How to Decrease the Lead Content in Babbitt Alloys

• What sort of quantity?
• In what form is this alloy?
• Would it be better to re-order the material with a lower Pb content instead of carrying out the separation locally?
• Would any separated Pb represent a local disposal problem?
• What form would the post-separated material have to take on?

Hello

Thanks for your cooperation. Your questions' answers are as follow:

1-The quantity of alloy is about 300 kg.

2-The alloy is in molten form.

3-Unfortunately, babbitt alloys are not produced in Iran and we have to buy it from foreign countries and this purchase process takes a long time. For this reason I prefer to carry out separation locally.

4-Certainly, seperated Pb will represent disposal problems, but we have to solve this problem in proper ways.

5-Post-seperated material will be used to re-babbitt gas turbine bearings.

Buy it.

White Metal Bearing Alloys (Babbitt Metal) - Lead and Tin Based ...

The lead will melt first.......................

There are Tin based Babbitt alloys with 0.35 Pb (ASTM grades 1,2 and 3). You may use them if fit for intended purpose.

http://www.frymetals.com/pdf_uploads/referenceguide.pdf

I held off commenting on this one to see what came up. The OP's choice of verbs is instructive. he "HAVE" not "Needs" so he rally wants to know how to convert what he "have" to a lower than 0.3% max lead content. 1) Add dilutive elements that will allow him to have a huge quantity of remixed babbitt. ie 10.4X the weight of all other elements would get the lead to 0.3% by weight, but then it would not be the same alloy (though it would be low lead) and the expense of the additions would be well, at least 10.4X the amount he has tied up in the curent material. 2) Chemically react the alloy with chemical that would preferentially react with and remove the lead. I do not know the reactions to do that in the mixture given. Meaning no disrespect, but reframing the question to 'do other low lead babbitt's exist?' does not provide the O.P.with the answer that he seeks: "HOW CAN I DECREASE PB amount from 4% to 0.3% or less than it?" My 2 cents. milo"no smiley face to add, I'm using my macbook and they aren't showing up on the page"

I agree with Milo. Once again we have a first time poster with a loaded question. We really need to know how much he has, what for, why the change.

An alloy is just that, I don't think you can take it apart, back to the original ingredients, and then re-adjust the mix. Like Milo says, you can dilute the lead with a re-melt and adding the correct ingredients, maybe.

Now you're into some dangerous alchemy. Some of the ingredients are not safe when heated, release bad vapors. Acids will release bad vapors when put on this metal,too.

And also the end of the day the composition must be a babbit

In normal babbit, Pb is critical for its properties as the bearing metal (provoded you are using it for the purpose)

Now as you dilute it/ chemically remove it, you are in a new alloy and whether it serves the purpose or not has to be checked. it is likely to need addition of proper percentage of elements.

http://www.alchemyextrusions.com/babbitt/default.asp

or

http://www.maycoindustries.com/babbitt.htm

will provide the chemical composition of some babbits.

exactly. I suspected that 0.3% number has something to do with one of the ELV, REACH, WEEED directives out of EU, but you have recognized the ENGINEERING issue implied by the OP question. Not only 'How can we?' but also 'If we do it will it still perform as Babbitt? milo