Statistical Modelling of Sulphuric Acid Leaching of TiO2, Fe2O3 and A12O3 from Red Mud

2001 ◽  
Vol 79 (5) ◽  
pp. 291-296 ◽  
Author(s):  
E. Şayan ◽  
M. Bayramoğlu
Keyword(s):  
Sulphuric Acid ◽  
Red Mud ◽  
Acid Leaching ◽  
Statistical Modelling

scholarly journals PURIFICATION OF INDONESIAN NATURAL GRAPHITE AS CANDIDATE FOR NUCLEAR FUEL MATRIX BY ACID LEACHING METHOD: CHEMICAL CHARACTERIZATION

2020 ◽  
Vol 26 (3) ◽  
Author(s):  
Deni Mustika ◽  
Torowati Torowati ◽  
Arbi Dimyati ◽  
Sudirman Sudirman ◽  
Adel Fisli ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Nuclear Fuel ◽  
Hydrofluoric Acid ◽  
Acid Leaching ◽  
Chemical Characterization ◽  
Ash Content ◽  
Natural Graphite ◽  
Nuclear Graphite ◽  
Purity Level ◽  
Graphite Matrix

PURIFICATION OF INDONESIAN NATURAL GRAPHITE AS CANDIDATE FOR NUCLEAR FUEL MATRIX BY ACID LEACHING METHOD: CHEMICAL CHARACTERIZATION. Graphite matrix in Pebble Bed Reactor (PBR) – High Temperature Gas Cooled Reactor (HTGR) has an important role as heat transfer medium, neutron moderator and structural material to protect fuel. Thus, graphite matrix must fulfill chemical and physical characteristics for PBR-HTGR fuel. Indonesia has graphite sources in several regions that can potentially be purified. This research aimed to purify Indonesian natural graphite by several variation of acids and to perform chemical characterizations. Natural graphite from flotation process was purified by several variations of acid, i. e., hydrofluoric acid (HF), sulphuric acid + nitric acid (H2SO4 + HNO3) and hydrofluoric acid + hydrochloric acid + sulphuric acid (HF + HCl + H2SO4) and subsequently followed by chemical characterizations such as purity level, ash content, and boron quivalent. The highest purity was obtained in the purification process by HF with carbon content up to 99.52%; this purity level fulfills the specification of nuclear graphite (>99%). Ash content analysis shows a value in compliance with the specification requirement, i.e., < 100 ppm, and boron equivalent value also fulfills the specification value of < 1 ppm. It can be concluded from this study that the graphite purified by acid leaching with HF can be used as fuel matrix candidate but is qualified as low quality. Futher research is required to produce high quality nuclear graphite, particularly research in the minimization of the impurity by evaporation at temperatures over 950 oC to by far lower the ash content.Keywords:  Indonesian natural graphite, purification, nuclear fuel matrix, acid leaching, chemical characterization.

scholarly journals Characterization of dross and its recovery by sulphuric acid leaching

2018 ◽  
Vol 985 ◽  
pp. 012033 ◽  
Author(s):  
S A Rahmani ◽  
A Meidianto ◽  
M I Amal ◽  
A S Wismogroho ◽  
W B Widayatno
Keyword(s):  
Sulphuric Acid ◽  
Acid Leaching

Phosphorus recovery from the sludge generated from a continuous bipolar mode electrocoagulation (CBME) system

2019 ◽  
Vol 79 (7) ◽  
pp. 1348-1356 ◽  
Author(s):  
M. Damaraju ◽  
H. Yoshihara ◽  
D. Bhattacharyya ◽  
T. K. Panda ◽  
K. K. Kurilla
Keyword(s):  
Oxalic Acid ◽  
Sulphuric Acid ◽  
Acid Leaching ◽  
Renewable Resource ◽  
Phosphorus Recovery ◽  
Raw Material ◽  
Time Intervals ◽  
Operational Conditions ◽  
Bipolar Mode ◽  
Palm Oil Mill

Abstract Phosphorus is known to be a limited non-renewable resource. Phosphorus is obtained from phosphate rock, which is likely to be depleted in the next few decades. Therefore, it is very important to find alternate sources of phosphorus from which phosphorus can be recycled and recovered. This study focuses on the recovery of phosphorus from the sludge generated from a continuous bipolar mode electrocoagulation (CBME) system, used for treating a palm oil mill effluent (POME). The sludge generated from the CBME system is leached with oxalic acid and sulphuric acid for phosphorus recovery with and without thermal treatment. Acid leaching was carried out at various time intervals using various liquid/solid (L/S) ratios of acids and sludge. The CBME system caused a 73% removal of phosphorus from POME, where phosphorus is precipitated in sludge as iron phosphates or adsorbed as phosphates depending on the pH in the system. Acid leaching resulted in nearly 85% recovery of phosphorus with both sulphuric acid and oxalic acid for sludge combusted at 900 °C. Statistical analysis was carried out to find the significance of the operational conditions on the phosphorus yield. Acid leaching results in the formation of orthophosphates, which can be used as a raw material for synthesis of chemical fertilizers.

scholarly journals Study on Enhancing Zinc Dusts with Direct Sulphuric Acid Leaching

2015 ◽  
Vol 27 (8) ◽  
pp. 2801-2805
Author(s):  
H.Y. Sun ◽  
X. Kong ◽  
W. Sen ◽  
G.Y. Liu
Keyword(s):  
Sulphuric Acid ◽  
Acid Leaching

Recovery of Lanthanides in the Sulphuric Acid Leaching Process of Kola Apatites

1995 ◽  
Vol 15 (1-4) ◽  
pp. 142-142 ◽  
Author(s):  
IGOR A. DIBROV ◽  
DIMITRI E. CHIRKST ◽  
K. N. CHALIYAN
Keyword(s):  
Sulphuric Acid ◽  
Acid Leaching ◽  
Leaching Process

Kinetics of sulphuric acid leaching of a zinc silicate calcine

2007 ◽  
Vol 89 (3-4) ◽  
pp. 337-345 ◽  
Author(s):  
A.D. Souza ◽  
P.S. Pina ◽  
E.V.O. Lima ◽  
C.A. da Silva ◽  
V.A. Leão
Keyword(s):  
Sulphuric Acid ◽  
Acid Leaching ◽  
Zinc Silicate ◽  
Kinetics Of

Leaching Studies of Spent Zinc-Manganese Alkaline Batteries with Sulphuric Acid

2008 ◽  
Vol 587-588 ◽  
pp. 763-767 ◽  
Author(s):  
R.N.G. Guerra ◽  
Carlos A. Nogueira ◽  
Fernanda Margarido
Keyword(s):  
Sulphuric Acid ◽  
Process Development ◽  
Acid Leaching ◽  
Alkaline Batteries ◽  
Confidence Levels ◽  
Positive Effects ◽  
Hydrometallurgical Processing ◽  
Zinc Oxides ◽  
Metals Recovery ◽  
Low Levels

The hydrometallurgical processing of metal bearing residues is one of the established routes envisaging metals recovery. In these processes, the leaching operation plays a central role as allows the solubilization of metals for further separation and recovery as pure products. This route can be applied to spent domestic batteries recycling, which studies on sulphuric acid leaching of spent alkaline batteries are reported in this paper. Material samples used in the trials were prepared concerning the real proportion of the most common sizes and shapes of batteries found in the usual stream of this type of wastes. The research involved the evaluation of some factors which affect leaching yields namely temperature, reaction time and stirring speed, through a two-level factorial design methodology and analysis of variance. In this study, other factors related with leachant concentration and stoichiometry were maintained constant. Zinc leaching yields were generally high and even near 100% when the high levels of the variables were used, meaning that zinc oxides present in the electrodes are very reactive to acid leachant. The variables had all positive effects being temperature the most significant factor (confidence level 99%) while the other factors were less significant (98.8% for time and 95% for stirring speed). Concerning manganese, leaching yields obtained were more dependent from the factors, being also positive and varying from 11% (for low levels of factors combination) to 89% (for high levels of factors combination). Temperature and time were highly significant (confidence levels above 99.9%) while stirring speed was less significant (97%). Contamination of leach liquors with iron was also evaluated since it is an impurity which requires special attention during the process development. For the higher levels of the factors (t = 1 h, T=80°C and ω=400 rpm) the final solution contained 10 g/L Zn, 15 g/L Mn and 3.2 g/L Fe. The removal of the iron from the solution is a necessary step prior to the separation and recovery of zinc and manganese.

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