The Warring States bronze sword in the furnace melting ingredients

 The melting point of copper is 1084.5 ℃ in the ancient furnace smelting copper smelting difficult. In proportion to the "cut to kill the vector Qi" literally, copper 60%, 40% tin into the furnace melting due to the melting point of tin is only 232 ° C, quickly melted in a furnace, sink into the bottom , at which point the solid copper did not become the alloy, do not tin material fall from the sky low melting furnace. It follows that all the new metal material melting, is not directly practical alloy. When the firing better the bronze sword need to open the furnace casting, alloy material with a 50-50 blend of new metal materials for melting, the melting speed will be greatly improved. Noted in passing that the quantities of bronze casting production, there will always generate a lot of back charge. By the late of Shang, the bronze art advanced in a big step.
These back to the charge does not refer to cast specially formulated alloy material, but the waste generated in the mass production of bronze castings, cast when some attachments, such as outlet riser, Phi seam running fire material, and no casting after remaining materials. These metal materials have become the alloy is easier to melting of the charge. Many of the bronze were carved with inscriptions. In April 1978, Ezhou City, the town of Yan Angeles Dam Kok village farmers in the village near the cursory Lake reclaim land, about 30 cm deep in the Lake Branch of the silt in the mud layer, dig a large earthenware urn filled with copper weapons fragments of about 30 kg. Arrowheads, spear of copper, copper pot lid, decorated horses, crossbow, hook and accessories, the other bronze pieces, of which the largest number of the fragments of a bronze sword.
 Figure 8 is part of a bronze sword in this earthenware waste film. It should be noted that this earthenware bronze scrap, bronze casting workshop generated a lot of waste, is a normal phenomenon. As the ancients name the copper as gold (Jin in Chinese), the words on the bronze are called “Jin Wen” that is inscription.  When each furnace smelting bronze, in addition to adding a new metal materials in the furnace, but also joined about half of the back charge, only by adopting such a charge preparation, to be able to avoid the waste of metal raw materials, the most effective use of charcoal heat, the fastest melting speed required alloy according to the ratio of melting out. According to the above assumptions, the Warring States bronze sword in the furnace melting ingredients, with the exception of charcoal loaded in the furnace should be added to half of the recycled materials and half of new metal materials.
At this time, the first molten liquid metal has long been submerged in the bottom, while the furnace is also no liquid metal smelting good will quickly cool down. When this happens, the only non-melting good liquid metal vent baked, in order to re-melted melting. In order to understand the melting process of the Warring States Period, the melting of the Warring States era, the simulation of the bronze alloy melting test. The highly skilled craftsmanship with both a sense of mystery and reality as well as the ferocious and awesome artistic beauty constitutes the bronze art. With mud made of a high 20cm, 20cm in diameter furnace, dried, calcined into a semi-ceramic, and conducted two tests in October 1999 and December respectively. The first test, with the usual cast mirror back to the charge 2kg, its chemical composition of alloys is approximately Cn73% Sn24% Pb3%. Bottom place the charcoal, the alloy in the middle, above, and then covered with charcoal, the air duct on the furnace in the middle, the air inlet duct with a 25w electric fan blower, as shown in Figure 6.