Abstract: The leaching of a zinc silicate concentrate-hemimorphite was studied in ammonia-ammonium sulphate solution. The influence of technical parameters, such as lixiviant concentration, molar ratio of NH₃ to (NH₄)₂SO₄, the ratio of liquid to solid, reaction time, temperature and stirring rate of the leaching effect of Zinc were studied. The result shows that under the condition of maximum zinc extraction condition:total ammonia concentration 8.5 M, molar ratio of NH₃ to (NH₄)₂SO₄ 2, leaching time 1h, temperature 45 ℃, liquid/solid ratio 1:5 and stirring rate250 r/min, leaching ratio of zinc reach 93.84 %