Recycling of bismuth oxides

OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 23 No. 3 2021 Recycling of bismuth oxides Alexey Korolev 1, a , Sergey Sergeichenko 1, b , Konstantin Timofeev 2, с , Gennady Maltsev 1, d , Roman Voinkov 1, e 1 JSC “Uralelektromed”, 1 Prospect Uspensky, Verkhnyaya Pyshma, 624091, Russian Federation 2 «UMMC-Holding Technical University», 3 Prospekt Uspensky, Verkhnyaya Pyshma, 624091, Russian Federation a https://orcid.org/0000-0002-0338-9774, A.Korolev@elem.ru , b https://orcid.org/0000-0002-3786-7957, sesv@elem.ru, c https://orcid.org/0000-0002-9525-6476, K.Timofeev@elem.ru , d https://orcid.org/0000-0002-0750-0070, mgi@elem.ru , e https://orcid.org/0000-0001-6697-1596, R.Voinkov@elem.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2021 vol. 23 no. 3 pp. 155–165 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2021-23.3-155-165 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 17 June 2021 Revised: 28 June 2021 Accepted: 17 August 2021 Available online: 15 September 2021 Keywords : Bismuth oxides Throttles Bismuth lead Charge Chalcogen Rough bismuth Restorative melting ABSTRACT Introduction. The paper is devoted to the creation of an environmentally safe, technologically efficient and cost-effective high-performance integrated scheme for the recycling of lead-containing industrial products and waste, in particular, bismuth oxides and drosses formed during the melting of copper-electrolyte sludge, with the production of commodity monoelement products. To solve the problem, a combined technology is used, which is based on hydrometallurgical operations that allow separating chemical elements with similar properties with high extraction into finished products. The aim of the work is to study and develop fundamental approaches and rational integrated technologies for recycling bismuth drosses and oxides-industrial products of refining rough lead, using reducing melts of raw materials and bismuth-enriched sludge, electrolysis of bismuth lead to obtain rough bismuth containing ≥ 90 % Bi with its direct extraction of ≥ 70 %. Methods and approaches : melting at a temperature of 1,100…1,150 o C a charge of optimal composition containing bismuth oxides, sodium carbonate, silicon dioxide and carbon. Novelty: a decrease in the content of noble metals and accompanying chalcogenes in secondary copper- containing raw materials with an increase in the amount of impurity elements. Results and discussion : joint melting (1,100…1,150 °C) of bismuth oxides, sodium carbonate, silicon dioxide and carbon, taken in the mass ratio 100 : (15‒66) : (11‒25) : (5‒7), allows to transfer 89.0 – 93.6 % of bismuth and 99.5 ‒ 99.7 % of lead from the initial oxides to bismuth lead containing ~7 % Bi and ~80 % Pb. The main phase of the Pb-Bi alloy is elemental lead. The increased flux consumption leads to an increase in the amount of recycled silicate slags that are poor in target metals, into which it passes,%: 1.4 Bi; 2 Pb; 47 Zn; 23 Sb; 33 Sn. Main slag phases are following: Na 2 CaSiO 4 , Na 4 Mg 2 Si 3 O 10 , MgO, Pb, ZnS, PbS. The practical relevance is determined by the optimal mode of reducing melting of bismuth oxides (100 %) to obtain lead bismuth, %: 66 Na 2 CO 3 , 25 SiO 2 , 5 C; the process temperature is 1,150 ° C. The presence of impurities makes it necessary to introduce reagent treatment of lead bismuth into the technological scheme for recycling bismuth oxides. Decontamination and alkaline softening will make it possible to obtain a Pb-Bi alloy suitable for pyroelectrometallurgical recycling. For citation: Korolev A.A., Sergeichenko S.V., Timofeev K.L., Maltsev G.I., Voinkov R.S. Recycling of bismuth oxides. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2021, vol. 23, no. 3, pp. 155–165. DOI: 10.17212/1994- 6309-2021-23.3-155-165. (In Russian). ______ * Corresponding author Maltsev Gennady I. , D.Sc. (Engineering), Associate Professor JSC “Uralelektromed”, 1 Prospekt Uspensky, 624091, Verkhnyaya Pyshma, Russian Federation Tel.: 8 (922) 144-60-65, e-mail: mgi@elem.ru Introduction Reducing the amount of conditioned raw materials for non-ferrous metallurgy stimulates the devel- opment of cost-effective technologies for the extraction of non-ferrous and rare metals from intermedi- ate products and industrial waste to obtain marketable products [1–5]. Non-ferrous Alloys Production Branch of JSC “Uralelektromed” applies Betterton-Kroll process at one of the rough lead pyrometal- lurgical refining stages. Betterton-Kroll process is used to remove bismuth from lead by calcium and