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المستخلص
the purpose of the present work is recover nickel from spent steam reforming catalyst.
Nickel supported catalyst are used in petroleum, fertilizer, and iron production industries. This spent catalyst represents one of the hazardous solid waste and poses an envirorunental problem due to its large tonnage and volume.
The present work is divided into two parts, in the first part, the catalyst was leached from the ground catalyst using sulphuric acid. The leaching was done as single stage and three stages leaching. The results obtained in single stage leaching show that the percent recovery increases with increasing percent acid concentration up to 25%, then the percent recovery decreases. Also, the percent recovery increases as the time of leaching increases. The optimum time was three hours, with three stages. Using multi-stage leaching reduces the time required to reach the sarm percentage recovery of nickel, but at the same time using a larger amount of acid. With 25% h2so4 in a three hours single stage gave 82% recovery, while using two stages for two hour~ gave 84% recovery using the same concentration of acid. Increasing the number of stages leads to the use of lower concentration of acid.
In the second part of the work, the dectrodeposition of nickd from the resulting leachatt ”resulting solution” was studied. It was found that the highest current etlicieney was obtainec using 20 mA/m2 current density. Also, the amount of nickel recovercd by electrodepositior increases by increasing initial concentration of nickel in the bath and by increasing the temperature 0f the bath.