Magnesium Elektron Ltd.

In April 2002 Lührfilter Ltd. installed and commissioned a fabric filter for the collection of dust and fume arising from Magnesium melting furnaces at the works of Magnesium Elektron Ltd, Swinton Manchester.

This plant was the third of its kind to be installed by Lührfilter for Magnesium Elektron since 1999. The first plant was installed as part of a total foundry upgrade in Magnesium Elektron’s No. 2 Foundry and was commissioned in February 2000. The second plant was installed as part of the Magnesium Elektron European foundry project in the Czech Republic and was commissioned October 2001. The latest plant was commissioned in April 2002 and being a major upgrade of the melting facility in the No. 3 Foundry of Magnesium Elektron.

All three plants are of similar size (between 60,000 & 69,000 Nm3/hr) and are operating on similar processes.

The first two plants were installed as part of foundry re-developments and on these installation was scheduled and integrated into the re-development programme. On both of these projects Lührfilter supplied extraction hoods, ducting and exhaust stacks.

This last installation at the Manchester plant had to be carefully planned and programmed as production had to be maintained during the installation period with minimum downtime for connection into the existing furnace system plus commissioning. A one week (9 day) shutdown was agreed to complete the necessary work within the foundry and the commissioning of the unit, this was completed with in excess of one day to spare.

The Magnesium melting process is problematic to filtration systems by virtue of the fluxes used in the process and their hygroscopic nature. These fluxes not only produce high levels of moisture but also release gaseous elements and additionally there can be hyrocarbons present on the charge materials.

On the first two installations our filter model MWF ‘Semi-Offline’ using medium pressure ambient air as the filter cleaning medium was utilised. On the third unit due to a higher level of pollutants on the furnace charge materials it was decided to change to our model DWF ‘Semi -Offline’ using Compressed Air as the filter cleaning medium.

In addition to the particulate emissions from the filtration plant the emissions for Hydrogen Fluoride (HF) and Hydrogen Chloride (HCl) were also guaranteed. Typically the particulate emission was guaranteed to 5mg/Nm3 and was measured after commissioning at less than 0.5mg/Nm3.

The filtration system utilises our KUVIII dust re-circulation and dry gas scrubbing to reduce the acidic compounds. This involves the injection of a reagent powder into the process gas stream, a reaction chamber is provided at the inlet to the filter. A Lührfilter patented conditioner drum operates within the reaction chamber the function of these two items is to provides a high utilization of the reagent therefore increasing the efficiency of acidic adsorption.

All three plants are able with the minimum of modification to be upgraded to enable the adsorption of Dioxins when legislation deems it necessary