Best Available Techniques for the Surface Treatment of metals and plastics.pdf

EUROPEAN COMMISSION

DIRECTORATE-GENERAL JRC

JOINT RESEARCH CENTRE

Institute for Prospective Technological Studies

Integrated Pollution Prevention and Control

Reference Document on

Best Available Techniques for the Surface Treatment of

Metals and Plastics

Dated September 2005

Edificio EXPO, c/Inca Garcilaso s/n, E-41092 Sevilla - Spain

Telephone: direct line (+34-95) 4488-284, switchboard 4488-318. Fax: 4488-426.

Internet: http://eippcb.jrc.es ; Email: JRC-IPTS-EIPPCB@cec.eu.int

This document is one of a series of foreseen documents as below (at the time of writing, not all

documents have been drafted):

Full title

BREF code

Reference Document on Best Available Techniques for Intensive Rearing of Poultry and Pigs

ILF

Reference Document on the General Principles of Monitoring

MON

Reference Document on Best Available Techniques for the Tanning of Hides and Skins

TAN

Reference Document on Best Available Techniques in the Glass Manufacturing Industry

GLS

Reference Document on Best Available Techniques in the Pulp and Paper Industry

Reference Document on Best Available Techniques on the Production of Iron and Steel

I&S

Reference Document on Best Available Techniques in the Cement and Lime Manufacturing Industries

Reference Document on the Application of Best Available Techniques to Industrial Cooling Systems

Reference Document on Best Available Techniques in the Chlor – Alkali Manufacturing Industry

CAK

Reference Document on Best Available Techniques in the Ferrous Metals Processing Industry

FMP

Reference Document on Best Available Techniques in the Non Ferrous Metals Industries

NFM

Reference Document on Best Available Techniques for the Textiles Industry

TXT

Reference Document on Best Available Techniques for Mineral Oil and Gas Refineries

REF

Reference Document on Best Available Techniques in the Large Volume Organic Chemical Industry

LVOC

Reference Document on Best Available Techniques in the Waste Water and Waste Gas

Treatment/Management Systems in the Chemical Sector

CWW

Reference Document on Best Available Techniques in the Food, Drink and Milk Industry

Reference Document on Best Available Techniques in the Smitheries and Foundries Industry

Reference Document on Best Available Techniques on Emissions from Storage

ESB

Reference Document on Best Available Techniques on Economics and Cross-Media Effects

ECM

Reference Document on Best Available Techniques for Large Combustion Plants

LCP

Reference Document on Best Available Techniques in the Slaughterhouses and Animals By-products

Industries

Reference Document on Best Available Techniques for Management of Tailings and Waste-Rock in

Mining Activities

MTWR

Reference Document on Best Available Techniques for the Surface Treatment of Metals

STM

Reference Document on Best Available Techniques for the Waste Treatments Industries

Reference Document on Best Available Techniques for the Manufacture of Large Volume Inorganic

Chemicals (Ammonia, Acids and Fertilisers)

LVIC-AAF

Reference Document on Best Available Techniques for Waste Incineration

Reference Document on Best Available Techniques for Manufacture of Polymers

POL

Reference Document on Energy Efficiency Techniques

ENE

Reference Document on Best Available Techniques for the Manufacture of Organic Fine Chemicals

OFC

Reference Document on Best Available Techniques for the Manufacture of Specialty Inorganic

Chemicals

SIC

Reference Document on Best Available Techniques for Surface Treatment Using Solvents

STS

Reference Document on Best Available Techniques for the Manufacture of Large Volume Inorganic

Chemicals (Solids and Others)

LVIC-S

Reference Document on Best Available Techniques in Ceramic Manufacturing Industry

CER

Executive Summary

EXECUTIVE SUMMARY

The BAT (Best Available Techniques) Reference Document (BREF) entitled ‘Surface

Treatment of Metals and Plastics (STM)’ reflects an information exchange carried out under

Article 16(2) of Council Directive 96/61/EC (IPPC Directive). This executive summary

describes the main findings, a summary of the principal BAT conclusions and the associated

consumption and emission levels. It should be read in conjunction with the preface, which

explains this document’s objectives; how it is intended to be used and legal terms. It can be read

and understood as a standalone document but, as a summary, it does not present all the

complexities of this full document. It is therefore not intended as a substitute for this full

document as a tool in BAT decision making.

Scope of this document

The scope of this document is based on Section 2.6 of Annex 1 of the IPPC Directive 96/61/EC:

‘Installations for the surface treatment of metals and plastics using an electrolytic or chemical

process where the volume of the treatment vats exceeds 30 m 3 ’ . The interpretation of ‘where the

volume of the treatment vats exceeds 30 m 3 ’ is important in deciding whether a specific

installation requires an IPPC permit. The introduction to Annex I of the Directive is crucial:

‘Where one operator carries out several activities falling under the same subheading in the

same installation or on the same site, the capacities of such activities are added together’ .

Many installations operate a mixture of small and large production lines, and a mixture of

electrolytic and chemical processes, as well as associated activities. This means that all

processes within the scope, irrespective of the scale on which they are carried out, were

considered in the information exchange.

In practical terms, the electrolytic and chemical processes currently used are water-based.

Directly associated activities are also described. The document does not deal with:

• hardening (with the exception of hydrogen de-embrittlement)

• other physical surface treatments such as vapour deposition of metals

• hot-dip galvanising and the bulk pickling of iron and steels: these are discussed in the

BREF for the ferrous metals processing industry

• surface treatment processes that are discussed the BREF for surface treatment using

solvents, although solvent degreasing is referred to in this document as a degreasing

option

• electropainting (electrophoretic painting), which is also discussed in the STS BREF.

Surface treatment of metals and plastics (STM)

Metals and plastics are treated to change their surface properties for: decoration and reflectivity,

improved hardness and wear resistance, corrosion prevention and as a base to improve adhesion

of other treatments such as painting or photosensitive coatings for printing. Plastics, which are

cheaply available and easily moulded or formed, retain their own properties such as insulation

and flexibility while the surface can be given the properties of metals. Printed circuit boards

(PCBs) are a special case where intricate electronic circuits are manufactured using metals on

the surface of plastics.

STM does not in itself form a distinct vertical sector as it provides a service to a wide range of

other industries. PCBs might be considered products but are widely used in manufacturing, for

example, computers, mobile phones, white goods, vehicles, etc.

PT/EIPPCB/STM_BREF_FINAL

September 2005

Executive Summary

The market structure is approximately: automotive 22 %, construction 9 %, food and drink

containers 8 %, electrical industry 7 %, electronics 7 %, steel semis (components for other

assemblies) 7 %, industrial equipment 5 %, aerospace 5 %, others 30 %. The range of

components treated varies from screws, nuts and bolts, jewellery and spectacle frames,

components for automotive and other industries to steel rolls up to 32 tonnes and over 2 metres

wide for pressing automotive bodies, food and drink containers, etc. The transport of

workpieces or substrates varies according to their size, shape and finish specification required:

jigs (or racks) for single or small numbers of workpieces and high quality, barrels (drums) for

many workpieces with lower quality and continuous substrates (ranging from wires to large

steel coils) are processed on a continuous basis. PCBs have particularly complex production

sequences. All activities are carried out using jig equipment, therefore the activities are

described and discussed for jig plants, with supporting sections describing specific issues for

barrel, coil and PBC processing.

While no overall figures exist for production, in 2000 the large scale steel coil throughput was

about 10.5 million tonnes and about 640000 tonnes of architectural components were anodised.

Another measure of the industry size and importance is that each car contains over 4000 surface

treated components, including body panels, while an Airbus aircraft contains over two million.

About 18000 installations (IPPC and non-IPPC) exist in EU-15, although the loss of

engineering manufacturing, largely to Asia, has reduced the industry by over 30 % in recent

years. More than 55 % are specialist sub-contractors (‘jobbing shops’) while the remainder

provide surface treatment within another installation, usually an SME. A few large installations

are owned by major companies although the vast majority are SMEs, typically employing

between 10 and 80 people. Process lines are normally modular and assembled from a series of

tanks. However, large installations are typically specialist and capital intensive.

Key environmental issues

The STM industry plays a major role in extending the life of metals, such as in automotive

bodies and construction materials. It is also used in equipment that increases safety or reduces

consumption of other raw materials (e.g. plating of aerospace and automotive braking and

suspension systems, plating precision fuel injectors for automotive engines to reduce fuel

consumption, plating materials for cans to preserve food, etc.). The main environmental impacts

relate to energy and water consumption, the consumption of raw materials, emissions to surface

and groundwaters, solid and liquid wastes and the site condition on cessation of activities.

As the processes covered by this document are predominantly water-based, the consumption of

water and its management are central themes, as it also affects the usage of raw materials and

their loss to the environment. Both in-process and end-of-pipe techniques affect the quantity and

quality of waste waters, as well as the type and quantity of solid and liquid wastes produced.

Although practice and infrastructure in the industry has improved, it is still responsible for a

number of environmental accidents and the risk of unplanned releases and their impacts is seen

to be high.

Electricity is consumed in electrochemical reactions and to operate plant equipment. Other fuels

are predominantly used for heating process vats and work space, and for drying.

The key emissions of concern to water are metals which are used as soluble salts. Depending on

the process, emissions may contain cyanides (although decreasingly), as well as surfactants

which may have low biodegradability and accumulative effects, e.g. NPE and PFOS. Effluent

treatment of cyanides with hypochlorite may result in the production of AOX. Complexing

agents (including cyanides and EDTA) can interfere with the removal of metals in waste water

treatment or remobilise metals in the aquatic environment. Other ions, e.g. chlorides, sulphates,

phosphates, nitrates and anions containing boron may be significant at a local level.

September 2005

PT/EIPPCB/STM_BREF_FINAL

Executive Summary

The STM industry is not a major source of emissions to air, but some emissions which may be

locally important are NO X , HCl, HF and acid particulates from pickling operations, hexavalent

chromium mist released from hexavalent chromium plating, and ammonia from copper etching

in PCB manufacture and electroless plating. Dust, as a combination of abrasives and abraded

substrate, is generated by the mechanical preparation of components. Solvents are used in some

degreasing operations.

Applied processes and techniques

All but a few simple activities require some pretreatment (e.g. degreasing), followed by at least

one core activity (e.g. electroplating, anodising or chemical processing) and finally drying. All

processes have been developed for components hung on racks or jigs; some processes are also

carried out on components in rotating barrels, and a few are carried out on reels or large coils of

substrate. PCBs have complex manufacturing sequences that may comprise over 60 operations.

Additional information is given for barrel, coil and PCB activities.

Consumptions and emissions

The best data would relate to production throughput based on surface (m 2 ) treated, but little is

available on this basis. Most data are for emission concentrations for specific plants, or ranges

for sectors or regions/countries. Apart from some cooling systems, the major use of water is in

rinsing. Energy (fossil fuel and electricity) is used for heating processes and drying. Electricity

is also used for cooling in some cases, as well as driving electrochemical processes, pumps and

process equipment, supplementary vat heating, work space heating and lighting. For raw

materials, the usage of metals is significant (although not globally, for example, only 4 % of the

nickel marketed in Europe is used in surface treatment). Acids and alkalis are also used in bulk

quantities, while other materials such as surfactants are often supplied in proprietary mixes.

Emissions are primarily to water, and about 300000 tonnes of hazardous waste is produced per

year (an average of 16 tonnes per installation), mainly as sludge from waste water treatment or

spent process solutions. There are some emissions to air of local significance, including noise.

Techniques to consider in the determination of BAT

Important issues for the implementation of IPPC in this sector are: effective management

systems (including the prevention of environmental accidents and minimisation of their

consequences, especially for soils, groundwater and site decommissioning), efficient raw

material, energy and water usage, the substitution by less harmful substances, as well as

minimisation, recovery and recycling of wastes and waste waters.

The issues above are addressed by a variety of process-integrated and end-of-pipe techniques.

Over 200 techniques for pollution prevention and control are presented in this document, under

the following 18 thematic headings:

1. Environmental management tool s: Environmental management systems are essential for

minimising the environmental impact of industrial activities in general, with some measures that

are specifically important to STM, including site decommissioning. Other tools include

minimising reworking to reduce environmental impacts, benchmarking consumptions,

optimisation of process lines (most easily achieved with software) and process control.

2. Installation design, construction and operation: A number of general measures can be

applied to prevent and control unplanned releases, and these prevent the contamination of soil

and groundwater.

PT/EIPPCB/STM_BREF_FINAL

September 2005

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