the processing of ores（ introduced poorly分词定语）主语
controlled谓语
changes in the concentrations of minor and trace elements in the resultingmetal.宾语
trace 名词修饰名词 elementstrace是与changes in the concentrations of minor并列还是与the concentrations of minor并列？changes （in the concentrations of minor and trace elements in the resultingmetal 修饰“changes”） in the concentrations of minor and trace elements在介词短语中 minor and trace elements做of 后面的宾语 in the resultingmetal 介词短语修饰elements