Hi Andrea,

I'm posting part of an older reply of mine on the same topic, hope it helps. If you see any odd phrases it's because it was originally a reply to another poster. Here's a link to the original post:

http://agoracom.com/ir/POETTechnologies/forums/discussion/topics/579201-thanks-for-the-great-info/messages/1817374#message

Half of the Gallium Arsenide used for electronics in the US comes from scrap Gallium Arsenide. Also, GaAs is fully recyclable. This means that obsolete GaAs chips can be collected and used again in the process to make updated chips.

Also, from today's article and from Lee's Toronto presentation we learned that the many chips in mobile devices could be replaced with a single POET GaAs chip. In many ways the possible environmental risks posed by GaAs are mitigated by the reduced processing required to make numerous chips.

Another thing to consider along with my last point is that the number of GaAs chips will not increase as a result of POET adoption. all that would happen is that the functionality of the whole device will be moved onto that single GaAs chip.

I think better recycling efforts should be in place even now with the industry in it's current state, let alone when GaAs becomes the semiconductor material of choice. Hopefully countries can streamline the retrieval process and recycle more of the obsolete chips than they do currently.

Lastly, to address the supply of GaAs in the event that demand increases drastically, there are a couple of options. First of all, Gallium is processed first from aluminium and zinc mining. There are very few virgin gallium producers in the US currently, Gold Canyon (GCU.v) owns the rights to mine a Gallium deposit. I think the cost of Gallium is currently too low to justify their project, but if the price was to rise as a result of POET adoption I think GCU would take another look.

So in the end, neither the environmental hazards associated with GaAs nor the sudden demand should be a problem. GaAs will not replace Si overnight.

***

And here's another paper and link on the same topic:

Gallium Mining and Extraction Process Overview

Similar to indium, gallium is a minor metal with no primary mining activity. Gallium is extracted from bauxite as part of the bauxite-alumina refining flow that most commonly utilizes the Bayer liquor process.

By all accounts, gallium-containing bauxite is plentiful in the earth’s crust and is widely distributed both geographically and politically. Similar to indium, this contributes to the stability of the supply of gallium feedstocks. More interesting, only a small portion (less than ten percent) of the potentially available gallium in the bauxite is actually extracted. Hence, the existing flow of bauxite processing offers tremendous capacity increases. Historically, the low extraction volume was limited more by the relatively small demand and economics of relatively low prices. For all practical purposes, gallium output is limited only by facilities investment and capacities.

As a conclusion, gallium is plentiful with intermittent volatility. The 2000 – 2001 mega price run-up was primarily due to inventory stocking by the cell-phone supply chain fearful of a shortage. In addition, poor communication up and down the supply chain contributed to the Availability of Indium and Gallium hoarding of material against a phantom demand. Hence, a massive over-supply (glut) followed the hoarding, driving prices to historic lows. The more recently constrained availability of gallium during 2007 and the resultant price run-up is an example of this intermittent volatility and does not reflect any long-term concern about supply.

GaAs wafers used for ICs in wireless devices consume the majority of gallium today. LED devices represent the second largest consumer of gallium followed by solar, batteries, alloys, and other minor applications. The reclaimed gallium from the GaAs wafer production is a significant part of the gallium reclaim and refining process. Any near-term supply and demand shortfall will only be due to the time required to bring facilities on-line.

Conclusion

Indium- and gallium-containing raw materials exist abundantly worldwide. The metals industry has been investing in process improvements and capacity over the last few years to bring more indium and gallium to the market. Suppliers can and will continue to do so if the demand continues. As described, price volatility and short-term availability may continue intermittently due to numerous factors, including the time-lag required to install additional capacity, government regulation, and the lack of information suppliers receive about future demand. Overall, we anticipate adequate indium and gallium supply and continued price affordability for current, emerging, and new applications.

http://www.commodityintelligence.com/images/2010/jan/11%20jan/availability_of_indium_and_galliumwhite_papermikolajczak_sept09.pdf