Brief Introduction and Current Situation of Green Sand
Green sand, also known as green mold sand, refers to the sand that can be used for molding and core making without drying the sand mold (core) and can be directly poured in the casting production after the sand mixture is mixed with bentonite as binder and water and other additives.
Green sand is the oldest casting process and the most widely used. In the vigorous development of various chemical bonded sand, clay green molding sand is still the most important molding material. Its wide range of application and large consumption are incomparable with any other molding material.
Raw Materials for Green Sand
Green sand is composed of raw sand, bentonite, additives and water in a certain proportion. The common feeding sequence is to mix the recycled sand and new sand, bentonite, coal powder and other dry materials, and then add water to mix them to the required indexes. The proportion of molding sand shall be determined according to the casting alloy type, casting characteristics and requirements, molding method and process, cleaning method and other factors, and then determined according to the variety and specification of various molding raw materials, sand treatment method and equipment performance, sand iron ratio and other factors.
Application of Fused Ceramic Sand in Green Sand
Fused ceramic sand, that is, spherical special sand for casting, has been widely promoted by manufacturers and foundries and has been applied to various casting processes such as sand mold casting (green mold sand, sodium silicate self-gardening sand, resin self-hardening sand, hot core box, shell molding, cold core box, etc.), lost foam casting and various casting alloys such as cast iron, cast steel and non-ferrous alloy. It has achieved remarkable economic benefits and good environmental protection effects, and is known as the "green casting new material of the 21st century".