Table 1. Percent Change From Baseline When Using Collagen-Alkali Silicate Binders
and shakeout. Downstream recycling of iron products and their recovery were not considered because the innovative tech- nologies would not affect these processes. Figure 1 illustrates the baseline input-
Foundry Facility VOCs Costs Labor
output boundaries for the analysis. Te major upstream activities-power produc- tion, coke making and sand mining- provide inputs of electricity, coke and sand, generate emissions and require fuel and raw materials. Cupola melting and the balance of foundry activities are the two major functional units on the right of Figure 1. Tese activities require melting inputs, such as ferrous metal alloys, scrap metal and natural gas. Tey also require process inputs, such as parts and sup- plies. Tis process chain produces finished iron castings and potential environmental discharges.
Materials Other cost Total
Projected Payback (in years)
Core Changes: Collagen-Alkali Silicate Binders Conventional metalcasting facilities commonly create
cores via a coldbox process that uses a phenolic urethane binder cured with an amine gas that creates air pollution. Moreover, when subjected to molten metal in the mold, these core binders pyrolyze and release VOCs and hazardous air pollutants. Conventional core binders are the predominant source of VOCs and hazardous air pollutants from iron cast- ing facilities. Recent bench-scale and pilot-scale trials have shown a
hybrid of collagen and alkali silicates will create a core binder that emits far less VOCs and hazardous air pollutants than phenolic urethane binders, while retaining the comparable strength and thermal resistance of conventional phenolic urethane. During the curing of the collagen-silicate hybrid, a proprietary system for heat-curing blown sand- binder systems warms the corebox by heating it with air, moisture or carbon dioxide under a vacuum. Te system requires a modified core machine and proprietary instrumen- tation, but it does not require an amine scrubber and does not produce scrubber brine. Te only emission from the core shop is water. Based on limited partner foundry experience, this coremaking process is more efficient, with lower cycle time, less corebox cleaning and less core scrap than conventional coremaking. Recent studies of low-emission
Energy Fossil
Non-fossil Emissions
Greenhouse gas Criteria pollutants Particulates VOCs
Materials Coke (as alloy) Scrap & other materials
hybrid core binders are awaiting publication so this data is offered only as potential improvement, but collagen-alkali silicate-based binders for green sand molds can potentially reduce total operating costs by 1.3% and emissions of VOCs by 35% (Table 1).
Costs
Energy Labor
Materials
Other costs Total
9.7
-0.8 2.4
-0.9 1.7
Electric induction furnaces melt approx. half the iron in the U.S. Non-fossil fuels include nuclear, hydro, etc.
熔化分解：电感应炉与冲天炉的对比
由于冲天炉炉料中加有石灰石，可采用 杂质含量高的废铁和碳源。分批熔炼的感 应电炉用电熔炼，要求使用价格较高的（
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FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION June 2014
-100.0 81.8
-7.6 5.8
-3.6 -1.3 0.4
-35
图1描述了供分析用的基础性输入- 输出界限。主要的上游生产活动包括 为铸造企业提供电力、焦炭和砂子的 作业，包括：发电、焦炭生产、采 砂，以及其产生的排放物和需要的燃 料和原材料。图1右侧显示了冲天炉熔 炼和其他铸造生产活动，这是两项主 要的功能性单元。这些生产活动需要 输入熔炼材料，例如钢铁合金，废金
属和天然气。还要求工艺过程中的输入，例如部件和补 给。该工艺链生产出最终的铸铁件，也产生数量可观的 排放物。
芯子的改变：胶原-碱性硅酸盐粘结剂
Table 2. Percent Change When an Electric In- duction Furnace Replaces the Baseline Cupola
Total System (including upstream)
常规的铸造厂一般都采用冷芯盒工艺制芯，冷芯盒工 艺用气态胺硬化的酚醛尿烷粘结剂，会造成空气污染。 此外，金属液注入铸型时，芯子的粘结剂会发生热解， 释放挥发性有机化合物和有害气体。常规的芯子粘结剂 是铸铁厂挥发性有机化合物和有害气体的主要来源。 最近，小规模和试生产已经表明：混合胶原和碱性 硅酸盐，可以制成芯子用粘结剂，其释放的挥发性有机 化合物和有害气体比使用酚醛尿烷粘结剂少得多，同 时，还保有与使用酚醛尿烷粘结剂可比较的强度和耐热 性。在胶原-硅酸盐混合物的硬化过程中，有一套专利 的热硬化型砂粘结剂系统，在真空条件下由空气、湿气 或二氧化碳加热芯盒。该系统要求一个改 良的制芯机和专用工具，但不需要尾气洗 涤塔，也不产生洗涤残留的盐液。制芯车 间产生的唯一排放物就是水。在合作铸造 厂有限的经验基础上，相比传统的制芯 工艺，这种制芯工艺更高效，周期时间更 短，需要较少的芯盒清洗，产生较少的 废芯。
206.7 206.9
58 150
-28.3 88
Foundry Facility
关于低排放混合制芯粘结剂的最新研究 还未发布，因此，这里提供的数据只是有 可能的改进提高，但是胶原-碱性硅酸盐 粘结剂在粘土湿砂造型方面，可能使总运 营成本降低1.3%，挥发性有机化合物的 排放减少35%。
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