What’s New in the Hayes Lab?

The Hayes Group Rocked Denver GSA!
Rob Root rocked his talk on the fate of toxic metals at the Iron King Mine Site, a project he has continued after Sarah left the Chorover lab, in the Session honoring Kirk Nordstrom.  In the same session, Nicole and Sarah got lots of interesting discussion at their posters.  Sarah presented the mineral weathering trajectory story from the Iron King Mine site while Nicole showed some preliminary results from her study at the Delamar site in Nevada.  Amy’s talk on Te behavior during copper extraction went very well and generated a lot of discussion afterwards.  Sarah also co-presented a talk  on how to put together a successful Grant proposal for the GSA Student Grants Committee.  Great job everyone!

Hang with us at GSA Denver (October 26-30)
The big news is that Amy is giving her first professional talk in session 313.  Go Amy!
Sarah and Nicole are presenting posters in session 245, and Rob Root is also giving a talk in the oral portion of the same session (113).  Overall a great showing for the Hayes group!

Sarah’s invited to speak at the SSRL User’s Meeting (October 2, 2013)
Geochemistry of tellurium: resources, extraction, and weathering
Basically, I’m talking about my entire science plan!  Super fun!

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Sarah goes to Washington, DC …At least on a poster
Sarah was featured on a NUFO (National User Facility Organization) poster in Washington highlighting the importance of user facilities like SSRL, the Stanford Synchrotron Radiation Lightsource where we do a lot of work, to environmental science.

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Field work practice
We all went on a practice field trip to collect cores for Nicole to practice her core sampling techniques before starting to work on the high value samples.

Summer 2013- Ready to Rock!
Our first full summer at UAF has finally arrived.  I know I am excited to get some work going in the lab- I have some Te sorption experiments planned.  Amy and Nicole both got a great jumpstart on their research with their Departmental Seminars this spring, and I am looking forward to seeing their research progress this summer.

 

April 16, 2013 at 4pm- Nicole’s Departmental Seminar
Te speciation and distribution as a function of depth in Delamar mine tailings

Abstract: Increased use of tellurium (Te) in high-tech devices is accompanied by increased geographical dispersal.  Telluride-bearing mine wastes exposed to oxidative weathering will weather to tellurite or tellurate forms.  Te is potentially bioaccessible and toxic to natural and human ecosystems, depending on transport, exposure route, and speciation.  In this study, the weathering of semi-arid, Te-containing historic mine tailings at Delamar, NV was examined.  Samples were collected as a function of depth and the mineral assemblage includes quartz, various clay minerals (kaolinite, illite/mica, vermiculite, and smectite), and lower concentrations of sulfide and sulfate minerals.  Surficial enrichment of Te and other toxic metals (e.g., Pb, Bi, Cu, and As) have been observed, pointing to the accumulation of efflorescent salts, which often are highly bioaccessible.  Supporting the identification of efflorescent salts are X-ray absorption measurements indicating the predominance of oxidized S and Te species. Furthermore, a strong spatial correlation between Te-Ca-S has been is identified using micro-focused X-ray fluorescence measurements.  These data lend insight into the weathering behavior of Te under oxic conditions and can act as a proxy for other telluride phases, whether produced as wastes from mining, industrial manufacturing, or disposal of consumer products.

 

February 28, 2013 at 4pm- Amy’s Departmental Seminar
Recovery and Application of Tellurium in Copper Mining
Abstract: Nearly all commercially available tellurium (Te) is a byproduct of copper mining.  Tellurium has a low crustal abundance (≤ 0.01 mg kg-1).  The development of new technologies, such as high efficiency CdTe-based solar panels, has increased demand for tellurium and changes in end use markets.  However, little is known about the behavior of this metalloid during copper processing, prompting this study of the behavior of Te during Cu smelting and refining.  Examination of the ASARCO smelter and refinery finds that only 27% of the Te in the concentrate is actually produced as a byproduct, while 67% and 11% is lost in the slag and dust, respectively.  This recovery rate is similar to previous studies, but differences exist in the distribution of the tellurium lost to slag and dust.  These results represent an important step in understanding the recovery and loss of Te during Cu processing.