硫氰酸钾-十六烷基三甲基溴化铵-水体系浮选分离Fe^(3+)

The Flotation Separation of Fe(Ⅲ)with Potassium Thiocyanate-CTMAB-Water System

废水中的Fe^(3+)浓度过高引起水体色相变化,难以满足《污水综合排放标准》(GB8978—1996)对色度的相关要求。实验利用KSCN为络合剂,十六烷基三甲基溴化铵(CTMAB)为浮选剂,采用离子浮选的方式,建立了一种三元离子缔合体系分离富集微痕量Fe^(3+)的新方法。分别考察了离子价态、KSCN溶液用量、CTMAB溶液用量、酸度、盐、放置时间、干扰离子对浮选率的影响,结果表明,在25mL磨口比色管中,当体系中Fe^(3+)的含量为50μg时,控制体系的酸度为pH=2,加入0.6mL0.2mol/LKSCN溶液,0.6mL0.01mol/LCTMAB溶液,用水稀释至10.00mL,充分震荡,静置2min,体系形成界面清晰的液固两相,Fe^(3+)与KSCN、CTMAB反应生成的离子缔合物定量浮选至溶液上层。方法成功应用于合成水样中Fe^(3+)的定量分离,在最优的实验条件下,Fe^(3+)的浮选率在93.4%~99.1%,而Zn^(2+)、Co^(2+)、Ni^(2+)、Pb^(2+)、Cd^(2+)等常见金属离子仍留在水相中,从而实现了Fe^(3+)与这些离子的定量分离。该体系不使用有毒的有机溶剂,具有设备简单、操作方便、成本低廉等优点,具有一定的应用前景。

The high concentration of Fe^(3+)in industrial waste water causes the change of chroma,which is difficult to meet the relevant requirements in the integrated wastewater discharge standard(GB 8978-1996).This paper presents a novel method for the flotation separation of Fe^(3+)by potassium thiocyanate-cetyl trimethyl ammonium bromid(CTMAB)system using ion flotation method.The effects of different parameters,such as the dosages of KSCN and CTMAB,various salts,acidity,stored time,interfering ion etc,on the flotation yield of Fe^(3+)have been investigated to select the experiment conditions.The results showed that by controlling pH=2.O,when the dosage of 0.2 mol/L KSCN solution was 0.6 mL and 0.01 mol/L CTMAB solution was 0.6 mL respectively in a 25 mL ground colorimetric tube,the solution was diluted to 10.O0 mL with distilled water.After sufficient oscillation and standing for 2 min,the water-insoluble ternary association complex of Fe(SCN)-·3CTMAB+,which produced by Fe^(3+)and SCN-,CTMAB cation(CTMAB+),floated above water phase and liquid-solid phases were formed with clear interface.The proposed method was successfully applied to the quantitative separation of Fes+in synthetic water samples,the flotation yield was 93.4%-99.1%under optimal experimental conditions.While Zn^(2+),Co^(2+),Ni^(2+),Pb^(2+)and Cd^(2+)ions remained in the water phase,realizing a quantitative separation of Fe^(3+)from these ions.This system does not use toxic organic solvents and has advantages such as simple equipment,convenient operation,and low cost,which have certain application prospects.