Johnson Jeremiah, Schewel Laura, Graedel T E
Program in Environmental Engineering, Yale University, and School of Forestry and Environmental Studies, Yale University, USA.
Environ Sci Technol. 2006 Nov 15;40(22):7060-9. doi: 10.1021/es060061i.
Chromium is an essential engineering metal used in stainless and alloy steels, chemicals, and refractory products. Using material flow analysis, all major anthropogenic chromium flows are characterized for the year 2000, from mining through discard, on three spatial levels: fifty-four countries, nine world regions, and the planet. Included is the first detailed quantification of chromium in internationally traded finished products and diverse waste streams. Findings include (1) 78% of chromium flow entering final use is added as a net addition to stock on the global level; most countries are close to this figure; (2) the majority of mining occurs in Africa (2400 Gg Cr/yr) and the Commonwealth of Independent States (1090 Gg Cr/yr), while the major end-users are Asia, Europe, and North America at 1150, 1140, and 751 Gg Cr/yr, respectively; (3) waste flows of chromium are the greatest in Europe (420 Gg Cr/yr), Asia (370 Gg Cr/yr), and North America (290 Gg Cr/yr), but the composition of these waste flows varies greatly among the world regions; (4) releases of chromium by the global system, which total 2630 Gg Cr/yr, are nearly evenly divided among tailings, ferrochromium slag, downgraded scrap, and post-consumer losses; (5) many countries have a heavy foreign dependence on chromium in the all forms, as is demonstrated for the United States. The findings relating to in-use stock changes and finished product trade are relevant to industry, allowing for more accurate planning for future scrap availability. The quantification of releases due to discards and dissipation hold environmental and human health relevance, while the full life cycle international trade assessment addresses local scarcity.
铬是一种用于不锈钢、合金钢、化学品及耐火产品的重要工程金属。利用物质流分析，对2000年从采矿到废弃整个过程中所有主要的人为铬流在三个空间层面进行了特征描述：54个国家、9个世界区域以及全球。其中包括对国际贸易成品和各种废物流中铬的首次详细量化。研究结果包括：（1）进入最终用途的铬流中，78%在全球层面作为净增量添加到存量中；大多数国家接近这一数字；（2）大部分采矿活动发生在非洲（每年2400千兆克铬）和独立国家联合体（每年1090千兆克铬），而主要终端用户是亚洲、欧洲和北美，分别为每年1150千兆克铬、1140千兆克铬和751千兆克铬；（3）欧洲（每年420千兆克铬）、亚洲（每年370千兆克铬）和北美（每年290千兆克铬）的铬废物流最大，但这些废物流的组成在世界各区域差异很大；（4）全球系统每年排放的铬总量为2630千兆克铬，在尾矿、铬铁渣、降级废料和消费后损失之间几乎平均分配；（5）许多国家在各种形式的铬方面严重依赖外国，美国就是例证。与在用存量变化和成品贸易相关的研究结果对行业具有参考价值，有助于更准确地规划未来的废料供应。对因丢弃和损耗导致的排放进行量化具有环境和人类健康方面的意义，而全生命周期国际贸易评估则涉及当地的稀缺问题。
