Magnesium diecasting and waste 1

[Chiefxxx]

Hello,

I am trying to gain an understanding of magnesium diecasting in the automotive industry. I would like to know about most of the life, of a part from casting to disposal with specific interest in the following:

1, I know that mag casing alloy can be recycled in house, but what percentage and what percentage is lost and why? what does it consist of ?

2, After a component is machined, what happens to the sward/chip? is it recycled ? if so in what applications as I know that it is contaminated and surface area is an issue, also what yield can be expected here ?

3, for post consumer scrap, a car is shredded, what percentage of mag is recovered and how much is lost to shredding and loss in asr?

4, What happens to the recovered lumps of mag? what are they used for as they are too contaminated ? in what percentages and what value do they have in terms of percentage against the primary mag alloy.

5, Finally, what is the value of recycled mag alloy, is it the same as virgin? if not what is the knoch down in value.

I would really appreciate all the help i can get with all of these, or any if possible. Any references to papers would also be well recieved.


Many thanks in advance!

 

[CoryPad]

You can find the papers yourself by searching at various sites:

Google Scholar

Scirus

SAE Tecnical Papers

DOE

 

[Chiefxxx]

Hi,

I have already searched many papers, however I can find general information, but the more specific is much more difficult.

Thanks anyway

 

[TVP]

This is a huge request, so it is unlikely anyone is going to post details on every question that you asked. Here is some information for your consideration:

1. 100% of Mg is recycled internally at die casting facilities if it is in the form of as-cast parts (dimensional samples, test parts, rejects for casting issues like cosmetics, mechanical properties, underfill, etc.). There is always melt loss due to oxidation, so the recoverable amount depends upon the process-- I don't know the typical amount off the top of my head. Here are some links to good articles on Mg recycling:

http://iweb.tms.org/Mg/magtech2002/010.pdf

http://www.magnesium-elektron.com/data/downloads/262.pdf

http://www.nrcan-rncan.gc.ca/mms-smm/busi-indu/rad-rad/pdf/2002-13(cf)cc-eng.pdf

2. Mg machining chips/swarf are recycled. The chips must be cleaned at some point to remove oil, lubricants, etc. Companies like MagReTech (

http://www.magretechinc.com/about.htm)

take chips/swarf and turn them into recycled ingot suitable for subsequent die casting or other uses like desulfurizing iron or alloying of aluminum.

3. It is my understanding that virtually all metals, including Mg, are successfully recovered during automobile disposal. ASR is primarily the stuff that cannot be recovered, meaning foam, glass, rubber, etc. If it is a distinct part, such as a steering column housing, engine accessory bracket, steering wheel armature, etc., then it is removed prior to shredding and recycled into new ingot.

4. I am not sure what you mean by lumps of Mg. Almost everything gets recycled, so there isn't a lot of Mg residing in landfills. The purity of recycled alloys depends on how it is cleaned, melted, the type of fluxing used, etc. In general, recycled Mg has somewhat higher amounts of impurity elements, chiefly Fe, and contains more oxides, but it is possible to produce extremely high quality recycled Mg. Search through the various SAE Technical Papers or Proceedings from the International Conference on Magnesium Alloys for more information. As an example, there are over 100 pages in the 2007 Proceedings:

http://www.wiley.com/WileyCDA/WileyTitle/productCd-3527317643,descCd-tableOfContents.html

5. The value is high, if it is properly processed. There is likely some information freely available on the internet from presentations given by Clark & Marron, CRU, etc. Here are some links to explore:

http://clarkandmarron.com.au/images/cm_mg_report.pdf

http://www.google.com/search?hl=en&lr=&as_qdr=all&q=magnesium+recycling+die+casting+filetype:pdf

 

[Chiefxxx]

TVP,

Many thanks for your post, I appreciate the time you took to answer. I find the links super useful!

Thanks again