This paper presents the extraction and separation of nickel (II) fromsulfate solutions using the extractants 2-amino-3-(4- (X) phenyl azo)-8,9-dihydro- 8,8-dimethyl-7H-pyrazolo [1,5-a] quinazolin-6- one (H2NXPQ)/benzene (X= Br, Cl or CH3) that have been previously prepared by the authors. Several experiments were performed to optimize the extraction controlling factors. The maximumextraction efficiency was achieved froma synthetic aqueous solution of pH 2.5 and assaying 20 mg/l Ni (II) ions by using 2.42×10-3 M concentration of (H2NXPQ)/benzene at (1/1)A/O ratio for 10 min. contact time at roomtemperature. Themaximumloading capacity remained constant after the four loading cycle fromthe synthetic acidic solution. The values of pH1/2 and Kex as well as the values for the thermodynamic parameters ÄG, ÄH, and ÄS have been calculated. The extracted Ni (II) was effectively stripped from the organic phase using 0.5M HCl solution. The optimized extraction conditions have then been applied for Ni (II) extraction fromthe uranium- bearing leach liquor of El Sela mineralization.