. Transactions. ts per millionparts :—Copper, 4,000 ; ferric iron, 1,000 ; ferrous iron, 20,000 ;free sulphuric acid, 10,000 ; and arsenic, 300. The large quan-tities of ferrous iron and free sulphuric acid present are due tothe fact that the waste liquor from the cementation tanks afterthe copper has been precipitated ( salida liquor as it is called),is pumped back and used for washing the heaps in addition tofresh water, and consequently these solutions tend to becomeconcentrated. The liquor is then run from the reservoirs atabout 300 per hour through the precipitation tanks overpig-ir
. Transactions. ts per millionparts :—Copper, 4,000 ; ferric iron, 1,000 ; ferrous iron, 20,000 ;free sulphuric acid, 10,000 ; and arsenic, 300. The large quan-tities of ferrous iron and free sulphuric acid present are due tothe fact that the waste liquor from the cementation tanks afterthe copper has been precipitated ( salida liquor as it is called),is pumped back and used for washing the heaps in addition tofresh water, and consequently these solutions tend to becomeconcentrated. The liquor is then run from the reservoirs atabout 300 per hour through the precipitation tanks overpig-iron in order to precipitate the copper in the form of so-called cement copper or copper precipitate. These ce-mentation tanks are arranged in series on the slope of a hill,the liquor passing backwards and forwards until it is dischargedfrom the lowest tank of the series free from copper. Each series consists of three tanks in parallel arranged sothat the liquor can be divided up and passed along as many I [Q Surface of Heaps Arranged fob WashingFig. 2.
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
