Metals subcategory precious

Table 9.5 shows the concentrations of pollutant parameters found in the precious metals subcategory raw waste streams. The major constituents are silver and gold, which are much more commonly used in metal finishing industry operations than palladium and rhodium. Because of their high cost, precious metals are of special interest to metal finishers. 

Concentrations of Pollutants Found in the Precious Metals Subcategory of Raw Wastewater... 

Table 9.2 lists the unit operations associated with each of the seven industry subcategories (raw waste characteristics). Common metals are found in the raw waste of all 44 unit operations. Precious metals are found in only seven unit operations complexed metals are found in three unit operations hexavalent chromium is found in seven unit operations and cyanide is found in eight unit operations. Within the organics, oils are found in 22 unit operations and solvents are found in nine unit operations. A unit operation will often be found in more than one subcategory. 

Data source EGO Combined Data Base Point source Metal finishing Subcategory Common metals precious metals complexed metals hexavalent chromium solvents... 

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