scholarly journals A Brief Note on the Heap Leaching Technologies for the Recovery of Valuable Metals

2019 ◽  
Vol 11 (12) ◽  
pp. 3347 ◽  
Author(s):  
Thriveni Thenepalli ◽  
Ramakrishna Chilakala ◽  
Lulit Habte ◽  
Lai Quang Tuan ◽  
Chun Sik Kim
Keyword(s):  
Low Cost ◽  
Precious Metals ◽  
Heap Leaching ◽  
Green Energy ◽  
Environmental Benefits ◽  
Energy Applications ◽  
Leaching Process ◽  
Attractive Option ◽  
Industrial Mining ◽  
The Cost

Heap leaching is a low-cost technology used in industrial mining to recover precious metals such as gold and uranium, along with several other highly sought after metals like copper, from their primary resources (ores and minerals). For many decades, there has been a growing demand for heap leaching due to its environmental benefits. Heap leaching provides mining operators with a benign, effective and economical solution for the environment and produces only minor emissions from furnaces. The cost of the heap leaching process is low, making this process an attractive option from a financial standpoint. Here, we shall present a brief review of the heap leaching process when applied to the extraction of different metals from primary resources (ores and minerals). This paper presents a roadmap to satisfy future national demands for rare earth elements (REEs). This heap leaching process is applicable for the recovery of REEs from secondary resources such as mining and coal residues. Heap leaching plays a significant role in the recovery of critical elements which are used in clean and green energy applications. In the mining sector, heap leaching is a distinguished method for the recovery of valuable/beneficial metals from low-quality ore. In the present study, we shall report briefly on the heap leaching technologies for valuable metal recovery with economic advantages.

scholarly journals A climate investment trap in developing economies

2021 ◽  
Author(s):  
Nadia Ameli ◽  
Olivier Dessens ◽  
Matthew Winning ◽  
Jennifer Cronin ◽  
Hugues Chenet ◽  
...  
Keyword(s):  
Cost Of Capital ◽  
Developing Economies ◽  
Low Cost ◽  
Energy Transition ◽  
Green Energy ◽  
Electricity Production ◽  
Green Electricity ◽  
Net Zero ◽  
Sustainable Finance ◽  
The Cost

Abstract Finance is vital for the green energy transition, but the access to low cost finance is uneven as the cost of capital differs substantially between regions. This study shows how modelled decarbonisation pathways of developing economies are disproportionately impacted by assumptions around their cost of capital (WACC). For example, representing regionally specific WACC values indicates 35% lower green electricity production in Africa for a cost-optimal 2°C pathway. Moreover, results show that early convergence of WACC values for green and brown technologies in 2050 would allow Africa to reach net-zero emissions approximately 10 years earlier than when convergence is not considered. A “climate investment trap” arises for developing economies when climate-related investments remain chronically insufficient. Elements of sustainable finance frameworks currently present barriers to these finance flows and radical changes are needed so that capital is better allocated to the regions that most need it.

Utilization of Sugar Sediment Waste for a Low Cost Lightweight Concrete Development with Environmental Impact Reduction

2017 ◽  
Vol 730 ◽  
pp. 369-374
Author(s):  
Atthakorn Thongtha ◽  
Somchai Maneewan ◽  
Chantana Punlek
Keyword(s):  
Construction Industry ◽  
Industrial Waste ◽  
Lightweight Concrete ◽  
Low Cost ◽  
Environmental Benefits ◽  
Health Impacts ◽  
Impact Reduction ◽  
Wide Scale ◽  
Aerated Concrete ◽  
The Cost

Waste sugar sediment was included in the mix of lightweight concrete. The optimum mix that we identified was 10% by weight replacement of lime by sugar sediment. The resultant product exhibited the highest compressive strength of approximately 5.5 N/mm2, and demonstrated that a substantial proportion of the 872 million kgs of waste sugar sediment produced in Thailand per year could be diverted from landfills, providing substantial economic and environmental benefits. Our analysis indicates that about 13 million kgs of lime could be replaced by an equal amount of sugar sediment, 13 million kgs, per year, if the improved composition of lightweight autoclaved aerated concrete is adopted by the construction industry on a wide scale. As the cost of lime is about 2 Baht per kg, and sugar sediment is essentially a free input, an estimated 26,000,000 Baht per year savings is achievable. The economic, environmental and health impacts of reducing this industrial waste going into landfill areas by 13 million kgs per year must also be seen as substantial.

Computational/Theoretical Modeling of Flow Physics and Transport in Disk Rotor Drag Turbine Expanders for Green Energy Conversion Technologies

2010 ◽  
Author(s):  
Van P. Carey
Keyword(s):  
Energy Conversion ◽  
Capital Investment ◽  
Waste Heat ◽  
Low Cost ◽  
Green Energy ◽  
Hot Water ◽  
Cfd Modeling ◽  
Modeling And Analysis ◽  
Energy Applications ◽  
Advantages And Disadvantages

This paper explores the theoretical and computational challenges associated with modeling of flow, momentum transport, and energy conversion processes in disk rotor drag turbine expanders. This category of expander devices, also known as Tesla turbines, has distinct advantages for Rankine power generation using low temperature heat from renewable source such as solar, waste heat, or geothermal steam or hot water. Specifically, the nozzle and rotor designs and the overall expander can be simple to manufacture, low cost, and durable, making this type of expander an attractive option in green energy technology applications where low maintenance costs and rapid capital investment payback are important qualities. Efficient energy conversion performance in rotor disk drag expanders requires that the nozzle efficiently convert flow exergy to fluid kinetic energy, and the rotor be designed to efficiently convert fluid angular momentum to shaft torque and power. To achieve these goals, modeling and analysis tools must provide the designer with a means to predict the performance of these components that accurately represents the physics, and can be effectively used to illuminate the parametric trends in performance. Two categories of modeling are examined in this paper: (1) computational fluid dynamics (CFD) modeling, and (2) more idealized one- and two-dimensional analysis frameworks. The advantages and disadvantages of these two approaches are examined here for the specific flows of interest in this type of expander design. The implications of model predictions for optimal design of disk rotor expanders for green energy applications are also discussed.

scholarly journals Higher cost of finance exacerbates a climate investment trap in developing economies

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nadia Ameli ◽  
Olivier Dessens ◽  
Matthew Winning ◽  
Jennifer Cronin ◽  
Hugues Chenet ◽  
...  
Keyword(s):  
Cost Of Capital ◽  
Developing Economies ◽  
Low Cost ◽  
Weighted Average ◽  
Energy Transition ◽  
Green Energy ◽  
Electricity Production ◽  
Low Carbon ◽  
Policy Interventions ◽  
The Cost

AbstractFinance is vital for the green energy transition, but access to low cost finance is uneven as the cost of capital differs substantially between regions. This study shows how modelled decarbonisation pathways for developing economies are disproportionately impacted by different weighted average cost of capital (WACC) assumptions. For example, representing regionally-specific WACC values indicates 35% lower green electricity production in Africa for a cost-optimal 2 °C pathway than when regional considerations are ignored. Moreover, policy interventions lowering WACC values for low-carbon and high-carbon technologies by 2050 would allow Africa to reach net-zero emissions approximately 10 years earlier than when the cost of capital reduction is not considered. A climate investment trap arises for developing economies when climate-related investments remain chronically insufficient. Current finance frameworks present barriers to these finance flows and radical changes are needed so that capital is more equitably distributed.

scholarly journals Tradeoffs among Ecosystem Services, Performance Certainty, and Cost-efficiency in Implementation of the Chesapeake Bay Total Maximum Daily Load

2013 ◽  
Vol 42 (1) ◽  
pp. 196-224 ◽  
Author(s):  
Lisa A. Wainger ◽  
George Van Houtven ◽  
Ross Loomis ◽  
Jay Messer ◽  
Robert Beach ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
Low Cost ◽  
Pollution Abatement ◽  
Total Maximum Daily Load ◽  
Environmental Benefits ◽  
Potomac River ◽  
Compliance Costs ◽  
The Cost ◽  
Total Maximum ◽  
Daily Load

The cost-effectiveness of total maximum daily load (TMDL) programs depends heavily on program design. We develop an optimization framework to evaluate design choices for the TMDL for the Potomac River, a Chesapeake Bay sub-basin. Scenario results suggest that policies inhibiting nutrient trading or offsets between point and nonpoint sources increase compliance costs markedly and reduce ecosystem service co-benefits relative to a least-cost solution. Key decision tradeoffs highlighted by the analysis include whether agricultural production should be exchanged for low-cost pollution abatement and other environmental benefits and whether lower compliance costs and higher co-benefits provide adequate compensation for lower certainty of water-quality outcomes.

Development of Catalytic Converter Using Non-Precious Metals

2015 ◽  
Vol 1115 ◽  
pp. 462-467 ◽  
Author(s):  
A.K.M. Mohiuddin
Keyword(s):  
Co Oxidation ◽  
No Reduction ◽  
Catalytic Converter ◽  
Low Cost ◽  
Flow Characteristics ◽  
Precious Metals ◽  
Catalyst System ◽  
Rich Mixture ◽  
Fluid Flow Characteristics ◽  
The Cost

This paper shows the uses of low cost metal for the development of catalytic converters. While bringing down the cost, attention must be paid on the performance capability of the catalytic converter. The objective of this work is to develop and design a low cost catalytic converter using copper as the main catalyst in the catalyst system. Copper powder was chosen as the alternative catalyst to reduce the use of precious group metals (PGMs) platinum, palladium, and rhodium. A spark ignition engine’s catalytic converter has to perform the oxidation of CO, oxidation of HC and reduction of NOxsimultaneously in order to satisfy its performance requirement. These three chemical reactions are taking place simultaneously in a three way catalytic converter. To investigate the chemical kinetics and fluid flow characteristics of a catalytic converter, simulations have been carried out using COMSOL. From COMSOL MULTIPHYSICS, catalytic converter’s velocity field and pressure distribution have been simulated. From COMSOL REACTION ENGINEERING LAB, NO and CO concentration from a catalytic converter kinetics model have been plotted. NO and CO conversion for different air to fuel ratio had shown that for rich mixture, NO reduction reaches its maximum but CO oxidation is at its minimum. In lean mixture, CO oxidation is at its maximum but NO reduction is at its minimum. Simulations have shown the actual characteristics of the catalytic converter performance. The flow throughout catalytic converter and the backpressure have successfully determined and the catalyst conversion efficiency also shown clearly.

scholarly journals Development and Performance Analysis of a Low-Cost Hydrogen Generation System Using Locally Available Materials

2020 ◽  
Vol 68 (1) ◽  
pp. 49-56
Author(s):  
Gour Chand Mazumder ◽  
SM Nasif Shams ◽  
Md Habibur Rahman ◽  
Saiful Huque
Keyword(s):  
Hydrogen Generation ◽  
Low Cost ◽  
Small Scale ◽  
Bipolar Electrode ◽  
Performance Study ◽  
Outlet Port ◽  
Energy Applications ◽  
In Series ◽  
And Performance ◽  
The Cost

In this paper, a low-cost water electrolyzer is developed and its performance study is presented. Locally found materials are used to develop the electrolyzer. The electrolyzer has two cells connected in parallel and bipolar electrode configuration. In common, different cells are connected in series but for this electrolyzer parallel connection has been tested. A very thin polymer, Nylon-140 has been used as separator membranes for this electrolyzer. In separator membrane assembly, the designed geometry creates two separate gas channels internally which enables the direct collection of hydrogen and oxygen gas from the designated outlet port of the electrolyzer. The geometry excludes the need of external tubing into each cell-compartments to collect hydrogen and oxygen separately. The developed electrolyzer is found to be 42% efficient with its highest production rate of 227.27 mL/min. The purity of hydrogen is found to be more than 92% and justified with the burn test. The cost is 20 times less than the commercial electrolyzers. The development method and scheme can be helpful to popularize the small scale use of hydrogen in Bangladesh for various renewable energy applications. Dhaka Univ. J. Sci. 68(1): 49-56, 2020 (January)

scholarly journals Hybrid Micro-Energy Harvesting Model using WSN for Self-Sustainable Wireless Mobile Charging Application

2021 ◽  
Vol 3 (3) ◽  
pp. 157-169
Author(s):  
Haoxiang Wang
Keyword(s):  
Energy Harvesting ◽  
Energy Efficient ◽  
Low Cost ◽  
Base Station ◽  
Green Energy ◽  
Microelectronic Devices ◽  
Proposed Model ◽  
Mobile Charger ◽  
The Cost ◽  
Deployment Cost

The self-sustainable Wireless Sensor Networks (WSNs) face a major challenge in terms of energy efficiency as they have to operate without replacement of batteries. The benefits of renewable and green energy are taken into consideration for sensing and charging the battery in recent literatures using Energy Harvesting (EH) techniques. The sensors are provided with a reliable energy source through Wireless Charging (WC) techniques. Several challenges in WSN are addressed by combining these technologies. However, it is essential to consider the deployment cost in these systems. This paper presents a self-sustainable energy efficient WSN based model for Mobile Charger (MC) and Energy Harvesting Base Station (EHBS) while considering the cost of deployment. This system can also be used for low-cost microelectronic devices and low-cost Micro-Energy Harvesting (MEH) system-based applications. While considering the deployment cost, the network lifetime is maximized and an extensive comparison of simulation with various existing models is presented to emphasize the validity of the proposed model.

Investigation Using Simulations for the Development of Low Cost Catalytic Converter from Non-Precious Metals

2012 ◽  
Vol 445 ◽  
pp. 899-904 ◽  
Author(s):  
A.K.M. Mohiuddin ◽  
Ataur Rahman
Keyword(s):  
Catalytic Converter ◽  
Low Cost ◽  
Precious Metals ◽  
Fuel Mixture ◽  
Rich Condition ◽  
Emission Regulation ◽  
Performance Capability ◽  
Full Throttle ◽  
The Cost ◽  
Catalyst Distribution

This paper discusses the uses of non-precious metals in catalytic converters to bring down the cost without sacrificing the performance capability. Copper powder and nickel catalyst were chosen as the alternative catalysts to reduce the use of precious group metals (PGMs) platinum, palladium, and rhodium. Simulation by COMSOL has shown that Nickel and copper were very effective in reducing NOx during rich condition of air-fuel mixture while oxidizing CO and HC during lean condition. Simulations using FLUENT and COMSOL have shown the actual characteristics of the catalytic converter performance. The flow throughout catalytic converter and the backpressure have successfully determined. Furthermore, catalyst conversion efficiency also has been shown clearly. On the other hands, the experimental results have excellently validated the simulation results in terms of the nature and trends of the catalytic converter performance as well as its efficiency. Catalyst distribution and application of the non-zoning monolith substrates have further contributes to cut down the production cost. It was found that the low cost catalytic converter was able to meet the EURO 2 emission regulation control and has optimum backpressure at full throttle.

scholarly journals Metal Streaming Instruments As an Tool to Increase Mining Project Values

2017 ◽  
Vol 33 (2) ◽  
pp. 129-144
Author(s):  
Herbert Wirth ◽  
Maciej Koński
Keyword(s):  
Low Cost ◽  
Precious Metals ◽  
Development Stage ◽  
Fundamental Analysis ◽  
Project Financing ◽  
Positive Potential ◽  
Mining Project ◽  
Company Valuation ◽  
Mining Projects ◽  
The Cost

Abstract Stream financing is an important instrument that supports bringing projects from their development stage into production and maximizing their value. Taking relatively significant difficulties encountered by mining companies with securing project financing in recent years into account and, on the other hand, based on fundamental analysis, the positive potential of the copper market in the upcoming years, stream financing instruments can play a significant role in the copper market by supporting the development of new mining projects owned by companies with limited access to basic sources of funding. On the basis of a fundamental analysis of the copper market, the article explains and justifies presumptions for using metal streaming transactions in financing the development of mining projects at different stages of advancement. T he article explains key metal streaming structuring and valuation rules in such transactions. Additionally, it explains the main requirements related to project stages of development and the competitive position that determines the ability of efficient capital raising by means of streaming. The performed analysis justifies the potential of using metal streaming instruments to maximize project value. Disadvantages of metal streaming are related mainly to the lack of participation in potential further metal price increase in relation to the prices used in streaming instruments. Due to the discount in company valuation that may occur in the event the cost of production increases after additional revenue from precious metals no longer exists, streaming instruments are suitable mainly to the low cost assets.

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