FROM THE 'LOW CAUSTIC LEACHING AND LIMING' PROCESS DEVELOPMENT TO THE JONQUIERE SPENT POTLINING TREATMENT PILOT PLANT START-UP, 5 YEARS OF PROCESS UP-SCALING, ENGINEERING AND COMMISSIONING

摘要

The LCL&L process is a hydrometallurgical route developed by researchers of Rio Tinto Alcan (RTA) to treat, both environmentally and economically, spent potlining (SPL) generated by aluminium cells. Considering local characteristics, including the low capacity of cement producers to recycle SPL, there is a high SPL inventory that has accumulated over the last 25 years. LCL&L was selected as the preferred solution for the treatment of RTA's SPL in Quebec, and as a sustainable solution for other Quebec aluminium producers. This paper describes LCL&L process characteristics, including valorization alternatives for the by-products and special chemical analysis methods developed for process control. Some technological challenges faced and managed during scale-up from laboratory and mini-pilot process development, design and construction of the industrial scale pilot plant will be discussed. Finally, preparations for the plant commissioning, start-up in April 2008 as well as some early operational highlights will be discussed.