RD casting bentonite is a clay rock with montmorillonite as its main mineral component. In the foundry industry, it plays a key role as a binder for molding sand, enabling the molding sand to have good plasticity, strength, and permeability to meet various requirements of foundry production. 
　　Product Characteristics 
　　● Strong Binding: It can firmly bind the molding sand particles together to form a sand mold with a certain strength, effectively preventing the collapse or scouring of the sand mold during molding and pouring, ensuring the dimensional accuracy and surface quality of the castings. 
　　● Good Plasticity: When mixed with molding sand, with appropriate moisture content, it can help the molding sand to be molded arbitrarily, meeting the production needs of various castings with complex shapes, making the production of casting models, boxes, and sand cores more convenient. 
　　● High Thermal Stability: It can withstand high temperatures during the casting process. Under the high-temperature radiation of molten metal, the bentonite in the molding sand will not rapidly lose its strength and performance, preventing the surface of the molding sand from expanding, peeling, or warping due to heat, thereby reducing defects such as scouring, sticking, and rat tails in the castings. 
　　Production Process 
　　● Coarse Grinding: The raw bentonite ore is initially crushed to meet certain particle size requirements for subsequent processing. 
　　● Sodium Treatment: This is a key step in the production of casting bentonite. By mixing the raw bentonite ore with a relative proportion of soda ash and water, the traditional stacking method can be used, or extrusion can be performed using a double-roll extrusion device to ensure that the soda ash and raw bentonite ore are fully in contact. Generally, it is left for 6-12 hours to convert calcium-based bentonite into sodium-based bentonite to improve the performance of the bentonite. 
　　● Drying: The bentonite after sodium treatment contains a lot of water and needs to be dried to reduce the moisture content to a suitable range for subsequent grinding and use. 
　　● Grinding: The dried bentonite is further ground to make the particle size finer, meeting the fineness requirements of casting production. Generally, it is required that 95% pass through a 200-mesh sieve to improve the specific surface area and activity of the bentonite and enhance its binding performance. 
　　● Packaging: The ground casting bentonite is packaged for storage, transportation, and sales. 
　　Product Applications 
　　Mainly used in clay-bonded sand molding in the foundry industry, including the production of various metal castings, such as automotive parts, machinery parts, and pipe fittings. It can be used to manufacture casting models, boxes, and sand cores, suitable for various advanced molding processes such as high-pressure molding, squeeze molding, air-blown molding, isostatic pressing, and vibration-free vacuum pressure molding.

Product Specifications