Improvıng The Method For The Productıon Of Cobalt Sulfate In Hıgh Purıty From Nıckel-Cobalt Hydroxıde Product Produced By Hıgh Pressure Acıd Leachıng


Thesis Type: Postgraduate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2019

Student: JANSET SİNE ŞEKERCİ

Supervisor: ÖZKAN MURAT DOĞAN

Abstract:

The increase in the tendency for low-emission, environment-friendly electric vehicles and the batteries in these vehicles becoming a current issue have been factors that increase the use of cobalt and its compounds. The aim of this thesis is to develop the method for obtaining the cobalt sulfate product from the mixed hydroxide precipitate (MHP) obtained by leaching of the lateritic ore in Manisa-Gördes region under 245-250 oC temperature and 44-46 bar pressure and subsequent purification. The production of cobalt sulphate, which will serve to the battery sector, primarily from the MHP containing 36-40% Ni, 1,5-3% Co, firstly the leaching of the MHP and the removal of the metals in the solution, purification of the solution by the precipitation and solvent extraction (SX), concentrating and crystallization. MHP leaching was performed with sulfuric acid at pH 2, 60 oC, 15% solids for 1 hour and 90% Ni and 85% Co yield was observed. Then, the leaching solution was purified by precipitation with calcium hydroxide at pH 4,6 to obtain pregnant leach solution (PLS). With the DEHPA SX from PLS, impurities were removed as 88% Mn, 95% Ca, 85% Zn, etc. The cobalt-rich raffinate with a Cyanex 272 SX extracted 92% Co in a ratio of 1/1 O / A to pH 5.2 at 45 °C. In order to concentrate the solution, the stripping of the loaded CO was carried out at 10/1 O/A at pH 2, and 96% of the Co was stripped. The process through which the process has been passed from MHP until cobaltic-laden solution has a 60% Co gain and as a result of this process, cobalt sulphate product containing 18,7% Co in 89,2% purity was obtained.