不同浓度KCl和NH4Cl溶液中H3BO3介稳区的性质

摘要

测定了H3BO3在0～25℃内于不同浓度KCl和NH4Cl溶液中的溶解度和超溶解度,得到了H3 BO3的介稳区宽度,并推算出表观成核级数m,给出了成核速率方程.研究了KCl和NH4Cl对H3BO3介稳区性质的影响,并对影响的机理进行了探讨.结果表明,KCl使H3 BO3介稳区向低温方向移动；NH4Cl使H3BO3介稳区向高温方向移动；根据所得结论分析了KCl和NH4Cl在柴达木西部油田水析硼过程中的影响,认为KCl和NH4Cl在蒸发过程中浓度的变化是造成硼分散析出而不能富集的因素之一.%The solubility and ultra solubility of boric acid in aqueous were measured in the presence of diffe rent concentrations of KC1 and NH4C1 from 0 ℃ to 25 ℃. The metastable zones and the crystal nucleation or ders of H3BO3 were calculated. Effects and action mechanism of KG and NH4C1 on metastable zone property of H3 BO3 were studied. The result shows that the existence of KC1 makes the metastable zone of H3 BO3 move to higher temperature by increasing solubility of H3BO3. According to the adsorption effect, NH4C1 makes metastable zone of H3BO3 move to lower temperature. Concentration variation of KC1 and NH4C1 in evaporation of Nayishan oilfield brine is one of the reasons that boron crystallizes dispersedly.