Environmental LCA and rational development order concerning resources development

采矿和加工过程中的设备和消耗品成本根据存款位置、采矿方法、生产规模等，使用原USBM发布的采矿成本估算数据库进行估算。开发了一个数据库应用程序，该程序根据每个矿山的能源和材料消耗量，通过根据各自的国内价格转换成本来估计，计算出矿山产品的单位CO_2排放量。根据日本冶炼厂主要铜精矿和锌精矿供应商各自的单位CO_2排放量，估算了日本冶炼铜精矿和锌精矿的单位CO_2排放量。7家主要供应商生产铜的加权平均单位CO_2排放量为2. 063 kg-CO_2/kg。由于国内铜产量的三分之二来自这七个矿山的精矿，因此国内铜的单位CO_2排放量应在2kg-CO_2/kg左右。关于锌，九个主要精矿供应商中只有四个矿山的数据可用。锌冶炼过程中CO_2的单位排放量比铜冶炼过程中的单位排放量更重要，因为即使是这四个矿山中最高的CO_2单位排放量，如Mt.伊萨仅占锌的单位CO_2排放总量的一半。生产成本与单位CO_2排放量并不总是相互关联的，在征收30美分/kgCO_2的碳税后，7个铜矿中有4个矿山的总成本几乎相等。事实表明，合理的发展顺序，可以根据碳税的税率而改变。

Costs of equipment and consumables in both mining and processing process are estimated according to location of deposit, mining method, production scale, etc. using Mining Cost Estimation Database issued by former USBM. A database application is developed, which calculates an unit CO_2 emission of a mine product, based on consumed amount of energy and materials in each mine, estimated by converting the costs according to the respective domestic prices. Complete unit CO_2 emissions for copper, and zinc smelted in Japan are estimated, based on respective unit CO_2 emissions, estimated for major copper and zinc concentrates suppliers for Japanese smelters. The weighted average unit CO_2 emission of copper produced by seven major suppliers was 2.063kg-CO_2/kg. As two third of domestic copper production comes from, the concentrates of these seven mines, the unit CO_2 emission of domestic copper should be approximately 2 kg-CO_2/kg. Concerning zinc, data for only four mines out of nine major concentrates suppliers was available. Unit CO_2 emission from the smelting process plays more important role for zinc compared to copper, because even the highest unit CO_2 emission among these four mines e.g. that of Mt. Isa, only consists one half of the total unit CO_2 emission of zinc. Production costs and unit CO_2 emissions are not always correlating each other so that total costs of four mines out of the seven copper mines become almost equal under imposition of carbon tax at the rate of 30cents/kg CO_2. The fact indicates that the rational order of development, could change according to the rate of carbon tax.