J Radioanal Nucl Chem (2014) 299:81–87 DOI 10.1007/s10967-013-2732-3
Leaching behavior of uranium and vanadium using strong sulfuric acid from Korean black shale ore Joon Soo Kim • Kyeong Woo Chung • Hoo In Lee • Ho-Sung Yoon • Jyothi Rajesh Kumar
Received: 28 March 2013 / Published online: 17 September 2013 Ó Akade´miai Kiado´, Budapest, Hungary 2013
Abstract The present scientific study focused on leaching behavior of uranium and vanadium from Korean domestic ore. The leaching process experimental conditions optimized for uranium and vanadium metals recovery from Korean domestic ore and developed the basic experimental procedures such as time, particle size, acid influence, temperature effect and pulp density (PD) behavior. Acid influence on leaching process was tested and noted that 2.0 M sulfuric acid concentration is the optimized conditions for present study. The time influence on leaching process was observed and its optimized 2 h for complete leaching process. The temperature influence tested and optimized the 80 °C for complete leaching process and PD is 50 % (wt%). The bench scale experiments developed in a laboratory and tested in pilot level each batch 100 kg of ore sample. Keywords Leaching Uranium Vanadium Black shale ore Sulfuric acid
Introduction The metal uranium have major advantage in the countries industrial growth, it influences the economic developments
This paper was presented in TMS 142nd annual meeting and REWAS 2013: Enabling Materials Resource Sustainability held on 3–7 March 2013 at San Antonio, TX, USA [1]. J. S. Kim K. W. Chung H. I. Lee H.-S. Yoon J. R. Kumar (&) Mineral Resources Research Division, Extractive Metallurgy Department, Korea Institute of Geoscience and Mineral Resources (KIGAM), Taejon 305-350, Korea e-mail:
[email protected];
[email protected]
of the country. Countries like Korea having very limited uranium resources and founded deposits having low grade metal values. Mid of the twentieth century uranium play key role in war activities; whereas now i.e. new millennium it is playing very important, peaceful and meaningful role in electricity generation. The research efforts are focusing towards extraction and recovery process developments of the uranium any other valuable metal components like vanadium from low grade ores [2]. Uranium is the main source to generate the nuclear power as cheap and more quantity of the electricity will generate. For this reasons the upcoming researchers in developed/developing countries are establishing more research and development on extraction and separation technologies for uranium. Uranium need going very fast in developed countries and Korea; at the same time the available minerals/ores having low quantity of uranium content associated with valuable metal vanadium and other impurities like iron, aluminium, silicon predominantly. The present study focused on both metals such as uranium and vanadium recovery and separation for country needs. For the recovering process leaching is the first step in hydrometallurgical methodology. The first stage targeted both metals leaching in next stage separate the each other. Any country concentrates on future prospects as well as price, supply and demand for nuclear power plant of yellow cake (nuclear fuel material). At the same time the available uranium deposits, average grade and properties were tested. In Korea, the available uranium deposits are Okcheon black shale-uranium ore. Purpose of this study is technological development for the preparation of yellow cake and vanadium penta-oxide through basic research and detail engineering aspects. Figure 1 shows that status of the electric power plant according to fuel sources of Korea [3]. In Korea, future demands based on the estimations
123
82
Fig. 1 Ratio of fuel sources for the generation of electric power in Korea (adopted from [1])
7,039 tU to generate 22,196 MW electric power for country needs. For environmental concern uranium recovery from the nature is gives good advantage for human health. The uranium demand growing very fast in Korea as well as all over the world, the present scientific methodology developed the environmentally friendly. Before began the any process the literature review will give the past reported information as well as new ideas for present study. The literature review noted the following reported methodologies on uranium leaching process. Uranium content in phosphate rock was leached with alkaline solutions like ammonium carbonate and bicarbonate and produced uranyl carbonate by Guzman et al. [4]. The uranium leaching process established by using Fe2(SO4)3 with H2SO4 as one set then sulfuric acid having low nitric acid combination as another set by Shakir et al. [5], further the leach liquor proceeded by liquid-gel extraction. Buck et al. [6] from Argonne National Laboratory developed a procedure to remove the uranium(IV) by carbonate leaching process in presence of oxygen. Uranium in fourth oxidation stage leached by above said process was follows: 4 UO2 þ 1=2 O2 þ 3CO2 þ2OH ð1Þ 3 ¼ UO2 ðCO3 Þ3 The new leaching system hydrogen peroxide and sodium sulfate with sulfuric acid was applied for uranium. Advantage of this methodology is to reduce the sulfuric acid concentration 700–400 g acid kg-1 [7]. Uranium content in various oxidation states such as four and six was selectively leached by HCl [8]. Nanomaterials [zero-valent iron nanoparticles (nZVI)] used for micro level metal contents uranium and vanadium and other metals such as arsenic, beryllium, cadmium, chromium, copper, nickel and zinc from in situ uranium leaching [9]. From the various sources like rock samples and wastes uranium leaching process studied by long term process (142 days) [10]. Uranium leaching from
123
J Radioanal Nucl Chem (2014) 299:81–87
glass fiber conducted by chemically, nitric acid and sodium carbonate as reagents and the major advantage of this method was after precipitation of the targeted metal possible to re-use the nitric acid for further cycle [11]. Other leaching methods like in presence of ultrasound at the time of leaching process uranium recovery was enhanced at the same time energy consumption concerns the leaching rate was improved compared with normal leaching process [12]. Uranium leaching used by oxidative process for SIMFUEL using sodium carbonate and hydrogen peroxide combination solution successfully [13]. Uranium and thorium mixed oxide (U1-xThxO2) sintered pellets were prepared by crystallized U1-xThx(C2O4)22H2O at low temperature, these material leached by using nitric acid the time studied range was 0–100 min [14]. The recovery of uranium using leaching methodology for mine waste processing by using carbonate reagents successfully [15]. High arsenic content (2,446 mg/L) low uranium content (64 mg/L) associated with other metals like copper, lead, nickel and zinc was leached by using sulfuric acid combines with sodium sulfide and ferric chloride at 80–90 °C with 1:1 solid liquid ratio [16]. Vanadium leaching methodologies also developed by several researchers; very recently from uranium ore residue containing high concentration of vanadium (6,781 mg/L) it was leached by using fungal and proposed the statistical design [17]. From various sources such as black shale [18], LD converter slag [19], roasted residue of stone coal [20] and carbonaceous shale [21] vanadium was leached by acid and pressure methodologies. The present scientific study focused on leaching process for uranium and vanadium metals from Korean black shale ore. And further processes, recovery as well as each other separation procedures going to establish by using extraction process in future studies. Properties of Okcheon black shaleuranium; looks like to uraminite (UO2), brannerite [(U, Ca, Ce, Y)2(Ti, Fe)2O6] or francevillite [(Ba, Pb)(UO2)2 (VO4)25H2O]. The recognized amount of deposits in Korea is 115 million tons and the map of the deposits given as Fig. 2. The present scientific methodology developed for the environmentally friendly ore leaching processing using sulfuric acid is presented as general flowsheet as Fig. 3.
Experimental Apparatus and reagents Uranium and vanadium metals analysis was carryout using inductively coupled plasma optimal emission spectrometer (ICP-OES) Perkin Elmer Model Optima 2000 Dr, USA. Digital pH meter supplied by Thermo Scientific, USA used for present study; pH standard solutions also supplied by same company and those are 1.68, 4.01, 7.00 and 10.01
J Radioanal Nucl Chem (2014) 299:81–87
83 Table 1 Chemical compositions of Korean domestic black shale ore sample Component U3O8 V2O5 SiO2
Content (%) 0.058 0.16 55.1
Component P2O5
Content (%) 0.25
ZnO
0.03
NiO
0.08
Al2O3
7.45
S
Fe2O3
3.47
Fixed carbon
CaO
0.35
H2O
MgO
0.85
0.19 26.9 *5.1
Ore identification studies Korean black shale ore composing coaly materials, quartz, mica, amphiboles, barite and pyrite materials and it was presented in Fig. 4. Based on geological properties, almost uranium component are adsorbed coaly materials, uraninite, brannerite and francelvilite type minerals. Leaching procedure
Fig. 2 Distribution map of Okcheon black shale uranium ore in Korea
used for pH meter standardization everyday. Sulfuric acid (95 %) supplied by Junsei Chemical Company Ltd., Japan. All reagents used were analytical reagent grade. The chemical compositions of the Korean domestic ore sample were presented in Table 1.
The experimental set up for the leaching process made by Pyrex material to face the sudden temperature changes in sulfuric acid leaching process. During a leaching process density of the water evaporation will occurred to prevent this reflux condenser was set to on upper portion. Loaded thermocouple will measures the temperature of the reaction water and set the temperature ±2 °C inside and outside of the room. After reaching the optimum temperature condition the uranium ore sample was added to sulfuric acid solution by systematically. Mechanical agitator used for proper mixing the sample with acid solution. The agitation
Fig. 3 The general flowsheet for the Korean black shale ore leaching processing
123
84
J Radioanal Nucl Chem (2014) 299:81–87
Fig. 4 Microscopic pictures of the Korean black shale ore sample (mu mica, qz quartz, opq amphiholes)
speed keep 500 rpm for all experiments in the present study. Analysis of the metals was recorded by ICP-OES and leach rate was calculated and the present experimental data of leaching procedure having ±2 % variation of the experiments. The leaching behavior of uranium and vanadium in Korean black shale ore with sulfuric acid as follows: UO2 þ Fe2 O3 þ 3H2 SO4 ! UO2 SO4 þ 2FeSO4 þ 3H2 O ð2Þ V2 O5 þ H2 SO4 ! VOSO4 þ H2 O
ð3Þ
Results and discussion Effect of time The first experiment tested the time influence on leaching process. For complete understanding of the process to study the reaction kinetics; and liquid/solid reactions rates will be depending on transport rate of reactants, chemical reaction and products [22]. The present developed leaching process for uranium and vanadium recovery studies tested with time influence to understand the kinetics of the process. The obtained results presented as Fig. 5. The preliminary studies on time optimized 2 h time requires for both metals leaching process and all other experiments keep leaching process up to 2 h. Effect of particle size The particle size of the ore plays key role towards the degree of dissolution of metal during leaching process [23]. Particle size influence the leaching rate process based on
123
Fig. 5 Effect of time on Korean black shale ore leaching process
the size of the ore sample and acid surface area. If ore sample size is small solution surface area is large it leached more easily and comfortably [24]. Whereas particle size increases the amount of the ore sample leaching will be decreases [25]. And at the same time, the smaller particle size sample dissolution rate is fast, on the other hand particle size is large the dissolution rate will be slow [26]. The particle size of the Korean domestic ore sample was tested and obtained results are presented as Fig. 6. The results clearly demonstrate that, -48 mesh size is ideal for both metals. Effect of acid concentration The effect of sulfuric acid concentration on uranium and vanadium leaching process from uranium ore was carried out in between 1.0 and 7.0 M of acid concentration. The metal leaching rate increased with increases acid concentration and sharp increase in leaching rate with variation from 1.0 to 2.0 M of sulfuric acid concentration. Very slow increase in leaching rate with variation from 2.0 to 6.0 M
J Radioanal Nucl Chem (2014) 299:81–87
85 Table 2 Chemical compositions of pregnant solution Component
U
V
Al
Fe
Mg
Cu
Zn
Ni
Content (ppm)
1,136
1,760
26,920
25,120
302
246
30
70
Effect of pulp density [or solid/liquid ratio (S/L)]
Fig. 6 Particle size effect on Korean black shale ore leaching process
Fig. 7 Effect of sulfuric acid concentration on uranium and vanadium leaching process from Korean black shale ore
sulfuric acid. The present study concludes that, 2.0 M acidity is good to precede further experiments. The results were presented in Fig. 7. Effect of temperature Temperature influence play key role in leaching process and the present study carry out temperature effect on uranium ore processing. The temperature varied 60–80 °C and the results are presented as Fig. 8. The experimental results given final conclusions for uranium highest leaching rate observed at 80 °C where as for vanadium 60 °C temperature was suitable. Further experiments temperature fixed as 80 °C to leach both metals (Table 2).
Fig. 8 Effect of temperature on uranium vanadium leaching process from Korean black shale ore
The pulp density (PD) or solid/liquid ratio (S/L) role in leaching processing is the most important experiment. Productivity of the leaching process was interlinked with density. Based on PD concentration (weight of the ore sample) it increases or decreases the constant leach solution (acid or base or water etc) surface area per unit volume with specific time will influence the process [27]. PD is one of the vital factors of leaching process because solid PD is directly related to lixiviant (leaching reagent) concentration on process control as well as economical point of view [28]. Therefore, the selection of proper PD ratio is again important on development of a successful leaching flow sheet. For this reason it’s necessary to test the PD effect on the leaching operations and optimize the process. Very little variations in leaching rate was observed at various PDs from 20 to 60 wt%, for further experiments PD was fixed as *50 wt% (Fig. 9). Based on fundamental experimental results the uranium ore leach liquor final pH recorded as *0.3. The valuable metals such as uranium, vanadium are main elements and other associated metals like aluminium, iron, magnesium, copper, zinc, nickel etc. The chemical compositions of the uranium leach liquor without dilution obtained by optimum leaching conditions is as follows: 2 M H2SO4, acidity, 2 h time, 80 °C temperature, -48 mesh size, 50 % PD, 500 rpm. After bench scale studies, further pilot scale-up tests were conducted for uranium and vanadium leaching process from Korean black shale ore. 100 kg of Korean black shale ore mixed with 90 L water ? 20 kg concentrated
Fig. 9 Effect of PD on uranium vanadium leaching process from Korean black shale ore
123
86
J Radioanal Nucl Chem (2014) 299:81–87
leached vanadium at same temperature. The ideal PD optimized from present study was 50 % for both elements. The ideal conditions optimized for Korean domestic ore sample by present study was time 2 h, particle size -48 mesh, acidity 2 M sulfuric acid, 80 °C temperature, 50 % PD and 500 rpm agitation speed. Successfully, scale-up tests were conducted each bath up to 100 kg of Korean black shale ore. Finally, present research paper concludes that, the proper leaching conditions (above said conditions) will full fill the uranium and vanadium leaching process from Korean domestic ore. And countries like Korea future needs for yellow cake processing is going to full fill by developed leaching processing technology. Acknowledgments This work was supported by the Energy Efficiency and Resources Program (Physical and Chemical mineral dressing/refining of low grade uranium ore) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea Government Ministry of Knowledge Economy. The authors express thanks to TMS organizing committee, USA.
References
Fig. 10 Korean black shale ore scale-up test with present developed leaching process (each batch conducted 100 kg ore sample)
sulfuric acid solutions at 75–80 °C temperature, 2 h leaching processing time are the experimental conditions optimized by above study. The pilot scale-up tests set-up photographs were shown in Fig. 10. The above generated Korean black shale ore leach liquor further processing (solvent extraction) for uranium and vanadium recovery by adjusting the proper pH condition with proper dilutions.
Conclusions The following conclusions drawn from the present investigations on leaching process for uranium and vanadium metals from Korean domestic ore by using environmentally friendly method: the first experiment conduct on influence of time on leaching process and it concludes that 2 h time is sufficient for uranium and vanadium leaching process. Even the moderate sulfuric acid concentration i.e. 2 M acid leached *90–94 % of uranium leached whereas same experimental condition *65–72 % of vanadium was leached from ore sample. The target metals uranium and vanadium was leached above 90 % of uranium at 80 °C where as *65 %
123
1. Kim JS, Chung KW, Lee HI, Lee JY, Kumar JR (2013) Leaching of uranium and vanadium from Korean domestic ore. In: Kvithyld A, Meskers C, Kirchain R, Krumdick G, Mishra B, Reuter M, Wang C, Schlesinger M, Gaustad G, Lados D, Spangenberger J (eds) REWAS 2013: enabling materials resource sustainability., pp 20–26 2. Merritt RC (1971) The extractive metallurgy of uranium, Colorado School of Mines Research Institute, Library of Congress Catalog Card No. 71-157076 3. Kim JS (2013) Research and development for the recovery of uranium and vanadium from Korean black shale ore. J Korean Inst Res Rec 22:3–10 4. Guzman ETR, Regil EO, Malagon GP (1995) Uranium leaching from phosphate rock. J Radioanal Nucl Chem Lett 201:313–320 5. Shakir K, Aziz M, Beheir ShG (1992) Studies on uranium recovery from a uranium bearing phosphatic sandstone by a combined heap leaching-liquid-gel extraction process. 1. Heap leaching. Hydrometallurgy 31:29–40 6. Buck EC, Brown NR, Dietz N (1996) Contaminant uranium phases and leaching at the Femald site in Ohio. Environ Sci Technol 30:81–88 7. Yuksel A, Eral M, Olmez S (1995) Leaching of uranium with the H2O2–Na2SO4–H2SO4 (HSS) system and the efficiency of acigol lake water. J Radioanal Nucl Chem Lett 200:169–179 8. Fouad HK (2010) Determination of hexavalent and tetravalent uranium in phosphate ores through hydrochloric acid selective leaching. J Radioanal Nucl Chem 285:193–197 9. Klimkova S, Cernik M, Lacinova L, Filip J, Jancik D, Zboril R (2011) Zero-valent iron nanoparticles in treatment of acid mine water from in situ uranium leaching. Chemosphere 82:1178–1184 10. Patra AC, Sumesh CG, Mohapatra S, Sahoo SK, Tripathi RM, Puranik VD (2011) Long-term leaching of uranium from different waste matrices. J Environ Manage 92:919–925 11. Kim GN, Park HM, Choi WK, Moon JK (2012) A device for uranium series leaching from glass fiber in HEPA filter. J Radioanal Nucl Chem 293:157–166 12. Avvaru B, Roy SB, Chowdhury S, Hareendran KN, Pandit AB (2006) Enhancement of the leaching rate of uranium in the presence of ultrasound. Ind Eng Chem Res 45:7639–7648
J Radioanal Nucl Chem (2014) 299:81–87 13. Chung DY, Seo HS, Lee JW, Yang HB, Lee EH, Kim KW (2010) Oxidative leaching of uranium from SIMFUEL using Na2CO3– H2O2 solution. J Radioanal Nucl Chem 284:123–129 14. Hingant N, Clavier N, Dacheux N, Barre N, Hubert S, Obbade S, Taborda F, Abraham F (2009) Preparation, sintering and leaching of optimized uranium thorium dioxides. J Nucl Mater 385:400–406 15. Santos EA, Ladeira ACQ (2011) Recovery of uranium from mine waste by leaching with carbonate-based reagents. Environ Sci Technol 45:3591–3597 16. Roshani M, Mirjalili K (2009) Studies on the leaching of an arsenic–uranium ore. Hydrometallurgy 98:304–307 17. Gharehbagheri H, Safdari J, Roostaazad R, Rashidi A (2013) Two-stage fungal leaching of vanadium from uranium ore residue of the leaching stage using statistical experimental design. Ann Nucl Energy 56:48–52 18. Li M, Wei C, Fan G, Li C, Deng Z, Li X (2009) Extraction of vanadium from black shale using pressure acid leaching. Hydrometallurgy 98:308–313 19. Aarabi-Karasgani M, Rashchi F, Mostoufi N, Vahidi E (2010) Leaching of vanadium from LD converter slag using sulfuric acid. Hydrometallurgy 102:14–21 20. Zhu Y, Zhang G, Feng Q, Lu Y, Ou L, Huang S (2010) Acid leaching of vanadium from roasted residue of stone coal. Trans Nonferrous Met Soc China 20:107–111
87 21. Zhang X, Yang K, Tian X, Qin W (2011) Vanadium leaching from carbonaceous shale using fluosilicic acid. Int J Miner Process 100:184–187 22. Moore JJ (1981) Chemical metallurgy. Butterworth & Co (Publishers) Ltd, London 23. Senanayake G, Das GK (2004) A comparative study of leaching kinetics of limonitic laterite and synthetic iron oxides in sulfuric acid containing sulfur dioxide. Hydrometallurgy 72:59–72 24. Hariprasad D, Dash B, Ghosh MK, Anand S (2007) Leaching of manganese ores using sawdust as a reductant. Miner Eng 20:1293–1295 25. Habashi F (1980) Extractive Metallurgy: hydrometallurgy, vol. 2. Gordon and Breach Science Publishers Inc., New York 26. Barik SP, Park KH, Parhi PK, Park JT (2012) Direct leaching of molybdenum and cobalt from spent hydrodesulphurization catalyst with sulphuric acid. Hydrometallurgy 111–112:46–51 27. Jha MK, Kumari A, Choubey PK, Lee JC, Kumar V, Jeong J (2012) Leaching of lead from solder material of waste printed circuit boards (PCBs). Hydrometallurgy 121–124:28–34 28. David D, Nedam A (2002) A fundamental study of the reductive leaching of chalcopyrite using metallic iron part I: kinetic analysis. Hydrometallurgy 66:37–57
123