 Probably the easiest to recycle would be bismuth @-@ containing fusible alloys in the form of larger objects , then larger soldered objects . Half of the world 's solder consumption is in electronics ( i.e. , circuit boards ) . As the soldered objects get smaller or contain little solder or little bismuth , the recovery gets progressively more difficult and less economic , although solder with a higher silver content will be more worthwhile recovering . Next in recycling feasibility would be sizeable catalysts with a fair bismuth content , perhaps as bismuth <unk> , and then bismuth used in galvanizing and as a free @-@ machining metallurgical additive . 
