Science
Related: About this forumThe Fate of Vanadium after the Mount Polley Mine Tailings Spill.
The paper I'll discuss in this brief post is this one: Origin and Fate of Vanadium in the Hazeltine Creek Catchment following the 2014 Mount Polley Mine Tailings Spill in British Columbia, Canada (Karen A. Hudson-Edwards et al, Environ. Sci. Technol2019, 53, 4088?4098)
I'm catching up on some reading, and actually missed or overlooked this issue of EST and came across this disaster, of which I was unaware.
Vanadium is an important alloying element used in steels, particularly high strength steels such as are used in high quality tools and, um, things like wind turbines. It is widely distributed on Earth, and is commonly found in synthetic uranium ores prepared by passing seawater over amidoxime resins, a technology designed to exploit the fact that the ocean contains about 5 billion tons of uranium as a result of the geochemical uranium cycle.
The metal exhibits a plethora of oxidation states, and has been suggested for use in "flow batteries" because batteries are often the subject of fantasies about "storing" so called "green energy" even though there is very little of said popularly imagined but endlessly hyped energy to actually store, this after half a century of wild cheering for it, and even though the 2nd law of thermodynamics irrefutably requires that the storage of energy wastes it, and finally even though betting the planetary atmosphere on massive amounts of mining is almost certainly not a good idea and is most definitely not a pro-environmental policy.
However a problem with vanadium is that in some of its common oxidation states its very toxic.
From the introduction to the paper:
Humans can be exposed to vanadium mainly through inhalation and ingestion, potentially causing long-term respiratory and digestive problems, respectively.(13) Aqueous vanadate [V(V)] can also be taken up in benthic organisms such as Hyalella azteca(14) and have been shown to cause genotoxic and cytotoxic effects in higher plants.(15) Vanadium can be distributed in water, soil, sediment, and air through the weathering of natural materials and through releases from anthropogenic activities, including the burning of fossil fuels, application of pesticides and phosphate fertilizers, steel, aerospace, and other industries, and mining.(9,16,17) For example, mining activities have led to contamination of waters and soils with V (e.g., 76208 ?g/L in groundwaters and 1494800 mg/kg in soils of the Panzhihua mining and smelting area in China(18,19)). There is, however, a lack of information about, and understanding of, the geochemicalmineralogical cycling of V in mining-affected environments,(20) but these are required to determine health effects and to develop management and remediation schemes...
The fourth August 2014 failure of the tailings storage facility (TSF) at Mount Polley, British Columbia, Canada, is the second largest by volume on record.(23) Approximately 25 Mm3 of material, comprising 7.3 Mm3 of tailings solids, 10.6 Mm3 of supernatant water, 6.5 Mm3 of interstitial water, and 0.6 Mm3 of tailings dam construction materials were discharged into the Quesnel River Watershed.(23?25) The material flowed north into and plugged Polley Lake and then was diverted southeast into Hazeltine Creek for 9.5 km. A significant proportion of the tailings and interstitial water (18.6 ± 1.4 M m3)(25) and eroded soils and vegetation(26) were deposited into the West Basin of Quesnel Lake (Figure 1). Deposition of tailings (average 1 m thick, but up to 3.5 m thick in the upper part of the area nearest the TSF) also occurred within the Hazeltine Creek catchment up to 100 m from the channel, especially near Polley Lake and Lower Hazeltine Creek.(25)...
In this paper, we focus on V due to its high environmental risk potential(2,8?10) and the relative lack of data on its behavior in mining-affected environments.(20) We aim to understand the geochemical cycling of V in the Hazeltine Creek catchment and its implications for the origin, transport, fate, and potentially toxicity of V in other river systems. The objectives of the study are to determine (1) V concentrations and speciation in stream, inflow, and pore waters using aqueous composition data and PHREEQC modeling, (2) solid-phase V concentrations and speciation in the deposited tailings and secondary Fe oxyhydroxides using electron microprobe, automated mineralogy analysis, and X-ray absorption spectroscopy (XAS) analysis, and (3) the environmental origin, fate, and potential hazard of the deposition of V-bearing tailings in mining-affected catchments following tailings dam failures and remediation. We present, for the first time to the best of our knowledge for natural systems, evidence that dissolution of V-bearing magnetite and titanite may contribute to aqueous V. The results will also inform restoration and management schemes for river systems receiving V from other natural and anthropogenic sources.
The authors determined the concentration of vanadium and a bunch of other elements using ICP-OES, which is not the most sensitive inorganic element analytical tool (ICP-MS) is, but is perfectly acceptable where concentrations are relatively high, and they also utilized, and in some cases an older model ICP-MS, not however an instrument with which I am familiar. Speciation was determined by coupling these detectors to an ion chromatograph.
I don't have time for all the details of this paper, but we can look at the pictures:
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My kid knows more about this technique than I do; I'll ask him about it when he comes home again later in the summer.
Some discussion by the authors of their results:
...The significance of the Mount Polley tailings spill with respect to water quality and V transport is illustrated in Figure S4, where V flux (kilograms per year) and yield (kilograms per square kilometer per year) are compared to those of unaffected regional watersheds in British Columbia and other mining-affected watercourses around the world. The level of transport of V in the stream is elevated compared to those of nearby regional streams, even when the flux data are weighted by watershed area. In addition, under high-flow conditions, the V yield (measured at HC-9 in 2016) was comparable to (low-flow) yield values recorded in Torna Creek, Hungary, following the 2010 Ajka bauxite residue tailings spill.(71) The V transport data reported here show a departure from background concentrations and fluxes larger than the departure of those reported for Cu at Mount Polley.(37) Particulate transport of V appeared to be more dominant under high flow than low flow, suggesting physical mobilization of residual tailings could be an important transport mechanism for V during spring freshets and summer rainfall-runoff events. However, the bulk of the tailings remaining after our sampling in 2015 and 2016 was removed from the Hazeltine Creek watershed and returned to the tailings storage facility (L. Anglin, personal communication, 2018), suggesting that the effects of such physical mobilization could be minimal in the future.
Now the good news so you can not worry and be happy:
Don't worry about your Vanadium mine if you have lots of iron or titanium ores nearby.
None of this of course, implies that having a leaky vanadium flow battery in your garage would be good for you, but again, don't worry, be happy. I often hear that batteries are "green," and even though I know better, who am I to rain on the happy parade?
I hope you'll enjoy the up coming holiday weekend. I hope as well that we can all try to take a few minutes to remember a dead soldier, because that's what the holiday is supposed to be about.
GemDigger
(4,305 posts)On the other hand, I want an oxidized piece. Just a little one.