Integrated Recovery Processes for Precious Metals from Urban Mine Sources and Case Studies

Author(s):  
Sadia Ilyas ◽  
Hyunjung Kim ◽  
Rajiv Ranjan Srivastava
2013 ◽  
Vol 778 ◽  
pp. 990-997
Author(s):  
Douglas Porter ◽  
Ron W. Anthony

The settlement of the American West was directly dependent on the extraction of resources including minerals, precious metals, timber, and the commerce that resulted. The infrastructure that developed around these extraction activities was intended to be merely functional, and therefore temporary. Readily available forest resources made timber structures relatively inexpensive and easy to build; they could be put into service quickly and were adequate to immediate needs. Many of these structures survive today at former mining and milling sites, along with remnants of the railroad lines that served them. Together they provide a compelling picture of the development of the American West and the technologies used to extract, refine, and transport the materials that initiated settlement of the region. Preservation of these sites and structures poses many interesting problems: Most of the structures were designed to meet short-term needs and have already outlasted their intended service life; Most of the structures were strictly utilitarian, and maintenance of them was discontinued when mining or logging operations ceased; Exposure of these structures to severe weather conditions is typical. The structures are at remote sites and access is extremely limited; Many of the structures are dangerous due to the extent of deterioration and proximity to open mines, adits, and industrial waste. In this presentation, the authors will use three case studies to illustrate preservation issues common to remote resource extraction sites, techniques used to access the timber structures, and some of the stabilization strategies implemented at each of the sites. The case studies include the aerial tramway of the Keane Wonder Mine in Death Valley National Park, the Cable Mountain Draw Works in Zion National Park, and the Hanging Flume in Colorado.


2018 ◽  
Vol 10 (8) ◽  
pp. 2658 ◽  
Author(s):  
Esther Thiébaud ◽  
Lorenz Hilty ◽  
Mathias Schluep ◽  
Heinz Böni ◽  
Martin Faulstich

The increased use of digital information and communications technologies (ICT) is giving rise to fast-growing waste streams that contain important material resources. In contrast to bulk materials and precious metals, the recovery of most critical metals has not yet been commercially established, and they are thus lost within the recycling process. In this article, we used dynamic material flow analysis to explore the stocks and flows of indium, neodymium, and gold incorporated in end-user devices in Switzerland. Our analysis covered the use, collection, recycling, and disposal phases. This enabled us to track the three metals from their entry into Switzerland as components of new devices until their recovery, disposal in landfills, or dissipation to the environment. Using statistical entropy analysis (SEA), we further analyzed the dilution or concentration of the metals during their route through the current system. The data uncertainty was addressed employing a probabilistic approach. The largest quantities of all three metals are found in the devices currently in use. The second-largest stocks are slags disposed in landfills for indium, slags used for construction for neodymium, and the output of metal recovery processes for gold. The SEA illustrates how the current collection and recycling system successfully concentrates all three metals. While 70% of gold leaving the use phase is recovered, indium and neodymium are dissipated to slags after smelting and incineration processes due to the lack of economic incentives and lacking recovery processes on a commercial scale.


2019 ◽  
Vol 2 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Jacek Sitko

Abstract The article presents the technologies of obtaining precious metals as a byproduct in the processing of copper concentrates in KGHM POLSKA MIEDŹ SA and in the processing of zinc and lead concentrates in Huta Cynku “MIASTECZKO ŚLĄSKIE”. Discussed technologies for recovery of silver from secondary raw materials such as: used silver catalysts, scrapped electronic devices, defective transistors, scrap of silver-plated glasses, used solutions used for processing photosensitive materials are discussed. Jewellery and tableware and technical coatings in electronics and electrical engineering. The high reflectivity of the light rays from the silver surface was used in the production of special reflectors and mirrors, and chemical resistance in the construction of apparatus (such as equipment resistant to molten hydroxide alkali metals).


2003 ◽  
Vol 9 (1) ◽  
pp. 2-11 ◽  
Author(s):  
Dexter Dunphy

ABSTRACTThis paper addresses the issue of corporate sustainability. It examines why achieving sustainability is becoming an increasingly vital issue for society and organisations, defines sustainability and then outlines a set of phases through which organisations can move to achieve increasing levels of sustainability. Case studies are presented of organisations at various phases indicating the benefits, for the organisation and its stakeholders, which can be made at each phase. Finally the paper argues that there is a marked contrast between the two competing philosophies of neo-conservatism (economic rationalism) and the emerging philosophy of sustainability. Management schools have been strongly influenced by economic rationalism, which underpins the traditional orthodoxies presented in such schools. Sustainability represents an urgent challenge for management schools to rethink these traditional orthodoxies and give sustainability a central place in the curriculum.


1978 ◽  
Vol 9 (4) ◽  
pp. 220-235
Author(s):  
David L. Ratusnik ◽  
Carol Melnick Ratusnik ◽  
Karen Sattinger

Short-form versions of the Screening Test of Spanish Grammar (Toronto, 1973) and the Northwestern Syntax Screening Test (Lee, 1971) were devised for use with bilingual Latino children while preserving the original normative data. Application of a multiple regression technique to data collected on 60 lower social status Latino children (four years and six months to seven years and one month) from Spanish Harlem and Yonkers, New York, yielded a small but powerful set of predictor items from the Spanish and English tests. Clinicians may make rapid and accurate predictions of STSG or NSST total screening scores from administration of substantially shortened versions of the instruments. Case studies of Latino children from Chicago and Miami serve to cross-validate the procedure outside the New York metropolitan area.


2014 ◽  
Vol 23 (1) ◽  
pp. 42-54 ◽  
Author(s):  
Tanya Rose Curtis

As the field of telepractice grows, perceived barriers to service delivery must be anticipated and addressed in order to provide appropriate service delivery to individuals who will benefit from this model. When applying telepractice to the field of AAC, additional barriers are encountered when clients with complex communication needs are unable to speak, often present with severe quadriplegia and are unable to position themselves or access the computer independently, and/or may have cognitive impairments and limited computer experience. Some access methods, such as eye gaze, can also present technological challenges in the telepractice environment. These barriers can be overcome, and telepractice is not only practical and effective, but often a preferred means of service delivery for persons with complex communication needs.


ASHA Leader ◽  
2013 ◽  
Vol 18 (1) ◽  
pp. 12-13
Author(s):  
Kristen Chmela

In November, Kristen Chmela—executive director of the Chmela Fluency Center in Long Grove, Ill.—chatted with participants from ASHA’s online conference, Case Studies in Fluency Disorders. The Leader listened in.


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