The effect of mechanical activation on the kinetics of ammoniacal thiosulfate leaching of a refractory oxide gold ore containing 2.8 ppm Au was investigated. The gold extraction of 99.81% was achieved by 16 h leaching of a sample mechanically activated for 60 minutes. The gold extraction observed for a similar reference sample without mechanical activation was only 55%. Studies revealed that le...

synthesis and characterization of two functionalized gold nanoparticles by using of two poly functional amino acids (l-arginine and l-aspartic acid) are reported. the gold nanoparticles were reduced by sodium citrate and functionalized with l-arginine at the ph of 7 and 11 and l-aspartic acid at the ph of 7. transmission electron microscopy, uv-vis spectroscopy, dynamic light scattering, zeta p...