This document discusses emission reduction from copper and aluminum production. It outlines the primary production processes for both metals and describes the main sources of emissions. For copper, emissions are primarily from roasting and smelting sulfidic concentrates, though modern smelters now achieve over 98% sulfur fixation. For aluminum, emissions are from polyfluorinated compounds during electrolysis and solid wastes. The document also describes flash furnace smelting as an energy efficient technique used in Europe for copper and nickel production. Finally, it discusses future requirements for emission control techniques in copper production.

1. Reduction Emission
from Copper &
Aluminum Production

2. Contents
• Copper & Aluminium Production
• Sources of emission
• Technology: Flash furnace smelting
• Future requirement for emission control (Techniques)

3. Copper Production
• Approximately 90 % of the world copper production from
ores is now manufactured from sulphidic ores by
pyrometallurgical techniques (see Figure 1). Five steps can
be distinguished in the primary production of copper:
• I. mining of copper ores
• II. isolation of the copper mineral particles in an ore by
flotation
• III. smelting of the resulting concentrate to molten high
copper matte
• IV. converting of molten matte to molten blister copper
• V. fire- and electrorefining of the blister to pure copper.

4. Aluminium
Production
• Primary aluminium is produced from aluminium oxide
(alumina), [ 6, McLellan and Partners Ltd 1993], [ 97,
Lijftogt, J.A. et al 1998], [ 312, VDI 2008] in a two-stage
process starting from bauxite.
• Stage one: the production of alumina from bauxite.
• Stage two: the production of primary aluminium from
alumina, usually at a different site to the site carrying out
stage one production, mainly for logistical reasons and
the availability of electricity.
• Some alumina’s, known as speciality alumina’s, do not go
through the second stage process if they are mostly
intended for metal production.
• Secondary aluminium is produced from the scrap
melting. Two main features of secondary aluminium
production are the diversity of raw materials encountered
and correspondingly the variety of furnaces used.

5. Source of emissions
• Emissions from copper: The major environmental problem associated with the production of
copper from primary sources was the emission of sulphur dioxide to air from the roasting
and smelting of sulphidic concentrates. This problem has been effectively solved by the EU
smelters which now achieve on average a 98.9 % fixation of the sulphur and produce
sulphuric acid and liquid sulphur dioxide. The main environmental issues associated with the
production of secondary copper are also related to the flue-gases from the various furnaces
in use.
• Emissions from aluminium: The main environmental issues for primary aluminium are the
generation of polyfluorinated hydrocarbons and fluorides during electrolysis, the production
of solid waste from the cells and the production of solid waste during the production of
alumina. Regarding the production of secondary aluminium, there are potential emissions of
dust and PCDD/F from poorly operated furnaces and poor combustion and the production
of solid wastes (salt slag, spent furnace linings, dross, and filter dust).

6. Technology: Flash furnace smelting
• European producers, e.g., in Finland, Germany, Spain and Bulgaria use energy efficient flash
smelting which can be used in copper and nickel production. In China, use of molten bath
and top blown methods have become increasingly common despite of poorer energy
performance. The benefit of flash smelting is that it uses the energy within the concentrate
feed mixture and additional energy is needed only to compensate for the heat losses.
• One of the most cutting edge technologies aluminium producers are working on today is
the inert anode process. It's a unique revolutionary process that can allow aluminium
producers to stop using carbon anodes altogether. The inert anode can potentially be used
ad infinitum, but most importantly, what the inert anode based reduction process emits into
the atmosphere is not carbon dioxide, but pure oxygen. One inert anode call can produce as
much oxygen as 70 hectares of forest. Currently, the inert anode process is being developed
in secret and undergoing industrial trials but who knows, maybe in the near future it will turn
the aluminium industry into the lungs of our planet.

7. Future requirement for emission control (Techniques)
A recent report from McKinsey Global Institute predicts that copper consumption will rise by 43% by 2035. This is
likely to be partly driven by green technologies, such as solar and wind power and electric vehicles. The best
available technique to produce copper from sulphidic concentrates consists of the following unit processes:
• The concentrates are stored indoors and dried in multicoil steam dryers.
• A loss-in-weight feeding system is used to feed the concentrate.
• The flash smelting flash converting process is used.
• The slag is cleaned.
• Blister copper is refined in the anode furnace and cast into anodes.
• Copper anodes are electro refined to cathodes using permanent cathodes.
• The cleaned gas stream from the furnaces is routed to a modern double contact acid plant.
• The plant is equipped with a good environmental control system

8. References
• https://eippcb.jrc.ec.europa.eu/sites/default/files/2020-01/JRC107041_NFM_bref2017.pdf
• The Copper Flash CC Smelting Process :: Total Materia Article
• Environment > Best Available Techniques (BAT) in Finland (ymparisto.fi)
• *Energy_Efficiency_of_Metals_Production_Industry_in_Finland_-_December_2020.pdf
(motiva.fi)
• SYKE 316 (helsinki.fi)
• carbon-footprint-of-boliden-main-metals_2021_executive-summary.pdf
• How aluminium is produced (aluminiumleader.com)
• How aluminium is made (hydro.com)