Classical Studies 2700A/B Lecture Notes - Lecture 14: Lost-Wax Casting, Propane Torch, Blow Torch
1 Feb 2017
School
Department
Professor
Document Summary
Slides showing reconstruction of early copper mining and smelting at timna (in negev desert) at c. 3,800 bc. Ore mined is (green) malachite, then crushed to consistency of gravel. Temp. required to reduce this ore is at least 815 c, and higher is desirable. Combination of hard-wood charcoal (from acacia trees) and ground-up ore; temp. raised by workers blowing through tubes fitted with tuy res. Small amounts of copper found amid blackish slag. Casting of copper was a separate process; evidence from a village called abu matar, c. 160 km. New type of tappable furnace made this high output possible; it ran non-stop for several days. Seems about 3800 bc when they first started getting copper out of ores. Copper ore had to be worked at, and it is a long slow process. Bronze: modern bronze can range from 3% to 25% tin, though small amounts of lead and zinc usually added as well.
