. Transactions. Fig. 1.—Copper melted ix uncovered crucibles. the fact that when a charge of copper is overpoled it cannot be rightedby a simple addition of cuprous oxide, but the charge must be reworkedto set copper. Effect of Sulfur on the Conductivity of Copper A comparison of the conductivity tests arranged according to increas-ing sulfur contents is shown in Table 5. 316 RELATION OF SULFUR TO THE OVERPOLING OF COPPER Table 5.—Effect of Sulfur on Conductivity Per Per Conductivity Nil
. Transactions. Fig. 1.—Copper melted ix uncovered crucibles. the fact that when a charge of copper is overpoled it cannot be rightedby a simple addition of cuprous oxide, but the charge must be reworkedto set copper. Effect of Sulfur on the Conductivity of Copper A comparison of the conductivity tests arranged according to increas-ing sulfur contents is shown in Table 5. 316 RELATION OF SULFUR TO THE OVERPOLING OF COPPER Table 5.—Effect of Sulfur on Conductivity Per Per Conductivity Nil Cathode copper Copper melted under flux Copper melted under charcoal. Sulfur allojS. NilNil PiQ 2.—Copper melted under ch.\rco.\l and poled before pouring. DISCUSSION 317 Since the sulfur contents of refined copper is within the hmits to per cent., the conductivity of commercial copper cannotbe said to be directly affected by the sulfur it contains. It is the cu-prous oxide, which must be left in the copper to counteract the sulfur,that lowers the conductivity. This is more evident by comparing Tables3 and 4, where the overpoled bars show high electrical conductivities,whereas the level set bars, high in oxygen, show low conductivity. It takes a comparatively large amount of cuprous oxide to counteracta trace of sulfur; this explains why, in the refining of copper, the gasesfrom fresh fuel will often overpole the copper during the casting period,and also why copper cannot be held in the furnace at the proper pitch formore than a few hours. It also explains the limit of recharging cathodesheets into the furnace after the copper has been worked to the properpit
Size: 1864px × 1340px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
