Fig. 2. Seacoal
reduces the wetability of molten metal by the precipitation of lus- trous carbon onto the mold face, produces a reduction atmosphere inside the mold cavity for the prevention of oxidation defects, seals mold surfaces and reduces compres- sive stresses inside the mold.
图2 通过光亮碳在模 型表面的沉积，煤 粉降低了熔融金属 的浸润性；为防止 氧化缺陷，在型腔 内形成还原气氛； 密封模型表面并降 低型内压应力
Understanding Your Emissions Testing performed in the Casting Emission Reduction
Program (CERP) by Technikon LLC, McClellan, Calif., has been a key element in the discussion of emissions in pouring, cooling and shakeout. CO is regulated as a criteria pollutant, and in the U.S., emissions frequently trigger the Environ- mental Protection Agency’s (EPA) major source thresholds for Part 70-Title V and Prevention of Significant Deteriora- tion (PSD) before other pollutants. EPA databases and reference documents do not quantify
CO emissions from metalcasting pouring, cooling and shake- out operations. Historical research has focused on hazardous air pollutants (HAPs). During recent years, some metalcast- ing facilities have begun testing CO from iron green sand pouring, cooling and shakeout operations. Te CERP research has identified the sources of HAPs in
an iron casting facility and demonstrated green sand molds and cores make up 90% of the emissions. Many of the CERP emissions tests have quantified CO emissions from different molding process and metals.
Reducing Your Emissions Both oxygen and high temperatures are required to pro-
duce CO and carbon dioxide emissions from carbon sources. In the metalcasting process, the energy to break down organic or other carbon sources is provided by molten metal. Because different metals have different pouring temperatures and melting energy requirements, the temperature at which this occurs is variable. Carbon sources and the availability of oxidation products
also can be considered a variable. Research testing performed at the CERP facility (Table 1) shows green sand molds both with and without cores emit between 4.23 and 5.6 lbs. of CO per ton of metal. Test results from graphite parting, which contains little or no seacoal, are in the same range as those from inorganic core tests. Regardless of mold and core con- figuration, CO results remain relatively constant. Terefore, the potential sources of carbon necessary to form CO and carbon dioxide are: Seacoal and other carbon-based green sand mold additives.
• Molten metal.
直有一个关键因素。CO作为标准污染物被限定。在美 国，其排放量频繁地触发了环境保护署（EPA）相关文 件第五部分第70条的主要资源临界值及重大污染预防法 （PSD）。 EPA的数据库和参考文献并未量化来自铸造浇注、冷 却和落砂操作过程的CO排放量。以往的研究主要关注 了有害气体的污染问题，不过，近几年来，一些铸造厂 已经开始检测湿型砂铸铁件生产中浇注、冷却和落砂操 作过程中的CO量。
CERP研究已经确定了铸铁厂中有害气体污染的来 源，并指明90%的排放量由湿砂型和砂芯组成。CERP 排放测试的许多项目已经量化了不同成型工艺和金属的 CO排放量。
降低你的排放量
氧气和高温是使碳源氧化成CO和CO2的条件。在 铸造过程中，分解有机物或其它碳源的能量是由熔融 金属提供的。因为不同的金属有不同的浇注温度和不 同的熔化能条件要求，因而发生氧化情况的温度是个 变量。
碳源和氧化产物也可被视作变量。由CERP设备执行 的研究测试显示，湿砂型在没有和有砂芯时每吨金属散 发的CO量在4.23和5.6磅。对很少或几乎没有使用煤粉 的石墨界面的检测结果与对无机砂芯检测的结果是在相 同范围。无论砂型和砂芯如何组合，CO值都保持相对 稳定。因此，形成CO和CO2的碳的潜在来源是： 煤粉和其它碳基湿砂型添加剂。
• 熔融金属 • 有机砂芯材料
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FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION May 2013
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