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To realize the high value-added utilization of zinc hypoxide in a rotary hearth furnace, nano-ZnO was prepared by H2SO4 wet leaching combined with the Na2CO3 precipitation process. The effects of different process conditions on the leaching rate of Zn were analyzed, and the feasibility of preparing nano-ZnO from zinc hypoxide was discussed. The results showed that the optimal process conditions for H2SO4 leaching of zinc hypoxide in a rotary hearth furnace were as follows: H2SO4 concentration 2.0 mol·L−1, leaching temperature 60 °C, leaching time 90 min, and liquid-solid ratio 8:1. Under these conditions, the leaching rate of Zn reached 95%. The calculation results of leaching kinetics showed that the restrictive link of the H2SO4 leaching process was a chemical reaction process; the apparent activation energy was 14.45 kJ·mol−1; and the reaction order was 0.6. The precursor obtained by Na2CO3 precipitation treatment was Zn5(OH)6(CO3)2. After calcination at 400 °C, the nano-ZnO with a diameter of less than 100 nm and length greater than 1 μm was obtained. H2SO4 leaching combined with the Na2CO3 precipitation process provided a new approach for high value-added utilization of zinc hypoxide in a rotary hearth furnace.

With the increase of zinc resource consumption, the recovery and utilization of zinc resources in zinc suboxide has become one of the current research hotspots. In this study, the electrochemical method was used to remove the impurities in the zinc leaching night and enrich the zinc ferrite in the ammonia leaching residue for the solution and ammonia leaching slag after the ammonia leaching of zinc hypoxide, in order to realize the comprehensive utilization of the essence of zinc immersion night and new resources. The results showed that the reduction potentials of copper, lead, cadmium, and zinc in the ammonia leaching solution were analyzed by electrochemical testing methods to be −0.76 V, −0.82 V, −0.94 V, and −1.3 V, respectively. Through constant potential electrodeposition, the removal rate of copper, lead, cadmium. The removal rate of cadmium is 98.73%, and the removal rate of lead and copper is more than 99%. The purified ammonia leaching solution is evaporated at 90 °C for 25 min to obtain basic zinc carbonate. The purity of ZnO obtained after calcination at 500 °C for 120 min is 96.31%. The ammonia leaching residue was pickled with 3 mol·L−1 acetic acid for 30 min to effectively remove PbCO3, and then magnetic separation was carried out with a current intensity of 1.4 A. The final zinc ferrite content was 83.83%.