Jarosite Residue Research Articles

Understanding the Role of the Composition of Alkaline Solutions in the Hardening Behaviour of Fe-Rich Binder Based on Jarosite Residue Slag

Understanding the Role of the Composition of Alkaline Solutions in the Hardening Behaviour of Fe-Rich Binder Based on Jarosite Residue Slag

Recovery of indium from jarosite residues of zinc refinery by a hydrometallurgical process

Indium is a strategic element essential in technological development; its recovery from jarosite produced as waste in a Zn refinery operated using a hydrometallurgical flowsheet was studied. Indium content in the residue was 86 mg/kg. A laboratory optimization for the indium extraction processes was done using multifactorial regression analysis. First, the optimal leaching conditions were determined: stirring time 97.7 h; HCl concentration 6.8 M and using a ratio 9.403 g of residue per 50 mL of leaching solution obtaining 96.8% of leaching yield. Secondly, two extraction methods were evaluated, using either a solvent extraction or polymeric inclusion membranes. The proposed optimal conditions for solvent extraction are: aqueous to organic phase ratio 10; feeding phase pH 3.0, 40%(V/V) D2HEPA in kerosene and a stirring time of 4.5 min with 2 consecutive extractions resulting in 83.2% of indium recovery, giving an indium concentration of 97.1 mg/L. The optimal conditions for indium recovery using polymeric inclusion membranes are: stirring time of 3.1 h, a mass ratio of 1.44 (mD2HEPA/mPVC), a feeding phase pH = 3.0 and [HCl] 6.0 M in the re-extraction phase with 100% indium recovery and an indium concentration of 110 mg/L after ten extractions. The polymer inclusion membranes (PIMs) offer more advantages for indium recovery because of its high reusability, lower cost, simple operation process and little environmental pollution. The co-extraction of Fe(III) was minimized, reducing Fe(III) to Fe(II) using Fe° and Sn(II). A selective precipitation using ammonia was carried out to enrich and purify indium, and to recover it in solid form as indium hydroxide. The methodology proposed in this study that managed to efficiently extract In from a metallurgical waste could be the basis for developing methodologies to the extraction of In and/or other strategic elements from other metallurgical waste, given the reuse of these wastes as alternative sources of strategic elements.

Preparation of Monoclinic Pyrrhotite by Thermal Decomposition of Jarosite Residues and Its Heavy Metal Removal Performance

Jarosite residues produced by zinc hydrometallurgical processing are hazardous solid wastes. In this study, monoclinic pyrrhotite (M-Po) was prepared by the pyrolysis of jarosite residues in H2S atmosphere. The influence of gas speed, reaction temperature, and time was considered. The mineral phase, microstructure, and elemental valence of the solids before and after pyrolysis were analyzed using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. The performances of the prepared M-Po on the removal of Zn and Pb from aqueous solution were evaluated. The results show M-Po to be the sole product at the reaction temperatures of 550 to 575 °C. Most of the M-Po particles are at the nanometer scale and display xenomorphic morphology. The phase evolution process during pyrolysis is suggested as jarosite → hematite/magnetite → pyrite → pyrite+M-Po → M-Po+hexagonal pyrrhotite (H-Po) → H-Po. The formation rate, crystallinity, and surface microtexture of M-Po are controlled by reaction temperature and time. Incomplete sulfidation may produce coarse particles with core–shell (where the core is oxide and the shell is sulfide) and triple-layer (where the core is sulfate, the interlayer is oxide, and the shell is sulfide) structures. M-Po produced at 575 °C exhibits an excellent heavy metal removal ability, which has adsorption capacities of 25 mg/g for Zn and 100 mg/g for Pb at 25 °C and pH ranges from 5 to 6. This study indicates that high-temperature sulfidation is a novel and efficient method for the treatment and utilization of jarosite residues.

Fe(II)-induced transformation of Jarosite residues generated from zinc hydrometallurgy: Influence on metals behaviors during acid washing

As hazardous materials, jarosite residues pose severe challenge to the environment due to the presence of coexistent metals. Although acid washing conducted in the industrial process could recover acid extractable metals, a significant amount of strongly surface-bound, entrapped, and lattice-incorporated metals in jarosite residues could not be extracted easily. Fe(II) has received increasing attention for its effect on triggering the release of elements, as well as the transformation of Fe minerals. This study, for the first time, aims to simulate acid washing to assess the acid extractable metals (Zn, Pb, and Cu) in an actual jarosite residue with and without Fe(II)-induced transformation. Metals (i.e., Zn, Pb, and Cu) showed enhanced acid extractability in the process of 2nd acid washing after Fe(II)-induced natrojarosite transformation to goethite, especially for Pb and Cu, the highest concentrations of which were 17 and 7-time as much as those before the transformation, respectively. In addition, it has been found that metals have different behaviors during Fe(II)-induced transformation and acid washing, possibly due to their different speciation in jarosite residue. This room-temperature and impurity-free strategy of Fe(II)-induced transformation has the potential for jarosite residues treatment and metal recovery.

Comprehensive recovery and recycle of jarosite residues from zinc hydrometallurgy

In this paper, a new method for the comprehensive recovery and recycle of jarosite residues (JR) is proposed. By direct reduction followed by magnetic separation, lead, zinc and iron are separated and recovered from JR and sulfur is fixed. The non-magnetic tails (NMT) of the magnetic separation is used for removing of Cd, As and Pb heavy metal ions from acidic wastewater of zinc hydrometallurgy. Test work results showed that the volatilization rates of lead and zinc were 96.97% and 99.89%, respectively, the sulfur fixation rate with CaO was 98.91% under optimal conditions of reduced roasting at 1523 K for 60 min. A magnetic iron concentrate was obtained containing 95.68% iron at a recovery of 76.26% by grinding-magnetic separation process. The removal rates of Cd, As and Pb ions were 99.98%, 93.75% and 99.80% respectively. The content of Cd, As and Pb ions in the treated wastewater met the emission standards at 120 g/L NMT dosage and for a contact time of 90 mins. The proposed method is considered as an environmentally-friendly and efficient approach to the comprehensive recovery and recycle of JR and the removal of toxic cadmium, arsenic and lead ions from acidic wastewater of zinc hydrometallurgy.

Metal mobility and toxicity of zinc hydrometallurgical residues

About 80 % of zinc is produced by “roasting-leaching-purifying-electrodeposition”. Lead-silver and jarosite residues are generated during this process, posing a serious threat to the ecosystem and environment since it contains a lot of heavy metals such as Pb. To better understand metal mobility and toxicity of these two zinc hydrothermal residues, it was analyzed by standard leaching toxicity procedures, bioavailability test and sequential extraction procedures. The results showed that the main phases of lead-silver and jarosite residues are KFe3(SO4)2(OH)6, CaSO4·2H2O, PbSO4, Fe3O4 and ZnFe2O4. These two residues contain a high content of Fe, Pb and Zn and also a significant amount of precious metals, such as Ag and In, showing a great resource potential. Meanwhile, lead-silver and jarosite residues are classified as hazardous waste both in China and the USA since their toxicity leaching concentration of Cd, Pb and Se exceeds the threshold of 1, 5 and 1 ppm. Metals contained in these two residues could easily be released to the environment, especially Cd, Pb and Zn, though metals are mainly in the form of residual, higher than 85 %. In addition, lead-silver and jarosite residues also show a significant biohazardous potential since EDTA and DTPA extractable Zn, Pb, Mn, Cd, Cu and As of these two residues are considerably high. All these results could help the zinc manufactories, governments and also the recycling companies better understand the risk of zinc hydrometallurgical residues and urge them to hind this harm to the ecosystem, and most importantly the human being itself.

ZnFe2O4 nanoparticles imbedding in carbon prepared from leaching liquor of jarosite residue as anode material for lithium-ion batteries

ZnFe2O4 has attracted much attention as an anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity. However, the fast capacity fading and poor rate performance severely hamper its practical application. To overcome these problems, herein, ZnFe2O4 nanoparticles uniformly embedded in carbon matrix (ZnFe2O4/C composite) were fabricated by a facile chemical co-precipitation method and subsequent calcination process with leaching liquor of jarosite residue, NaCO3, and ammonium citrate as raw materials. The prepared ZnFe2O4/C composite shows superior high-rate capability (with 731 mAh g−1 at 0.5 A g−1 and 321 mAh g−1 at 10 A g−1) and excellent cycling stability (with reversible capacity of 644 mAh g−1 after 1000 cycles at 2 A g−1). Cyclic voltammetry (CV) analysis reveals significant pseudocapacitive contributions during the discharge/charge processes of ZnFe2O4/C composite. This work provides a facile, efficient, and eco-friendly strategy for the preparation of high-performance transition metal oxides electrode materials for LIBs.

The effect of pellet technology on direct reduction of jarosite residues from zinc hydrometallurgy

The effect of pellet technology on direct reduction of jarosite residues from zinc hydrometallurgy

3D hierarchical porous ZnFe2O4 nano/micro structure as a high-performance anode material for lithium-ion batteries

3D porous nano/micro ZnFe2O4 has been prepared from the leach liquor of jarosite residue via a facile chemical coprecipitation method followed by sintering at 800 °C in air atmosphere. As anode material for lithium ion batteries, the prepared ZnFe2O4 exhibits high specific capacity, excellent rate capability, and good cycling stability, which can be due to the beneficial effects of primary nanocrystals of ZnFe2O4, the unique 3D porous nano/micro structure, and the associated pseudo-capacitive behavior during discharge/charge processes.

Sulfidation and Sulfur Fixation of Jarosite Residues During Reduction Roasting

This study investigated the sulfidation and sulfur fixation of jarosite residues during reduction roasting in the presence of carbon. The effects of roasting temperature and carbon dosage were investigated based on thermodynamic calculation. The results indicated that more than 98 pct of zinc contained in the residue was converted into zinc sulfides, and more than 91 pct of sulfur was fixed in the roasted residue. Carbon addition promoted not only the sulfidation of zinc but also the fixation of sulfur, thereby eliminating SO2 emission. The growth of sulfide particles was strongly influenced by roasting temperature. The size of sulfide particles significantly increased when the temperature was above 1173 K (900 °C) because of the formation of a liquid phase during the roasting process. However, high temperature could increase the consumption of carbon powder.

Selective Metal Recovery from Jarosite Residue by Leaching with Acid-Equilibrated Ionic Liquids and Precipitation-Stripping

The recovery of valuable metals from industrial process residues is complex because those metals are often present in very low concentrations and locked in complex matrices. Hence it is important t...

Alternativna metoda za valorizaciju vrednih metala iz jarosit ostatka

Alternativna metoda za valorizaciju vrednih metala iz jarosit ostatka

Methanesulfonic acid: a sustainable acidic solvent for recovering metals from the jarosite residue of the zinc industry

Leaching the industrial jarosite residue with pure methanesulfonic acid resulted in a solid–liquid separation of iron from dissolved lead and zinc by precipitation.

Preparation of ZnFe2O4/α-Fe2O3 Nanocomposites From Sulfuric Acid Leaching Liquor of Jarosite Residue and Their Application in Lithium-Ion Batteries.

Recycling Zn and Fe from jarosite residue to produce high value-added products is of great importance to the healthy and sustainable development of zinc industry. In this work, we reported the preparation of ZnFe2O4/α-Fe2O3 nanocomposites from the leaching liquor of jarosite residue by a facile chemical coprecipitation method followed by heat treatment at 800°C in air. The microstructure of the as-prepared ZnFe2O4/α-Fe2O3 nanocomposites were characterized by X-ray diffraction (XRD), Mössbauer spectroscopy, scanning transmission electron microscope (STEM), and X-ray photoelectron spectrum (XPS). The results demonstrated that the ZnFe2O4/α-Fe2O3 composites are composed of interconnected ZnFe2O4 and α-Fe2O3 nanocrystals with sizes in the range of 20–40 nm. When evaluated as anode material for Li-ion batteries, the ZnFe2O4/α-Fe2O3 nanocomposites exhibits high lithium storage activity, superior cyclic stability, and good high rate capability. Cyclic voltammetry analysis reveals that surface pseudocapacitive lithium storage has a significant contribution to the total stored charge of the ZnFe2O4/α-Fe2O3, which accounts for the enhanced lithium storage performance during cycling. The synthesis of ZnFe2O4/α-Fe2O3 nanocomposites from the leaching liquor of jarosite residue and its successful application in lithium-ion batteries open up new avenues in the fields of healthy and sustainable development of industries.

Thermal Processing of Jarosite Leach Residue for a Safe Disposable Slag and Valuable Metals Recovery

In electrolytic production of zinc, the iron levels in the solutions are controlled by precipitation of jarosite or goethite. These precipitates also co-precipitate unrecovered valuable metals (Zn, Pb, Cu, Ag) as well as elements of concern (As, Cd, Hg). After stabilization, the residues are traditionally landfilled. This work investigates pyrometallurgical treatment of jarosite residue to convert the material into reusable clean slag and to recover the valuable metals within the residue. The pyrometallurgical treatment is divided into two functional steps. First, the material is melted in an oxidizing atmosphere, after which the oxide melt is reduced to produce an inert, clean slag. Then, a liquid metal or speiss phase collects the valuable metals, such as silver. The aim was to examine the optimal process conditions for reaching the target values for remaining metals in the slag; Pb < 0.03 wt %, Zn < 1 wt %. As a conclusion, the limiting factor in sulfur, lead, and zinc removal is the contact between the oxidizing or reducing gas and the molten sample. The mass transfer and volatile metals removal were significantly improved with a gas lance installation. The improved gas-liquid interaction enabled the first steps of gas flow rate optimization and ensured the sufficiently low end-concentrations of the aforementioned elements.

New pyrometallurgical route for separation and recovery of Fe, Zn, In, Ga and S from jarosite residues

This paper developed a new pyrometallurgical route for separation and recovery of Fe, Zn, In, Ga and S from hazardous jarosite residues based on the understanding of the thermal decomposition and desulfurization of jarosite and its importance to the subsequent separation and recovery of metal elements. The main steps in the proposed process included preliminary roasting of jarosite residue for dehydration and desulfurization, reductive roasting for selective volatilization of Zn and In, and smelting for producing Fe, Ga-bearing alloy and clean slag. To achieve this goal, the residual S content of the jarosite residue in principle should be less than 1.3%, which was usually attainable by pre-roasting at high temperatures of above 1200 °C. In this case, more than 99% Zn and about 85% In were volatilized with reductive roasting of the pre-desulfurized jarosite residue at 1200 °C for 70 min, while more than 93% Fe and 90% Ga were finally recovered in the alloy when smelting the reduced jarosite residue at 1500 °C for 20 min with a slag binary basicity of 0.8. Meanwhile, a clean slag was obtained which were believed to be safe for storage or potentially used as construction materials.

A cleaner process for valuable metals recovery from hydrometallurgical zinc residue

Most of hydrometallurgical zinc residues were stored in slag dump and unprocessed worldwide. Heavy metal and acid contained in these residues can be dissolved in rain water and then transfer to soil and groundwater system whereas threatening the health of aquatic systems and ecosystem. In this work, an innovative slag cleaning technique (reducing-matting smelting-thermal decomposition reduction) was proposed to harmlessly co-treat jarosite residue and lead silver residue, which can avoid environmental pollution and at the same time, effectively recover the valuable metal. Thermodynamic analysis and experimental results indicated that reducing atmosphere was a significant smelting parameter for recovery of valuable metal. Sulfur contained in various residues can be fixed in the form of solid sulfide (ferrous matte) without generation and emission of SO2(g). Moreover, the matte product is a good collector for silver collection. In addition, various smelting parameters were investigated in detail to detect and obtain the smelting optimum condition: 12% coke addition, FeO/SiO2 = 1.6, CaO/SiO2 = 0.4, smelting temperature 1300 °C and smelting time 2.5 h. Under these smelting condition, the recovery of Cu, Zn, Pb and Ag can reach 98.82%, 98.84%, 90.35% and 97.17%. The feasibility and reliability of this innovative process were confirmed. The main phases in the slag are CaFe·2SiO2,NaCaAlSi2O7 and silicate. It can be used in cement production so that the secondary pollution of slag can be avoided. Copper matte is comprised of FeS, Cu10(Pb,Fe)S6,Cu5FeS6 and Fe9S11. Ag is inlaid in copper mattes in the form of silver particles.

Thermodynamic Considerations for a Pyrometallurgical Extraction of Indium and Silver from a Jarosite Residue

Indium and silver are technologically important, critical metals, and in the majority of cases, they are extracted as a by-product of another carrier metal. The importance of indium has seen recent growth, and for technological reasons, these metals can be found in industrial residues from primary zinc production, such as the iron precipitate—jarosite. To secure the supply of such metals in Europe, and with the idea of a circular economy and the sustainable use of raw materials, the recycling of such industrial residues is coming into focus. Due to the low value of jarosite, the focus must lie simultaneously on the recovery of valuable metals and the production of high-quality products in order to pursue an economical process. The objective of this article is to give the fundamentals for the development of a successful process to extract the minor elements from roasted jarosite. As such, we use thermodynamic calculations to show the behavior of indium and silver, leading to a recommendation for the required conditions for a successful extraction process. In summary, the formation of chlorine compounds shows high potential to meet the challenge of simultaneously recovering these metals together with zinc at the lowest possible energy input.

Comprehensive recovery of lead, zinc, and iron from hazardous jarosite residues using direct reduction followed by magnetic separation

Lead, zinc, and iron were recovered from jarosite residues using direct reduction followed by magnetic separation. The influence of the coal dosage, reduction temperature, and reduction time on the volatilization rates of lead and zinc and the metallization rate of iron were investigated. The results show that the volatilization rates of lead and zinc were 96.97% and 99.89%, respectively, and the iron metallization rate was 91.97% under the optimal reduction roasting conditions of a coal dosage of 25.0wt% and reduction roasting at 1250°C for 60 min. The magnetic concentrate with an iron content of 90.59wt% and an iron recovery rate of 50.87% was obtained under the optimum conditions in which 96.56% of the reduction product particles were smaller than 37 μm and the magnetic field strength was 24 kA/m. Therefore, the results of this study demonstrate that recovering valuable metals such as lead, zinc, and iron from jarosite residues is feasible using the developed approach.

Study on recovery of lead, zinc, iron from jarosite residues and simultaneous sulfur fixation by direct reduction

Study on recovery of lead, zinc, iron from jarosite residues and simultaneous sulfur fixation by direct reduction