Why is Ceramic Foundry Sand called the ideal foundry material by many foundrymen and factories? Let's give two simple examples to illustrate this question.
Application of Ceramic Sand in V-Method Casting and Lost Foam Casting
Under V -method casting, all is dry sand molding. Most of lost foam casting is dry sand molding, too. If use silica sand, it will cause a lot of diffuse silicon dust during sand shakeout and let the working conditions become worse, which became a big problem to be solved. But if we use ceramic foundry sand instead of silica sand, it could significantly reduce the dust of distribution and improve working conditions and environmental protection. Besides, it has the following benefits:
1. Ceramic foundry sand is higher than the silica sand on refractoriness, and the modelling compaction degree is higher. Therefore, it can make the surface quality of castings better and lower the scrap rate.
2. The liquidity of spherical ceramic foundry sand is very good. So in the complex shaped castings, like at corners, deep sunken place, which is difficult to fill positions, the spherical sand is easy to fill into. Thus, sand defects can significantly reduce the workload of cleaning and finishing.
3. If used in resin coated sand molding, the resin could be saved 1/3 comparing with other sands.
Replacing Chromite Sand in the Production of Large Steel Castings
Except the bulk density is lower than the chromite sand, some of the main thermal physical properties, such as thermal conductivity, thermal expansion rate, refractoriness and so on, ceramic sand is similar to chromite sand. In terms of particle shape and breakage resistance, ceramic sand is much better than that of chromite sand, while the price is only about half of the chromite sand. On the basis of comprehensive analysis, obviously, ceramic sand is an ideal alternative materials for chromite sand.
Japanese special steel have been used in the production of sintered ceramsite instead of chromite sand, the effect is good, shortcomings is easy to produce castings surface adhering sand defects. But it is obtained by experimental research, the solution is to add 4% of the nodular iron oxide.
Ceramic sand surface condition is far better than the sintered ceramsite. In fact, many factories have already had several steel-casting factories use ceramic sand instead of chromite sand, got very good effect. Use ceramic sand instead of chromite sand could not only improve the quality of the surface of the casting, reduce the production cost, but also facilitate the regeneration and reuse of the old sand.