posted 07-01-2008 12:10 PM            

However, since one of my recent books was read for work rather than for pleasure, I feel justified in taking some work time to review it. Hence….

My agency is in the process of buying a newspaper printing plant for conversion to a bus maintenance facility (because the existing bus maintenance facility will be converted to a commuter rail maintenance facility). A newspaper printing plant might have a few interesting environmental issues on its own; but the particular thing that interests me about the site is an earlier tenant, the Argo Smelter.

I therefore thought I’d better track down some information about the environmental liabilities associated with smelters; it was surprisingly hard to do so. I finally settled on this book:

Which, although geared more toward mining than smelting, was the best I could do.

After an introduction to the history and scope of mining, Mine Wastes focuses on individual issues: sulfidic wastes, mine water, tailings, cyanidation waste, radioactive wastes, and phosphate wastes. While I had some general idea of the issues involved with all of these, the detail provided was excellent; for example, although I knew that acid mine drainage was attributable to the oxidation of pyrites, I didn’t realize that it is iron-containing pyrites that cause the greatest problem, because the conversion of iron (II) sulfide to sulfuric acid and iron (III) hydroxide is autocatalytic. I’d also been under the impression that bacterial oxidation was important; that now seems not to be the case; although iron and sulfur oxidizing bacteria like Acidothiobacillus ferroxidans and Acidothiobacillus thiooxidans are generally present in acid mine waters, they are more a result than a cause. Other interesting little tidbits were the comment that although it’s the cyanide in precious metal cyanidation that gets all the press, it’s actually the heavy metals extracted by the cyanide that are the largest environmental problem; the Rio Tinto region in Spain has been mined for more than 5000 years and the river contains over 1200 species of microorganism unique to the high acid environment, and phosphate mining is a larger producer of radioactive wastes than uranium mining.

There were a couple of minor problems; author Bernd Lottermoser consistently describes the results of radon decay as “solid particles”; the book is heavily focused on the Australian mining industry; and like most Springer products, it was very expensive. And, unfortunately, I didn’t find out that much about smelter wastes; there were a couple of paragraphs noting that although runoff from smelter sites can have elevated heavy metal levels, smelter slag is generally fully oxidized and thus insoluble.

posted 07-01-2008 12:36 PM            

quote:

---

Originally posted by setnahkt:
LibraryThing

---

D*** you, Set. There goes my weekend. OCD sufferers really need to not feed off each other.

quote:

---

I’d also been under the impression that bacterial oxidation was important; that now seems not to be the case; although iron and sulfur oxidizing bacteria like Acidothiobacillus ferroxidans and Acidothiobacillus thiooxidans are generally present in acid mine waters, they are more a result than a cause.

---

Interesting. If I recall correctly, low-grade copper ore has been economically extracted by leaching -- in effect, deliberately creating acid mine drainage as a source of dissolved copper. The bacteria were supposedly a big part of making this work.

quote:

---

Other interesting little tidbits were the comment that although it’s the cyanide in precious metal cyanidation that gets all the press, it’s actually the heavy metals extracted by the cyanide that are the largest environmental problem; the Rio Tinto region in Spain has been mined for more than 5000 years and the river contains over 1200 species of microorganism unique to the high acid environment, and phosphate mining is a larger producer of radioactive wastes than uranium mining.

---

I'll admit the cyanide statement surprises me. The phosphate statement does not; most of the uranium deposits in the Colorado Plateau are complex phosphates of vanadium and uranium.

posted 07-01-2008 03:15 PM            

'Interesting. If I recall correctly, low-grade copper ore has been economically extracted by leaching -- in effect, deliberately creating acid mine drainage as a source of dissolved copper."

Affirmative. In more-than-one hard-rock copper mine, the lower-grade ores and tailings are spread out in gigantic leach fields - tens or hundreds of acres - many feet deep over an impermeable membrane, then rinsed with a solution of sulphuric acid, which extracts the copper as dissolved copper sulphate. The smell must be overwhelming. And some copper mines are now being developed which work entirely on the leaching process - injection- and recovery-wells perform the same process on the ore in-situ. The copper is then extracted by electrolytic processes.

llater,

llamas

------------------
. . . a truly bad and evil man. So bad and evil that he's banned by Kim du Toit.

"All things are ready, if our minds be so."
King Henry V, Act 4, scene 3

posted 07-01-2008 04:27 PM            

quote:

---

D*** you, Set. There goes my weekend. OCD sufferers really need to not feed off each other.

---

Your weekend? I've been doing it for months. I was lucky in that I had already entered a lot of books I owned into Amazon (even if I didn't purchase them there) by checking the "I own this" box on the main book page. LibraryThing allows importation of text data with ISBN numbers; the format doesn't matter, the import process just recognizes a ISBN whenever it sees one. I was thus able to cut and paste my list of owned books from Amazon. LibraryThing also sells a cheap bar-code scanner that will allow you to read in ISBNs from bar codes. Most movies nowadays have ISBNs, so I was able to enter those, too; CDs, alas, do not, so I've had to enter all those manually.

quote:

---

The bacteria were supposedly a big part of making this work.

---

Lottermoser doesn't talk that much about copper (except in his discussion of the Rio Tinto region). I assume this is because copper isn't terribly important in Australia. I should have been more specific on the bacteria; they are not that important in acid mine drainage involving pyrite or arsenopyrite or other pyrites containing iron, because chemical oxidation by iron (III) does the job. However, bacteria are still effective in oxidation of other sulfide ores.

quote:

---

I'll admit the cyanide statement surprises me.

---

Lottermoser is pretty defensive about cyanide, commenting that it has a bad press due to its association with judicial execution and mass murder. The actual concentration of cyanide in a heap leach solution is relatively small. Cyanide ion is so reactive it will form metal complexs with just about anything; thus the "pregnant" solution from heap leaching contains not only disolved gold and silver but cadmium and arsenic and thallium and just about anything else. The gold and silver get knocked out preferentially when the solution is processed, and the solution is recycled. When you have a spill from a heap leach, the "cyanide" present is almost all as various cyanate, thiocynate and ferrocyanates, none of which are particularly toxic; the heavy metal cations associated with these are not so. (In the event you get a cyanide spill into low pH waters, things are different, since the cyanide ions will now go to hydrogen cyanide; fortunately, this is volatile enough that it will go atmospheric relatively quickly. The book provides a list of major cyanide releases from mining operations, including on in Guyana in 1995 that released 4.2M cubic meters of heap leach waste; there were no human fatalities in any of these incidents - although they were generally pretty hard on aquatic life. On the other hand, there are reports of cyanide poisoning in the Third World from cassava, and in the US and Europe from cherry or peach pits. There's a Dorothy Sayers murder mystery that (IIRC) hinges around some sort of peach liquer that while develop a cyanide-rich layer if allowed to settle.

We had a bus facility next to the former site of the first cyanide leach plant in Colorado and the third in the US, operated by Horace Tabor of "Baby Doe" fame. There was no trace of cyanide in the groundwater. Lots of zinc, cadmium, lead, arsenic, copper, antimony, indium, and probably all the other metals in the periodic table if we had bothered to look for them.

I've seen a picture (can't find it with Google, alas) of what was essentially a "hobbyist" heap leach process in Arizona. The owner had found silver-bearing ore on his land, set up his own relatively small heap, and was spraying cyanide solution over it with an ordinary oscillating lawn sprinkler. Although I agree the dangers from heap leaching are exaggerated, I think I'd be a little concerned about overspray if I were that guy's neighbor.

posted 07-01-2008 06:50 PM            

quote:

---

Originally posted by setnahkt:

Your weekend? I've been doing it for months.

---

I think you have more books.

quote:

---

Cyanide ion is so reactive it will form metal complexs with just about anything;

---

posted 07-02-2008 06:31 AM            

'There's a Dorothy Sayers murder mystery that (IIRC) hinges around some sort of peach liquer that while develop a cyanide-rich layer if allowed to settle.'

'Bitter Almonds', a Montague Egg short story, published in the compilation 'In the Teeth of the Evidence', mid-1930s. The liqueur is something in the creme de noyuax family.

The title story of this compilation also plays an interesting game with a variant of the Rouse murder, the seminal 'body in the blazing car' case from 1930.

llater,

llamas

------------------
. . . a truly bad and evil man. So bad and evil that he's banned by Kim du Toit.

"All things are ready, if our minds be so."
King Henry V, Act 4, scene 3

posted 07-03-2008 01:00 PM            

LibraryThing username: kgbudge. For anyone who cares.