(昆明理工大學 冶金與能源工程學院，昆明 650093)
摘 要: 利用高溫下金屬硫酸鹽易結晶沉淀的化學原理，開展了水熱結晶脫鎂行為研究，研究了初始Zn2+濃度、反應溫度、反應時間、初始 濃度、初始硫酸濃度對水熱結晶脫鎂過程的影響規(guī)律。結果表明：在初始Zn2+和Mg2+濃度分別為120 g/L和25 g/L、反應溫度為200 ℃、反應時間3 h、初始 濃度為145 g/L、初始硫酸濃度為5×10-4 g/L的條件下，鎂以MgSO4？6H2O的形式結晶析出，其脫出率可達到94.42%。升高反應溫度以及初始 和Mg2+的濃度、延長結晶時間均有利于提高鎂的結晶脫出率。受同離子效應影響，當Zn2+濃度由0增大至120 g/L可有效降低Mg2+的結晶析出溫度，并使Mg2+的結晶脫出率增大40%以上，相近的ZnSO4？xH2O和MgSO4？xH2O微觀結構抑制了水熱條件下MgSO4？6H2O向MgSO4？H2O的轉變。受初始硫酸濃度及溶液中 電離平衡引起 和H+濃度變化的影響，Mg2+的結晶析出率隨初始硫酸濃度的升高先增大后減小。水熱結晶除鎂法可實現(xiàn)濕法煉鋅含鎂硫酸鋅溶液中Mg2+的清潔高效脫出。
關鍵字: 濕法煉鋅；水熱法；除鎂；結晶；結晶脫出率
（Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:The hydrothermal crystallization of magnesium sulfate was studied by using the chemical principle of easy crystallization precipitation of metal sulfate in high temperature. The effect of initial concentration of Zn2+, reaction temperature, reaction time, initial concentration of and initial concentration of sulfuric acid on hydrothermal crystallization process of de-magnesia was studied. The results show that, under the conditions of initial Zn2+ and Mg2+ concentrations of 120 g/L and 25 g/L, reaction temperature of 200 ℃, reaction time of 3h, and initial concentration of 145 g/L, magnesium is crystallized out in the form of MgSO4？6H2O, with release rate of 94.42%. Increasing the reaction temperature and the initial concentration of and Mg2+, and prolonging the crystallization time are beneficial to improving the crystallization rate of magnesium. Under the influence of the same ion effect, when the concentration of Zn2+ increases from 0 to 120 g/L, the crystallization temperature of Mg2+ can be effectively reduced and the crystallization rate of Mg2+ increases by more than 40%. The similar microstructures of ZnSO4？xH2O and MgSO4？xH2O prevent the transformation of MgSO4？6H2O into MgSO4？H2O under hydrothermal conditions. Under the influence of the initial sulfuric acid concentration and the concentration changes of and H+ caused by the equilibrium of ionization in the solution, the crystallization rate of Mg2+ first increases and then decreases with the increase of the initial sulfuric acid concentration. The hydrothermal crystallization method of magnesium removal can realize the clean and efficient removal of Mg2+ from zinc sulphate solution containing magnesium.
Key words: zinc hydrometallurgy; hydrothermal process; magnesium removal; crystallization; crystallization removal rate
