tag:blogger.com,1999:blog-1592992209402300549.post3365159743749555902..comments2024-03-28T08:06:43.198-04:00Comments on The Silicon Graybeard: Have You Been Noticing Precious Metals?SiGraybeardhttp://www.blogger.com/profile/00280583031339062059noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-1592992209402300549.post-75539020695321099432020-02-07T16:13:48.864-05:002020-02-07T16:13:48.864-05:00This comment has been removed by a blog administrator.Anonymoushttps://www.blogger.com/profile/06084259533488236920noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-28318921878634759372020-01-28T21:06:01.472-05:002020-01-28T21:06:01.472-05:00I bet there's more interesting stories in ther...I bet there's more interesting stories in there - it's a world very few of us ever see anything about.<br /><br />In the Wikipedia link I have above the table of metals, that source has rhenium as one of the rarest elements. SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-65529178842846928002020-01-28T17:20:28.595-05:002020-01-28T17:20:28.595-05:00I spent 35 plus years in a steel melting facility....I spent 35 plus years in a steel melting facility. We made steel in open air, and also under vacuum. The open air metals was used for basic items, like food service equipment, boat propellers, gun parts, helicopter landing gear, etc. The vacuum melted steels,called super alloys, were almost universally used in jet airplane applications. They were obviously much more high tech, with more tightly controlled specs, including nitrogen and oxygen, the reason for melting under vacuum. <br />Some of these super alloys contained trace elements of rare earth metals, to obtain different desirable properties. One of these trace elements was Rhodium. Another was Rhenium. Hafnium,Tantalum, and a few others, were also added for the properties that they lent to the final alloy. But only Rhodium and Rhenium were so expensive that they were delivered to our melt shop via armored car. With armed guards,and a level of attention to detail that would be required of diamonds. <br />These rare earths, precious metals, really, were used in 8,000 pound heats. Sometimes we would melt over 200 pounds of Rhenium at a time in our vacuum furnaces. I ran one of the furnaces for several years, on two different occasions in my time there. And I hated to melt the Rhenium because it was almost a powder, and we had to wrap it into a nickel foil bag,to keep it from burning off, before we got the dome closed to start melting the heat. We had to open the dome each time we melted another heat, in order to get the poured metal molds out and to recharge the furnace. We poured our metal into tall steel pipes, with walls about 1 inch thick. After they cooled, we then pushed the bars out of the molds,and cleaned them up and sold the bars for remelt. <br />Pratt and Whitney, Rolls Royce, Airbus, Boeing,and General Electric were all customers of our vacuum alloys.Pigpen51https://www.blogger.com/profile/01683463718454987063noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-73528995203322065482020-01-28T01:51:27.055-05:002020-01-28T01:51:27.055-05:00This comment has been removed by a blog administrator.ufo 3dhttps://www.blogger.com/profile/05788228492055841549noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-18827227756055701312020-01-27T22:34:18.308-05:002020-01-27T22:34:18.308-05:00Don't forget a reasonable amount of lead - it ...Don't forget a reasonable amount of lead - it might very well be the most 'precious' of all metals if things go really bad. ;-)Anonymousnoreply@blogger.com