Nav: Home

High-precision on-site analysis of precious metals in metallurgical waste spills

July 26, 2018

Precious metals come in limited supply but are in high demand. They are mainly sourced through mining, but the possibility of recycling them from metallurgical waste leachates (waters that have passed through the treated materials during mineral processing and thus contain some of the compounds present in the minerals) is attracting growing attention. To this end, compact and portable instruments to perform the analysis of wastewaters in on-field rapid analysis are highly desirable to improve the efficiency of the recovery of precious metals.

Liquid-electrode plasma-optical emission spectrometry (LEP-OES) has emerged as a tool to implement on-site analysis of elements in aqueous matrices, as it is portable and much less costly than traditional methods. However, when the concentration of noble metals is very low, as is the case for precious metals in waste spills, the sensitivity of the technique become insufficient to produce accurate analysis -- one of the problems is that in metallurgical waste leachates there are several ions that interfere with the analysis. In this case, analyte separation and enrichment steps (that is, steps that remove other substances and increase the concentration of the analyte to make detection easier) have to be included in the analysis of the samples for accurate detection of the precious metals.

This is what Suman Barua, Ismail M.M. Rahman, Hiroshi Hasegawa and colleagues from Kanazawa University and Fukushima University did, reporting the first application of LEP-OES in combination with a solid-phase extraction (SPE) system (which is used as the pre-treatment step to eliminate the competing ions and to enrich the noble metals) for the rapid on-site simultaneous analysis of the precious metals gold, palladium and platinum. The SPE parameters were optimized to maximize retention and recovery of the precious metals; the LEP-OES parameters to maximize the emission peaks for the individual elements. The method was tested both on certified reference material for wastewater and on real aqueous waste samples, from which more than 95% of the precious metals were recovered. The high-precision on-site measurements could be performed in less than 15 minutes, opening the way to practical analysis of the precious metal content of wastewaters.
-end-


Kanazawa University

Related Precious Metals Articles:

Liquid metals the secret ingredients to clean up environment
Liquid metal catalysts show great promise for capturing carbon and cleaning up pollutants, requiring so little energy they can even be created in the kitchen.
Gem-like nanoparticles of precious metals shine as catalysts
Northwestern University researchers have developed a new method for making highly desirable catalysts from metal nanoparticles that could lead to better fuel cells, among other applications.
Precious metal flecks could be catalyst for better cancer therapies
Tiny extracts of a precious metal used widely in industry could play a vital role in new cancer therapies.
Sunscreens release metals and nutrients into seawater
Beachgoers are becoming increasingly aware of the potentially harmful effects UV filters from sunscreens can have on coral and other marine organisms when the protective lotions wash off their bodies into the ocean.
Bending the rules: A revolutionary new way for metals to be malleable
For nearly 100 years, scientists thought they understood everything there was to know about how metals bend.
How light steers electrons in metals
Researchers in the Department of Physics of ETH Zurich have measured how electrons in so-called transition metals get redistributed within a fraction of an optical oscillation cycle.
New epidemic forecast model could save precious resources
When governments and institutions deploy epidemic forecast models when facing an outbreak, they sometimes fail to factor in human behavior and over-allocate precious resources as a result.
BioSA -- Bridging the gap with biodegradable metals
The University of Malta has teamed up with Mater Dei Hospital to address the shortcomings of current bone scaffolds on the market in a project entitled Biodegradable Iron for Orthopaedic Scaffold Applications -- BioSA.
High reaction rates even without precious metals
Non-precious metal nanoparticles could one day replace expensive catalysts for hydrogen production.
New process to rinse heavy metals from soils
Poisonous heavy metals contaminating thousands of sites nationwide threaten to enter the food chain, and there's been no easy way to remove them.
More Precious Metals News and Precious Metals Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.