高硅高钙低硫型低品位硫氧混合锌矿的矿相重构—氨浸研究

Study on Phase Transformation and Ammonia Leaching of Low-Grade Sulfur-Oxygen Mixed Zinc Ore Bearing High Silicon and Calcium and Low Sulfur

根据硫氧混合锌矿含钙、硅高的特点,充分利用矿石所含CaCO_3和CaO的固硫作用,在较低温度下氧化焙烧,使矿石中的异极矿和闪锌矿转化为易于溶出的ZnO,硫转化成CaSO_4。结果表明,最佳焙烧温度为300℃,所得焙砂在氨—硫酸铵溶液中的锌浸出率可达75%,而矿石直接浸出时锌的浸出率只有52%。通过氧化焙烧过程产生矿相重构,既提高了锌的浸出率,又避免了SO_2的逸出,还能彻底消除硅胶的生成。

Based on characteristics of low grade sulfur-oxygen mixed zinc ore bearing high silicon and calcium and low sulfur, sphalerite and hemimorphite in ore were transformed into easily soluble ZnO, and sulfur was fixed as CaSO4 by CaCO3 and CaO contained in ore applying oxidation roasting process at low temperatures. The results show that 75% of zinc can be leached with ammonia-ammonium sulfate solution from roasted products at optimum temperature of 300 ℃, while only 52% of zinc can be leached directly from sulfur-oxygen mixed zinc ore. Leaching rate of zinc is improved by phase transformation in oxidation roasting without emission of SO2 and formation of silica gel during leaching.