scholarly journals Bioleaching of Iron, Copper, Lead, and Zinc from the Sludge Mining Sediment at Different Particle Sizes, pH, and Pulp Density Using Acidithiobacillus ferrooxidans

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1013
Author(s):  
Dana Rouchalova ◽  
Kamila Rouchalova ◽  
Iva Janakova ◽  
Vladimir Cablik ◽  
Sarah Janstova
Keyword(s):  
Particle Size ◽  
Acidithiobacillus Ferrooxidans ◽  
Waste Product ◽  
Mining Industry ◽  
Absorption Spectrometry ◽  
Ore Deposits ◽  
Point Of View ◽  
Pulp Density ◽  
Bacterial Cells ◽  
Economic Point

Globally, the amounts of metal ore deposits have been declining, so the research directions investigating the extraction of metals from materials that are classified as waste are gaining more importance every year. High concentrations of Cu, Pb, Zn, and Fe were analyzed in the sludge sediment (Zlaté Hory, Czech Republic), which is a waste product of the mining industry. In the bioleaching process, bacterial cells have been established as being able to convert metals from solid to liquid phase. However, the most important parameters of bioleaching are particle size, pH, and pulp density, thus our research focused on their optimization. The acidophilic and mesophilic bacteria Acidithiobacillus ferrooxidans were applied due to the high Fe content in the sample. The recovery of metals in the leachate was determined by F-AAS and the residual metal concentrations in the waste fraction were analyzed by XRF. The grain size fractions <40 µm –200 µm were investigated. The atomic absorption spectrometry (AAS) results show that the highest Fe (76.48%), Cu (82.01%), and Pb (88.90%) recoveries were obtained at particle size of 71–100 μm. Zn was dissolved for all fractions above 90%. Experiments with different pH values were performed at a pH of 1.6–2.0. The highest dissolution rates of Zn, Fe, and Cu were achieved with a suspension pH of 1.8, where 98.73% of Zn, 85.42% of Fe, and 96.44% of Cu were recovered. Due to the high percentage dissolution of metals, experiments were performed under pilot conditions in a bioreactor at a pulp density of 2.5% and 4.2% (w/v). From an economic point of view, the leaching time of 28 days was evaluated as sufficient.

An isotopic and trace element investigation of gossans from Troodos ophiolite, Cyprus

2020 ◽  
Author(s):  
Nina Zaronikola ◽  
Vinciane Debaille ◽  
Sophie Decree ◽  
Ryan Mathur ◽  
Christodoulos Hadjigeorgiou ◽  
...  
Keyword(s):  
Massive Sulfide ◽  
Major And Trace Elements ◽  
Ore Deposits ◽  
Point Of View ◽  
Economic Point ◽  
Troodos Ophiolite ◽  
Zinc Isotopes ◽  
Copper And Zinc ◽  
Vms Deposits ◽  
Set Up

&lt;p&gt;The Troodos ophiolite is widely accepted to be a fragment of Mesozoic oceanic crust, which uplifted during Alpine orogeny, due to the collision of Eurasia and Africa (Gass and Masson-Smith, 1963; Vibetti, 1993; Adamides, 2011; Antivachis, 2015). It belongs to supra-subduction ophiolites, which probably set up during subduction initiation associated with back-arc spreading (Pearce, 1975; Rautenschlein et al., 1985; Pearce and Robinson, 2010; Martin et al., 2019). The Troodos ophiolite is mentioned to be one of the most well studied and well-preserved ophiolitic sequences (Moores and Vine, 1971; Benn and Laurent, 1987; Patten et al., 2017), presenting significant Cyprus-type sulphide deposits (Constantinou and Govett, 1973; Adamides, 2014).&lt;/p&gt;&lt;p&gt;Cyprus-type deposits are generally, considered as mafic type volcanogenic massive sulfide deposits (VMS), mainly rich in copper and subsidiary zinc, with average grade of 1.3 &amp;#177; 1.1% Cu and 0.8 &amp;#177; 0.4% Zn (Hannington et al., 1998; Barie and Hannington, 1999; Patten et al., 2016). VMS deposits are formed in the sea floor, along mid-ocean ridges, by the circulation of high temperature hydrothermal fluids, which their source is seawater (Gillis and Robinson, 1988; Richards et al., 1989; Patten et al., 2017; Martin et al., 2019). In many different regions along the Troodos ophiolite, the VMS deposits are covered by thick, Fe oxides enriched gossans (Bear, 1960; Herzig et al., 1991). In general, those can be formed, when the VMS deposits are exposed to weathering and oxidizing conditions (Herzig et al., 1991), but still the conditions for their formation are debated. The studied gossans from Troodos ophiolite are variegated due to the presence of white silica, red hematite and yellow jarosite. Gossans are always a very interesting part of the ophiolitic sequence from an economic point of view, as they present not only significant amount of extractible copper and zinc, but also, gold and silver (Bear, 1960; Herzig et al., 1991).&lt;/p&gt;&lt;p&gt;We aim to examine the major and trace elements of gossans, which have been collected from different mines (West Apliki, Skouriotissa and Agrokipia mines) of Troodos ophiolite, and define their enrichment or depletion in copper and zinc, by coupling copper and zinc stable non-traditional isotopes. We combined copper with zinc isotopes in a very novel and original approach in order to give information about the conditions prevailing in the system of interest. As many authors mentioned before, supergene enriched environments are the best places to examine the behavior of Cu isotope fractionation under the weathering conditions of ore deposits (Mathur et al., 2008). On the other hand, Zn isotopes are not redox sensitive, but pH-sensitive (Pons, 2016). By coupling them, it can bring light in understanding the way, the nature of fluids that led to gossans formation and their enrichment in copper and zinc in different locations of Troodos ophiolite.&lt;/p&gt;

A Study on the Synthesis of SiC Powder from the Silicon Sludge of the Photovoltaic Industry

2012 ◽  
Vol 724 ◽  
pp. 49-52 ◽  
Author(s):  
Woo Teck Kwon ◽  
Soo Ryong Kim ◽  
Y. Kim ◽  
Yoon Joo Lee ◽  
Eun Jin Jung ◽  
...  
Keyword(s):  
Particle Size ◽  
Solar Cell ◽  
Silicon Powder ◽  
Point Of View ◽  
Economic Point ◽  
Heat Treated ◽  
Particle Size Analyzer ◽  
Different Temperatures ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

β-SiC powder was synthesized directly from silicon sludge with carbon black. Large amount of silicon sludge is generated from Solar Cell industry. In an environmental and economic point of view, recycling silicon sludge is important. In this study, two kinds of silicon sludge were characterized using XRD, SEM/EDS and FT-IR. SiC powder was synthesized by the reaction of ball-milled silicon powder for 3h in vacuum at different temperatures (1350 and 1600). Physical properties of the heat treated SiC have been characterized using a SEM, XRD, Particle size analyzer and FT-IR Spectroscopy.

scholarly journals X ray Diffraction (XRD) Analysis of Coir Pith Concrete

2020 ◽  
Vol 8 (5) ◽  
pp. 717-719
Keyword(s):  
Surface Treatment ◽  
Outer Surface ◽  
Waste Product ◽  
Xrd Analysis ◽  
Alkaline Treatment ◽  
Point Of View ◽  
X Ray Diffraction ◽  
River Sand ◽  
Economic Point ◽  
Coir Pith

The usage of waste product in concrete decreases the major issue of dumping problems in the society and as well as its economical also. Coir pith is one among that product from coconut industry. In this examination accentuation was made on the practicality of utilization of coir pith as a fractional substitution of regular sand in concrete. The XRD analysis has been done for treated coir pith material and the concrete in which the same has been added. Thus the result of the XRD test shows the presence of each component in that particular material with accurate percentage and so it reveals that whether it matches all the necessary components which are present in river sand. This research paved the way to overcome the disposal problems caused by the waste materials as well as in economic point of view. Adding coir pith in the concrete needs an outer surface treatment in advance, which actually removes the dirt and dust. The effectiveness of the outer surface treatment carried out on the coir pith is assessed by XRD examination. Alkaline treatment causes a slight change in the structure of the cellulose. By dying coir pith treated with NaOH, the range of treated coir pith shows an adjustment in the expulsion of hemicellulose and lignin from the outside surface of coir pith. These outcomes demonstrate that the treatments were done effectively to change the qualities of the outside surface of the coir pith by removing the dirt and dust. Thus after treating this coir pith with NaOH, it is now ready to partially replace with sand in concrete

scholarly journals NEW METALLOGENETIC CONCEPTS AND SUBSTAINABILITY PERSPECTIVES FO NON-ENERGY METALLIC MINERALS IN CENTRAL MACEDONIA, GREECE

2017 ◽  
Vol 43 (5) ◽  
pp. 2437 ◽  
Author(s):  
N.D. Arvanitidis
Keyword(s):  
Mining Industry ◽  
Precious Metals ◽  
Mineral Resources ◽  
Ore Deposits ◽  
Point Of View ◽  
Social Growth ◽  
Genetic Types ◽  
Wide Range ◽  
Economic Perspectives ◽  
Efficient Exploration

Greece’s geology favours a potent and dynamic use of mineral resources, which became a major incentive of the country’s mining business, and economic and social growth. Among the Non-Energy Metallic Minerals (NEMM) commodities, base and precious metals, in particular copper and gold, is becoming an increasingly important and rapidly growing target of the mining industry. In the region of central Macedonia, where most of their deposits are hosted, the NEMM occur in a wide range of genetic types related to Alpine orogenic and subduction related ore forming processes extending from Mesozoic to Cenozoic times, and culminating during the Tertiary (Arvanitidis and Amov, 2006). From the global metallogenetic point of view the post-Alpine Tertiary geodynamic systems in SE Europe are potential in producing high-grade ore deposits of base and precious metal sulphide minerals. The classification of NEMM mineralizations to specific genetic types, along with the geological knowledge available, is contributing (a) to more efficient exploration and prospect evaluation (b) to safer assessment of ore potential and economic perspectives (c) to rational management of resource production, and (d) in applying sustainable development practices.

Recovery of Silicon and Silicon Carbide Powder from Waste Silicon Wafer Sludge

2013 ◽  
Vol 761 ◽  
pp. 65-68 ◽  
Author(s):  
Woo Teck Kwon ◽  
Soo Ryong Kim ◽  
Y. Kim ◽  
Jee Ban Poudel ◽  
Sea Cheon Oh
Keyword(s):  
Silicon Carbide ◽  
Particle Size ◽  
Linear Equation ◽  
Silicon Wafer ◽  
Point Of View ◽  
Carbide Powder ◽  
Drying Rate ◽  
Economic Point ◽  
Particle Size Analyzer ◽  
Silicon Carbide Powder

In an environmental and economic point of view, recycling of silicon wafer sludge is important. The aim of this work is to investigate the recycling method of silicon wafer sludge. Therefore, drying rate of silicon wafer sludge has been studied for separation of liquid and solid from sludge. Silicon and silicon carbide powder obtained from silicon wafer sludge were analyzed by SEM, XFR, XRD and particle size analyzer. The recovered oil was also characterized using GC-MS. From this work, it can be seen that the falling drying rate of silicon wafer sludge is linear equation. Various metal components have been found in recovered solid powder caused by wire sawing processing.

Sophie Laws, with Caroline Harper and Rachel Marcus. Research for Development: A Practical Guide. New Delhi: Vistaar Publications. 2003. xiii+475 pages. Paperback. Indian Rupees 450.00.

2003 ◽  
Vol 42 (2) ◽  
pp. 170-172
Author(s):  
Mir Annice Mahmood
Keyword(s):  
Policy Research ◽  
Point Of View ◽  
Basic Question ◽  
New Delhi ◽  
Economic Point ◽  
Scarce Resources ◽  
Is Research ◽  
The Subject ◽  
Development Workers

To implement any successful policy, research about the subject-matter is essential. Lack of knowledge would result in failure and, from an economic point of view, it would lead to a waste of scarce resources. The book under review is essentially a manual which highlights the use of research for development. The book is divided into two parts. Part One informs the reader about concepts and some theory, and Part Two deals with the issue of undertaking research for development. Both parts have 11 chapters each. Chapter 1 asks the basic question: Is research important in development work? The answer is that it is. Research has many dimensions: from the basic asking of questions to the more sophisticated broad-based analysis of policy issues. The chapter, in short, stresses the usefulness of research which development workers ignore at their own peril.

Bleak Weather for Sun-Shine AG: A Case Study of Impairment of Assets

2014 ◽  
Vol 30 (2) ◽  
pp. 113-126 ◽  
Author(s):  
Dominic Detzen ◽  
Tobias Stork genannt Wersborg ◽  
Henning Zülch
Keyword(s):  
Real Life ◽  
Accounting Standards ◽  
Point Of View ◽  
Professional Judgment ◽  
Economic Point ◽  
Instructional Resource

ABSTRACT This case originates from a real-life business situation and illustrates the application of impairment tests in accordance with IFRS and U.S. GAAP. In the first part of the case study, students examine conceptual questions of impairment tests under IFRS and U.S. GAAP with respect to applicable accounting standards, definitions, value concepts, and frequency of application. In addition, the case encourages students to discuss the impairment regime from an economic point of view. The second part of the instructional resource continues to provide instructors with the flexibility of applying U.S. GAAP and/or IFRS when students are asked to test a long-lived asset for impairment and, if necessary, allocate any potential impairment. This latter part demonstrates that impairment tests require professional judgment that students are to exercise in the case.

The Role of Economic Evaluation in Dissemination and Implementation Research

2017 ◽  
Author(s):  
Ramesh Raghavan
Keyword(s):  
Service Providers ◽  
Implementation Strategies ◽  
Cost Effective ◽  
Point Of View ◽  
Dissemination And Implementation ◽  
Economic Point ◽  
Open Questions ◽  
Public Health Organizations ◽  
Quality Health ◽  
Dissemination And Implementation Research

This chapter presents an overview of how D&I research can be evaluated from an economic point of view. Dissemination and implementation imposes costs upon knowledge purveyors, provider organizations, public health organizations, and payers (including governments). However, whether these added costs will result in improved service delivery and, perhaps more importantly, client outcomes and improvements in population health remain as open questions. If emerging studies reveal that defined implementation strategies are more cost effective than “usual” implementation, then policymakers and service providers will need to resource these added costs of implementation in order to assure the success and sustainability of high-quality health services over the long term.

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