Dross in the context of "Pig iron"

Purgatory (Latin: purgatorium, borrowed into English via Anglo-Norman and Old French) is a belief in Catholic theology. It is a passing intermediate state after physical death for purifying or purging a soul before entering Heaven. A common analogy is dross being removed from gold in a furnace.

In Catholic doctrine, purgatory refers to the final cleansing of those who died in the State of Grace, and leaves in them only "the holiness necessary to enter the joy of heaven"; it is entirely different from the punishment of the damned and is not related to the forgiveness of sins for salvation. A forgiven person can be freed from his "unhealthy attachment to creatures" by fervent charity in this world, and otherwise by the non-vindictive "temporal (i.e. non-eternal) punishment" of purgatory.

A hammer mill, hammer forge or hammer works was a workshop in the pre-industrial era that was typically used to manufacture semi-finished, wrought iron products or, sometimes, finished agricultural or mining tools, or military weapons. The feature that gave its name to these workshops was the water-driven trip hammer, or set of hammers, used in the process. The shaft, or 'helve', of the hammer was pivoted in the middle and the hammer head was lifted by the action of cams set on a rotating camshaft that periodically depressed the end of the shaft. As it rose and fell, the head of the hammer described an arc. The face of the hammer was made of iron for durability.