CONVERSION OF FILTER ELEMENTS FOR AFINERY (LA10)

ISSUE

In a copper refinery located in Quebec (CA), the copper-containing process liquor must be filtered before passing through ion exchange resins. This step is carried out using a leaf filter: pressure filter equipped with square filter trays covered by folded woven media. The folded media being difficult to clean, it clogs quickly despite regular filter backwashing. This results in a gradual decline in the filtered liquor flowrate which limits the production capacity of the equipment. The media must be replaced every 2 months to maintain a good production capacity. However, regular media replacements results in significant maintenance and labor costs.

TECHNOLOGICAL CHALLENGE

The goal of the project is to reduce the annual replacement and maintenance costs of the filter by converting the current filter elements into filter elements with much longer operational life while providing similar filtration performance. These new elements had to be able to be installed without permanent nor major modifications of the filter.

RECOMMENDED SOLUTION

STS Canada evaluated several types of filter elements to identify those that would replace the old trays without modifying the existing filter. Following this selection, the design of the new filtration elements and manifolds required for the new filter elements installations was carried out by STS Canada. Finally, prototypes of the filter elements and manifold were created and tested at the factory.

RESULTS

Following the completion of this project, STS Canada delivered to its customer the prototype of a new concept of filter elements, the plans and specifications of this prototype as well as the names and quotes of the manufacturers able to manufacture it. This new filter element concept has met the needs of the equipment in terms of filtration capacity and operational life without the need for mechanical filter modifications. In addition, the economic evaluation related to the use of this new type of filter element has demonstrated a payback period of 9 to 12 months.