EEPOET ON THE PHOSPHATE FIELDS OF SOUTH CAROLINA. 
These numerous and widely varying factors make it very difficult 
to strike an average for the cost of producing high-grade South 
Carolina phosphate, but the following figures, compiled from data 
obtained in these fields and from the author's own observation, are 
probably as close approximations as can be obtained. 
Table III. — Average cost per ton of 
producing South Carolina phosphate. 
Item. 
Expense. 
Item. 
Expense. 
SI. 50 
.10 
.05 
.30 
.04 
.12 
.40 
$0.05 
.05 
.10 
.75 
Total 
3.46 
WASTE MATERIAL. 
In mining and preparing South Carolina rock for the market the 
same sources of waste are encountered as in the production of Florida 
phosphate. . The loss of finely divided phosphate (held in suspension 
and passing through the cylinder screens) incident to the present 
method of cleaning the rock is very great, though not as great propor- 
tionally as the loss in washing the Florida product. 1 The phosphate 
stratum will yield on an average about 40 per cent phosphate rock; 
the remaining 60 per cent, consisting of sand, clay, and finely divided 
phosphate, is discharged upon the waste heaps. An analysis of mate- 
rial from the dumps made by the Bureau of Soils showed a content of 
about 13 per cent bone phosphate of lime, which means that over 20 
per cent of the phosphate taken from the mines is discarded. An- 
other, though minor, source of waste is at the picking board or belt 
where the clay balls, marl, etc., are removed by hand Inexperienced 
and careless pickers frequently throw away much good material. 
DISPOSAL OF PRODUCT. 
Although some specimens of South Carolina rock contain as high 
as 75 per cent of bone phosphate of lime, the average grade of 
the marketed product is about 61 per cent. Almost the entire 
output is sold in the State on a guaranty of 60 per cent of bone 
phosphate and made into acid phosphate by the local factories. 
The present price of South Carolina rock f. o. b. at the mines is 
about $4 per ton. 
Some rock is shipped to neighboring States and a small amount 
as far north as Richmond, Va., but the freight rates will hardly 
admit of its shipment any great distance. The price of the higher 
grade Tennessee and Florida phosphate f. o. b. at the mines is so 
1 Waggaman, Bui. No. 76, Bureau of Soils, U. S. Dept. Agr. (1911). 
