Tween 80 - Salt - Water Liquid - Solid Extraction System Of Cobalt And Nickel Separation And Enrichment Research

Cobalt and nickel are the elements of group VIIIof the forth period, their atomic numbers are 27 and 28 respectively. With the similar character, they often coexist in minerals. The separation of Cobalt and nickel are of great significance both in theory and practice.Liquid-solid extraction system based on polymer-salt-water is a new kind of extraction and separation system developed only in the recently ten years. In the presence of inorganic salts, polymers solution can be separated into liquid and solid phases and the extracted matter selectively distributes in two phases, thus extraction and separation will be realized with some conditions controlled. Compared with the traditional methods, this one has the advantage of convenient operation, high extractability and innocuity of reagents.Choosing Nitroso-R-salt as extraction solvent and emptying Tween80 -Na2SO4 H2O -solid extraction system, this research separates trace Co (II) and Ni (II) in and a complex spectrophotometric method based on liquid-solid extraction without organic solvent was established for determination of trace Co (II). The main jobs are as follows:l.This paper discusses the elements influencing the phase diagram,and polymers solution was separated into two phases in Polymer-salt-water system, such as the concentration of polymer, the concentration and the kinds of salts, molecules mass of polymer, the PH of solution based on the previous researches.2.Choosing Nitroso-R-salt as extraction solvent and emplying Tween80-Na2SO4- H2O liquid-solid extraction system, the experiment was made to analyze the elements influencing the extration rate Co-NRS chelate. This paper focuses on the functions of the elements such as the pH of solution, dosage of extraction solvent, dosage of salt, concentration of polymer, time of extraction.3.This paper determines the best extraction and separation condition, that is, 3ml buffer solution(pH= 5), complex stable ions and 1.5m110.2%Nitroso-R-salt,fiveminutes later, adding 0.5miHCI(1:1) to increase the strength of acid, add 7ml30% Tween 80 solution, the total bulk of fixed system is 14ml (adding distilled water if insufficient), add 3g sodium sulfate , polymers solution was separated into two phases . The research also makes an experiment to mix extract Co (II) and Ni (II), with the extraction rate of Co (II) in solid is more than 97%,the rate of recovery of Ni (II) in liquid is more than 93%.4.The research examines the quantitation separation of formation and the composition of the stability constant of Co-NRS chelate in Tween80 employing mole ratio method and continuous variation method.5.The research explores a complex spectrophotometric method based on liquid-solid extraction for determination of trace Co(II) in Tween80-Na2S04-Nitroso-R-salt system. After choosing the best experiment condition, the content of Cobalt is in the range of 0-3 g-ml-, beer's law is obeyed. The results are satisfied in terms of the examination of self-made liquid.