氯化钠-二乙基二硫代氨基甲酸钠-酚酞体系分离富集铜(Ⅱ)

Separation and enrichment of copper(Ⅱ) with sodium chloride- sodium diethyldithiocarbamate-phenolphthalein system

研究了氯化钠-二乙基二硫代氨基甲酸钠（DDTC）-酚酞体系分离富集铜（Ⅱ）的新方法.探讨了二乙基二硫代氨基甲酸钠溶液用量、酚酞溶液用量、各种盐和酸度等因素对Cu2＋富集率的影响,讨论了Cu2＋的富集机理.结果表明,控制pH 6.0,在0.5 g NaCl存在下,当1.0×10-2 mol/L DDTC溶液用量为2.00 mL,50 g/L酚酞乙醇溶液用量为1.00 mL时,Cu2＋与DDTC形成的螯合物沉淀-Cu（DDTC）2]可被定量吸附至微晶酚酞表面,形成界面清晰的液-固两相,而在此条件下Cd2＋、Zn2＋、pb2＋、Fe2＋、Al3＋等不被吸附,实现了Cu2＋与这些金属离子的定量分离,据此建立了分离富集Cu2＋的新方法,并成功用于合成水样中Cu2＋的定量分离,富集率为93.0％～105.4％.

A novel method for separation and enrichment of copper（Ⅱ） with sodium chloride-sodium di- ethyldithiocarbamate-phenolphthalein system was investigated. The effects of different parameters, such as the dosages of sodium diethyldithiocarbamate（DDTC） solution and phenolphthalein（PP） solu- tion, various salts and acidity on the enrichment yield of Cu2＋ have been investigated, the enrichment mechanism was examined. The results showed that, in the presence of 0.5 g of NaCl, when 2.00 mL of 1.0 × 10^ 2 mol/L DDTC solution and 1.00 mL of 50 g/L phenolphthalein ethanol solution was se- lected, the chelate precipitate [Cu（DDTC）2] formed with Cu2＋ and DDTC could be quantitatively ad- sorbed on the microcrystalline phenolphthalein surface at pH 6.0, forming liquid-solid phases with a clear interface, while in this condition, Cd2＋ , Zn2＋ , Pb2＋ , Fe2＋ and A1a＋ were not adsorbed, thus a- chieving the quantitative separation of Cu2＋ from these metal ions. Consequently, a novel method for separation and enrichment of Cu2＋ was established. This method was successfully applied to quantita- tive separation and enrichment of Cu2＋ in the synthetic water samples with enrichment yield of 93.0%-105.4 % .