(1) Applicability
The provisions of this rule shall apply to each
superphosphoric acid phosphate plant having a design capacity of more than 15
tons of equivalent P2O5 feed per
calendar day. For the purpose of this rule, the affected facility includes any
combination of evaporators, hotwells, acid sumps and cooling tanks commenced on
or after February 9, 1977.
(2) Definitions.
(a) "Superphosphoric acid plant" means any
facility which concentrates wet-process phosphoric acid to 66 percent or
greater P2O5 content by weight
for eventual consumption as a fertilizer.
(b) "Total fluorides" means elemental
fluorine and all fluoride compounds as measured by reference methods specified
in subparagraph .01(5)(g) of this chapter, or equivalent or alternative
methods.
(c) "Equivalent
P2O5 feed" means the quantity of
phosphorus, expressed as phosphorous pentoxide, fed to the process.
(3) Standard for Fluorides. On and
after the date on which the performance test required to be conducted by
paragraph .01(5) of this chapter is completed, no owner or operator subject to
the provisions of this rule shall cause to be discharged into the atmosphere
from any affected facility any gases which contain total fluorides in excess of
5.0 g/metric ton of equivalent P2O5
feed (0.010 lb/ton).
(4) Monitoring of Operations. The owner or
operator of any granular diammonium phosphate plant subject to the provisions
of this rule shall:
(a) Install, calibrate,
maintain, and operate a flow monitoring device which can be used to determine
the mass flow of phosphorus-bearing feed material to the process. The flow
monitoring device shall have an accuracy of ±5 percent over its operating
range.
(b) Maintain a daily record
of equivalent P2O5 feed by first determining the total mass rate in metric
ton/hr of phosphorus-bearing feed using a flow monitoring device meeting the
requirements of subparagraph (a) of this paragraph and then by proceeding
according to part (5) (c)2. of this rule.
(c) Install, calibrate, maintain, and operate
a monitoring device which continuously measures and permanently records the
total pressure drop across the scrubbing system. The monitoring device shall
have an accuracy of ±5 percent over its operating range.
(5) Test Methods and Procedures.
(a) For determining the concentration of
total fluorides and the associated moisture content, the sampling time for each
run shall be at least 60 minutes and the minimum sample volume shall be at
least 0.85 dscm (30 dscf) except that at shorter necessitated by process
variables or other factors, may be approved by the Technical
Secretary.
(b) The air pollution
control system for the affected facility shall be constructed so that
volumetric flow rates and total fluoride emissions can be accurately determined
by applicable test methods and procedures.
(c) Equivalent
P
2O
5 feed shall be determined as
follows:
1. Determine the total mass rate in
metric ton/hr of phosphorus-bearing feed during each run using a flow
monitoring device meeting the requirements of subparagraph (4)(a) of this
rule.
2. Calculate the equivalent
P2O5 feed by multiplying the
percentage P2O5 content, as
measured by the spectrophotometric molybdovanadophosphate method (AOAC Method
9), times the total mass rate of phosphorus-bearing feed. AOAC Method 9 is
published in the Official Methods of Analysis of the Association of Official
Analytical Chemists, 11th edition, 1970, pp. 11-12. Other methods may be
approved by the Technical Secretary.
(d) For each run, emissions expressed in
g/metric ton of equivalent P
2O
5
feed shall be determined using the following equation:
Click
to view Image
where:
E = Emissions of total fluorides in g/metric ton of
equivalent P2O5 feed.
Cs = Concentration of total fluorides in mg/dscm.
Qs = Volumetric flow rate of the effluent gas stream in
dscm/hr.
10-3 = Conversion factor for mg to
g.
MP2O5 =
Equivalent P2O5 feed in metric
ton/hr.