

Processes have been developed to produce a solid biofuel with high energy density and low ash content from kraft lignin precipitated from black liquor. Pilot-scale tests of the lignin biofuel were carried out with a 150 kW powder burner and a 12 MW circulating fluidized bed (CFB) boiler. Lignin powder could be fired in a powder burner with good combustion performance after some trimming of the air flows to reduce swirl. Lignin dried to 10% moisture content was easy to feed smoothly and had less bridging tendencies in the feeding system than did wood/bark powder. In the CFB boiler, lignin was easily handled and cofired together with bark. Although the filter cake was broken into smaller pieces and fines, the combustion was not disturbed. When cofiring lignin with bark, the sulfur emission increased compared with bark firing only, but most of the sulfur was captured by calcium in the bark ash. Conventional sulfur capture also occurred with addition of limestone to the bed. The sulfur content in the lignin had a significantly positive effect on reducing the alkali chloride content in the deposits, thus reducing the high temperature corrosion risk.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Battlefields from Event to Heritage

2020 ◽  
Author(s):  
John Carman ◽  
Patricia Carman
Keyword(s):  
Twentieth Century ◽  
Security Studies ◽  
New Developments ◽  
Critical Security Studies ◽  
The Past ◽  
New Approaches ◽  
Large Numbers ◽  
The World ◽  
War And Conflict ◽  
Modern War

What is—or makes a place—a ‘historic battlefield’? From one perspective the answer is a simple one—it is a place where large numbers of people came together in an organized manner to fight one another at some point in the past. But from another perspective it is far more difficult to identify. Quite why any such location is a place of battle—rather than any other kind of event—and why it is especially historic is more difficult to identify. This book sets out an answer to the question of what a historic battlefield is in the modern imagination, drawing upon examples from prehistory to the twentieth century. Considering battlefields through a series of different lenses, treating battles as events in the past and battlefields as places in the present, the book exposes the complexity of the concept of historic battlefield and how it forms part of a Western understanding of the world. Taking its lead from new developments in battlefield study—especially archaeological approaches—the book establishes a link to and a means by which these new approaches can contribute to more radical thinking about war and conflict, especially to Critical Military and Critical Security Studies. The book goes beyond the study of battles as separate and unique events to consider what they mean to us and why we need them to have particular characteristics. It will be of interest to archaeologists, historians, and students of modern war in all its forms.

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