Pyrometallurgical Research Articles

An Overview on Resource and Recovery Prospectives of the Critical Element Neodymium

AbstractNeodymium is critically scarce and is often used in supportable technologies such as permanent magnets, batteries, and catalysts. The extraction of it from virgin ores causes environmental degradation and recycling of end‐of‐life (EOL) products proves to be an alternative to meet its future criticality. From an environmental and economic point of view, magnets produced from recovered neodymium perform better than the ones produced from virgin neodymium. In this review various technologies such as hydro metallurgy, pyro metallurgy, supercritical CO2 extraction, desalination, and adsorption have been discussed for the recovery of this metal from different EOL sources. The advantages and limitations of these methods are summarized. Different experimental status like sources, temperature, aqueous phase composition, organic phase make up, and maximum recovery efficiency are also looked upon. This review may prove beneficial for the researchers to design recovery road maps under different circumstances.

Low-grade chalcopyrite ore, heap leaching or smelting recovery route?

Chalcopyrite, the major mineral source of copper, is commonly treated pyrometallurgically, using froth flotation, smelting, converting and electrorefining processes. The ore treatment however is limited to the cut-off grade concentration below which the extraction is not economically viable. In this study a comparison of feasibility of the pyrometallurgical and hydrometallurgical treatment of low grade (0.23%–0.35% Cu), high content chalcopyrite (>90% CuFeS2) ore were studied from both technical and economic viewpoints. On a technical stance, the results of a pilot test on froth flotation of 100 t of low-grade ore are presented. The pilot test results confirm the generation of a Cu concentrate of a grade range 23.3–19.6% Cu with a copper recovery in the range 90.9–78.1%. For the hydrometallurgical treatment, bio heap leaching of 40,000 t of low-grade ore using agglomeration and aeration was proven to achieve a copper recovery of 32.6% for the chalcopyrite portion of the ore over 326 days of operation.On the economic side, the operating cost of the process per tonne of copper cathode for both processes were reported. The operating cost for the pyrometallurgical (PM) processing plant was calculated to be 1.4 times less than the hydrometallurgical (HM) processing plant. The sales revenue of the PM route was also higher than that of the HM route due to the byproducts credit. Capital cost estimates were made assuming that the current solvent extraction/electrowinning (SX/EW) facilities in a HM route and the current smelting and electrorefining plants in the PM route have enough free capacity to absorb the upstream outputs. Applying the copper extraction efficiencies of the pilot plants, the profitability indicators for both routes in treatment of 3000,000 t ore/year was studied. The impact of the interest rate was found significant in economic preference of the HM route over the PM route. This is due to the high capital cost of the mineral processing plant despite of the higher operating cost of the HM plant. The capital cost of the mineral processing plant can make the HM route feasible at interest rates higher than 27.5%. At discount rates lower than 27.5%, the PM route process is viable over the HM route at copper market price of US$9500/t. A drop in copper selling price to US$6000/t acts in favor of the HM route, making it feasible at interest rates higher than 22.4%. For a general scenario where the construction of SX/EW and smelter/refinery plants are required, the discount rate at which the net present value (NPV) of the two routes are equal has decreased from 27.5% to 17%. In this scenario, for discount rates higher than 17%, the HM route with 31% total copper recovery is more feasible than the PM route with 79% recovery.

Environmentally Friendly Suspension Electrolysis Technology for Regenerating Lithium Cobalt Oxide

The extensive usage of portable electronic products and the acceleration of their replacement have led to the discarding of a growing amount of LiCoO2 batteries. It is necessary to recycle the batteries from the both viewpoints of environment and economic benefits. Current recycling approaches for LiCoO2 are dominantly based on hydrometallurgy and pyrometallurgy, which usually require multiple complicated steps and involve the use of high temperature or harmful chemicals, like acids and alkalis. There remains an urgent need for a green and simple process. In this paper, suspension electrolysis technology is proposed to recycle spent batteries, in order to achieve the leaching, purification and regeneration of LiCoO2 in one step. The most advantageous of the present technology are that reacting in one reactor at atmospheric condition and no use of highly corrosive and harmful reagents. The reaction of LiCoO2 leaching in the anode region and simultaneously re-synthesizing in the cathode region in ammonia electrochemical system is established for the first time. This work provides a promising method for recovering LiCoO2 efficiently and environmentally friendly, promoting the sustainable utilization of the resources.

Comparative Life Cycle Assessment of three Recycling Approaches for Electric Vehicle Lithium-ion Battery after Cascaded Use

With increasing concerns on environmental impacts of retired lithium-ion batteries (LIBs) and supply risk of critical materials, second life and recycling are considered as promising strategies to mitigate the environmental impacts of retired automotive LIBs. In this life cycle assessment (LCA) study, we investigate environmental benefits of second life and recycling methods on three types of widely adopted, commercialized automotive LIBs, including lithium manganese oxide (LMO), lithium nickel manganese cobalt oxide (NCM) and lithium nickel cobalt aluminum oxide (NCA). The results show that when subjected to second life, LIBs with both superior energy storage capacity and energy density generate more environmental benefits than LIBs that is less competitive in either working performance (31 % - 44 %, 16 % - 21 % and 50 % - 56 % reduction in environmental impacts). This is in line with the current trend towards the development of electric vehicles with larger energy storage capacity and longer battery life. We also found that direct cathode recycling outperforms hydrometallurgical and pyrometallurgical recycling regardless of battery chemistry. Among all recycling methods, only pyrometallurgical recycling is carbon intensive. The recovery of cathode active material and metals, including copper and aluminum, are critical to the environmental performance of batteries.

Alternative Technology of Nickel-Cadmium Batteries Recycling

The issue of operated-off alkaline nickel-cadmium batteries recycling is currently relevant due to a number of aspects: economic, environmental and social. It is most acute across the national corporation JSC Russian Railways. The article deals with some technological features of operated-off alkaline nickel-cadmium batteries recycling with valuable components being extracted (from the example of nickel-cadmium storage batteries of JSC "RZD" rolling equipment). The results of leaching in Trilon B synthetic oxides solution, the presence of which is possible in the raw material being processed, are presented in the study. Based on the study of leaching processes of CdO, NiO, FeO, Femet and Fe2O3 in Trilon B solution, the dependence of complexing on the pH of the solution was revealed. The experimental site of the hydrometallurgical processing of the research center (OCGP IC) in the GMO KhMC PJSC "Uralelectromed" was selected as the testing one for the technology proposed. As a raw material for the tests, a lot of negative lamellae packed in alkaline storage batteries of two different types were used. They were obtained as a result of preliminary drying and cutting at OOO Kursk factory "Accumulator". The particle size is 90% - 0.1 mm. The results obtained during the research allowed the author to formulate a hypothesis about the practical use of Trilon B for the processing of operated-off alkaline nickel-cadmium batteries with the extraction of valuable components having greater economic, environmental and social benefits compared to methods based on pyro metallurgy.

Status of Pyrometallurgical Treatment Technology of EAF Dust

Status of Pyrometallurgical Treatment Technology of EAF Dust

A Review of Spent Lead-Acid Battery Recycling Technology in Indonesia: Comparison and Recommendation of Environment-friendly Process

Indonesia is one of the largest recycler of Lead Acid Battery (LAB) in Asia suffering for lead contamination which is classified as one of the top poisonous heavy metal pollutant. The corresponding Issues have already caused significant public concern. This paper describes a brief overview and comparative study of some pyro metallurgy and hydrometallurgy processes by collecting data of input materials, energy consumption, environmental impact and main products. Subsequently, mass flow of lead and entire cycle of lead recovery process is calculated semi-quantitatively. According to the result, some of primary lead recycling processes can be cut off along with minimizing environmental issues due to the emission products, if the proper management of waste is implemented. This research provides a guideline for the saver life cycle of recovering lead from spent lead paste of LAB aiming to contribute for green efficient cycle of secondary lead in Indonesian Industry.

Features of Nickel-Cadmium Batteries Recycling

<div class="page" title="Page 1"><div class="layoutArea"><div class="column"><p><span>The issue of operated-off alkaline nickel-cadmium batteries recycling is currently relevant due to a number of aspects: economic, environmental and social. It is most acute across the national corporation JSC Russian Railways. The article deals with some technological features of operated-off alkaline nickel-cadmium batteries recycling with valuable components being extracted (from the example of nickel-cadmium storage batteries of JSC ”RZD” rolling equipment). The results of leaching in Trilon B synthetic oxides solution, the presence of which is possible in the raw material being processed, are presented in the study. Based on the study of leaching processes of CdO, NiO, FeO, Femet and Fe</span><span>2</span><span>O</span><span>3 </span><span>in Trilon B solution, the dependence of complexing on the pH of the solution was revealed. The experimental site of the hydrometallurgical processing of the research center (OCGP IC) in the GMO KhMC PJSC ”Uralelectromed” was selected as the testing one for the technology proposed. As a raw material for the tests, a lot of negative lamellae packed in alkaline storage batteries of two different types were used. They were obtained as a result of preliminary drying and cutting at OOO Kursk factory ”Accumulator”. The particle size is 90% - 0.1 mm. The results obtained during the research allowed the author to formulate a hypothesis about the practical use of Trilon B for the processing of operated-off alkaline nickel-cadmium batteries with the extraction of valuable components having greater economic, environmental and social benefits compared to methods based on pyro metallurgy.</span></p></div></div></div>

Use of Gases in Pyrometallurgy

Use of Gases in Pyrometallurgy

Pyrometallurgy Process for a Low Graded Gold Alloy with PbO and CaO

Pyrometallurgy Process for a Low Graded Gold Alloy with PbO and CaO

Trends of Publications and Patents on Metallic Fuel Development for Fast Reactors

Higher breeding ratio, high thermal conductivity, shorter doubling time and high plutonium production make metallic fuels a viable solution compared to oxide/nitride/carbide/silicide fuels for cost-effective commissioning of many power reactors. Metallic fuels lend themselves to compact and simplified reprocessing and re-fabrication technologies, a key feature in a novel concept for the deployment of fast reactors. Satisfactory physical and technical characteristics of fuel rods with metallic fuel have been demonstrated at high burn-ups, and comparatively easy reprocessing of spent fuel using the pyro-metallurgical method makes this fuel relevant in fast reactors development. The present work is complemented with a scientometric study.

Phase Relations, Precious Elements Distribution, and Activities in the Cu-Fe-Pb-As System Saturated with Carbon at 1473 K (1200 °C)

In order to develop a new pyrometallurgical process for the elimination of detrimental arsenic and the recovery of precious elements, such as, silver, gold, and platinum from arsenic-rich copper-lead scraps, the phase relations in the Cu-Fe-Pb-As system saturated with carbon and the distribution of precious elements between the condensed phases generated during the equilibrium at high temperature were investigated. The investigation was carried out by performing a series of laboratory scale experiments using an electrical furnace at 1473 K (1200 °C), followed by the quenching of molten samples taken on the final stage. The samples obtained from the experiments were analyzed using electron probe X-ray micro analysis, inductively couple plasma, and carbon infrared spectrometry techniques. The results were discussed on the basis of the activity coefficient of arsenic, interaction parameters of minor components, and distribution parameters for precious metals in the three equilibrated alloy phases of lead-rich, copper-rich, and iron-rich that coexists in the corresponding miscibility gap. The present results suggest that the recovery of valuable silver and gold into the copper-rich alloy and lead-rich alloy phases and the elimination of arsenic and iron into the iron-rich alloy phase might be feasible.

New Approaches on non Ferrous Metals Electrolysis

Engitec Technologies is a relatively young company active in the field of non ferrous metals recovery from diverse sources. Since the beginning, the company has studied systems based on innovative hydrometallurgical processes trying to avoid, when possible, the use of pyrometallurgical techniques.In particular, the company has developed two systems based on very different and unusual electrolytes: Fluoboric acid - for primary and secondary Pb and Cu. Ammonium chloride - for primary and secondary Zn and Pb. For the fluoboric acid system, a demo plant campaign on primary Pb concentrate was recently completed and we are currently preparing proposals for industrial plants. This electrochemical system is based on a diaphragm divided cell were Pb metal is plated at the cathode and Fe3+ is produced at the anode insteadof evolving oxygen. The Fe3+ produced is then used to leach the Pb from the mineral concentrate closing the process loop.For the ammonium chloride system, the electrolysis is run in a more traditional open cell. Unlike other chlorine electrolysis systems, this cell has no chlorine gas emissions. Instead, where chlorine is produced at the anode it is immediately converted to nitrogen by a chemical reaction with ammonia in the bulk solution. A small industrial plant was operated for several years in Italy producing Zn from electric arc furnace dust generated during the production of steel from steel scrap.In addition, we are electrowinning Pb from ammonium chloride electrolyte in a bi-polar flow cell working at 8,000-10,000 A/m2 without any need for cathode stripping. This is currently being piloted at our facility in Milan, Italy.This paper will describe these industrial electrochemical approaches in more detail.

レアメタル・白金族金属の乾式製錬とリサイクル技術

日本はレアメタル資源のほぼすべてを輸入し，ハイテク製品を大量に生産するレアメタル生産大国であると同時にレアメタルの消費大国でもある。そのため，いまや国内には膨大な量のレアメタルが製品やその廃棄物という形態で蓄積されている。これらの廃棄物は鉱物資源をほとんど持たない日本にとっては貴重な資源となり得るため，廃棄物からのレアメタルの回収技術は重要であることは論をまたない。特にレアメタルの中でも，自動車用排ガス浄化触媒や電子機器材料に欠かすことのできない白金族金属は，産出国が南アフリカとロシアに極端に偏在しており，年間産出量もレアメタルの中でも極めて少なく，供給量に制限がある。また，BRICs諸国の経済発展に伴って，白金族金属の需要はますます増加すると予想される。本稿では，世界的にも関心の高まる白金族金属のリサイクル技術について乾式製錬プロセスを用いた手法を中心にその概況を解説する。

Iron smelting in pre-colonial Zimbabwe: Evidence for diachronic change from Swart village and Baranda, northern Zimbabwe

In conventional reconstructions of southern African archaeology, the production of iron has been seen as unchanging for the last 2000 years. Significantly, this contrasts with the changes that have been noted in broader society and other classes of material culture of the same period. Despite iron being used as a chronostratigraphic indicator, virtually nothing is known on the patterns of iron production within the Iron Age and whether change in technology and the socio-cultural context of production took place. From a combined archaeological and metallurgical perspective, the historical development of iron working has never been explored. For example, it is not known whether similar types of furnaces were constantly operated throughout the last two millennia. Excavations at two sites in northern Zimbabwe, one Gokomere-Ziwa (800 - 1200 cal AD) and one Zimbabwe tradition (1500 - 1700 cal AD), have shown differences in iron pyrometallurgical debris, tentatively suggesting that they represent separate metal working practices. By comparing the archaeological and metallurgical evidence from the two sites, this paper represents an initial step in delineating patterns of indigenous iron production in one region of Zimbabwe.

Pyrometallurgical Technology for Processing Titanomagnetites from the Tebinbulak Deposit

Pyrometallurgical Technology for Processing Titanomagnetites from the Tebinbulak Deposit

A Technical and Ecomonic Suervey of Technologies for Recycling Exhausted Lead-Acid Battery

In this paper the Italian situation related to the regulation, the collection and the quantity of the exhausted lead acid batteries was examined. In 1998 Italian lead production was 210,000 tons, 90,000 of which derived from the recycling industry; this quantity was equal to 33% of the national requirement that is around 270,000 tons yearly. The quantity of exhausted lead-acid batteries collected in 1999 was 166,500 tons, equal to 95% of the total collected. The technologies of recycling allowed us to recover almost all the materials employed for their manufacture; in addition to lead, polypropylene and PVC were also recovered. In this paper the commonly used technologies of lead recovery, based on two processes: the pyrometallurgical and the electrochemical were examined from a technological, economic and environmental impact point of view. Both processes showed advantages and disadvantages, even if a general evaluation was difficult. In a global evaluation, taking into consideration the materials to recycle, the relationship between costs and benefits and the environmental implications, the available data allowed us to identify the pyrometallurgical process as that with the highest efficiency.

Prospects for the use of bubbling processes in pyrometallurgy

Prospects for the use of bubbling processes in pyrometallurgy

Book Review: Principles of Pyrometallurgy. By C. B. Alcock

Book Review: Principles of Pyrometallurgy. By C. B. Alcock

Interfacial energies in pyrometallurgical processes

AbstractThe effects of interfacial energies on foams, emulsions and the entrapment of metals in slags are reviewed and methods of measuring surface and interfacial energies are discussed. The difficulties of interfacial energy measurements are pointed out and the interfacial energy data pertinent to pyrometallurgical processes are summarized .A drop-pressure method of measuring interfacial energies is proposed and evaluated on the basis of room and high temperature measurements. The method is shown to be particularly suitable where surface and interfacial energies are to be measured under similar experimental conditions. Resume Cette etude fait a la fois la mise a jour des effets des energies interfaciales desmousses, et des dispersions en considerant les inclusions des metaux dans les laitiers, et aussides methodes de mesure de l'energie interfaciale. On fait ressortir les problemes relatifs aux measures de l'energie interfaciale incluant le relevedes donnees d' energie interfaciale relatives aux procede...