Bismuth: Behind the Numbers

Based on a recent post I published regarding the use of bismuth in solder alloys, John writes:

If Bismuth comes from the production of Pb, and if the use of Pb is being reduced, won’t the availability of Bi be reduced…and the price would increase?”

Just thinking…

Dr. Ron responds:

Lead has been banned from many of its original uses, paints, solders, water pipes, gasoline, etc. However, its increased use in batteries has actually caused lead consumption to rise. The USGS estimates that 88% of lead produced is used for lead-acid batteries.

Many of us in electronics assembly have been focused on the 2006 RoHS lead ban. This may have caused us to believe that lead use in electronics was significant. About 9 million metric tons (MT) of lead are consumed each year, only about 20,000 metric tons were used for solders prior to July 2006, this amount is only about 0.22% of the total. Electronics lead use being so small is likely why the lead industry had little visibility in fighting RoHS. Their important customers were making batteries.

Lead is quite effectively recycled, as about 60% of the 9 million MTs/yr. are from recycling and 40% from mining.

Over 100 million lead-acid auto batteries are sold each year in the US alone. In addition, the use of lead-acid batteries in forklifts, electronic vehicles, and golf carts has increased demand for lead. So, the bottom line is that lead use is expected to grow at about 2% per year.

Considering that we calculated that bismuth use in solders would be at most 5% of total bismuth production, it is unlikely that this use, or lead production reduction, would affect bismuth supplies.

Best Wishes,

Dr. Ron

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About Dr. Ron

Materials expert Dr. Ron Lasky is a professor of engineering and senior lecturer at Dartmouth, and senior technologist at Indium Corp. He has a Ph.D. in materials science from Cornell University, and is a prolific author and lecturer, having published more than 40 papers. He received the SMTA Founders Award in 2003.