Study on Adding Ammonium Hydrogen Fluoride to Improve Manganese Leaching Efficiency of Ammonia Leaching Low-Grade Rhodochrosite

The ammonia leaching method for treating low-grade rhodochrosite has the advantages of a good impurity removal effect and low environmental pollution. In this paper, aiming at the low leaching efficiency of low-grade rhodochrosite treated by the ammonia leaching method, studies on enhancing the leaching efficiency of manganese by using ammonium hydrogen fluoride as an additive are carried out. The effects of different ammonia concentrations, leaching temperatures, leaching times, liquid-solid ratios, stirring rates, and the addition of ammonium hydrogen fluoride on the leaching efficiency of manganese with and without ammonium hydrogen fluoride as an additive were comparatively studied, and the parameters of ammonia concentration, ammonia leaching temperature, and ammonium hydrogen fluoride dosage were optimized in the experimental study. The results indicated that ammonium hydrogen fluoride as an additive in the treatment of low-grade rhodochrosite by the ammonia leaching method could effectively increase the leaching efficiency of manganese, and the optimal process parameters were obtained. Meanwhile, the addition of ammonium hydrogen fluoride didn’t affect the quality of the steamed ammonia product.