Since the 1980s, P507 has been used for nickel and cobalt separation in China. The separation coefficient of P507 for nickel and cobalt has been improved by several orders of magnitude compared to P204, and it is suitable for sulfate and chloride systems with a large nickel to cobalt ratio range. However, P507 has the following disadvantages: (1) due to the limitation of the separation coefficient, it is difficult to separate the sulfate solution of high nickel and low cobalt (βNi / Co> 50); (2) P507 has a certain extraction of calcium, especially some calcium Extraction enters the organic phase, when using sulfuric acid (or sulfate) for washing or back extraction, calcium sulfate precipitation will occur and affect the normal operation; (3) The back extraction of P507 containing iron is more difficult, use 4 ~ 5mol / L hydrochloric acid or Sulfuric acid can only be back-extracted, and when iron is back-extracted to a certain amount, polyferric sulfate will be produced, resulting in production difficulties and increased organic consumption.
The efficient nickel-cobalt separation and extraction agent DZ272 has a separation coefficient of nickel and cobalt that is an order of magnitude higher than that of P507 under the same conditions. Iron stripping can be carried out in low concentration sulfuric acid, which is suitable for separating high nickel and low cobalt sulfate solutions. DZ272 can extract metals through cation exchange mechanism. It not only selectively extracts cobalt in the presence of nickel, but also extracts and separates other metals according to the different pH balance of extraction. DZ272 is completely miscible with ordinary aromatic and aliphatic diluents. Compared with P204 and P507, DZ272 is more stable to heat and hydrolysis.
Appearance: This product is colorless to light amber liquid.
Performance: DZ272 is an acidic phosphine extractant. Its active ingredient is bis (2,4,4-trimethylpentyl) hypophosphorous acid. The chemical structural formula is as follows:
①DZ272 has a high separation coefficient of nickel and cobalt βCo / Ni;
②Copper wire, manganese wire and cobalt wire are very close, DZ272 is difficult to separate copper, manganese and cobalt, so P204 must be used to remove copper, manganese and other impurities before nickel and cobalt separation;
③The cobalt wire is before the calcium wire and the magnesium wire, so controlling certain conditions during extraction can make calcium and magnesium rarely enter the organic phase, which is of great significance for improving the quality of cobalt products and improving the subsequent process operations;
④ DZ272 has a certain extraction capacity for lead, which is meaningful for the purification of nickel sulfate solution returned to the nickel system. The extraction sequence of DZ272 for certain metals in sulfate is: Fe3 +> Zn2 +> Cu2 +> Mn2 +> Pb2 +> Co2 +> Mg2 +> Ca2 +> Ni2 +.
⑤ Another feature of DZ272 is that its calcium extraction ability is very low, so there is no need to worry about the precipitation of calcium sulfate in the extraction process of sulfate medium.