The Heart of a Global Industry
August 2, 2009 11:50 PM Subscribe
The most valuable strategic square acreage on the planet? Or a modest, charmingly low-key town in the Blue Ridge mountains of North Carolina? The BBC provides a fascinating report on Spruce Pine - the Mineral City where the Unimin Corporation mines the world's main supply of high purity quartz from the local hills. High purity quartz is essential to the manufacture of silicon wafers.
Neat little article. One thing irked me: "North Carolina may be famous for its mountain folk and bluegrass music, but the mines are the only industry it has left." Really? Or does this sentence need a "This part of..." thrown in front of it?
posted by thecjm at 12:01 AM on August 3, 2009
posted by thecjm at 12:01 AM on August 3, 2009
You need the quartz to hold the silicon as it's being melted (as you can see in the video). In other steps quartz is used to make transparent containers to do the processing steps in, but you can also use stainless steel, IIRC.
posted by delmoi at 12:19 AM on August 3, 2009
posted by delmoi at 12:19 AM on August 3, 2009
Wow. I certainly never thought I would see Spruce Pine on the front page of Metafilter, let alone on the BBC website. My parents are both from Mitchell County. My father was born nearby and grew up in Bakersville. My mother was also born in Spruce Pine and lived there until she went away to college. My grandparents lived there when I was a child (my father's mother still does.)
I've spent a good part of my life visiting relatives up there. It's an interesting place. There's a lot of natural beauty surrounded by the detritus that accompanies intense rural poverty. While the reporter definitely misspoke--mining is only one of North Carolina's many industries--she's correct that mining is still very important to the western counties that have little other industries or services. Quartz mining in particular has always been a part of the economy up there. My grandfather worked in the quartz mines for decades. (In fact, it killed him.) Even with the increased demand for quartz, however, the town and surrounding county have remained incredibly poor. However, both Spruce Pine and Bakersville have had some success in recent years selling themselves as tourist destinations. Roan Mountain and Mount Mitchell are both nearby. This has brought a modest influx of artists and craftspeople (many from the Penland School of Crafts) to Mitchell County, where they've opened a number of (badly needed) galleries, bookshops, and cafes. Lately, I've even seen openly gay couples walking around downtown Bakersville, something I never would have imagined ten years ago. This has created an interesting culture clash between the old-time residents and the newcomers. Last March, Spruce Pine voted on an alcohol referendum--previously, all of Mitchell County had been dry. Frankly, I was surprised it passed. But maybe this, coupled with the new importance of the quartz industry, is a sign that Mitchell County can find a place for itself in the 21st century, unlike so many other places in this state.
posted by Rangeboy at 1:33 AM on August 3, 2009 [8 favorites]
I've spent a good part of my life visiting relatives up there. It's an interesting place. There's a lot of natural beauty surrounded by the detritus that accompanies intense rural poverty. While the reporter definitely misspoke--mining is only one of North Carolina's many industries--she's correct that mining is still very important to the western counties that have little other industries or services. Quartz mining in particular has always been a part of the economy up there. My grandfather worked in the quartz mines for decades. (In fact, it killed him.) Even with the increased demand for quartz, however, the town and surrounding county have remained incredibly poor. However, both Spruce Pine and Bakersville have had some success in recent years selling themselves as tourist destinations. Roan Mountain and Mount Mitchell are both nearby. This has brought a modest influx of artists and craftspeople (many from the Penland School of Crafts) to Mitchell County, where they've opened a number of (badly needed) galleries, bookshops, and cafes. Lately, I've even seen openly gay couples walking around downtown Bakersville, something I never would have imagined ten years ago. This has created an interesting culture clash between the old-time residents and the newcomers. Last March, Spruce Pine voted on an alcohol referendum--previously, all of Mitchell County had been dry. Frankly, I was surprised it passed. But maybe this, coupled with the new importance of the quartz industry, is a sign that Mitchell County can find a place for itself in the 21st century, unlike so many other places in this state.
posted by Rangeboy at 1:33 AM on August 3, 2009 [8 favorites]
What will be the value of high purity quartz after silicon (pdf)? Assuming some other material becomes a viable microprocessor option, will such quartz still be needed?
posted by filthy light thief at 9:01 AM on August 3, 2009
posted by filthy light thief at 9:01 AM on August 3, 2009
Interesting. I work for a silicon wafer company and I didn't know that the quartz was mined. I always assumed that it was artificial quartz. I always think of silicon wafer manufacturing as one of the modern marvels that EatTheWeak was on about the other day. The movie in the FPP captures the gist, but the figures are a little out of date now. The state of the art for high volume manufacture is 300mm wafers. It's still amazing to me every time I see the crystal growing to think that it's possible to grow a 2m long, 400kg chunk of silicon which has point defect densities so low that it's essentially a perfect crystal. And that's before you even get to the wafering.
About 25% of the silicon is lost as kerf (sawdust) when the ingot is sliced into wafers. The remaining wafer serves mostly as a structural support for the device region, which usually uses less than 10 microns of the wafer thickness. At the end of the chip fabrication process, the wafer will be ground down from the backside to a thickness that may be as low as 40 microns.
It always strikes me as funny that we go to all that trouble to make such a marvellous material, and in the end the vast majority of it is just thrown away.
posted by Jakey at 9:32 AM on August 3, 2009 [1 favorite]
About 25% of the silicon is lost as kerf (sawdust) when the ingot is sliced into wafers. The remaining wafer serves mostly as a structural support for the device region, which usually uses less than 10 microns of the wafer thickness. At the end of the chip fabrication process, the wafer will be ground down from the backside to a thickness that may be as low as 40 microns.
It always strikes me as funny that we go to all that trouble to make such a marvellous material, and in the end the vast majority of it is just thrown away.
posted by Jakey at 9:32 AM on August 3, 2009 [1 favorite]
flthy light thief, high purity quartz is also used to make parts for the furnaces used in the high temperature processing of wafers. AFAIK the new materials being postulated for mass manufacture also require some thermal processing, so I would guess that there will still be some call for the stuff in the future.
I should also note that reports of the demise of silicon have been greatly exaggerated. Some new wonder material appears every year at the conferences, but thus far none has, or looks like achieving, a use in anything but niche applications.
posted by Jakey at 9:44 AM on August 3, 2009
I should also note that reports of the demise of silicon have been greatly exaggerated. Some new wonder material appears every year at the conferences, but thus far none has, or looks like achieving, a use in anything but niche applications.
posted by Jakey at 9:44 AM on August 3, 2009
Neat little article. One thing irked me: "North Carolina may be famous for its mountain folk and bluegrass music, but the mines are the only industry it has left." Really? Or does this sentence need a "This part of..." thrown in front of it?
I don't know what you're talking about. I'm toiling in the mines of Greensboro as we speak.
Mine conditions in the Research Triangle are particular brutal, but the mountain folk of downtown Charlotte is not to be missed.
posted by thivaia at 11:29 AM on August 3, 2009
Also the only industry left in the western part of the state is tourism.
posted by thivaia at 11:32 AM on August 3, 2009
posted by thivaia at 11:32 AM on August 3, 2009
Whoa! Just spent last week near there up on Mt. Mitchell!
posted by toastchee at 11:35 AM on August 3, 2009
posted by toastchee at 11:35 AM on August 3, 2009
I work for a silicon wafer company and I didn't know that the quartz was mined.
It's cut from gallonz. I thought everyone knew that.
posted by dhartung at 12:37 PM on August 3, 2009
It's cut from gallonz. I thought everyone knew that.
posted by dhartung at 12:37 PM on August 3, 2009
Unimin, definitely an evil corporation. I state this purely based on it's name and association with x amount of world supply of something.
posted by Phantomx at 1:16 PM on August 3, 2009
posted by Phantomx at 1:16 PM on August 3, 2009
Nah, not gallonz. Pegmatitic, quartz monzonite plutonz.
Unimim is the American subsidiary of SCR-Sibelco NV (formerly Sablières et Carrières Réunies), purveyors of fine sand and rocks since 1872. Secretive? Yes. Evil? ... I've spent half the night and day looking for the evil. All I can find is some people making money selling rocks and sand. But that Unimin website still tingles my Spidey senses.
posted by shoesfullofdust at 2:21 PM on August 3, 2009
Unimim is the American subsidiary of SCR-Sibelco NV (formerly Sablières et Carrières Réunies), purveyors of fine sand and rocks since 1872. Secretive? Yes. Evil? ... I've spent half the night and day looking for the evil. All I can find is some people making money selling rocks and sand. But that Unimin website still tingles my Spidey senses.
posted by shoesfullofdust at 2:21 PM on August 3, 2009
Who run silicone town?
posted by Smedleyman at 2:32 PM on August 3, 2009
posted by Smedleyman at 2:32 PM on August 3, 2009
flthy light thief, high purity quartz is also used to make parts for the furnaces used in the high temperature processing of wafers. AFAIK the new materials being postulated for mass manufacture also require some thermal processing, so I would guess that there will still be some call for the stuff in the future.
The reason people use quartz to grow the crystal is that quartz is silicon dioxide, so it doesn't contaminate the silicon crystal. Other materials would need different containers to melt them in.
Erm, anyway The idea that we are going to move entirely away from Silicon is a little ridiculous. Making silicon chips is really difficult already, and making chips from other materials is even more difficult. We might see other types of semiconductors in the future in ultra-high-end chips, but for most chips we would still use silicon.
posted by delmoi at 3:43 PM on August 3, 2009
The reason people use quartz to grow the crystal is that quartz is silicon dioxide, so it doesn't contaminate the silicon crystal. Other materials would need different containers to melt them in.
Erm, anyway The idea that we are going to move entirely away from Silicon is a little ridiculous. Making silicon chips is really difficult already, and making chips from other materials is even more difficult. We might see other types of semiconductors in the future in ultra-high-end chips, but for most chips we would still use silicon.
posted by delmoi at 3:43 PM on August 3, 2009
> Erm, anyway The idea that we are going to move entirely away from Silicon is a little ridiculous.
We haven't even started with the silicon-based life forms yet.
posted by jfuller at 6:10 AM on August 4, 2009
We haven't even started with the silicon-based life forms yet.
posted by jfuller at 6:10 AM on August 4, 2009
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