1. Primary Copper Smelting
Example Mini-Project Problem Presentation
Stephen Zemba

2. Copper Smelters (from web sources)

3. Interesting Facts About Copper
Copper produced in 13 states, 60% in Arizona (EPA AP42)
Bingham Canyon, Utah – largest excavation in world =>
Trace-level nutrient in humans, toxic to many aquatic species

4. Definitions New Source Performance Standards from 40 CFR 60
Definitions New Source Performance Standards from 40 CFR (Subpart P)
Primary copper smelter means any installation or any intermediate process engaged in the production of copper from copper sulfide ore concentrates through the use of pyrometallurgical techniques.
Smelting means processing techniques for the melting of a copper sulfide ore concentrate or calcine charge leading to the formation of separate layers of molten slag, molten copper, and/or copper matte.
Secondary smelting involves the extraction and purification of copper from secondary materials other than ore

5. Copper (Cu) Production
Raw ore has 1% copper
Enrichment by mechanical separation (grinding and floatation) to 15-35% Cu, 25% S
“Smelting” entails:
Roasting, Smelting, Refining, & Melting
Most steps involve fuel use
Figure at right from Lead Locating and Estimating document

6. Schematic of Flash Furnace

7. Emissions and Controls
Primary emissions are SO2 and PM; lead is % PM (AP42)
NSPS are 650 ppm SO2 and 50 mg/dscm PM
Typical controls are sulfuric acid (SO2) production and electrostatic precipitation (PM)

8. Title V Permit Kennecott Utah Copper LLC
No information in RACT/BACT/LAER Clearinghouse
2007 permit issued by Utah Division of Air Quality, approved by U.S. EPA Region 8
114 pages long!
Covers the smelter and a sulfuric acid plant
Explicitly covers 47 sources
Many sections for 40 CFR 60
Conditions, monitoring, record-keeping, reporting
40 CFR 60 Subpart P limits are met or more stringent
50 mg/dscm for dryer is the same as the Subpart P NSPS
Max opacity of 15% required instead of 20%
SO2 effluent at 250 ppm max instead of 650 ppm

9. Other Emissions Data and Information
Metal
Percentage of particulate matter
Size ranges in µm
0 to 2.5
2.5 to 10
0 to 30
Antimony 6
5.6
5.917
Arsenic 24 38
26.893
Bismuth
0.4
0.317
Cadmium
0.51
0.46
0.5
Chromium
0.014
0.017
0.015
Copper 3
2.4
2.876
Indium
0.023
0.018
Iron
0.29
0.313
Lead 18 16
17.587
Manganese
0.009
0.01
Molybdenum
0.1
0.134
0.107
Nickel
0.04
0.07
0.046
Silver
0.12
Tellurium
0.17
0.18
0.172
Tin
0.39
0.398
Vanadium
0.016
Zinc
4.2 4
4.159
Above: Converter diagram from Lead Locating and Estimating document
Left: Table of PM composition from EPA Speciate program

10. Copper Smelters Example Summary Sheet
Copper Production
Copper is mined in 13 states in the western U.S.
Raw ore has ~1% copper and must be extracted and purified
Concentration is first enriched by mechanical separation (grinding and floatation) to 15-35% Cu, 25% S
“Smelting” involves heating, melting, and separating the components of the ore
A facility typically use roasting, smelting, refining, melting, and other processes
Most steps involve fuel use; some reactions provide heat as well
Copper Smelters
Example Summary Sheet
New Source Performance Standards (apply to effluent)
Particulate matter (PM): 50 mg/dscm
Sulfur dioxide (SO2): 0.065%
No visible emissions > 20% opacity
Continuous emissions monitoring and compliance for opacity (6-min) and SO2 (6-hr)
Method 5 stack testing for PM
SO2 on a dry basis
Pollutant emissions and controls
Main pollutants are Particulate matter (PM) and Sulfur dioxide (SO2)
Emissions depend on the process (furnace type) and the ore quality
PM includes trace levels of arsenic, antimony, cadmium, lead, selenium, and cobalt at trace levels (e.g., % lead)
SO2 control (~98-99%) is typically through production of sulfuric acid (commercial product) due to high sulfur content of effluent gas (> 3%)
PM controlled typically by electrostatic precipitators (95% control achievable)
Title V Permit for Kennecott Utah Copper
Particulate matter (PM): 50 mg/dscm
Sulfur dioxide (SO2): 0.025% (6-hr)
No visible emissions > 15% opacity

11. d=(1 – opacity)/s=-ln(1 – 0.2)/0.163 m-1 = 1.4 m
Air Pollution Problem
What is the optical path length at which the NSPS of 50 mg/dscm matches the visible emissions limit of 20% opacity?
Lv = 1200/C = 1200/50,000 = km = 24 m
s=3.91/Lv = 3.91/24 m = m-1
d=(1 – opacity)/s=-ln(1 – 0.2)/0.163 m-1 = 1.4 m