Differentiate fixed costs and variable costs. 1  Total cost is the sum of fixed and variable costs.  Variable costs change according to the quantity of a good or service being produced. The amount of materials and labor that is needed for to make a good increases in direct proportion to the number of goods produced.
Xtrata is a top five producer of copper, thermal coal, coking coal, ferrochrome, zinc and nickel and has operations in 19 countries. The company's copper production in 2010 was over 900 thousand metric tons and it has copper facilities located in Australia, Chile, Peru, Argentina, and Canada.
S. ore. Fourteen domestic mines accounted for more than 95 percent of the 1.45 megagrams (Mg)(1.6 millon tons) of ore produced in 1991.Copper is produced in the U. S. primarily by pyrometallurgical smelting methods.Pyrometallurgical techniques use heat to separate copper from copper sulfide ore concentrates.xpressed as kg of pollutant/Mg of concentrated ore processed by smelter.Approximately 4 unit weights of concentrate are required to produce 1 unit weights of copper metal.Based on test data for several smelters with 0.1 to 0.4% lead in feed throughput.