Miljøprojekt, 1116 – Brancheindsats for jern- og metalstøberier - Delprojekt 2 - Forbedring af datagrundlaget til UMIP-databasen med hensyn til støbeprocesser

Brancheindsats for jern- og metalstøberier

Summary and conclusions

Background

A few years ago, the Association of Danish Foundries (www.foundry.dk) launched an Action Plan in connection with a project entitled ”Preliminary investigation for a collective action for Danish iron and metal foundries”.

The Action Plan pointed out several focus areas, among others the need for collection of further data for assessing environmental impacts, as, at that time, there was a distinct lack of data for this purpose.

Based on the conclusions from the preliminary investigation, a new project was drawn up, with the specific goal of updating and quality-assuring existing data and increasing the data amount to comprise the most used materials and processes in both iron and metal casting.

Another important goal was to provide guidelines and tools, enabling the industry to calculate the environmental data and present simplified Life Cycle Assessments of foundry products or parts, for use both internally within the company and externally to customers and other stakeholders.

The investigation

The project was carried out in four consecutive phases:

Overview of processes
Collection of data
Quality assurance of data
Developing and demonstrating simplified calculation tools.

At the time of project kick-of, the UMIP/GABI database contained seven or eight-year old data for the following three foundry processes: sand casting of cast iron, pressure die casting of aluminium and zinc. As technical developments had progressed over the years, these three processes did not cover the foundry industry’s data needs. Therefore, the first phase of the investigation was to create an overview of all foundry processes used for manufacturing iron and metal components and, subsequently, to select processes and materials, which, in relation annual output and expected environmental impacts, were significant for the database. This first phase resulted in identification of the following nine processes covering 90 per cent of the Danish Foundries’ total annual production of 120,000 tonnes

1. Casting of cast iron in clay bonded sand with or without core (60-65%)

2. Casting of cast iron in chemically bonded sand with or without core (12-14%)

3. High-pressure die casting of aluminium (9-11%)

4. Casting of brass and bronze in clay bonded sand with or without core (1.5-2.5%)

5. Casting of brass and bronze in chemically bonded sand with or without core (1.5-2.5%)

6. High-pressure casting of zinc (<2%)

7. Casting of aluminium in clay bonded sand with or without core

8. Casting of aluminium in chemically bonded sand with or without core

9. High-pressure die casting of magnesium (< 0.5%)

The remaining 10% cover various other casting processes. These are either very low in quantity or without significant environmental impact.

For each of the listed nine casting processes, process information and data were collected and translated into a process description (flow chart). For each process, the flow chart describes all process steps, and, based on this, an inventory of input-output of each process is made.

Within the discipline of life cycle assessment, it is acknowledged that the result of the assessment depends on data reliability and quality. The project phase 3 comprised data quality assurance, where data suppliers and project group meticulously checked all process information and data.

In phase 4, simplified calculation tools were developed and the subsequent modelling in the tools was tested.

Conclusion

For nine of the most used processes in iron and metal manufacturing in Denmark, data were collected, processed and quality assured.

The collected data was integrated into the UMIP/GABI^[1] database. This database is available on www.foundry.dk

A simplified calculation tool was developed and made available for the industry. The tool can be used for the company’s internal environmental activities. It can also be used to make rough calculations of environmental impacts of foundry processes, for the purpose of comparison between foundry processes and alternative manufacturing processes.

Because of availability of validated data, it is possible to perform a reliable life cycle assessment (LCA) on foundry processes in the UMIP/GABI LCA tools.

Projects results and industrial case examples have been presented to the foundry industry in Denmark through a series of dissemination workshops.

Project results

One major result is validated data on foundry processes integrated in the UMIP/GABI database, permitting environmental assessments (Life Cycle Assessments) to be performed.

Another result is the simplified tool, which permits shortcuts to environmental knowledge by calculating three environmental indicators for the most used foundry processes.

The indicators in this simplified methodology are:

Total energy consumption (primary energy) per unit material or per unit process. The unit is given in Mega Joule and is credited for loss and
energy consumption back to extraction of resources from nature.
Resource consumption, calculated as the fraction of total global consumption of resources. The unit is Milli Person Reserves, allowing for scarcity of certain resources.
The amount of surplus sand allocated to clay bonded sand, chemically bonded sand and sand, which can be used for other purposes. The unit is kg sand.

The software (in Danish) supports the calculation of these three parameters as a function of the manufacturing conditions.

The software including a case example can be downloaded free of charge from

http://www.foundry.dk/index.php?page=49 .

Fodnoter

^[1] More information on the UMIP/GABI database and tools is available at LCA-center, Denmark, www.lca-center.dk