Mandatory
Nonphosphate -
Heavy Mineral Mines
The
Mining and Minerals Regulation Program administers the laws and regulations
related to the reclamation of mined land and the protection of water
resources (water quality, water quantity and wetlands) at heavy mineral
mines.
What are heavy minerals?
Subsection 378.403(7), Florida Statutes, defines heavy minerals as
those resources found in conjunction with sand deposits which have a
specific gravity of not less than 2.8, and includes an admixture of such
resources as zircon, staurolite, and titanium minerals as generally mined
in this state. Heavy mineral mining began in Florida in 1916. A variety of
minerals are found in the heavy mineral sand deposits. These include the
titanium minerals of ilmenite, leucoxene and rutile. Ilmenite and rutile
are primary source materials used to manufacture titanium dioxide
pigments. These pigments are often used in the manufacture of paint,
varnish and lacquers, plastics, and paper. Another heavy mineral, zircon,
has been marketed to the ceramics industry.
Who is mining heavy minerals in Florida?
- E. I. du Pont de Nemours & Company, Inc.
Florida Plant
Post Office Box 753
Starke, Florida 32091
(904)964-1200
Where are the heavy mineral mines in Florida?
Heavy minerals have been found and mined in several locations in
Florida. At this time, the industry is mining only in Bradford, Clay, and
Putnam Counties, and small areas in Baker and Duval Counties.
How are heavy minerals mined in Florida?
Prior to mining the trees are harvested by normal silvicultural
practices. One foot of topsoil is removed and stockpiled along the edge of
the mine for later use in reclamation. The topsoil storage piles are also
used to contain sediment and stormwater within the project limits.
The heavy minerals occur as sand grains mixed in with lighter clays and
quartz sand grains. Within the ore body, less than 5 percent of the grains
may be heavy minerals. Above the ore body is the overburden of clays and
quartz sand without marketable product. Two mining methods are used:
suction dredging and auxiliary mining.
- In the suction dredging method, an electrically powered suction
dredge floats within a 15- to 20-acre man-made pond. At one end of the
pond, the dredge draws in overburden, ore and water and transfers the
mixture to a floating wet mill. Vibrating screens block out roots and
other large objects. Spiral centrifuges are then used to concentrate
and separate the heavy mineral sands from the lighter clays and quartz
sands. The now 80 percent heavy mineral concentrate is then pumped to
a stock pile area before being transported to a plant for further
processing. The tailings of clays and quartz sand is discharged back
into the pond behind the suction dredge. As the dredge moves forward,
the area behind the dredge is recontoured, covered with topsoil, and
revegetated to meet reclamation standards.
- Auxiliary mining is used in locations that are not suitable for
suction dredging. The overburden is removed with heavy earth moving
equipment and stock piled for later use in reclamation. The ore body
is then loaded on to trucks and hauled to an area in front of the
suction dredge. The suction dredge than processes this material as
described above. Tailings from the suction dredge are pumped back into
the auxiliary area to back fill the mined out pits. The auxiliary
areas are then backed filled with overburden, recontoured, covered
with topsoil, and revegetated to meet reclamation standards.
For more information on heavy minerals mining in Florida, please
refer to:
E. C. Pirkle, William A. Pirkle, and W. H. Yoho, (1977) The Highland
Heavy-Mineral Sand Deposit on Trail Ridge in Northern Peninsular
Florida. Report of Investigation No. 84. Bureau of Geology, Florida
Department of Natural Resources.
Mining and Minerals Regulation Home
2051 E. Paul Dirac Drive (Collins Building) Tallahassee, FL 32310-3760 Phone
(850) 488-8217 Fax (850) 488-1254
2012 State of Florida