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tion dislodges the condensed volatiles from the clay and sand surfaces, restores the hydrophilic bind- ing propensity of the clay, and prevents them from re-volatilizing as VOCs during molding, pouring, cooling and shakeout. In pilot-scale production, reclaimed sand was clean enough to use as core sand. When used in a full-scale demonstration, reclaimed sand cores produced cast- ings of equal or better quality than when using cores from pristine commercial sand. The AO-HAC system can reclaim 85% of normally disposed green sand. Based on this performance data and the synergistic effects of AO-HAC relative to an advanced oxida- tion-blackwater clarifier system, the life cycle and cost comparisons in Table 4 show that the AO-HAC system, even when used for baghouse dust only, can significantly reduce VOC production.


Innovations for Implementation


The most significant cost, energy and material savings occur when metalcasting facilities adopt a combination of these innovative technologies. One such strategy combines 50% coke replacement with advanced oxidation-hydroacoustic cavitation and a collagen-alkali silicate binder for core production. Some of these options are symbiotic. For example, when a water-based low-emission collagen-alkali silicate binder replaces a phenolic urethane binder, VOCs and hazardous air pollutants will be dimin- ished during the binder’s first exposure to molten iron and during subsequent passes as the advanced oxida- tion process cleans the sand and clay grains. Addi- tionally, the water-based system potentially improves the cleaning of the water-based binder residuals off core sand when compared to residual phenolic ure- thane binders off core sand in the green sand system at shakeout. Table 5 shows the life cycle and cost analysis


for these three technologies. This “Foundry of the Future” could decrease life cycle energy costs by 15%, new sand consumption by 85%, VOCs by 57%, home iron scrap by 9% and clay, coal and coke use by 50%. Overall, this could translate to a 6.6% reduction in total costs. Advanced oxidation systems that recycle baghouse dust and sand offer clear cost savings and environ- mental benefits, primary reasons why 60 facilities in the U.S. have adopted some form of the technology. The operating costs savings from adopting these sustainable technologies are significant, and they yield fast payback periods of 0.2-1.4 years. Given dwin- dling supplies and higher prices for high-grade met- allurgical grade coal for coke making, coke replace- ment could provide significant cost savings. 


Tis article is based on a paper (14-062) that was presented at the 2014 AFS Metalcasting Congress in Schaumburg, Ill.


在小规模生产中,再生砂足够清洁,可以当芯砂 使用。在全面演示中,用再生砂芯子生产的铸件质 量与使用原始商品砂的质量一样或更好。AO-HAC 系统可以回收85%的正常处理的粘土湿型砂。基于 这样的运行数据,以及AO-HAC系统与先进的氧化 技术——“黑水”沉淀系统的协同效应,表4中生 产活动范围和成本的比较表明:即使只用于袋式除 尘器收集的粉尘,AO-HAC系统也可显著减少挥发 性有机化合物的产生。


为实际应用而创新


铸造厂综合采用上述创新技术,就可以最有效地 节约成本、能源和原材料。一个策略是采用50%的 焦炭替代物,同时配合采用先进的氧化、水声、空 化法以及用胶原-碱性硅酸盐粘结剂制芯。 有些方案具有共生性。例如,用水基低排放的胶 原-碱性硅酸盐粘结剂取代酚醛聚氨酯粘结剂时, 挥发性有机化合物和有害气体在粘结剂第一次接触 铁液和随后的工艺过程中,由于先进氧化工艺对砂 粒和粘土颗粒的清洁作用,挥发性有机化合物和有 害空气污染物会减少。此外,与脱除芯砂的残留酚 醛尿烷粘结剂相比,在湿型砂系统的落砂环节中, 水基系统将有可能改善水基粘结剂残留物从芯砂上 的清除效果。


表5表明了三项技术的生产活动范围和成本分 析。“未来的铸造”模式将生产活动范围中的能耗 减少15%,新砂使用量减少85%,挥发性有机化 合物减少57%、回炉废铁减少9%,粘土、煤和焦 炭减少50%。总的来看,将实现总成本降低6.6%。 回收袋式除尘器灰尘和沙子的高级氧化系统,带 来明显的成本节约和环境效益,这也是60家美国工 厂采用某种形式技术的主要原因。采用这些可持续 技术对于节省运营成本意义重大,并可在0.2 -1.4 年的周期快速收回投资回报。由于用于生产焦炭的 高档冶金煤炭的供应减少、价格上涨,焦炭替代物 将可以产生显著的成本节约。 


本文是基于在伊利诺伊州绍姆堡举办的2014年美国铸造 协会铸造大会上发表的一篇论文。


June 2014 FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION | 55


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