含镍磁黄铁矿硝酸浸出液中硝酸镁与硫酸镁的分离

来源期刊：中南大学学报(自然科学版)1989年第4期

论文作者：张多默 刘志宏 陈惠光 罔田茂 矢沢彬

文章页码：382 - 389

关键词：结晶； 分离； 硫酸镁； 硝酸盐； 镁化合物

Key words：crystallization； separataion； magnesium sulfate； nitrate； magnesium compound

摘    要：硝酸催化浸出是处理金属硫化物的有效方法。用这种方法在较低温度和氧压下成功地处理了含镍磁黄铁,但矿石中的氧化镁与硫酸和硝酸反应生成硫酸镁和硝酸镁,后者消耗了大量硝酸;因而需要分离硫酸镁,返回使用硝酸镁才能保证浸出过程经济地进行。本研究测定了Mg(NO₃)_2-MgSO₄-H₂O系在343K,308K,以及Mg(NO₃)₂-MgSO₄-C₂H₅OH-H₂O系在298K的平衡相图。结果表明,蒸发结晶法及乙醇结晶法均能有效地分离出硫酸镁,但后者更为节能。加10％乙醇即可使硫酸镁与硝酸镁较好分离。

Abstract: As an effective method for digesting metal sulfides, the catalytic leaching with nitric acidin sulphate system has been used to treat nickel-bearing pyrrhotite successfully at much lower tem-perature than that of high oxygen pressure leaching. In this process, magnesium oxide will react withsulphuric acid and nitric acid to form magnesium sulfate and magnesium nitrate. The latter willconsume a large volume of nitric acid if it is not separated from magnesium sulfate and recovered. In this research, the phase equilibriums of Mg(NO₃)₂-MgSO₄-H₂O system at 343K, 308K and ofMg(NO₃)₂-MgSO₄-C₂H₅OH-H₂O system at 298 K have been studied. According to the phase diagramsobtained, the separation of Mg(NO₃)₂ from MgS_O4 has been discussed in details. The results indi-cate that evaporation and alcohol crystallization are both effective in separating pure magnesiumsulfate from magnesium nitrate. Furthermore, alcohol crystallization results in savings on energy.Addition of 10% ethanol to a Mg(NO₃)₂ and MgSO₄ solution results in an almost complete cry-stallization of magnesium sulfate.