Leaching Mo and Ni by Direct Oxygen Pressure from Black Shale with any other only water

Transcription

1 4th International Conference on Sutainable Energy and Environmental Engineering (ICSEEE 2015) Leaching and by Direct Oxygen Preure from Black Shale with any other only water DENG Zhi-gan1, a, WEI Chang1, LI Xing-bin1, LI Cun-xiong1, FAN Gang1 1 Faculty of Metallurgical and Energy Engineering, Kunming Univerity of Science and Technology, Kunming , China a dengzhigan83@163.com Keyword: Black Shale, lybdenum and ckel, Oxygen Preure Water Leaching Abtract. The hydrometallurgical proce of leaching molybdenum and nickel from black hale without reagent wa invetigated. The extraction of and from molybdenum-nickel ore by oxygen preure leaching, which exploit the characteritic of molybdenum-nickel mineral contain high concentration amorphou ulfide which ha highly active, and make the mot of eaily oxide to ulfuric acid and ulfate at low temperature and exce oxygen preence of the amorphou ulfide. Under oxygen preure condition, coniderable molybdenum and almot all the nickel were extracted into olution in the leaching proce. The reult how that with the leaching time for 3~4h, temperature at 150oC, liuid-to-olid ratio of 2mL g-1, mineral granularity of 0.074mm, oxygen partial preure of 0.4~0.5MPa without other reagent, molybdenum leaching percentage can be over 80% and nickel leaching percentage can be more than 97%. Furthermore, about 80% ulfur in the - ore ha been tranformed into ulfuric acid. Introduction The black hale i an important molybdenum and nickel ource, which a a ediment-hoted ore layer of the lower Cambrian black hale ha been known to local geologit for at leat 50 year in China[1-2]. Apartial evaluation of the - ore depoit and their genei ha been attempted in pat decade [3]. The - ore contain more than 4wt%, at leat 2wt%, up to 2wt% Zn, 2.5wt% A and 1~2g/t of preciou metal, primarily Au, Pt, Pd, and O. The claic proce for molybdenum and nickel recovery i roating, melting and concentration to produce a high impurity nickel-molybdenum alloy. In the proce, ulfur dioxide (SO2) and arenic trioxide (A2O3) releae may caue eriou environmental pollution. Mineral proceing route have been propoed for the - ore[4], however, it i inefficient to enrich nickel and molybdenum through ore-dreing owing to the ore complex mineralogical characteritic. Several combined pyro-hydrometallurgical method have been propoed to recover molybdenum from the - ore, uch a roating, NaOH/Na2CO3 leaching under active oxygen condition [5], direct leaching with NaOH+Na2CO3/NaClO3 [6], direct NaOH leaching under active oxygen condition [8] and direct leaching with H2SO4 for nickel recovery only [8]. reover, direct bioleaching of molybdenum and nickel from the - ore ha been invetigated uing a molybdenum-reitant thermophilic bacterium ulfolobu metallicu, but the percentage leached i not very high and reuire further reearch[9]. In thi paper, a direct hydrometallurgical proce of extraction molybdenum and nickel from molybdenum-nickel ore by preure water leaching without reagent wa tudied. Variou characteritic of the - ore are ued beneficially and partial ulfur i tranformed into ulfuric acid under oxygen preure. The extraction of and from molybdenum-nickel ore by oxygen preure leaching, which exploit the characteritic of molybdenum-nickel mineral contain high concentration amorphou ulfide which ha highly active, and make the mot of eaily oxide to ulfuric acid and ulfate at low temperature and exce oxygen preence of the amorphou ulfide The author - Publihed by Atlanti Pre 527

2 Experimental Material The chemical compoition of - ore of black hale wa lited in Table.1. The XRD pattern of the raw - ore wa hown in Fig.1. It wa confirmed that the - ore conit crytalline pyrite [FeS 2 ], uartz [SiO 2 ], calcite [CaCO 3 ], millerite [S], elemental ulfur. ckel occur mainly a vaeite [S 2 ], millerite [S] [10-11]. Table. 1 Chemical compoition of the - ore component wt.% component wt.% V Fe S C SiO 2 Al 2 O CaO MgO P F Cu Zn Ti Pb < FeS SiO2 Intenity(count) CaCO S ----S Theta, Fig. 1 XRD pattern of the - ore The diffraction peak of the molybdenum (6.89%) wa not detected in the XRD pattern, which occur mainly due to in the form of amorphou ulfide, which wa confirmed that molybdenum primarily exit in the form of jordiite[s 2 ] in the - ore, and co-exit with clay, uartz. Experimental procedure The ample were cruhed and ball milled to 85% < mm and dried at 75 C in an oven for 24 h. Leaching experiment were conducted at an oxygen partial preure of 0.4~0.5MPa in an autoclave with 2L titanium alloy cylinder reactor. Analytical method The metal content of the raw ore ample and leaching reidue were analyzed by ICP-AES (SPECTROBLUE, Germany), and X-ray diffraction (D/max 3B, Japan) to determine the phae of molybdenum and nickel. The olution wa analyzed by atomic aborption pectrometry (WFX-110B, Beijing) to determine the content of the chemical compoition, and the ph of the leaching liuor wa meaured uing a digital ph meter (PHSJ-5D, Shanghai). 528

3 Reult and dicuion Effect of leaching time on extraction The effect of leaching time on the extraction of molybdenum and nickel wa tudied under the condition of the reaction time wa varied between 3 and 9 hour, in 2 hour interval. A hown in Fig. 2, the extraction of nickel increae trongly with the increae in leaching time from 3 to 5 hour at 150 C with a liuid to olid (L/S) ratio of 2 ml g -1, and oxygen partial preure of 0.4~0.5MPa, 97% nickel extraction wa obtained in 5 hour without ulfuric acid. Thi i probably becaue the nickel ulfide oxidize to SO 4, which diolve eaily into the acid olution under uch condition. Therefore, 5 hour i ufficient for nickel extraction. While the extraction of molybdenum increae gradually with an increae in leaching time from 3 to 5 hour, a maximum extraction of 76% i reached at 5 hour. Therefore, to obtain high nickel and molybdenum recoverie, in ubeuent experiment, the leaching time wa choen to be 5 hour Extraction/ % Leaching time/ h Fig. 2 Effect of leaching time on extraction Effect of leaching temperature The effect of temperature on molybdenum and nickel extraction wa invetigated from 105 to 165 C with ditilled water, under an oxygen partial preure of 0.4~0.5MPa, and a liuid-to-olid(l/s) ratio of 2 ml g -1 for 5 hour without ulfuric acid. It can be een from Fig. 3 that nickel extraction increae with increae in leaching temperature from 105 to 150 C. Beyond 150 C, the extraction of nickel increae lowly with an increae in temperature. lybdenum extraction increaed with increaing temperature and increaed only lightly beyond 150 C Extraction/ % Leaching temperature/ o C Fig. 3 Effect of leaching temperature on extraction 529

4 Effect of liuid-to-olid ratio on extraction The effect of liuid-to-olid ratio on molybdenum and nickel extraction wa examined at an oxygen partial preure of 0.4~0.5 MPa, and temperature of 150 C for 5 hour without ulfuric acid. A erie of experiment were carried out by varying the liuid-to-olid ratio in the range of 1.5 to 6 ml g -1. It can be een from Fig. 4 that nickel extraction decreae lightly from 98 to 96% with increaing in liuid-to-olid ratio from 1.5 to 3.0 ml/g and decreae harply with increae in liuid-to-olid ratio from 3.0 to 6.0 ml g -1. lybdenum extraction decreae lowly from 76 to 75% with increae in liuid-to-olid ratio from 1.5 to 2.5 ml g -1 and alo decreae harply with increae in liuid-to-olid ratio from 3.0 to 6.0 ml/g. The extraction of molybdenum and nickel decreae harply with increae in liuid-to-olid ratio from 3.0 to 6.0 ml g -1.Conidering variou other factor uch a agitation and pipe-line delivery in indutrial plant, in ubeuent experiment, the leaching liuid to olid(l/s) ratio wa choen to be 2 ml g Extraction/% Characterization of the leaching reidue Liuid to olid ratio/ml/g Fig. 4 Effect of liuid-to-olid ratio on extraction The acid leach reidue ued in thi tudy (compoition in Table 2) wa obtained after oxygen preure leaching. Almot all nickel and a ubtantial part of the molybdenum were leached. The leaching rate of nickel and molybdenum achieve repectively 97% and 80%. Table.2 Chemical compoition of the acid leach reidue component wt.% component wt.% V Fe S C SiO 2 Al 2 O CaO MgO P F Cu Zn Ti Pb

5 FeS2 Intenity(count) SiO O3 H2O -----CaSO Theta, Fig. 5 XRD pattern of the acid leach reidue And in the proce, 80% ulfide wa oxidized to ulfate. The X-ray diffraction pectrum of the acid leach reidue hown in Fig. 5 indicate that the amorphou phae molybdenum diulfide (S 2 ) in the - ore had changed crytalline phae to O 3 H 2 O in the preure leaching proce. Concluion Oxygen preure condition, coniderable molybdenum and almot all the nickel were extracted into olution in the leaching proce. With leaching time for 3~4h, temperature at 150, liuid-to-olid ratio of 2mL g -1, mineral granularity of 0.074mm, oxygen partial preure of 0.4~0.5MPa without other reagent, molybdenum leaching percentage can be over 80% and nickel leaching percentage can be more than 97%. Furthermore, about 80% ulfur in the - ore ha been tranformed into ulfuric acid, which provided ufficient acid for the leaching of nickel and molybdenum. Then yielding the leach liuor of 10~15g/L H 2 SO 4. Acknowledgement Thi work wa financially upported by the National Natural Science Foundation of China ( ) and Yunnan Province Applied Foundation Reearch Program of China (2014FB126). Reference [1] Jingwen Mao, Bernd Lehmann, Andao Du, Guangdi Zhang, Dongheng Ma, Yitian Wang: Economic Geology, 2002,97(5), p [2] FAN D L, ZHANG T, JIE Y, PAAVA J, KRIBEK B, DOBES P, VARRIN I, ZAK K. : Ore Geology Review, 2004, 241(1-2), p [3] BAO Zheng-xiang: Geology and Mineral Reource Reearch, 1990, 3, p [4] WANG Xu-wen, PENG Jun, WANG Ming-yu, Ye Pu-hong, The role of CaO in the extraction of and from the - ore by calcification roating, ulphation roating and water leaching[j]. International Journal of Mineral Proceing, 2011, 100, p [5] WANG Ming-yu, WANG Xue-wen, LIU Wan-li: Hydrometallurgy, 2009, 97, p [6] LIU Wei-ping, XU Hui, YANG Xi-yun, SHI Xi-chang: Mineral engineering, 2011, 24, p [7] ZHAO Zhong-wei, Li Jiang-tao, CAO Cai-fang, HUO Guang-heng, ZHANG Gang, Li Hong-gui: Hydrometallurgy, 2010, 103, p

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