Ziii (■ f)('S ilrcr izcdin ii . 



95 



either a part or the whole of the first additions of zinc in the 

 next kettle. 



At Mansfield, poor lead is not tapped if it contains more than 

 one-tenth of an ounce of silver to the ton, and the merchant 

 pig assays 0.075 to 0.15 oz. 



When the nermania works were first bnilt, the Flack j^rocess 

 Avas used. The liquated zinc skimmings were charged in a blast 

 furnace with a very basic slag, and small jjressure of blast. The 

 result was rich lead, and -a rich slag. In the condensation 

 chambers, a very impure oxide of zinc was collected, which was 

 but a small j)art of that actually charged in the furnace. As 

 the use of this process occasioned a loss of from 118,000 to 

 $25,000 a year in zinc, it was abandoned, and the Faber du Faur 

 furnace was introduced in its place. 



It is always best to use good zinc for the separation. An 

 attempt was made at the Chicago Silver Smelting and Eefining 

 Works, to economize in this direction by using scrap zinc; but 

 it was found that the lead, after its use, sometimes contained 

 as high as 18 oz. to the ton, and the attemj^t had to be aban- 

 doned. 



The following statement of several charges at the Germania works is 

 made by the Superintendent, Mr. A. V. Weisse : ' 



No. of lbs. charged in the softening-furnace, - 

 No. of grammes* of silver, - - - - 



" gold, - - 



First addition of zinc, from 2d and 3d additions of a pre- 

 vious operation, in lbs., 



* Grammes of silver in lead after first addition. 

 Second addition of zinc in lbs. , ... 



* Grammes of silver in lead after the second addition. 

 Third addition of zinc in lbs. , - 



* Grammes of silver in lead after the third addition. 



No. 1. 



No. 2. 



41,614 



40,120 



5,700 



1,980 



110 



10 



4,000 



3,000 



1,360 



1,160 



600 



600 



20 



30 



80 



125 



trace. 



6 



The following tables were prepared by Mr, E. F. Eurich, of the 

 Pennsylvania Lead Co. : 



1 Mining Commissioners' Report for 1875. 



* The grammes are given per thousand kilogrammes. 



