Developments in Steel Casting Sand Binders
Researchers develop Bangni resin sand applications WANG HAIJIANG, MA JINGZHONG AND LI CHUANSHI
我国铸钢型砂粘结剂的一项新发展 邦尼树脂的研发和应用
王海江、马敬仲、李传栻
quality of steel castings produced in China has improved sig- nificantly. However, there still is a gap between China and other developed countries in the areas of process control, quality, envi- ronmental protection, energy efficiency and emission reduction. Chinese metalcasters are faced with changing from a big
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casting industry to a strong casting industry. In the devel- opment process of the steel casting industry, many new demands for sand binders are required to: • Reduce harmful gas emissions to satisfy the needs of envi- ronmental protection and industrial health and safety.
• Increase the recycling rate of used sand to maximize silica sand resources and reduce the discharge of waste sand.
• Reduce the cost of sand reclamation by using common and simple dry reclamation techniques to replace thermal and wet reclamation
• Avoid installing too much equipment and reduce energy consumption during production.
• Improve the properties of binders to improve casting quality and reduce production cost.
The Current Status of Widely Used Binders Currently, the binders used in the Chinese steel casting
industry are mainly silicate (water glass) binder and alkaline phenolic resin. Some metalcasters also use furan resin(s) or urethane resins. Silicate binder—Silicate bonded sand for steel castings,
which has been used for around 60 years in China, has played an important role. Te preparation process for silicate binders is simple.
Tere are abundant resources for the manufacture of silicates, and their cost is low. Several methods are employed for moldmaking using
vacuum replacement hardening (VRH) and organic ester hardening processes.
silicate as a binder such as: CO2 gas-hardening technology,
n recent years, the steel casting industry in China has developed rapidly; in 2010, the total production of various steel castings was 5,300,000 metric tons, accounting for 51.8% of the total world steel casting production. Te
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年来，我国铸钢行业发展很快。2010年， 我国各类铸钢件的总产量为530万吨，占世 界各国铸钢件总产量的51.8%，在铸件档次
和质量方面，也都有了明显的提升。但是，与其他工业 国家相比，我们在工艺过程控制、铸件质量、环保、节 能、减排等方面，仍然有颇大的差距。 今后，我们面临的任务是，尽快地实现我国铸造行 业‘由大到强’的转变。从而，在铸钢行业的发展过程 中，对型砂粘结剂也提出了很多新的要求，如： • 减少有害气体的排放，以适应环保和工业卫生方面 的要求；
• 提高旧砂的回用率，使硅砂资源得到充分的利用，并 减少废弃砂的排放；
• 降低旧砂再生的处理成本，以常用的干法再生代替热 法再生或湿法再生，以避免装设过多的辅助设备、 并降低生产中的能耗；
• 改进粘结剂的性能，以提高铸件的质量、并降低生 产成本。
一、 对当前我国铸钢行业广泛应用用型砂粘结 剂的简要分析
目前，我国铸钢行业使用的型砂粘结剂，主要是硅酸 盐（水玻璃）和碱性酚醛树脂，也有一些企业采用呋喃 树脂或尿烷树脂，但为数不多。这里，只就硅酸盐和碱 性酚醛树脂作简要的分析。
1、关于硅酸盐粘结剂
我国铸钢行业采用硅酸盐粘结砂已有60来年的历 史。对于我国铸钢行业的发展，其作用和贡献是不可磨 灭的。
February 2013
FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION | 41
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