Abstract: A gold deposit in Inner Mongolia contains gold of 2.83 g/t.At present，the leaching process of sodium cyanide and resin adsorption is adopted to extract gold，and the total cyanide content in the leaching residue is as high as 50 mg/kg. In order to reduce the dosage of cyanide， Nielsen gravity separation and low-cyanide leaching process for tailings tests were conducted，so as to meet the filling technology standard. The condition including tailings grinding fineness， dosage of Jinxin and calcium oxide，the liquid-solid ratio，leaching time on leaching effect were studied. The results showed that:① Under the conditions of grinding fineness of -0.043 mm accounting for 87%，separation G value of 80 G，fluidized water flow of 3 L/min and feeding concentration of 50%， the process of "one roughing and two scavenging" was used in Nelson gravity separation.The cumulative recovery rate of gold reached 55.91% and the cumulative grade of gold was 35.48 g/t. Gold grade of gravity separation tailings is 1.34 g/t.② Low cyanide leaching conditions tests for gravity separation tailings were carried out. With the optimum grinding fineness -0.043 mm accounting for 79%，the dosage of calcium oxide of 5 kg/t，the dosage of Jinxin of 1 200 g/t，the leaching time of 36 h，the liquid-solid ratio of 1.5 mL/g，the gold leaching rate was 91.88% at this time. The comprehensive recovery rate of gravity separation and leaching process reached 96.42%. Under the above conditions， the adsorption rate of gold was 86.94% when the precious solution was treated by resin adsorption，and the comprehensive recovery rate of gold in the whole process of gravity separation， leaching and adsorption was 91.13%，indicating good indexes. The total cyanide concentration of the leaching residue was 0.50 mg/kg，which reached the technical standard of tailings filling.

Key words: refractory gold ore, Nielsen gravity concentration, low cyanide leaching, gold recovery rate