6 INJURY BY SMELTER. WASTES. 
arsenic and sulphur products which are carried to the flue. The slag 
is granulated in water and passed to the dump. The “matte” is 
carried to the converters, where it is treated in the same way as 
“matte ~ from the blast furnaces. 
The blast furnace receives a charge consisting essentially of the 
high-grade ores, converter slag, briquettes of siliceous fines and 
slimes from the concentrator, limestone, and coke. A large part of 
the sulphur passes off to the flue as sulphur dioxid and trioxid, 
and large amounts of arsenic are volatilized. The iron and silica 
in the ore, together with the lime, form a slag (containing a very 
small amount of copper) which is granulated in water and carried 
to the dump; the copper forms a “ matte” consisting principally 
of a combination of copper, iron, and sulphur. This, together with 
the “ matte” from the reverberatory furnaces, 1s next carried to the 
converters, the lining of which is a siliceous material that lasts for 
several runs. 
In the converter the sulphur which is present in the * matte” is 
oxidized to sulphur dioxid and trioxid and escapes up the flue, the 
remaining arsenic is volatilized and also goes up the flue, while the 
iron unites with the siliceous lining to form a slag which is returned 
to the blast furnaces, since it is a good flux and also contains con- 
siderable quantities of copper. The copper obtained by this process 
is carried to the preliminary refining apparatus, where air is passed 
over the molten mass to remove traces of sulphur and the small 
amount of slag which was not taken out in the converters is also 
eliminated. During this process some copper oxid is formed, but 
upon stirring this is again reduced to copper by the carbon of the 
converter poles. In this condition the copper is cast into ingots, 
which are sold to refineries not situated at Anaconda. 
The fumes from these processes are passed through long cooling 
chambers in order to condense the volatilized compounds of arsenic 
as far as possible, but in spite of this precaution large amounts of 
arsenic escape from the top of the chimney. No attempt is made to 
recover any of the sulphur compounds. 
RESULTANT WASTES. 
From this brief description of the process used at Anaconda, it 
will be evident that four wastes arise which may be injurious to plant 
or animal life. 
(1) The sulphur contained in the ore is gradually given off dur- 
ing the various processes of smelting, as sulphur dioxid and a little 
sulphur trioxid, which would have their injurious action on vegeta- 
tion. 
