Show cementation OF COPPER BY SPONGE IRON sponge iron has many advantages over scrap iron as a precipitant for copper the bureau of mines department of commerce has completed an investigation covering the rate of precipitation grade of product obtain obtainable abley completeness of precipitation and effects of temperature and acidity using various sponge iron products under different conditions it was found that sponge iron precipitates copper much more rapidly than does scrap iron or de tinned scrap on account of the fine state of subdivision of the sponge iron iron the precipitation must be carried out in apparatus designed fo for r that purpose these facts brought out in the earlier tests have been confirmed by a series of tests just completed |