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Selective dissolution of copper from copper-chromium spent catalyst by baking–leaching process
P.K.Parhi,T.R. Sethy,P.C. Rout,K. Sarangi 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1
The selective leaching of copper from the spent Cu-Cr catalyst was carried out with H2SO4. The effect ofdifferent parameters such as acid concentration, pulp density, temperature and particle size on leachingwas investigated. The maximum extraction of copper and chromium was 67.25 and 2.3%, respectively atparticle size 45–53 mm, pulp density 2.5%, temperature 90 8C, time 180 min. Therefore, baking followedby leaching approach was adopted for dissolution of spent copper-chromium catalyst using H2SO4 toenhance the metal leaching efficiency. At the optimum baking–leaching condition i.e. baking time 2 h,baking temperature 300 8C, baking acid concentration 0.5 M, leaching temperature 35 8C, time 60 min,[H2SO4] 4%, P.D. 2.5%, the extraction of copper and chromium was 99.9% and 1.2%, respectively, ensuringthe selective dissolution of copper. The XRD and Fe-SEM-Edax characterization analysis of typicalsamples (original, baked mass and typical residue) were compared and reported. The XRD and Fe-SEMEdaxanalysis of the baked mass indicated the complete sulfation of copper and chromium by H2SO4yielding CuSO4 (H2O) and (Cr)2(SO4)3, respectively in solid phase. The absence of XRD peakscorresponding to CuSO4 H2O in the final typical leach residue (obtained at optimum baking–leachingcondition) confirmed the complete dissolution of copper from Cu-Cr catalyst.
황산용액 중에서 Na2S2O8에 의한 코발트의 산화 침전
김현호 ( Hyun Ho Kim ),박경호 ( Kyung Ho Park ),남철우 ( Chul Woo Nam ),( P K Parhi ) 대한금속재료학회(구 대한금속학회) 2013 대한금속·재료학회지 Vol.51 No.12
Oxidation and precipitation of Co(II) in sulphate solution using Na2S2O8 as an oxidant was studied. The main factors affecting the oxidation of Co(II), the reaction time, temperature, pH of solution, agitation speed and amount of added Na2S2O8, were investigated. The results indicated that the oxidation rate of Co(II) was not affected by the agitation speed and the amount of the oxidant, but it increased obviously with an increasing pH of the solution and reaction temperature. The kinetics equation was established as .ln(1.X ) = k1.[H+].0.4755.exp ( 3800) .t with a first order reaction. The product precipitated by the oxidation T of Co(II) was CoOOH, and Co2O3 was obtained by calcination of CoOOH at 300 ℃ for 2 hours. The particle size of the precipitated product was influenced by the pH of the solution.
P. Parida,D.K. Gupta,S.K. Parhi 한국전산응용수학회 2013 Journal of applied mathematics & informatics Vol.31 No.3
The semilocal convergence of a third order iterative methodused for solving nonlinear operator equations in Banach spaces is establishedby using recurrence relations under the assumption that the secondFr´echet derivative of the involved operator satisfies the !-continuity conditiongiven by ∥F′′(x) − F′′(y)∥ ≤ ω(∥x − y∥), x, y ∈ Ω, where, ω(x) is anondecreasing continuous real function for x > 0, such that ω(0) ≥ 0. Thiscondition is milder than the usual Lipschitz/H¨older continuity conditionon F′′. A family of recurrence relations based on two constants dependingon the involved operator is derived. An existence-uniqueness theorem isestablished to show that the R-order convergence of the method is (2+p),where p ∈ (0, 1]. A priori error bounds for the method are also derived. Two numerical examples are worked out to demonstrate the efficacy of ourapproach and comparisons are elucidated with a known result.
A kinetic study on hydrochloric acid leaching of nickel from Ni–Al2O3 spent catalyst
P.K. Parhi,K.H. Park,G. Senanayake 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2
Hydrochloric acid leaching of nickel from spent Ni–Al2O3 catalyst (12.7% Ni, 39.2% Al and 0.68% Fe) has been investigated at a range of conditions by varying particle size (50–180 mm), acid concentration (0.025–2 M), pulp density (0.2–0.4%, w/v) and temperature (293–353 K). Nickel was selectively leached from the catalyst, irrespective of the different conditions. Under the most suitable conditions (1 M HCl,323 K, stirring at 500 rpm, 50–71 mm particle size), the extent of leaching of Ni and Al after 2 h was 99.9%and 1%, respectively. The XRD pattern of the spent catalyst corresponded to crystalline a-Al2O3 along with elemental Ni. The peak due to elemental Ni was absent in the residue sample produced at the optimum leaching conditions, confirming the complete dissolution of Ni from the spent catalyst. The leaching results were well fitted with the shrinking core model with apparent activation energy of 17 kJ/mol in the temperature range of 293–353 K indicating a diffusion controlled reaction.
Parhi, P.K.,Park, K.H.,Senanayake, G. Korean Society of Industrial and Engineering Chemi 2013 Journal of industrial and engineering chemistry Vol.19 No.2
Hydrochloric acid leaching of nickel from spent Ni-Al<SUB>2</SUB>O<SUB>3</SUB> catalyst (12.7% Ni, 39.2% Al and 0.68% Fe) has been investigated at a range of conditions by varying particle size (50-180μm), acid concentration (0.025-2M), pulp density (0.2-0.4%, w/v) and temperature (293-353K). Nickel was selectively leached from the catalyst, irrespective of the different conditions. Under the most suitable conditions (1M HCl, 323K, stirring at 500rpm, 50-71μm particle size), the extent of leaching of Ni and Al after 2h was 99.9% and 1%, respectively. The XRD pattern of the spent catalyst corresponded to crystalline α-Al<SUB>2</SUB>O<SUB>3</SUB> along with elemental Ni. The peak due to elemental Ni was absent in the residue sample produced at the optimum leaching conditions, confirming the complete dissolution of Ni from the spent catalyst. The leaching results were well fitted with the shrinking core model with apparent activation energy of 17kJ/mol in the temperature range of 293-353K indicating a diffusion controlled reaction.
Parida, P.K.,Gupta, D.K.,Parhi, S.K. The Korean Society for Computational and Applied M 2013 Journal of applied mathematics & informatics Vol.31 No.3
The semilocal convergence of a third order iterative method used for solving nonlinear operator equations in Banach spaces is established by using recurrence relations under the assumption that the second Fr´echet derivative of the involved operator satisfies the ${\omega}$-continuity condition given by $||F^{\prime\prime}(x)-F^{\prime\prime}(y)||{\leq}{\omega}(||x-y||)$, $x,y{\in}{\Omega}$, where, ${\omega}(x)$ is a nondecreasing continuous real function for x > 0, such that ${\omega}(0){\geq}0$. This condition is milder than the usual Lipschitz/H$\ddot{o}$lder continuity condition on $F^{\prime\prime}$. A family of recurrence relations based on two constants depending on the involved operator is derived. An existence-uniqueness theorem is established to show that the R-order convergence of the method is (2+$p$), where $p{\in}(0,1]$. A priori error bounds for the method are also derived. Two numerical examples are worked out to demonstrate the efficacy of our approach and comparisons are elucidated with a known result.
K.H. Park,김홍인,D. Mishra,C.W. Nam,J.T. Park,D.J. Kim,P.K. Parhi 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.6
Baking–leaching-solvent extraction process was investigated to recover metal values from waste petroleum catalyst. Baking of Mo–Ni/Al2O3 spent catalyst with H2SO4 followed by leaching of the baking mass concentrate was presented. Under optimum baking condition (temp. 300 8C, H2SO4 = 1.2stoichiometric, baking time 1 h), and low acid leaching condition (temp. 95 8C, H2SO4 = 2% (v/v), pulp density 5% and leaching duration 30 min), about 96% Mo, 99% Al and 95% Ni was dissolved. Baking–leaching results were interpreted by two different statistical analysis approaches namely Principal Component (PCA) and Multi Linear Regression Analysis (MLRA). The generated leach liquor was further subjected to the solvent extraction of Mo(VI) by LIX 84-I followed by aluminum using Na-Cyanex 272. A quantitative extraction of Mo(VI) and Al was achieved in 2-stage at A:O ratio of 1:1 with 40% LIX-84-I and 2-stages at 1:1 phase ratio with 60% neutralized Cyanex 272, respectively. While stripping the metals from loaded organic such as Mo(VI) using 20% NH4OH and Al with 3 M H2SO4, the metal concentration in the strip solution were enriched up to 1.5 times and 3 times in two and three number of stages, respectively. Based on the results of present study, a conceptual process flow diagram was proposed.