Detailed analysis of the performance of anode rods is one of the few aspects of smelter operations to which little attention is given. The economics and efficiency of reapired rods is not clearly understood. It is generally assumed that a repaired rod will perform both mechanically and electrically in much the same way as a newly fabricated rod.
The lack of proven identification systems suitable for the rodding shop and potroom environments are probably the biggest reason for the lack of rod monitoring. VHE has an operational system designed to address another rod identication problem, the incorrect placement of new rodded anodes in the reduction cell. This can result in poor electrical performance. Manual adjustment requires skill and experience.
VHE has developed and installed an anode rod indentification and indexing system at the Rio Tinto Alcan smelter in Iceland. The system is installed downstream of the rodded anode storage area just prior to the delivery point to the pot rooms. Indexing is initiated by the potrooms requesting an anode for a specific cell.
Two index lines are marked on the anode stem using VHE's powdered chalk marking technology. The first is a fixed index line, always marked at the same height from the top of the anode, and providing an optioon for manual anode setting. The second line is marked at the correct height for the pot stall in which it is to be inserted, this data being provided in realtime from an Oracle database. A bar code and six-digit numeric code identifying the potroom, cell, and stall is then laser-printed onto a coated area near the top of the rod stem.
The system reads the lines and barcode to ensure correct placement and readability and the indexed rodded anode is then automatically delivered to the correct potroom.
Velaverkstaedi Hjalta Einarssonar - VHE is a major mechanical fabricator, offering a comprehensive range of design, manufacturing and site services. VHE now provides all Stimir solutions to the primary aluminium industry, with particular focus on the Rodding Plant. All aspects of design and fabrication are undertaken at VHE's own facilities, ensuring total quality control and on-time delivery.