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Texas SIP: 30 TAC 112.14: Allowable Emission Rates—Nonferrous Smelter Processes

Regulatory Text: 
Section 112.14.  Allowable Emission Rates - Nonferrous Smelter Processes.

(Approved by EPA 08/30/93 (58 FR 45457) at 52.2270(c)(76) effective 10/29/93.)

   (a) This section is applicable to all processes in nonferrous smelters, including, but not limited to, roasters, smelting furnaces, converters, sintering machines, blast furnaces, fuming furnaces, retorts, slag treatment plants, and sulfuric acid plants.

   (b) No person may cause, suffer, allow, or permit emissions of sulfur dioxide (SO2) to the atmosphere from any process as specified in this section to exceed the applicable concentration of SO2 as follows:

Source SO2 Parts Per Million by Volume (ppmv) Maximum - Two-Hour Average SO2 Parts Per Million by Volume (ppmv) Maximum - Three-Hour*
(1) Primary Copper Smelter
for all purposes other than
those listed below:
-    650
    (A) Reverberatory Furnace -  6,000
(2) Primary Zinc Smelter   1,000 -
(3) Primary Lead Smelter - -
    (A) Sinter Machine Discharge End (provided gases do not pass through Sinter bed),   2,500 -
    (B) Sinter Handling Equipment Emission Collecting Systems   2,500 -
    (C) All Other Processes     650 -
(4) Other Primary Smelter   2,500 -
(5) Secondary Metal Recovery Facility   3,500 -
(6) Sulfuric Acid Plant -   650

*The three-hour standards will be based on a six-hour average until September 30, 1994.

   (c) Each stack or emission point in a primary smelter or secondary metal recovery facility shall have a standard effective stack height not less than that determined by the equation:

He = K(q)^0.5


He = standard effective stack height in feet
q = effluent flow rate in standard cubic feet per minute (scfm)
K = a constant dependent on the type of facility as follows: 

Type of Facility K
Primary Copper Smelter 0.50
Primary Lead Smelter
(all processes except Sintering
Machine, Discharge End, and
Equipment Ventilation)
Metallurgical Sulfuric Acid Plant 0.61
Primary Zinc Smelter 0.61
Other Primary Smelters 0.90
Primary Lead Smelter Sintering
Machine Discharge End and Equipment
Secondary Metal Recovery Facilities 1.17

When two or more gas streams either wholly or in part are discharged through a single stack, the combined flow rate of all streams shall be used to determine the required standard effective stack height.  If streams with different SO2 concentration allowables, as determined in subsection (b) of this section, are combined into a single stream, the required effective stack height is determined as follows:

     (1) Calculate a total combined stream SO2 concentration allowable as follows:

          (PPM1)(SCFM1)+(PPM2)(SCFM2) +  ..(PPMn)(SCFMn)
 PPMt = _________________________________________________

                  (SCFM1 + SCFM2 +  ..SCFMn)

PPMt = Allowable SO2 concentration in total combined stream, ppmv
PPM1 = Allowable SO2 concentration in stream No.1, ppmv
PPM2 = Same as PPM1 except for stream No. 2 
PPMn = Same as PPM1 except for Nth stream
SCFM1 = Effluent flow rate of stream No. 1, scfm
SCFM2 = Same as SCFM1 except for stream No. 2
SCFMn = Same as SCFM1 except for Nth stream 

     (2) Calculate interpolation constant (Kt) for the total combined stream as follows: 

       (PPMt-PPMx) (Kh-Kx)
 Kt = --------------------- + K


Kt = Interpolation constant for use in the following standard effective stack height equation

PPMt = Allowable SO2 concentration in total combined stream previously calculated and for the stated total ppmv, the other parameters are:

  650 to 1,000   650 1,000 0.50 0.61
1,000 to 2,500 1,000 2,500 0.61 0.90
        >2,500 2,500 3,500 0.90 1.17

     (3) Calculate standard effective stack height for total combined stream as follows: 

He = Kt(q)^0.5

He = Standard effective stack height in feet
Kt = Interpolation constant calculated previously
q = Total stack effluent flow rate in scfm 
      (SCFM1 + SCFM2 + ... SCFMn)

   (d) If a stack or emission point has an effective stack height less than the standard effective stack height as determined in subsection (c) of this section, the allowable concentration of SO2 must be reduced by multiplying it by the short-stack reduction factor.

   (e) The owner or operator of a nonferrous smelter shall utilize best engineering techniques to capture and vent fugitive SO2 emissions through a stack or stacks.  Such techniques shall include, but not be limited to, the following:

     (1) Operating and maintaining all ducts, flues, and stacks in a leak-free condition.

     (2) Operating and maintaining all process equipment and gas collection systems in such a fashion that leakage of SO2 gases will be prevented to the maximum extent possible.

     (3) Collecting SO2 emissions through the tallest stack or stacks serving the facility, whenever possible, using gas collection systems and/or ducting.

   (f) The owner or operator of any primary smelter subject to the provisions of this section shall install, calibrate, maintain, and operate a measurement system or systems approved by the Executive Director for continuously monitoring SO2 emissions in the effluent of each process subject to subsection (a) of this section.  The Executive Director shall not require continuous monitoring for sources emitting less than 25 tons per year of SO2 into the atmosphere. 

As adopted by TACB 09/18/92 effective 10/23/92