SECOND ANNUAL REPORT—MINERAL INDUSTRIES. 
237 
The total amount of phosphate marketed from the United States 
during 1908 was according to the reports of the United States Geolog¬ 
ical Survey 2,386,138 long tons. Of this amount Florida. produced 
70.9 per cent. Other states contributing to this total were: Tennes¬ 
see, 19.1 per cent; South Carolina, 9.4 per cent; Arkansas, Idaho, Utah 
and Wyoming combined .6 of one per cent. Of the world’s output of 
phosphate rock Florida is now producing approximately one-third. 
During 1906 the demand for phosphate exceeded the ready supply, 
and prices advanced accordingly. Florida hard rock phosphate which 
during the preceding year had sold for $7.50 to $7.75 per ton F. O. B. 
at ports advanced to $8 and $9 per ton. The shortage in the supply of 
hard rock centered attention upon the land pebble which sold by the 
close of 1906 as high as $6 per ton F. O. B. at ports. The high prices 
of 1906 were maintained during 1907, Florida hard rock selling during 
this year at $10.25 to $10.50 at ports, while land pebble was quoted by 
the close of 1907 as high as $7.50 to $7.75 F. O. B. at ports. During 
1908 the demand for phosphate became less active and the price de¬ 
clined, land pebble being quoted at the close of the year at $4.25 to 
$4.50 per ton and hard rock at $10 to $10.25 F. O. B. at ports. The 
quotations for June, 1909, as given by The Engineering and Mining 
Journal are: Hard rock, $7.50 to $8.00; land pebble, $3.75 to $4.00, 
F. O. B. at ports. 
The Florida phosphates are sold ordinarily under guaranteed anal¬ 
ysis. The guarantee which the producers are able to give varies with 
the kind of phosphate mined and to some extent with individual depos¬ 
its and methods of mining. Most of the hard rock is sold under a 
guarantee that the rock will average 77 per cent tricalcium phosphate 
(“bone phosphate of lime” of commerce) ; that iron and alumina com¬ 
bined will not exceed 3 per cent; and that the moisture will not exceed 
3 per cent. Much of the land pebble is sold under a guarantee of 68 
per cent tricalcium phosphate; iron and alumina combined not to exceed 
3.5 per cent to 4 per cent; and moisture not to exceed 3 per cent. Some 
of the producers of land pebble, however, are now able to guarantee as 
high as 72 per cent of tricalcium phosphate; river pebble is sold 
ordinarily under a guarantee of 60 per cent tricalcium phosphate, iron 
and alumina not to exceed 3 per cent; and moisture not to exceed 3 
per cent. 
The aluminous material such as clays which are associated with 
the phosphates are removed chiefly by washing and afterwards to some 
extent by drying. Thorough washing is effected by means of log 
washers. The clay being flooded out by water as the phosphate passes 
through the washer. During the process of drying the clay adhering 
to the phosphate is somewhat further reduced. 
