The foundry industry in Botou City, Hebei Province, has a history of more than 1,000 years and is a nationally renowned foundry town. In the 1980s, a 3-meter-high iron Buddha statue was unearthed in Fuzhen, Botou City. It was identified as a casting during the Five Dynasties and Ten Kingdoms period (907979). Over the past thousand years, Botou's casting technology has become increasingly sophisticated, from the original ancient dry mold casting to hard mold casting and metal mold casting, and then a cupola more than ten meters high was built to smelt pig iron. So far, the castings unearthed in Botou over a thousand years old are all made by traditional dry mold casting technology, which includes a series of processes such as making inner molds, outer molds, reducing branches, and combined casting. Making the outer shape of the product to be cast with loess or clay is called making the inner mold. When making the outer mold, first apply a thin layer of wax on the surface of the inner mold, and then cover the outer surface with a layer of hemp mud mixed with crushed hemp heads, the thickness of which depends on the size of the casting. After the outer mold 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 mark it to separate the outer layer of hemp knife mud from the inner mold. Reduction is to use sharp tools such as knives, shovels, hooks, spoons, etc. to scrape off the surface of the inner mold according to the thickness of the casting. Closing the mold is to restore the outer mold to the outside of the inner mold according to the engraved marks, forming a cavity in the middle, and then seal the parting surface to make a casting mouth. On the basis of dry mold casting, a semi-permanent hard mold casting technique has been developed. Its advantages are that it can have multiple molds in one mold, multiple molds can be cast at the same time, and it can be operated continuously. The key to this casting technique is to make a hard mold, which is called "slurry mold" in jargon. my country is the first country in the world to smelt pig iron, starting in 400 BC. Dry mold casting has important historical and scientific value. At present, there are only one or two companies in Botou that use dry mold casting techniques. The traditional pig iron smelting technique is in danger of being lost and needs to be protected urgently. (No pictures yet, welcome to provide.) (No pictures yet, welcome to provide.)