Nyrstar Laboratory Upgrade
Nyrstar Zinc Works is located on the western bank of the Derwent River in Hobart and is a large scale zinc smelter with a capacity of 280,000 tonnes.
The Hobart smelter is one of the worlds largest zinc smelters in terms of production volume. The site has been significantly upgraded and modernised over the last 25 years with improvements and modernisation of plant and processes which have increased the plants operating capacity.
Workplace monitoring identified that the Laboratory were exceeding the Short Term Weighted Average exposure to Ammonia when the Chemists used the Ion Exchange columns.
As the Chemists needed to “load” the columns from above, a traditional fume cupboard wasn’t an option due to lack of head room.
An overhead extraction hood with sufficient head room would require too much air volume and there was not enough Make up air capacity, and at very high air volumes noise would be an issue.
Nyrstar saw the challenges of such a project and sought the technical expertise of Masters Contracting Pty Ltd for the design, construction and commissioning of a fume extraction system that would satisfy their requirements i.e.
- Eliminate staff exposure to ammonia fumes
- Allow sufficient clearances for staff to operate
- Would fit a current work bench space
- System should be low noise level
With the above parameters set careful consideration was given to how the Chemists used the columns and the layout of the columns on the Laboratory bench and stand. A double side draft type capture hood was considered the best option to capture stray fumes, the hood also incorporates a roof to ensure rising fumes are captured by the side draft, drawing fumes horizontally was considered a better option than vertical capture as fumes are moved away from the Chemists breathing zone.