Copper smelting and bronze production occurred before Columbus but not where apologists claim the Book of Mormon happened. Iron smelting sites for the manufacture of swords have not been found because they exist only in the fantasy world of the Book of Mormon.
Andean people discovered the process of smelting 4,000 years ago to separate the copper from the rock, as well as working with gold and silver. Archaeologists now know that many people throughout the world independently learned how to smelt. America did it without needing anyone from anywhere else in the world coming to them to teach them how.
By 400 AD the people in South America were making bronze. Andean mariners traded their metal work up and down the western coast and about 800 AD they taught the people of western Mexico how to smelt.
The Metallurgy of West Mexico: revisited and revised
http://www.springerlink.com/content/c02342770771xn01/ From Metallurgy to Bronze Age Civilization: The Synthetic Theory
http://www.ajaonline.org/sites/default/ ... llag_0.pdfFour-thousand-year-old gold artifacts from the Lake Titicaca Basin, Southern Peru
http://www.pnas.org/content/105/13/5002.full.pdf+htmlIntensive Pre-Incan Metallurgy Recorded by Lake Sediments from the Bolivian Andes
http://www.sciencemag.org/content/301/5 ... 3.abstractAncient West Mexican Metallurgy: South and Central American Origins and West Mexican Transformations
http://onlinelibrary.wiley.com/doi/10.1 ... 0/abstractCold metal work with copper in the United States region began about 7,000 years ago, in the Lake Superior basin.
http://www.ramtops.co.uk/copper.htmlCopper work in North America was being done even before the time of Adam and Eve. Copper smelting in South America happened before Lehi, but bronze was not made until nearly the end of the Book of Mormon stories and was not in the popular geography of Meso-America until long after the fictional stories had ended.
No smelting was done in the region of the United States. Smelting and bronze making was not done in the region of Meso-America until nearly 400 years after the gold plates were allegedly buried and the civilization of Nephites destroyed. Neither of the Book of Mormon geography theories, of the region of the United States or in Meso-America are supported with professional research journal articles about ancient American metallurgy.