Sulfuric acid leaching of Turkish chromite concentrate

In this work a high grade chromite concentrate obtained from Pinarbasi-Kayseri district of Turkey was reacted with a solution of sulfuric acid and perchloric acid. The effect of sulfuric acid concentration, temperature, duration, and perchloric acid addition on leach recovery was studied. At the end of leach reaction chromium appeared in the solution as Cr3+ and it did not change to environmentally hazardous Cr6+. The final product in the solution was chromium(III) sulfate obtained with about 83% maximum recovery, under the optimum leaching conditions of 175 degreesC, 2 h, 70% H2SO4 and 1/2 perchloric acid/chromite ratio.


Optimization of conditions in sulfuric acid leaching of Turkish chromite concentrates
Ustaoğlu, Emre; Geveci, Ahmet; Department of Metallurgical and Materials Engineering (2006)
In this thesis work, a high grade chromite concentrate obtained from Pınarbaşı, Kayseri region of Turkey was reacted with sulfuric acid solution to determine the optimum conditions of leaching of chromite ores. Conventional methods for producing chromium are still valid in industry. The main process in production includes soda melting and taking it into solution in the form of chemical compounds such as sodium dichromate. Three and six valence states of chromium have importance in production. Trivalent chro...
Water-soluble poly(4-styrenesulfonic acid-co-maleic acid) stabilized ruthenium(0) and palladium(0) nanoclusters as highly active catalysts in hydrogen generation from the hydrolysis of ammonia-borane
Metin, Oender; ŞAHİN ÜN, ŞULE; Özkar, Saim (2009-08-01)
Water-soluble poly(4-styrenesulfonic acid-co-maleic acid), PSSA-co-MA, stabilized ruthenium(0) and palladium(0) nanoclusters were for the first time prepared in situ from the reduction of ruthenium(III) chloride and potassium tetrachloropalladate(II), respectively, by ammonia-borane during its hydrolysis at room temperature. PSSA-co-MA stabilized ruthenium(0) and palladium(0) nanoclusters having average particle size of 1.9 +/- 0.5 and 3.5 +/- 1.6 nm, respectively, were isolated from the reaction solution a...
Rare earth double sulfates from pre-concentrated bastnasite
Kul, M.; Topkaya, Yavuz Ali; Karakaya, İshak (2008-08-01)
A mixture of rare earth double sulfates was produced from a Turkish bastnasite-containing pre-concentrate (low grade concentrate) by sulfuric acid baking, subsequent water leaching and precipitation with sodium sulfate. The results of acid baking and leaching indicated that recoveries of rare earth elements up to 90% were readily obtained and the recovery of hydrofluoric acid as a by-product was also possible. Reasonable decontamination of the rare earth double sulfate salt from impurities such as Th, Fe, A...
Dynamic and steady state analysis of low temperature ethane oxidative dehydrogenation over chromia and chromia-vanadia catalysts
Karamullaoglu, Gulsun; Doğu, Timur (2007-11-02)
Oxidative dehydrogenation of ethane to ethylene was investigated over Chromia and Cr-V mixed oxide catalysts synthesized following a complexation procedure. With an O-2/C2H6 feed ratio of 0.17, Chromia exhibited a total conversion value of about 0.20 at 447 degrees C (at a space time of 0.24 s.g/mL) with an ethylene selectivity of 0.82. Chromia catalyst was more active than Cr-V mixed oxide at temperatures as low as 200 degrees C. Pulse-response experiments carried out with ethane pulses injected into O-2-H...
Oxidative dehydrogenation of ethane over a monolith coated by molybdenum-vanadium-niobium mixed-oxide catalyst
Karamullaoglu, G; Doğu, Timur (2003-10-01)
Oxidative dehydrogenation of ethane to ethylene was investigated using Mo0.71V0.21N0.08 mixed-oxide catalyst. in powder form and coated over a monolith. At 570degreesC and with a feed stream containing an O-2/C2H6 mole ratio of one. ethylene selectivity value reaching to 96% was obtained Lit a conversion level of about 5% with the monolith-supported catalyst. DRIFTS studies indicated the presence of adsorbed ethoxide species. The proposed reaction scheme for the production of ethylene includes the eliminati...
Citation Formats
A. Geveci and Y. A. Topkaya, “Sulfuric acid leaching of Turkish chromite concentrate,” MINERALS ENGINEERING, pp. 885–888, 2002, Accessed: 00, 2020. [Online]. Available: