Zone melting

Zone melting is a type of purifying process for metals. It helps get rid of impurities in metal. Here's how it works: A zone of metal (like a bar of metal) is heated up and melted at one end. The melted metal is slowly moved along the bar so the liquid (melted metal) warms up and melts the rest of the bar as it moves. As the melted metal moves down the bar, it collects any impurities along the way, like dirt or other metals. Then the melted metal is cooled down at the other end and the impurities are left behind, leaving us with a bar of pure metal.