The extractant CYANEX 272, which active component is di(2,4,4-trimethylpentyl)-phosphinic acid (C 8 H 17 ) 2 POOH, is effective for extraction of copper (II), cobalt (II) and nickel (II) ions. The extraction of metal ions using di(2,4,4-trimethylpentyl)-phosphinic acid as an extractant is carried out due to the formation of an organophosphorus complex with wide pH range: copper at pH > 2, cobalt at pH > 3, and nickel at pH > 5. They are extracted with an organic phase: copper at pH = 3-7, cobalt at pH = 4-7, and nickel at pH = 6-9, and precipitate in the organophosphorus compound: copper at pH > 7, cobalt at pH ≥ 8, and nickel at pH ≥ 10. The possibility of separation of copper (II) and cobalt (II) is insignificant, the stripping of copper (II) and nickel (II) happens at pH = 4-6, and the stripping of cobalt (II) and any of nickel (II) – at pH = 5-6. The obtained results of ion extraction of the investigated metals can be used not only for processing of technological solutions, but also for purification of effluents from industrial enterprises and mine waters, heap and underground leaching solutions, etc. from the ions of studied metal ions.
The design of an electrolyzer for electrowinning in dynamic conditions is developed. The dependence of the results of electrowinning of cobalt and manganese from sulfate and sulfate-chloride solutions under dynamic conditions using a titanium cathode and a lead anode with 1 % of silver was studied. It was found that the best extraction results for the current yield and the specific energy consumption were obtained by electrolysis from sulfate solutions at a low concentration of manganese in an electrolyser without a perforated baffle plate separating the cathode and anode spaces.
Extraction is studied by tributylphosphate (TBP) of ions of gold and silver from hydrochloric solutions during the portional and single time feed of extractant in dependence of the initial concentration of metal ions, temperature, concentration of hydrochloric acid, the ratio of organic (О) and water W phases О:W. The initial solutions contained soluble complex chlorides of gold and silver. When dissolving metal chlorides in the solution of common salt and hydrochloric acid, water soluble coordinate compound are formed that contain complex anions [AuCl 2 ] – , [AuCl 4 ] – , [AgCl 2 ] – , [AgCl 3 ] 2– , [AgCl 4 ] 3– , et al. As an extractant we used the tri-butyl ether of phosphoric acid (С 4 Н 9 О) 3 РО hat belongs to oxygen containing neutral extractants. The formation of coordinate (complex) compounds of TBP and metal polychlorides may be treated as the process of solvation of the extracted metal salt by the extractant. For selective extraction of ions of gold and silver from their hydrochloric solutions by tributylphosphate it is run feeding the extractant portionally to the solution at the minimal time of contact between the solution and the extractant; it helps extracting gold almost completely with the few first portions of the extractant at concentrations of 2n HCl 240 g/dm 3 NaCl and the temperature t = 60°С. Meanwhile the extraction of silver is kept to a minimum. Silver is extracted almost completely after the extraction of gold is over; it is done with tributylphosphate as well at concentrations of 3n HCl, 240 g/dm 3 NaCl and the temperature t = 20°С.
The high results of the silver ions extraction from the hydrochloric acid solutions of tributylphosphate during extractant portional introduction were obtained. The extractant batch inclusion increases silver extraction process and reduces the extractant expenditure. The best extraction results were obtained for the solutions with concentration 3N HCl, 240 NaCl g/dm 3 and temperature t = 20 °C. The principal technological scheme of the silver ions extraction from the hydrochloric acid solutions is presented.
The dependence of the results of electroextraction cobalt and manganese from aqueous solutions of their sulphate and chloride-sulfate solutions under static conditions was investigated. According to the results of current efficiency and specific energy consumption it has been found that the electrowinning of cobalt from aqueous solutions of cobalt and manganese in static conditions using a titanium cathode should be carried out at low concentration of manganese from sulphate-chloride solution without partitions and from sulphate solutions both without and with the perforated partitions separating the electrolytic cell into cathode and anode space.
The conditions of the selective and joint extraction of copper and ferrum impurities from a nickel electrolyte by extraction using a mixture of oleic acid and trietanolamine in kerosene were determined: extraction Fe (III) at 3 < рН ≤ 4, 1 ≤ В:О ≤ 4 and t = 40 °C; extraction Cu (II) at 5 ≤ рН ≤ 6, 1 < В:О ≤ 4 and t = 40 °C; joint extraction of copper and ferrum at рН = 5-6, 1 ≤ В:О ≤ 4 and t = 40 °C. The process flow sheet of selective extraction of ferrum and copper from a nickel electrolyte by extraction using a mixture of oleic acid and triethanolamine in kerosene is given.
High rates of iron (III) ion extraction from aqueous solutions with tributyl phosphate by sequential injection of the extractant and minimal contact time of the solution and the extractant were obtained. The sequential injection of the extractant increases iron extraction and reduces the amount of the extractant used. The best extraction results were obtained from the solutions with concentration 3N HCl, 240 g/dm 3 NaCl and temperature t = 60 С. The flow sheet of the selective iron ions extraction from the aqueous solutions is presented.
The thermodynamic analysis of aluminium hydroxide dehydration during calcination process at alumina production is carried out. The calcination of aluminium hydroxide is possible at ordinary pressure and temperature value more than 600 K. Diaspor dehydration process is possible by way of freezeout of water as an ice, water rendering or heating till decomposition temperature.
The extraction of copper and zinc ions from aqueous solutions with a mixture of oleic acid and triethanolamine has been studied. The optimal parameters of the extraction process were determined. The possibility of selective extraction of copper ions from aqueous solutions of zinc salts is shown.
