Clean recovery process of bismuth from secondary sources and use

Abstract

The invention that generated this patent application concerns a process for the clean recovery of bismuth from secondary sources. This process involves the acid leaching of secondary sources, such as fusible plugs from gas cylinders, and the use of an aqueous two-phase (ABP) system for the sequential extraction of bismuth, recovering it with high purity. The developed process can be used by different industries, increasing sustainability and reducing the environmental impact of bismuth extraction from natural sources.

Description

Descriptive report PROCESS FOR CLEAN RECOVERY OF BISMUTH FROM SECONDARY SOURCES AND USE Field of Invention 01. The invention that gave rise to this patent application relates to a process for the clean recovery of bismuth (Bi) from secondary sources. This process involves the acid leaching of secondary sources, such as fusible plugs from gas cylinders, and the use of an aqueous two-phase system (ATPS) for the sequential extraction of bismuth, recovering it with high purity. 02. Bi is used in the cosmetics industry as a pigment for lipsticks, blush, and eyeshadows; in medicine as a medication in the treatment of cancer and stomach upset; and in the preparation of metal alloys. Thus, the developed process is important for increasing the sustainability of these industries by reducing the environmental impact of bismuth extraction from natural sources. State of the Art 03. The process presented here uses a biphasic aqueous system (BAS), which allows the recovery of bismuth from discarded material, increasing the shelf life of this raw material. This provides better use of natural resources, as it avoids the extraction of bismuth from natural sources. Bismuth is strategic due to its low toxicity. Therefore, it is used in the cosmetics industry as a pigment for lipsticks, blush, and eyeshadows; in medicine as a medication in the treatment of cancer and stomach upset; and in the preparation of metal alloys. Petition 870180140970, dated 10 / 15 / 2018, page 14 / 27 2 / 12 such as, for example, Wood's alloy, which is composed of bismuth, lead, tin, and cadmium. Thus, the developed process is important for increasing the sustainability of these industries by reducing the environmental impact of bismuth extraction from natural sources and using a new environmentally safe extraction process, which utilizes the aqueous two-phase system. 04. The SAB is sustainable because it is mainly composed of water, and its other components are biodegradable and non-toxic (salts, ionic liquids, macromolecules). Furthermore, the SAB offers economic advantages because the reagents are low-cost and can be reused, and the rapid phase separation minimizes operating time. 05. O SAB tem sido aplicado com sucesso na extração de diferentes analitos como fenóis (RODRIGUES et al., A green and sensitive method to determine phenols in water and wastewater samples using an aqueous twophase system, 2010),( PI10010670), biomoléculas (ASENJO; ANDREWS, Aqueous two-phase systems for protein separation: Phase separation and applications, 2012; EVERBERG et al., Isolation of Escherichia coli inner membranes by metal affinity two-phase partitioning, 2006; SHAHRIARI et al., Measurement of partition coefficients of β-amylase and amyloglucosidase enzymes in aqueous two-phase systems containing poly(ethylene glycol) and Na2SO4 / KH2PO4at different temperatures, 2010), nanopartículas (BENAVIDES et al., Extraction and Purification of Bioproducts and Nanoparticles using Aqueous Two-Phase Systems Strategies, 2008), corantes (MAGESTE et al., Aqueous two-phase systems: An efficient, environmentally safe and economically viable method for purification of natural dye carmine, 2009, and Thermodynamics and optimization of norbixin transfer processes in aqueous biphasic systems formed by polymers and organic salts, 2012) e metais (DA CUNHA et al., Green recovery of mercury from domestic and industrial waste, 2016; DE LEMOS et al., Copper recovery. Petição 870180140970, de 15 / 10 / 2018, pág. 15 / 27 3 / 12 from ore by liquid-liquid extraction using aqueous two-phase system, 2012, and Green separation of copper and zinc using triblock copolymer aqueous two-phase systems, 2013; DE OLIVEIRA et al., Green selective recovery of lanthanum from Ni-MH battery leachate using aqueous two-phase systems, 2017; DURÁN et al., Mechanism of gold (III) extraction using a novel ionic liquid-based aqueous two phase system without additional extractants, 2016; LACERDA et al., Separation of Cd and Ni from Ni-Cd batteries by an environmentally safe methodology employing aqueous two-phase systems, 2009; LEITE et al., Hydrometallurgical separation of copper and cobalt from lithium-ion batteries using aqueous two-phase systems, 2017; PATRÍCIO et al., Application of aqueous two-phase systems for the development of a new method of cobalt(II), iron(III) and nickel(II) extraction: A green chemistry approach, 2011; and Chromium speciation using aqueous biphasic systems: Development and mechanistic aspects, 2016; RODRIGUES, et al.,. Application of hydrophobic extractant in aqueous two-phase systems for selective extraction of cobalt, nickel, and cadmium (BR1020120091631). The efficient extraction / separation of such varied analytes has been possible because the preferential transfer of the analyte to one of the phases of the aqueous two-phase system (ASS) is governed by the nature of the analyte and its specific interactions with the components of each phase. Thus, each successful application of the ASS is the result of a rigorous study of the appropriate analytical conditions (type and concentration of the components forming the ASS, temperature, pH, use of extractant, etc.) that allows the development of an efficient separation / extraction process for a given analyte. 06. Several studies have reported the ability of SAB to extract and separate metallic ions (DA CUNHA et al., Green recovery of mercury from domestic and industrial waste, 2016; DE LEMOS et al., Copper recovery from ore by liquid-liquid extraction using aqueous two-phase system, 2012, and Petition 870180140970, dated 10 / 15 / 2018, page 16 / 27 4 / 12 Green separation of copper and zinc using triblock copolymer aqueous twophase systems, 2013; DE OLIVEIRA et al., Green selective recovery of lanthanum from Ni-MH battery leachate using aqueous two-phase systems, 2017; DURÁN et al., Mechanism of gold (III) extraction using a novel ionic liquid-based aqueous two phase system without additional extractants, 2016; LACERDA et al., Separation of Cd and Ni from Ni-Cd batteries by an environmentally safe methodology employing aqueous two-phase systems, 2009; LEITE et al., Hydrometallurgical separation of copper and cobalt from lithium-ion batteries using aqueous two-phase systems, 2017; PATRÍCIO et al., Application of aqueous two-phase systems for the development of a new method of cobalt(II), iron(III) and nickel(II) extraction: A green chemistry approach, 2011; and Chromium speciation using aqueous biphasic systems: Development and mechanistic aspects, 2016; RODRIGUES et al., Application of hydrophobic extractor in two-phase aqueous systems for selective extraction of cobalt, nickel and cadmium 2013), as well as some patent documents PI 1107480-9, BR 10 2012 023181 6, BR 10 2015 011559 8, BR 10 2015 032500 2. 07. These studies and patent documents have demonstrated that it is not possible to predict which specific metal ion will be successfully extracted and under what specific conditions, hence the novelty of the developed process. To date, no other aqueous two-phase system has been used for the recovery of bismuth from secondary or even primary sources. 8. Bismuth recovery can be carried out through a hydrometallurgical process. This process comprises three stages: i) treatment of the metal source with acids (nitric, sulfuric or hydrochloric) for its solubilization; ii) bismuth separation process (chemical precipitation, adsorption, solvent extraction or electrolysis); and iii) electrodeposition to obtain metallic bismuth with high purity. Petition 870180140970, dated 10 / 15 / 2018, page 17 / 27 5 / 12 9. Several studies have been published emphasizing the bismuth separation step. One of the separation techniques investigated is solvent extraction. (BALMFORTH; LEESE; TASKER, Applications of selective solvent extractors in waste minimization and metal recovery, 1996; MANE; ANUSE, Studies on liquid-liquid extraction and recovery of bismuth (iii) from succinate media using 2-octylaminopyridine in chloroform, 2008; YANG; YANG; et al., Solvent separation extraction of bismuth and molybdenum from a low-grade flotation concentrator, 2009;Although solvent extraction is efficient for separating bismuth from concomitant metals, it uses organic solvents, which are highly impactful on the environment and health due to their high toxicity (causing cancer) and flammability. 10. Another technique for separating bismuth is chemical precipitation. It uses different reagents which can be salts, acids, or bases. The use of such reagents can increase the costs and / or toxicity of the process, depending on the reagent used. Furthermore, precipitation normally requires more time for the complete separation of bismuth from its concomitants, which also burdens the process (KIM; WANG, Bismuth recovery from hydrochloric acid solution, 2008; ZHANG et al., Recovery of bismuth and antimony metals from pressure-leaching slag, 2012; CHEN et al., Recovery of bismuth and arsenic from copper smelter flue dusts after copper and zinc extraction, 2012; JEON; ALORRO, Separation of Sn, Bi, Cu from Pb-free solder paste by ammonia leaching followed by hydrochloric acid leaching, 2017; Petition 870180140970, dated 10 / 15 / 2018, page 18 / 27 6 / 12 11. Liquid membranes have also been applied for the separation of bismuth (JEON; YOO; ALORRO, Separation of Sn, Bi, Cu from Pb-free solder paste by ammonia leaching followed by hydrochloric acid leaching, 2017; REYES-AGUILERA et al., Supported liquid membranes (SLM) for recovery of bismuth from aqueous solutions, 2008; MOKHTARI; POURABDOLLAH, Emulsion liquid membrane for selective extraction of bismuth from nitrate medium, 2013). However, it is well known that liquid membranes do not possess great physical stability. Furthermore, the efficiency of the membranes is compromised with an increase in the number of utilization cycles. 12. Other studies use functionalized or impregnated resins (BELKHOUCHE; DIDI, Extraction of Bi(III) from nitrate medium by D2EHPA impregnated onto Amberlite XAD-1180, 2010; CAMPOS et al., Bismuth recovery from acidic solutions using Cyphos IL-101 immobilized in a composite biopolymer matrix, 2008; NAVARRO et al., Bismuth(III) recovery from hydrochloric acid solutions using Amberlite XAD-7 impregnated with a tetraalkylphosphonium ionic liquid, 2014). However, in this separation process, the leaching of the extractant by the percolated solutions reduces the number of cycles and the efficiency of the resins. 13. In addition to the pyrometallurgical process, other processes such as electrolysis and smelting have also been used for bismuth recovery. However, these processes consume a high amount of energy, thus impacting the environment (ZERTOUBI; CHATELUT; VITTORI, Electrochemical recovery of bismuth in acidic media using a niobium electrode, 1993; YANG; TANG; et al., The separation and electrowinning of bismuth from a bismuth glance concentrate using a membrane cell, 2009; HE et al., Separation of bismuth from a bismuth glance concentrator through a low-temperature roughing process, 2013; Petition 870180140970, dated 10 / 15 / 2018, p. 19 / 27 7 / 12 as a powder from acidic sulfate effluents using an emew® cell, 2015; KOO; HONG; LEE, Recovery of bi and sb from copper spent electrolytes by electrowinning method, 2015; HA et al., Selective leaching and recovery of bismuth as Bi2O3 from copper smelter converter dust, 2015; LIN et al., Onestep extraction of bismuth from bismuthinite in sodium carbonate-sodium chloride molten salt using ferric oxide as sulfur-fixing agent, 2016; PENG et al., The Recovery of bismuth from bismuthinite concentrate through membrane electrolysis, 2017). 14. Although the aforementioned processes show good bismuth recoveries, they present several disadvantages as described above. In contrast, the process that is the subject of this patent application overcomes these disadvantages because it uses a two-phase aqueous system. This system is characterized by being composed mainly of water, with its other constituent components (polymers and inorganic salts) being non-toxic and non-flammable, making it an environmentally safe extraction system. It is also economically viable because its constituents are commercially accessible and low-cost. 15. A search of patent databases revealed documents CN105543479 and CN102586627, which report the recovery of bismuth using energy-intensive methods such as electrolysis, pyrometallurgical smelting, electrodeposition, among others. Patent documents CN101760612, JP2013155432, CN101082084, and JP2017066520 use precipitation as a process for metal recovery, often requiring the incorporation of different reagents, increasing costs. These separation processes have two main disadvantages: i) energy consumption, as they use high temperatures; ii) time-consuming, as it is necessary to wait more than 24 hours to separate bismuth from concomitant metals. Patent document JP2006089809 uses commercially functionalized resins that, in addition to... Petition 870180140970, dated 10 / 15 / 2018, page 20 / 27 While 8 / 12 methods have a high cost, they also present the disadvantage of leaching the extractant by the percolated solutions, which reduces the number of resin utilization cycles with good extraction efficiency. Patent documents CN103484694, CN106086935, CA2167026, and JP2010196140 deal with the recovery of bismuth from copper refining waste and therefore have no proven applicability to other types of samples. Patent document CN101289710 deals with the recovery of bismuth from ores. Documents CN103334018, CN105420508, and CN101831551 deal with methods applied to lead processing waste, which are also not applicable to samples with different compositions, since many of these lead wastes have bismuth contents close to 0.02%. 16. All patent documents found describe processes different from the process that is the subject of the current patent application, since the current process uses a two-phase aqueous system capable of recovering bismuth with high purity from secondary sources. 17. The present patent application aims to propose a new environmentally safe, low-cost and efficient process for the recovery of bismuth from secondary sources, such as gas cylinder plugs, employing a two-phase aqueous system without the use of extractant. Among the advantages offered by this process are: i) recycling of bismuth from waste materials for its subsequent reincorporation into production chains; ii) use of a method that does not use organic solvents; iii) low cost; iv) extraction efficiency; v) selectivity; and vi) short extraction time. Description of the Invention Petition 870180140970, dated 10 / 15 / 2018, pp. 21 / 27 9 / 12 18. This patent application describes a process developed for the selective extraction of bismuth from secondary sources, such as gas cylinder plugs, using a two-phase aqueous system without the use of an extractant. 19. The process utilizes a two-phase aqueous system consisting of L35 triblock copolymer, ammonium nitrate, and water at pH between 1.0 and 7.0 at a tie line length (TLL) of 50.95% (w / w). 20. Samples from secondary sources, such as gas cylinder plugs, are leached with 5.0 to 7.0 mol L-1 nitric acid until complete dissolution of the alloy, followed by filtration of the solid residue. A solid-to-liquid ratio (S:L) was established at 1:3. 21. The SAB L35 + NH4NO3 + H2O is prepared inside a centrifuge tube by mixing appropriate masses of the components (L35, NH4NO3, H2O and acidic sample solution from secondary sources) in order to obtain a CLA composition of 50.95% (m / m). 22. The tubes are manually shaken for 3 to 5 minutes, centrifuged to facilitate phase separation, and then left at 25-30°C to reach thermal equilibrium. This procedure is repeated at all stages of SAB formation. After this procedure, the bismuth is concentrated in the macromolecule-rich phase (MRP) of the formed SAB. 23. Subsequently, a sequential extraction solution (SES) containing the same composition but free of bismuth (Bi) is prepared and used for sequential extraction, as bismuth recovery is performed in three extraction steps. The upper phase of the first SES containing Bi is divided into two equal portions and placed in contact with an equal mass of electrolyte-rich phase (ERP) from the bismuth-free SES, thus forming the second SES containing Bi. The MRP of the second SES containing Bi is again divided into two portions and Petition 870180140970, dated 10 / 15 / 2018, pages 22 / 27 10 / 12 mixed with an equal mass of FRE from the Bi-free SAB to form the third SAB, where finally high-purity bismuth is obtained. Demonstration Experiment: Bismuth Recovery from a Fusible Plug of a Gas Cylinder 24. The procedure for preparing the fusible plug sample involved weighing the clean, dry plug. The plug had a mass of 12.179 g. Subsequently, the plug was placed inside a 500 mL Teflon beaker, and then 39.7 mL of a 7.0 mol L⁻¹ HNO₃ solution was added. The solution was left to stand for 80 minutes to allow the reaction to occur. After this period, the resulting solution was filtered, the solid material was dried and weighed, yielding a mass of 4.676 g. Thus, the mass corresponding to the Wood's alloy inside the plug was 7.503 g, meaning the Wood's alloy was completely dissolved. The filtrate containing the alloy in solution was designated leachate and was stored in a polypropylene container under refrigeration. The leachate had a density of 1.41 g mL⁻¹. 25. Bismuth recovery was carried out in three extraction steps. In the first, 4.21 g of leachate, 4.20 g of L35, 4.93 g of NH4NO3 and 1.75 g of H2O (pH = 1.0) were added to a test tube in order to obtain a biphasic aqueous system with a tie-line length (TLL) of 50.95% (w / w). Another test tube was prepared by adding exactly the same masses of L35, NH4NO3 and H2O (pH = 1.0), only replacing 4.21 g of leachate with 4.21 g of 7.0 mol L-1 HNO3 solution; this test tube was designated as the blank. The tubes were manually shaken for 3 min, centrifuged at 3000 g for 15 min, and left at 25 °C for 10 min, obtaining a bioassay containing Bi (BA) (BA1) and a blank BA. In the second step, 3.75 g of the biofilm formula from BA1, containing bismuth, was transferred to a new... Petition 870180140970, dated 10 / 15 / 2018, pages 23 / 27 11 / 12 centrifuge tube. Then, 3.75 g of FRE from the blank SAB was added. The tube was manually shaken for 3 min, centrifuged at 3000 g for 15 min, and left at 25 °C for 10 min, forming SAB2. Finally, in the third step, 1.9 g FRM of SAB2, containing bismuth, was transferred to a centrifuge tube. Then, 1.9 g of FRE from the blank SAB was added. The tube was shaken for 3 min, centrifuged at 3000 g for 15 min, and left at 25 °C for 10 min, obtaining SAB3. 26. To verify the efficiency of the Bi recovery process using SAB L35 + NH4NO3 + H2O, from samples of fusible gas cylinder plugs, the procedure was applied to the leachate obtained from a plug sample. After the three extraction steps proposed in this patent application, the separation of lead, copper, and tin from bismuth was achieved. A recovery of 62.5 g of bismuth per 1.00 kg of wood alloy from the plug was obtained, with a purity of 94.8%. Table 1. Concentrations of metals added in SAB1 and recovered in the upper phase of SAB3 L35+NH4NO3+H2O, and percentage of extraction of each metal after the 3 sequential extractions. Metal Concentration of metal added in SAB1 / 102 (mg kg-1) Concentration of metal recovered in upper phase / 102 (mg kg-1) %E Bismuth 75.6±0.2 46.7±1.2 61.8±2.1 Lead 61.1±0.1 1.37±0.04 2.24±0.07 Copper 347±1 2.12±0.15 0.610±0.045 Cadmium 21.4±0.0 0.207±0.019 0.960±0.087 Tin 0.654±0.001 0 0 Conclusion Petition 870180140970, dated 10 / 15 / 2018, pages 24 / 27 12 / 12 27. This patent application proposes the use of an alternative technique to conventional techniques for extracting bismuth, using a two-phase aqueous system that does not use organic solvents, and also presents high efficiency, low cost, simplicity of operation and speed in extraction. 28. The recovery of bismuth from a fusible plug sample from gas cylinders composed of bismuth, cadmium, lead, and tin (Wood alloy) and coated with copper was successfully carried out using the SAB formed by the macromolecule L35, ammonium nitrate electrolyte, and water at pH = 1.0 and in the absence of any extractant. After complete extraction, it was possible to recover 62.5 g of bismuth per 1.00 kg of Wood alloy in the plug, with a purity of 94.8%.

Claims

1. CLEAN BISMUTH RECOVERY PROCESS characterized by comprising the following steps: - Leaching of samples from secondary sources, Wood's metal alloy, with 5.0 to 7.0 mol L-1 (1:3) nitric acid until complete dissolution of the alloy, acid leachate from the sample; - Filtration of the solid residue; - Preparation of the aqueous two-phase system, SAB poly(ethylene oxide)11poly(propylene oxide)16-poly(ethylene oxide)11, L35, + NH4NO3 + H2O, referred to as the first SAB, mixing masses of the components L35, NH4NO3, H2O and acid leachate from the sample in order to obtain the composition equivalent to the tie line length, CLA = 50.95% (m / m); - Preparation of bismuth-free SAB with the same composition as the SAB containing bismuth, CLA = 50.95% (w / w); - Collection of the upper phase, FS, of the first SAB and mixing with an equal mass of the lower phase, FI, of the bismuth-free SAB, forming the second SAB;- Collection of the FS from the second SAB and mixing with an equal mass of FI from the bismuth-free SAB, forming the third SAB; - Obtaining bismuth from the FS of the third SAB separated from concomitant metals.

2. CLEAN BISMUTH RECOVERY PROCESS, according to claim 1, characterized by comprising a two-phase aqueous system consisting of L35 triblock copolymer, ammonium nitrate, water and acid leachate from the sample with pH values ​​between 1.0 and 7.0; in a tie line length, CLA, of 50.95% (w / w).

3. Use of the aqueous two-phase system defined in claim 2, characterized by being for obtaining bismuth from secondary sources, Wood's metallic alloy.