Section 440.37. Phosphate fertilizer industry: wet-process phosphoric acid plants.

 

(1)   Applicability and designation of affected facility.

(a) The affected facility to which the provisions of this section apply is each wet-process phosphoric acid plant having a design capacity of more than 15 tons of equivalent P 2 O 5 feed per calendar day. For the purpose of this section, the affected facility includes any combination of: reactors, filters, evaporators and hotwells.

(b) Any facility under par. (a) that commences construction or modification after October 22, 1974, is subject to the requirements of this section.

(2)   Definitions. As used in this section, terms not defined in this subsection have the meanings given in s. NR 440.02 .

(a) "Equivalent P 2 O 5 feed" means the quantity of phosphorus, expressed as phosphorus pentoxide, fed to the process.

(b) "Total fluorides" means elemental fluorine and all fluoride compounds as measured by reference methods specified in sub. (5) , or equivalent or alternative methods.

(c) ``Wet-process phosphoric acid plant" means any facility manufacturing phosphoric acid by reacting phosphate rock and acid.

(3)   Standard for fluorides. On and after the date on which the performance test required to be conducted by s. NR 440.08 is completed, no owner or operator subject to the provisions of this section may cause to be discharged into the atmosphere from any affected facility any gases to which contain total fluorides in excess of 10.0 g/Mg of equivalent P 2 O 5 feed (0.020 lb/ton).

(4)   Monitoring of operations.

(a) The owner or operator of any wet-process phosphoric acid plant subject to the provisions of this section shall install, calibrate, maintain and operate a monitoring device which can be used to determine the mass flow of phosphorous-bearing feed material to the process. The monitoring device shall have an accuracy of $ 5% over its operating range.

(b) The owner or operator of any wet-process phosphoric acid plant shall maintain a daily record of equivalent P 2 O 5 feed by first determining the total mass rate in Mg/hr of phosphorus bearing feed using a monitoring device for measuring mass flow rate which meets the requirements of par. (a) and then by proceeding according to sub. (5) (b) 3.

(c) The owner or operator of any wet-process phosphoric acid plant subject to the provisions of this section shall install, calibrate, maintain and operate a monitoring device which continuously measures and permanently records the total pressure drop across the process scrubbing system. The monitoring device shall have an accuracy of " 5% over its operating range.

(5)   Test methods and procedures.

(a) In conducting the performance tests required in s. NR 440.08 , the owner or operator shall use as reference methods and procedures the test methods in Appendix A of 40 CFR part 60 , incorporated by reference in s. NR 440.17 , or other methods and procedures as specified in this subsection, except as provided in s. NR 440.08 (2) .

(b) The owner or operator shall determine compliance with the total fluorides standard in sub. (3) as follows:

1. The emission rate (E) of total fluorides shall be computed for each run using the following equation: - See PDF for diagram

where:

E is the emission rate of total fluorides, g/Mg (lb/ton) of equivalent P 2 O 5 feed

C si is the concentration of total fluorides from emission point "i", mg/dscm (gr/dscf)

Q sdi is the volumetric flow rate of effluent gas from emission point "i", dscm/hr (dscf/hr)

N is the number of emission points associated with the affected facility

P is the equivalent P 2 O 5 feed rate, Mg/hr (ton/hr)

K is the conversion factor, 1000 mg/g (7000 gr/lb)

2. Method 13A or 13B shall be used to determine the total fluorides concentration (C si ) and volumetric flow rate (Q sdi ) of the effluent gas from each of the emission points. The sampling shall be at least 60 minutes and 0.85 dscm (30 dscf).

3. The equivalent P 2 O 5 feed rate (P) shall be computed for each run using the following equation:

P = M p R p

where:

M p is the total mass flow rate of phosphorus-bearing feed, Mg/hr (ton/hr)

R p is the P 2 O 5 content, decimal fraction

a. The accountability system of sub. (4) (a) shall be used to determine the mass flow rate (M p ) of the phosphorus-bearing feed.

b. The Association of Official Analytical Chemists (AOAC) Method 9, incorporated by reference in s. NR 440.17 , shall be used to determine the P 2 O 5 content (R p ) of the feed.

History: Cr. Register, January, 1984, No. 337 , eff. 2-1-84; am. (2) (intro.), Register, September, 1990, No. 417 , eff. 10-1-90; am. (4) (b), r. and recr. (5), Register, July, 1993, No. 451 , eff. 8-1-93; CR 06-109 : renum. (3) (a) to be (3) and am., am. (4) (b) and (5) (b) 1. and 3. (intro.) Register May 2008 No. 629 , eff. 6-1-08.