Sand casting is a kind of molding method that molten metal into flowing liquid alloy, then burned into the sand mold cavity with certain shape characteristics and size requirements, and then cooled and solidified to obtain the required parts. Sand casting can meet the requirements of various shapes, sizes and weights of castings, and is the most widely usedin the casting industry.
Sand casting mainly includes wetprocess, non clay sand casting process and sodium silicate self hardening sand casting process. There are many sand casting processes, including sand mixing, molding, core making, box closing, smelting, pouring, cooling, unpacking, sand dropping, shot blasting, cleaning, etc. According to its process mechanism, the sand casting process is summarized as four processes: smelting, molding, pouring and cleaning. In the smelting process, cupola, electric furnace and other equipment are mainly used to melt metal into molten iron; In the molding process, the molding sand and core sand obtained by mixing sand are mainly made into sand mold and core, and then the core is lowered and the box is combined to obtain the required mold; In the pouring process, molten iron is poured into the sand box manually or with a pouring machine, and then enters the cooling section for cooling to shape the metal; In the cleaning process, the metal castings are mainly taken out of the sand box and the surface of the metal castings is cleaned of the sand, the gating and riser are cut off, and the finished castings are obtained after grinding. The sand casting production process is characterized by many emission links, many input materials, large energy consumption and serious emission pollutants. See the table for the consumption and emission of each link.
|Casting process||Main equipment||Main resource and energy consumption||Main emissions|
|Smelting process||Cupola, medium frequency electric furnace, feeder||Pig iron, scrap steel, ferrosilicon, carburizing agent, slag remover, electric energy, etc||Volatile organic compounds, waste gas, waste residue|
|Modeling process||Sand mixer, molding machine, core making machine, mold lifting machine, box combining machine, etc||Molding sand, core sand, bentonite, mixed soil, film coating, electric energy, etc||Dust, waste gas, waste sand, etc|
|Pouring process||Pouring machine, crane, etc||Electric energy, etc||Dust, etc|
|Cleaning process||Shot blasting machine, sand blasting machine, grinding machine, etc||Steel shot, electric energy, etc||Dust, waste gas, waste sand, etc|