Lead:
Lead is ore is sulphide, PbS, called Galena or galenite. Its distribution is wide. There are practically no important deposits of lead in which galena is not present to some extent. Silver sulphide is scarely ever absent from galena, the amount is small, however, generally being less than 0.3 per cent.
Physical and mechanical properties:
Lead is a heavy metal with dull grey appearance. It has good corrosion resistance and has got good malleability. Sheet metal folds easily can be soldered. Resistant to atmospheric conditions. Its melting point = 419°C. In Europe, it was extensively used for roof protection. It was also used in plumbing. It can withstand sulphuric acid and previously this acid used to be stored in lead lined vessels. It has self lubricating properties. It was therefore used in lead-pencils. Sometimes, a small quantity of lead is added to steel and tin bronze to impart free cutting properties. It is used as accumulator plates for car batteries.
No comments:
Post a Comment