11. There are many more varieties of smelting processes , including the Kivset, Ausmelt, Tamano, EAF, and BF. 12. The cost of obtaining ore as well as limestone needed during the smelting process was high. 13. During ancient times, due to impurities in the smelting process , gold frequently turned a reddish color. 14. Ferrous and non-ferrous smelting processes produce different slags. 15. The smelting process generated large amounts of waste. 16. Demand for charcoal in the smelting process rapidly depleted Gwennap's ancient woodland, leaving a wild, moorland, landscape. 17. High electrical conductivity coppers are distinct from coppers deoxidized by the addition of phosphorus in the smelting process . 18. Arsenic and the other byproducts of the smelting process contaminated the soil, making the area resemble a moonscape. 19. These metal sulphides survived from oxidizing stage before smelting and therefore may also indicate a multi-stage smelting process . 20. Other forms of tin ores are less abundant sulfides such as stannite that require a more involved smelting process .
