Sand Mold for Fused Cast series Blocks
2015-07-31
Sand mold is a special mold used in casting technology which can make the molten raw material Form a fixed shape. As we know, fused cast series blocks is made through casting method which is melting the material into liquid, and then pouring the liquid material into a sand mold which can withstand high temperature of 1800 degrees. So there are high requirements to sand mold.
1. Material: The material of sand mold is made from natural raw materials sand and quartz sand, and quartz sand adopts two kinds of sand which is fine sand and surface sand, and silicon content is above 99%.
2. Sand blinder: Water glass is selected as the sand blinder of sand mold, as water glass has the characteristics of stable quality, low cost, easy to wash, no smell. What is more, sand mold is made by water glass with high pure silica can meet the following requirements:
Good heat crushing strength: there is heat crushing strength produced during the casting process of fused cast series block, which leads to a big temperature difference between inner and outside of the mold. However, sand mold has the stability even if under heating, as the refractoriness of sand is up to 1690 degrees, and its linear expansion coefficient between 20-450 degrees is about 0.03mm/ degree, so it can withstand the static pressure of high temperature molten liquid and do not break down.
Chemical bonded sand is not produced on surface of fused cast series block, fused cast molten liquid is contacted with sand mold with rapid cooling and solid, a thin layer of sodium silicate or silica sand is produced on surface of sand mold which does not react with fused cast azs block. The most suitable amount of water glass is confirmed by experiment is 5.7%, if less will reduce sand refractoriness, more can not form.
Besides, in order to prevent impurity contamination, every piece of sand should be coated with a certain thickness of surface sand.
Zhengzhou Sunrise Refractory Co., Ltd. is mainly engaged in the research and development of refractory products. Sunrise can provide excellent fused cast series blocks such as fused cast azs brick, fused cast alumina block, fused cast high zirconia block which have passed the ISO international certified. Over 30 years producing and marketing experience, with reliable quality, competitive price and prompt delivery, Sunrise has established long-term business and cooperation relationship with many customers in different countries and regions. For any further information, Contact us, we will do our best to help you.
