Technological Research of. Multicomponent Middlings Processing. II. Technological Scheme of Sulfide. Multicomponent Middlings Leaching

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1 Contemporary Engineering Sciences, Vol. 8, 2015, no. 24, HIKARI Ltd, Technological Research of Multicomponent Middlings Processing II. Technological Scheme of Sulfide Multicomponent Middlings Leaching Denis A. Rogozhnikov Ural Federal University, Mira st. 19, , Ekaterinburg, Russia Copyright 2015 Denis A. Rogozhnikov. This article is distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Technological research carried out of sulfide multicomponent middlings leaching in nitric acid, followed by stepwise selective isolation of components from the resulting productive solution to verify and confirm the results of laboratory tests. Material and water balances were calculated. Technological scheme of multicomponent sulfide middlings in nitric acid to produce a high-quality commercial products was offered. Keywords: Technological scheme, multicomponent middlings, nitric acid, stepwise selective isolation 1 Introduction The aim of this work is to carry out technological research by stepwise selective isolation of valuable components from nitric acid leaching solutions (results were covered in the first part of research [1]) and preparation of multicomponent sulfide middlings processing technological scheme based on calculated balances [2-4]. In our previous studies a middlings nitric acid leaching of «Maykain B» were conducted [5, 6].

2 1106 Denis A. Rogozhnikov 2 Experimental Stage 2. Nitrous gases formed by the interaction of nitric acid with sulfides middlings, were withdrawn from the reactor to three series of connected Petri bottles. Petri bottles filled with water served as sorption columns with a total height of 0,5 m. Air was fed to the reactor for gas oxidation to higher oxides of nitrogen. Nitrous gases and water vapor were cooled and condensed in cooler-condenser [7-10]. After first stage absorption towers gases were directed to stage 2 consisting of sanitary bubble column packed with 30% solution of urea (carbamide). The recovered nitric acid was analyzed, and then returned to the head of the process to the leaching stage. After three cycles of leaching we reached a concentration of nitrate ions of 6,1 mol/dm 3 in the first adsorption column. The absorption degree of the waste nitrogen oxides was 90,3%. Stage 3. Further, the obtained leaching solution was fed into a glass reactor (V = 1 dm 3 ) for separation of iron in the form of insoluble chelating agent Fe3H3(ntph)2. Nitrile three methylen phosphoric acid (NTP) was fed to the reactor to achieve the ratio of metal : ligand is 3 : 2. After process completion pulp was directed to filtering. The resulting solution was fed to the next process step. The iron precipitate was washed, dried and weighed. The resulting Fe-P cake can be used as an intermediate at the iron and steel plants to produce valuable iron-phosphate ligatures. The composition of the sediment is given in Table 1. Table 1. The chemical composition of the iron-containing residue, % wt Cu Zn Fe As Pb P S Ca Mg Al 0,67 0,73 14,11 0,07 0,08 16,40 0,65 1,28 0,19 0,02 Stage 4. Copper electrowinning process was conducted in an open electrolytic cell of 1 dm 3 with the circulation of the electrolyte, which was carried out by using a Masterflex peristaltic pump, model , with electrolyte exchange rate of 1,2 dm 3 /h. The cathode was made of stainless acid-resisting steel; anode was made of platinized titanium. Electrolyte (V = 500 cm 3 ), which came to the stage of electrodeposition, contained 21,1 g/dm 3 copper, total acidity 148,4 g/dm 3. The duration of the process was 16 hours.

3 Technological research of multicomponent middlings processing 1107 Cathodic current density was A/m 2, the cell voltage was 1,8-2,4 V. The current efficiency of copper was 92%, electricity consumption was 3100 kwh/t of cathode deposit. Once the cathode deposit was washed and weighed depleted electrolyte was fed to the next process step. Stage 5. Copper residual amounts sorption extraction on an Lewatit Monoplus TP-220 ion exchange resin for removal (up to 1 g/dm 3 ) from the electrolyte was carried out. Studies were carried out in a static mode in a glass reactor (V = 1 dm 3 ). The total contact time of the resin with a solution was up to 3 days. The residual concentration of copper in the mother solution was 0,005 g/dm 3, the recovery of copper 98,91%. The copper desorption was performed by sulfuric acid with concentration of 180 g/dm 3, the total time of contact with an acid ion exchanger was 1,5 hours with periodical stirring. The copper content in the desorbate was 4,25 g/dm 3. The solution after sorption contained up to 40 g/dm 3 zinc and up to 150 g/dm 3 sulfuric acid. 3 Results and discussion The results of technological research were used to compile technological scheme of hydrometallurgical processing of multicomponent sulfide middlings (Figure 1). Figure 1. Technological scheme of multicomponent middlings processing

4 1108 Denis A. Rogozhnikov While carrying out technological studies data were received that allowed us to calculate the material and water balances of the technological scheme of multicomponent sulfide middlings processing. On the results basis specification was compiled of basic technological equipment recommended to use to create a pilot plant for processing substandard multicomponent sulphide concentrates and middlings. The installation was designed for a capacity of 15 thousand tons of raw material per year. 4 Conclusions 1. The degree of absorption of exhaust nitrous gases at nitric acid leaching has reached 90,3%. 2. The degree of extraction of iron in the sediment was 99,6%. Copper and zinc completely transferred into solution, which confirms the selectivity of the selected reagent regarding Fe. 3. At electrowinning step current efficiency was 92% copper, the electricity consumption was 3100 kwh / ton of copper cathodes. 4. After sorption residual concentration of copper in the solution was 0,005 g/dm 3, the recovery of copper 98,91%. 5. The results obtained allowed to calculate the mass balance of the proposed multicomponent sulfide middlings processing flowsheet. References [1] D.A. Rogozhnikov, Technological Research of Processing of Refractory Multicomponent Middlings I. Nitric Acid Leaching, Contemporary Engineering Sciences, [In Print], [2] K.N. Bolatbayev, Complex use of Mineral Resources State, Reserves, Priorities, KazGos INTI, [3] K. Bolatbayev, State, problems and reserves enrichment technology polymetallic raw materials, Industry of Kazakhstan, 10 (2001), [4] V.S. Kozyrev, Some Trends in the Development of Raw Material Base of Ferrous Metallurgy Capitalist and Developing Countries, Tsvetnye Metally, 1991, no. 12, [5] D.A. Rogozhnikov, S.V. Mamyachenkov, S.V. Karelov, O.S. Anisimova, Nitric acid leaching of polymetallic middlings of concentration, Russian Journal of Non - Ferrous Metals, 54 (2013), no. 6,

5 Technological research of multicomponent middlings processing 1109 [6] D.A. Rogozhnikov, S.V. Karelov, S.V. Mamyachenkov, O.S. Anisimova, Technology for the hydrometallurgical processing of a complex multicomponent sulfide - based raw material, Metallurgist, 57 (2013), no. 3-4, [7] L. M. Bogacheva, and Kh. R. Ismatov, Hydrometallurgical processing of copper-containing materials, Publications: Tashkent, [8] A. A. Locman, M. M. Karavaev, Yu. A. Ivanov, A method of nitric acid producing, Pat. RF , [9] H.M. Brennecke, O. Bergman, Nitric-sulfuric leach process for recovery of copper from concentrate, Mining Engineering, USA, 33 (1981), no. 8, [10] L.M. Sokolenko, Collection and recycling of nitrous gases, Cherkassy: NIITECHIM, Received: September 9, 2015; Published: October 12, 2015