Pig iron smelting and casting technology (dry casting technology)

Name of China's national intangible cultural heritage: pig iron smelting and casting technology (dry casting technology)

Applicant: Botou City, Hebei Province

Project No.: 385

Project No.: VIII - 35

Time of publication: 2008 (second batch)

Category: traditional art

Region: Hebei Province

Type: Extension Project

Applicant: Botou City, Hebei Province

Protection unit: Botou Cultural Center

Brief introduction of pig iron smelting and casting technology (dry casting technology)

Applicant: Botou City, Hebei Province

Botou City, Hebei Province has a history of more than one thousand years. It is a famous foundry town in China. In the 1980s, a 3-meter-high iron Buddha standing statue was unearthed in Fu town, Botou City. It was identified as cast in the period of Five Dynasties and Ten Kingdoms (907-979). For more than a thousand years, Botou casting technology has become more and more exquisite, from the original ancient dry mold casting to hard mold casting and metal mold casting, and then built a ten meter high cupola to smelt pig iron.

So far, more than 1000 year old castings unearthed in Botou are all made by traditional dry casting process, which includes a series of processes, such as making inner mold, outer mold, reducing support, combined mold casting and so on. The shape of the product to be cast is made of loess or clay, which is called the inner mold. When making the outer mould, a thin layer of wax is coated on the surface of the inner mould, and then a layer of hemp knife mud mixed with broken hemp head is coated on the outside. The thickness depends on the size of the casting. After the outer casing is dried to a certain extent, a parting surface is determined, and then a sharp knife is used to cut along the parting surface, and a mark is engraved to separate the outer layer of hemp knife mud from the inner casing. According to the thickness of the casting, cutting off the surface layer of the inner casing with sharp tools such as knife, shovel, hook and spoon. For mold closing, the outer mold is restored to the outside of the inner mold according to the engraved marks, and a mold cavity is formed in the middle, then the parting surface is sealed, and the casting port is made well. On the basis of the first mock exam, a semi permanent casting technology is developed, which has the advantage of being multi mold, multi-mode casting and continuous operation. The key to this casting technique is to make a hard mold, which is called "slurry mold" in the jargon. China is the first country to smelt pig iron in the world, which began in 400 BC. Dry casting has important historical and scientific value. At present, there are only one or two enterprises using dry casting technology in Botou. The traditional pig iron smelting and casting technology is in danger of being lost and needs to be protected.