Zinc Ore Research Articles

The Effect of Various Parameters in the Sulfuric Acid Leaching of Low Grade Zinc Oxide Ore of Niğde-Türkiye

The aim of this study was to investigate the main parameters affecting the leaching of low grade zinc oxide ores with sulfuric acid. The influence of leaching time (5 to 480 minutes), sulfuric acid concentration (25 to 125 g/L), leaching temperature (25 to 90 °C), particle size (-104 µm, -82 µm, -60 µm, -49 µm) and solid/liquid ratio (1/10, 1/7.5, 1/5, 1/4) was investigated. The effects of these process parameters were studied with to achieve maximum zinc extraction with minimum iron extraction and acid consumption. The optimum parameters for sulfuric acid leaching of zinc ore were determined to be 60 min leaching time, 75 g/L sulfuric acid concentration, 80 oC leaching temperature, 1/10 solid/liquid ratio and -60 µm particle size. Under these optimum conditions, Zn extraction (%), Fe extraction (%) and acid consumption (ton H2SO4/ dissolved ton Zn) were obtained 88.68%, 25.83% and 5.47 ton H2SO4/ dissolved ton Zn respectively.

Cadmium Minimization in Grains of Maize and Wheat Grown on Smelting-Impacted Land Ameliorated by Limestone.

Cadmium (Cd) contamination in agricultural soils has emerged as a significant concern, particularly due to its potential impact on plant-based food. Soil pH reductions can exacerbate Cd mobility, leading to excessive accumulation in crops. While liming has been demonstrated as an effective method to mitigate Cd accumulation in rice grains in acid soils of southern China, its efficacy in remediating acid soils in northern China remains unclear. In this study, a multi-year field experiment was conducted on farmland impacted by zinc ore smelting at coordinates of 33.92° N 112.46° E to investigate the use of limestone for controlling Cd accumulation in wheat and maize grains. The results indicated that applying 7.5 t ha-1 of limestone significantly raised the soil pH from 4.5 to 6.8 as anticipated. Different rates of limestone application (2.25, 4.45, and 7.50 t ha-1) reduced Cd bioavailability in the soil by 20-54%, and Cd accumulation in wheat grains by 5-38% and maize grains by 21-63%, without yield penalty. The remediation effects were sustained for at least 27 months, highlighting limestone as a promising ameliorant for smelting-affected farmland in northern China.

Kill two birds with one stone: Efficient leaching of germanium and recovery of lignite from germanium-rich lignite by thionyl chloride

Germanium, a critical metal, is predominantly located in lignite and lead–zinc ore. The germanium was commonly extracted from the fly ash of germanium-rich lignite (GRL), however, facing the challenges of specific combustion conditions, low lignite’s thermal efficiency and value, high CO2 emissions, and waste acid treatment. Therefore, in this work, a novel method for directly leaching germanium from the GRL was proposed, facilitating low-carbon extraction under mild conditions, and reducing lignite loss during leaching process. Results showed that leaching germanium from the GRL using thionyl chloride achieved the goals of “kill two birds with one stone”, i.e., leaching efficiency of germanium above 95 wt% and recovery yield of lignite over 95 wt%. Specifically, the theoretical leaching efficiency of germanium reached 99.60 wt% while the recovery yield of lignite reached 86.35 wt%, at the temperature of 20 °C, liquid–solid ratio of 4 mL/g, and leaching time of 6 h. Most of the leached germanium was remained in the aqueous phase after the leaching solution was quenched, facilitating the subsequent separation of germanium. In this study, efficient extraction of germanium from the GRL was achieved with a high recovery yield of lignite, preserving the matrix structure and main composition of lignite. Therefore, this method provides a feasible way for efficient extraction of germanium from lignite with low-carbon emission under mild condition.

Production of Composite Cement Clinker Based on Industrial Waste

The possibility of producing cement clinker using low-energy, resource-saving technologies is studied. The composition of industrial waste for low-energy-intensive production of Portland cement clinker at factories in Southern Kazakhstan is analyzed. The possibility of replacing the deficient iron-containing corrective additive with “Waelz clinker for zinc ores” is shown. “Waeltz clinker from zinc ores” as part of the raw material charge performs several tasks: it is a ferrous corrective additive, works as a mineralizer for clinker formation processes, introduces coal into the charge and allows one to reduce the consumption of natural fuel. The processes of burning raw mixtures, wholly or partially consisting of industrial waste, are completed at 1350 °C. This reduces the consumption of main burner fuel for clinker burning and reduces CO2 emissions into the atmosphere. High-quality cement clinker is obtained based on raw material mixtures with Waeltz clinker from zinc ores from the Achisai Metallurgical Plant, phosphorus slag, coal mining waste from Lenger mines and sodium fluoride. The phase composition and microstructure of low-energy clinkers are revealed. Involving industrial waste in raw material circulation will reduce environmental pollution and improve the environment.

Use of Submarine Tailings Disposal as Alternative Tailings Management System

The importance of the mining/milling industry in increasing the growth level and welfare of countries is quite high. However, at the end of mining/milling processes, huge amounts of waste (often known as tails) are inevitably produced that have no economic value and can even be considered dangerous due to some heavy metals they contain. These tails are highly problematic due to both their volume (difficult to manage environmentally) and toxicity (potential to cause acid/leach waters) and need to be handled outside of existing disposal methods. This article presents the effective and sustainable handling and application of tails resulting from the enrichment of copper–zinc ores, which are actively engaged in metallic mining activities in the northeast of Türkiye, with the submarine tails disposal (STD) method. In the mining operation under study, some (~55–60 wt.%) of the tails are employed as underground fill, even though the residual part is disposed of by the STD method. The characterization of ore beneficiation tails, their transportation to the subsea via a pipeline system, and discharge monitoring results are detailed in the present investigation. According to the limitations which are indicated by the Turkish Control of Water Contamination regulation, the concentration of Pb-Cu found in the results was under the allowable limit of 0.05 mg/L. The allowed 2 mg/L limit for Zn was not surpassed mainly by the concentration found in the collected samples. pH values were almost above the allowable limit of pH > 5. The results reveal that the STD technique works quite well as an integrated mine tails method in the mine under study.

Geological formation conditions for lead and zinc ore deposits in the People’s Democratic Republic of Algeria

Geological formation conditions for lead and zinc ore deposits in the People’s Democratic Republic of Algeria

A novel zirconium glyphosine carbon nanotube composite for fast and ultraeffective In(Ⅲ) capture

Extraction of In(Ⅲ) from the tail liquid of zinc ore which possesses the large amounts of Zn(Ⅱ) and the characteristics of highly acidity, remains a critical challenge. Adsorption method can be considered as an effective and green strategy to recovery In(Ⅲ). However, the adsorption capacity of mostly reported adsorbents is unsatisfactory toward In(Ⅲ) in the acidic environment. In this work, an effective In(Ⅲ) trap is developed by using a mild, simple strategy that introduces zirconium glyphosine coordination networks in situ loaded on carbon nanotube. Benefiting from the characteristics of abundant carboxyl and phosphate groups, excellent hydrophilicity and thermal stability, the resultant zirconium glyphosine carbon nanotube composite (xZrGP-CNT) exhibits remarkable adsorption capacity (193.72 mg g-1) toward In(Ⅲ) under pH 2.5 exceeded most of the reported adsorbents, and its adsorption behavior is consistent with pseudo-second order kinetic and Langmuir isotherm models. In addition, the obtained 2ZrGP-CNT shows prominent kinetics that reaches equilibrium only within 2 h, superior selectivity and excellent regeneration performance for In(Ⅲ) capture, which indicates the highly encouraging potential for the recovery of In(Ⅲ) in practical ore fluids. Our work poses a new way to recovery of In(Ⅲ) under acidic environments with superior adsorption performance and broadens the potential of organocphosphonates for recovering In(Ⅲ).

A research on mineralogy and silver recovery technology of the zinc ore leaching tailing from a zinc processing plant in Yunnan, China

A research on mineralogy and silver recovery technology of the zinc ore leaching tailing from a zinc processing plant in Yunnan, China

Experimental and simulation study on the flotation separation of smithsonite from dolomite using phosphoryl carboxyl copolymer as a novel depressant

The increasing need for zinc resources and the diminishing supply of sulfide zinc ore reserves have made the extensive application of zinc oxide a significant topic of interest. This study investigates the effects of a newly depressant, phosphorus acyl carboxylic acid copolymer (POCA), in the sodium oleate (NaOL) collector system on the flotation separation of smithsonite from dolomite. Micro-flotation experiments under optimal conditions (pH 9, NaOL 80 mg/L) reveal that adding a minute quantity (5 mg/L) of POCA effectively inhibit dolomite, resulting in a significant recovery rate difference (>80 %). The assessment of POCA adsorption strength on the surface of the mineral, together with the level of ions in solution, provides convincing proof of POCA's dual behavior in selective adsorption and dissolution on the dolomite surface. These discoveries are additionally substantiated by the outcomes of zeta potential and Fourier Transform Infrared Spectroscopy (FTIR) tests. These tests show that the pre-adsorption of POCA diminishes the bond between NaOL and dolomite, while the impact of POCA on smithsonite is negligible. Furthermore, the chemical adsorption between POCA and dolomite has been confirmed through X-ray Photoelectron Spectroscopy (XPS). Atomic Force Microscope (AFM) reveals that POCA has a stronger adsorption-dissolution effect on dolomite than on smithsonite. These findings align with the outcomes of molecular dynamics and Density functional theory (DFT) simulations.

Sulfuric acid leaching of a complex zinc sulfide concentrate with high copper and lead concentrations under oxygen pressure

ABSTRACT This paper presents the use of an oxygen pressure-based acid leaching process for the selective extraction of basic metals from a complex zinc ore containing high concentrations of lead (6.00%) and copper (2.47%). The effects of leaching temperature, ore particle size distribution, leaching time, liquid-to-solid ratio, and oxygen partial pressure on the leaching efficiencies of zinc and copper were investigated, and the phase transformation behaviour of lead compounds was studied. Under the optimal conditions that is, a particle size of −48/+40 μm, initial sulfuric acid concentration of 150 g/L, liquid-to-solid ratio of 6:1, leaching time of 150 min, leaching temperature of 150°C, and oxygen partial pressure of 0.8 MPa – the leaching efficiencies of zinc, copper, and iron were 98.85%, 82.69%, and 33%, respectively. The leaching residue showed that almost all of the zinc sulfide was dissolved as ZnSO4, and most of the negatively charged bivalent sulfur was converted to zero-valent element sulfur. Through the pressure leaching reaction, galena in the concentrate was converted to lead jarosite (PbFe6(SO4)4(OH)12) and elemental sulfur. The formation of lead jarosite facilitated the removal of a significant portion of iron during leaching, reducing the subsequent purification burden.

Integrated management of abatement technology investment and resource extraction

As the need for increased renewable energy generation to meet climate goals grows, so does the demand for critical minerals in the industrial sector. This raises concerns about the availability of supply and the reliability of investment in critical minerals. Based on this, the study proposes an analytical framework for the integrated management of mineral extraction and renewable energy investments. Different from the previous strategy of separate management, this study has established an integrated model that utilizes new energy technology as the downstream application of emission reduction technology. It also utilizes copper, zinc, aluminum, rare earth elements, and other materials as the upstream raw material supply. In terms of minimizing costs, the entire supply chain process is optimized to achieve an empirical case. In addition, considering the significant uncertainty in the process of reducing emissions from new energy technologies, this study also incorporated a forward control stochastic programming method to model and solve it. We obtained confidence intervals for optimal technological investment paths and metal mining paths under various scenarios. Our findings indicate that: (1) Biomass, as a renewable energy technology with the lowest resource demand, should be prioritized for development. However, there is significant uncertainty surrounding the installed capacity of photovoltaics. (2) Copper ore reserves have little impact on the development of renewable energy technologies, while zinc ore and aluminum ore have a greater impact on wind energy and photovoltaics, respectively. (3) By optimizing the cut-off ratio of raw ore under a specific amount of ore storage, we can ensure the availability of materials needed for downstream energy technology.

Analysis of bioleaching characteristics and multi-element dissolution behavior of complex zinc ores

In order to recover low-grade complex zinc ore in a reasonable way, this study adopts bioleaching method to study it. The ore samples contain 1.52%, 2.03% and 14.4% zinc, respectively, which occurs in the form of sphalerite. Other major minerals include pyrite, galena, quartz and mica. The inoculation of the domesticated strain was basically free of adaptation period, and the cell concentration could be rapidly increased after a short decrease. The leaching extent of zinc increased continuously, while the leaching rate decreased gradually. After the bioleaching process, sliver, lead and iron were mainly present in the residue phase. X-ray diffraction spectroscopy analysis showed that sphalerite, galena and pyrite were dissolved, and the latter two further precipitated to produce PbSO4 and jarosite. In addition, the dissolution of calcium compounds can lead to the formation of gypsum precipitation. These precipitates covered the fresh ore surface may hinder the further bioleaching process. The Exponential model was used to simulate the bioleaching process, and it was found that the fit coefficients were all greater than 0.98, and a reasonable leaching cycle was further discussed. The results provide a good basis for the economic and environmentally friendly recovery of low-grade complex zinc ores.

Copper-cobalt cake as a potential source of germanium

Germanium is an important element used in crucial industry sectors like optical fibers for telecommunication or IR optics for night vision systems. However, its global output is limited. It is estimated that its annual global production is ca. 140 tons. Therefore, many world economies, including USA and EU, consider it as a critical raw material. One of the potential sources of germanium is zinc metallurgy. It is assumed that only 3% of germanium present in processed zinc ores is recovered. It was found that during the technological processes of Polish zinc smelters some by-products containing elevated germanium concentrations are produced. In the paper, potential germanium sources, including copper-cobalt cake obtained during the purification of zinc electrolyte and dross from the feeding furnace, are presented. The main components of the cake are cadmium, zinc, copper, nickel, cobalt, and lead, while the dross contains mainly zinc (>65%). Results of leaching tests for both materials using aqueous sulfuric acid solutions are shown. In the case of the cake, wet and dried material was investigated. It was found that the germanium leaching yield for the dried material reached 99%, while for the wet one was 46-86%, depending on leaching conditions (without or with oxidant). On the other hand, the germanium leaching yield for the dross reached 55%. Further processing of the solutions obtained after germanium leaching from the copper-cobalt cake was also analyzed. Two ways were proposed, including precipitation with tannic acid and solvent extraction with addition of complexing agents using a trioctylamine extractant.

Effect of acidic and basic leachants on the synthesis of ZnO nanoparticles from Egyptian zinc ore, their optical/surface characteristics and photocatalytic performance

It is of pivotal significance to optimize the parameters affecting the extraction of metals from natural ores to convert them to value-added products. Owing to their semiconducting nature, most metal oxides, including ZnO, have various electronic, optical, and photocatalytic applications. Hence, we are investigating the leaching of Zn from Smithsonite (an Egyptian ore) using acidic/basic leaching agents (leachants). The leached salts were employed in a co-precipitation method followed by calcination to obtain crystalline ZnO nanoparticles. Both photocatalytic performance of the ZnO nanoparticles obtained from acid leaching and basic leaching were investigated toward the photodegradation of Rhodamine B dye. The ZnO(A) prepared using the acid leaching route has achieved about 5.6-fold enhancement in the dye photodegradation% and 5.3-fold enhancement in the observed rate constant compared to ZnO(B) prepared from basic leaching. Finally, the superior photocatalytic activity of the ZnO(A) is attributed to the smaller particle size, larger surface area, and existence of some defects that enhanced the photocatalytic performance.

Smelting a Zn – Pb Sulfide Ore with Magnetite and Carbon for the Production of a Silicon Alloy and Extraction of Zinc and Lead into Sublimates

The article presents the results of thermodynamic prediction and electric smelting of Shalkiya sulfide zinc-lead-bearing ore in the presence of magnetite and coke. Using the HSC-6.0 software package, it was found that under equilibrium conditions in the presence of Fe3O4 and carbon, the reduction and formation of gaseous zinc from ZnS (according to ∆G° = 0) occurs at a temperature of 1205.7 °C, and the formation of ferroalloy at the interaction of the sulfide ore with magnetite and carbon begins at 1200 °C. About 58% of silicon is extracted into the ferroalloy at 1800–1900 °C; almost all zinc and 83–88% of lead turns into a gaseous state. Electric smelting of the sulfide ore in the presence of magnetite concentrate and coke makes it possible to obtain the FS45 grade ferrosilicon (42–43% of Si); the silicon extraction degree was 84–88%. At the same time, 97.3% of lead and 99.2% of zinc are extracted into the sublimates. The developed method for processing zinc sulfide ores allows us to increase the degree of raw materials' comprehensive use due to the extraction of not only zinc and lead, but also silicon. The technology can be used to process raw materials containing zinc, lead and silica, such as zinc ore concentration tailings.

Mineralogical Features Associated with Material Constitution and Process Properties of Difficult Lead–Zinc Ore

Mineralogical Features Associated with Material Constitution and Process Properties of Difficult Lead–Zinc Ore

Determination of Physical and Geomechanical Properties of Black Shale Hosting Lead and Zinc Ore in Eyingba, Ebonyi

This study was conducted to investigate the physical and geo-mechanical properties such as specific gravity, porosity, uniaxial compressive strength (UCS) etc. of shale, hosting lead and zinc ore in Enyigba, Ebonyi State, Nigeria. The strength properties of the black shale were analyzed because the variability in the strength of rock masses must be properly accounted for, to determine their utility in engineering design. Several tests were carried out on the intact shale samples, and the results were converted to bulk mass strength values using the Hoek–Brown criterion. The results showed that the UCS of the black shale ranged from 38.3 to 43.7 MPa for a geological strength index (GSI) value of 75; and from 54.2 to 60.4 MPa for a GSI value of 80. The specific gravity was 2.89 while the bulk density and porosity values were 290.3 kg/m3 and 15.56% respectively. Also, it was determined that there is a strong correlation between the UCS and specific gravity of the rock, with negligible levels of correlation, both positive and negative, between the UCS and the other mechanical properties examined. In conclusion, the black shale sample from Enyigba is characterized as a medium to hard rock that is suitable for engineering and mining projects.

Tracking two decades of global gallium stocks and flows: A dynamic material flow analysis

Gallium (Ga) has recently garnered significant attention as a crucial byproduct element due to its crucial role in advancing low-carbon technologies and its globally imbalanced supply-demand. Understanding the global Ga flows and stocks can contribute to discovering ways to mitigate potential supply risks. In this study, we applied a material flow analysis to map the global Ga cycle from 2000 to 2021. Our results reveal the following results: (1) Over the past two decades, a cumulative 15.3% (313240.8 tons) of the total Ga reserves has been consumed through host metals (i.e., bauxite and zinc ores) mining. However, affected by actual demand, only 5549.7 tons of Ga have been extracted. Moreover, China has gradually become the dominant supplier of primary Ga globally, relying on its robust alumina industry. (2) The consumption pattern of global Ga is becoming increasingly complex. Driven by the diffusion of low-carbon technologies, primary Ga consumption has grown from 101 tons in 2000 to 432 tons in 2021. With a low material efficiency, only 2143.4 tons of Ga ultimately enter final products from semi-products. (3) The global Ga stock reached 956.7 tons in 2021 with significant recycling potential. However, commercial recycling systems were not established, and Ga resources in end-of-life (EoL) final products are mostly wasted. Given the anticipated growth of Ga demand, more coordinated efforts among different regions to promote technological innovation and improve recycling and circularity rates are urgently needed to ensure global Ga supply and a shared green future.

Copolymers-functionalized metal-organic framework composite for efficient adsorption of rare-earth elements

Based on the Hard-Soft-Acid-Base theory, we developed and synthesized a unique crystalline adsorbent called MIL-101(Cr)-SMA-ED-PMG (SMA: styrene maleic anhydride; ED: ethylenediamine; PMG: N,N-di(phosphonomethyl)glycine). This adsorbent consists of polymer chains that are abundant in carboxyl and phosphate Lewis hard base groups. This was performed to enhance the efficient recuperation of electrophilic Lewis hard acid rare earth elements. The Neodymium(III) (Nd3+) and Europium(III) (Eu3+) ions reached adsorption equilibrium in the MIL-101(Cr)-SMA-ED-PMG material after 6 h at pH 5. The adsorption of Nd3+ and Eu3+ follows the pseudo-second-order kinetic and Langmuir models. The maximum adsorption capabilities were 102.7 mg/g for Nd3+ and 110.4 mg/g for Eu3+. In addition, when applying a concentration of 0.3 mol/L of HNO3 or HCl, the adsorbent was nearly completely desorbed, and it remained stable for five cycles. The order of adsorption for the different REE ions was as follows: Eu3+ > Nd3+ > Ce3+ > La3+. The MIL-101(Cr)-SMA-ED-PMG compound demonstrated a remarkable 84 % selectivity in adsorbing Eu3+ compared to the other metal ions in the mixture (Na+, Mg2+, Co2+, Ni2+, and Zn2+). Furthermore, the adsorption of Eu3+ was not significantly influenced by changes in the aqueous conditions. The experiment conducted on a zinc ore simulated leachate exhibited the material remarkable capacity for Eu3+ separation and enrichment. MIL-101(Cr)-SMA-ED-PMG exhibits strong adsorption properties, exceptional selectivity, effective desorption, and significant potential for the recovery of rare earth elements (REEs).

Flotation behavior and mechanism of smithsonite under the system of bidentate ligand sulfide sodium thiocyanate

The sulfuration pretreatment is essential in enhancing the floatability of zinc oxide ore during the flotation process. The conventional vulcanizing agent employed in the sulfuration process, however, has proven to be ineffective and environmentally unfriendly. The dosage of this agent must be strictly regulated to ensure optimal flotation efficiency of zinc oxide ore, as excessive or insufficient amounts can have a negative impact. To address these issues, a more efficient and environmentally friendly vulcanization agent called sodium thiocyanate (NaSCN) has been introduced to enhance the sulfuration flotation of smithsonite. It also demonstrated the effective sulfidation of smithsonite by sodium thiocyanate, which also exhibits superior vulcanization effects compared to sodium sulfide. By applying NaSCN at a concentration of 6 × 10-4 mol/L, the recovery rate of zinc ore can achieve 88.75 %. Moreover, the vulcanization conditions utilizing sodium thiocyanate offer greater ease of management. The vulcanization mechanism of smithsonite was investigated through FTIR, Zeta potential, and XPS analysis. The findings indicate that the dentate ligand SCN– derived from sodium thiocyanate can undergo chemical adsorption onto the surface of smithsonite through either sulfur (S) or nitrogen (N) elements. The interaction leads to the formation of zinc-thiocyanate anions, which enhance the surface hydrophobicity and expand the mineral collection sites. The overall findings suggest that sodium thiocyanate exhibits promising potential as a highly efficient vulcanization agent for smithsonite, providing valuable insights for the flotation of this mineral.