1、翻译部分Atmospheric emissions in the Canadian Mineral industryAbstract: Canada is an international leader in mining and related technologies. Metals and minerals are Canadas second-largest earner of foreign exchange. Canadians, along with the rest of the word, are increasingly concerned about the enviro
2、nmental impact of mining activities. The Canadian mineral industry has acknowledged the importance of its environmental responsibility by adopting a broad range of protective measures. This paper review the atmospheric impact of mining activities in Canada along with the initiatives taken by the Can
3、adian governments (federal and provincial) and the Canadian in the Canadian metals industry both in terms of green house gases and acid rain. Example of mining companies that succeeded to reduces air emissions will be discussed.Keywords: pollution, emissions, mineral, industry, mining, metallurgy.1.
4、 Acid rain occurrence in Canada1.1 sources of acid rain in CanadaAcid rain, or more precisely acid precipitation, is the word used to describe rainfall that has a ph level of less than 5.6. This form of air pollution is currently a subject of great controversy because of its worldwide environmental
5、damages. For the last ten years, this phenomenon has brought destruction to thousands of lakes and steams of nitrogen and sulfur combine with moisture in the atmosphere to make nitric and sulfuric acids. These acids can be carried away far from their origin.Sulphur dioxide () is generally a byproduc
6、t of industrial processes and burning of fossil fuels. Ore smelting, coal-fired power generators, and natural gas processing are the main contributors. In 1998, for instance, U.S. Emissions were estimated at 17.7 million tones more than six times greater than Canadas 2.7 million total tones. But the
7、 sources of emissions from the two countries are quite different. While 74%of Canadas emissions come directly form industrial sources, 67% of the U.S.S emissions are from electric utilities. In 2000 the most import sources of Canadas emission, in order of decreasing contribution were, nonferrous min
8、ing and smelting 36%, electric power generation 24%. Figure shows the evolution of emissions (k tones) by each Canadian province from non-ferrous mining and smelting.1.2 steps taken by government to reduce acid rainIn 1991, the United States and Canada signed an air quality agreement. Ever since tha
9、t time, both countries have taken action to reduce sulfur dioxide emission. The United States agreed to reduce their annual sulfur dioxide emission by about ten million tones by the year 2000. By 2010, the unite states expects to achieve a reduction in its emissions of about 40% form 1980 levels, me
10、eting or exceeding its commitments under the 1991 Canada-U.S. air quality agreement. In Canada, emissions of had declined by over 40% by 1999 form the 1980 base year. Despite this progress, acid rain will continue to exceed harmful levels in eastern Canada even after 2010, largely as a result of the
11、 transboundary flow if acidifying pollutants. More than half of the acid deposition in eastern Canada originates from emissions in the United States. Areas such ad muskoka-haliburton and Quebec City receive about there-quarters of their acid deposition form the unite states. In 1995, the estimated t
12、ransboundary flow of sulphur dioxide form the united stated to Canada was between 3.5 and 4.2 millions tones per year. The government of Canada, therefore, continues to seek emission reduction commitments from the unite states.Initiated in 1985, the eastern Canada acid rain program committed Canada
13、to cap emissions in the seven provinces form Manitoba eastward at 2.3 million tones by 1994, a 40% reduction form 1980 levels. Table 1 shows the reduction targets for Ontario. Quebec, New Brunswick and Nova Scotia. By 1994, all seven provinces had achieved or exceeded their targets. In 1998, the pro
14、vinces, territories and the federal government signed the Canada-wide acid rain strategy for post-2000, committing them further actions to deal with acid rain. In 1999, the most recent year for which data is available, emissions in eastern Canada totaled just 1.61 million tones 30% below the 2.3 mil
15、lion tones cap and a 58% reduction form 1980 level.1.3 efforts by Canadian industry to mitigate acid rain occurrencesFigure 2 shows the sulphur dioxide emissions and base metal production form eastern Canadian base metal smelters between 1980 and 1994, whereas figure 3 shows the sulphur dioxide emis
16、sion per kiloton of metal production at selected smelters in eastern Canada between 1980 and 1994.One of the most important signal sources of metallurgical emissions in Canada and north America in the last 40 years has been the cu-ni producing complex in the Sudbury region in northern Ontario. The deposition of acid particulates form the Sudbury smelters has had severe effects on aquatic ecosystem. Lake acidification in the area is ver
