Flotation Tailings Research Articles

The Development of Innovated Complex Process for Treatment of Old Flotation Tailings of Copper-Zinc Sulfide Ore.

The possibility of selective Cu and Zn leaching from the sample of old pyrite tailings, which is one of the most widespread types of solid waste forming during non-ferrous metal production, using sulfuric acid solutions and water was studied. It was shown that water leaching provided selective extraction of Cu and Zn and comparatively low iron ion extraction. At the same time, acid leaching provided the obtainment of pregnant solutions with high ferric ion concentration, which can be used for oxidative leaching of substandard copper concentrates. Water and acid leaching also provided increased Au recovery by cyanidation. The results suggest that acid leaching can be an effective approach for processing old flotation tailings, which allows the extraction of base metals from these wastes and treating flotation tailings for subsequent cyanidation. Effective flotation treatment methods should also provide environmental load reduction, which is caused by the long-term storage of metal-bearing wastes.

Mineralogical features of flotation tailings at the Krasnobrodskaya-Koksovaya coal preparation plant and their impact on washability

Mineralogical features of flotation tailings at the Krasnobrodskaya-Koksovaya coal preparation plant and their impact on washability

Characterization of the effects of acetic acid on the recovery of valuable contents from flotation tailings of non-sulfide metals

Non-sulfide lead flotation tailings draw attention in terms of their valuable contents. Dissolution studies have been carried out with strong inorganic acids, especially in ore form, but these acids have been unfavorable in removal in the context of metal recovery processes. Organic acids, on the other hand, are notable for their environmentally friendly properties and selective metal recovery opportunities. In this study, the effects of acetic acid on metal recovery from oxidized waste were investigated with different experimental parameters at a laboratory scale. Optimal conditions were determined depending on the increase in acetic acid concentration. At 0.75-1.0 M acid concentrations, 49-55% Pb and 49-54% Zn recovery efficiencies were obtained with grades of 7.0-7.2% and 19.5-19.7%, respectively. The recovery of Pb/Zn by the leaching process with acetic acid and the selective non-recovery of iron were also observed through characterization studies. With the Rietveld XRD method, an increase in iron minerals such as goethite and a decrease in smithsonite-hydrozincite minerals were determined. These changes were seen as a decrease in the contents of these minerals in SEM/EDX analysis and as a decrease in smithsonite mineral bond structures in the FT-IR analysis. This study showed that acetic acid has many advantages in the utilization of zinc-lead-containing oxide flotation tailings, which have high economic value, such as selective metal recovery, easy biodegradability, environmental friendliness, and non-corrosiveness.

Formulation Optimization and Performance Prediction of Red Mud Particle Adsorbents Based on Neural Networks.

Red mud (RM), a bauxite residue, contains hazardous radioactive wastes and alkaline material and poses severe surface water and groundwater contamination risks, necessitating recycling. Pretreated RM can be used to make adsorbents for water treatment. However, its performance is affected by many factors, resulting in a nonlinear correlation and coupling relationship. This study aimed to identify the best formula for an RM adsorbent using a mathematical model that examines the relationship between 11 formulation types (e.g., pore-assisting agent, component modifier, and external binder) and 9 properties (e.g., specific surface area, wetting angle, and Zeta potential). This model was built using a back-propagation neural network (BP) based on single-factor experimental data and orthogonal experimental data. The model trained and predicted the established network structure to obtain the optimal adsorbent formula. The RM particle adsorbents had a pH of 10.16, specific surface area (BET) of 48.92 m2·g-1, pore volume of 2.10 cm3·g-1, compressive strength (ST) of 1.12 KPa, and 24 h immersion pulverization rate (ηm) of 3.72%. In the removal of total phosphorus in flotation tailings backwater, it exhibited a good adsorption capacity (Q) and total phosphorous removal rate (η) of 48.63 mg·g-1 and 95.13%, respectively.

Analysis of the Possibility of Copper Recovery from Flotation Stratiform Copper Ore Tailings

ABSTRACT Flotation tailings produced at three concentrator plants operated by KGHM Polska Miedz SA (SW Poland) are all continuously deposited in the Zelazny Most Tailings Storage Facility. The aim of this study was to analyze the possibility of recovering copper from the stream of final tailings continually produced by the largest of the three KGHM concentrator plants. The tailings sample contained 0.25% of Cu and was characterized by a relatively fine grain size. The tests were performed for three narrow-range size fractions of the tailings sample: −0.040, 0.040–0.160 and +0.160 mm. The findings demonstrate that the coarse and fine fractions are the main carriers of copper-bearing minerals which can be recovered with satisfactory results, if the fractions are processed separately. The coarse grain fraction was milled and then floated in the presence of standard flotation reagents with satisfactory results. The fine fraction was floated in the presence of NaHS with a relatively good efficiency which requires further research. The presented results prove that copper losses in this material can be partially reduced already at the stage of the upgrading processes performed in the concentrator plant.

Atmospheric leaching of Ni, Co, Cu, and Zn from sulfide tailings using various oxidants

The growing demand for nickel and cobalt increases the interest in extracting metals from secondary sources, such as flotation tailings. A preferential strategy for the processing of the complex and/or low-grade secondary sources may be material integration into existing primary processes. In this research, a robust sulfuric acid leaching treatment was studied for metal extraction from sulfidic flotation tailings (Ni 0.45 %, Co 0.80 %, Cu 0.20 %, Zn 0.58 %). The impact of leaching parameters on metals extraction was studied; oxygen gas (1–2 L/min), ferric ions (0.05–0.3 M), and hydrogen peroxide (0.5–0.8 M), temperature (30–90 °C), sulfuric acid concentration (0.2–2 M), and solid–liquid ratio (50–100 g/L). It was found that after 30-minutes 20.0 % of nickel, 5.6 % of cobalt, and 33.0 % of the main impurity iron were extracted using oxygen as oxidant. Increasing temperature and sulfuric acid concentration were shown to have a positive effect on extraction. Also, with the further addition of ferric ions, cobalt extraction could be slightly increased (from 6.2 % to 8.3 %) whereas both nickel and cobalt could be increased with hydrogen peroxide (nickel 22.9 %, cobalt 14.2 %). However, the use of H2O2 can be challenging due to its high environmental footprint as well as partial decomposition by ferric ions, increasing H2O2 consumption further. The results suggest that the mineralogy of the investigated tailings limited feasible metals extraction using atmospheric conditions up to ≈ 20 % for nickel and ≈ 10 % for cobalt, with nickel distributing stronger into non-refractory minerals while cobalt reported more to pyrite. For other base metals, zinc extraction from sphalerite was shown to be efficient (up to ≈ 90 %) whereas copper extraction was limited (up to ≈ 30 %). In future, such atmospheric sulfuric acid leaching may provide a robust recovery route for non-refractory minerals present in the tailings, while full valorization of sulfide tailings matrix will require higher intensity processing with technologies such as pressure oxidation (POX), concentrated chloride leaching, bioleaching, roasting-leaching or very fine milling of the raw material prior to atmospheric leaching.

The Characterization of Residues Related to the Roasting– Leaching–Electrowinning Zinc Production Route for Further Metal Extraction

Super-hot acid leach residue is generated during zinc production in the roasting–leaching–electrowinning route, where both primary and secondary resources are used as feed material. This residue may contain valuable metals, such as lead, zinc, and iron, as well as precious metals, such as gold and silver. Four materials, namely super-hot acid leach residue, a residue formed when super-hot acid leach residue is selectively leached for lead with triethylenetetramine, as well as flotation concentrate, and flotation tailings formed in a selective silver flotation process with super-hot acid leach residue as the feed material were characterized to obtain a deeper understanding of possible further metal extraction. These four materials were characterized for chemical composition, mineralogy, and mineral distribution via chemical analyses, X-ray diffraction, and energy-dispersive scanning electron microscopy, respectively. The scanning electron microscope images showed that the materials have large variations in particle size distribution and composition. The results showed that the main lead phase in super-hot acid leach residue is lead sulfate, whereas it is mostly converted to lead sulfide during the selective lead leaching of the super-hot acid leach residue. The remaining lead sulfate is found in a solid solution with barium sulfate. Extracting lead from super-hot acid leach residue via triethylenetetramine leaching resulted in increased concentrations of gold and silver by 41% and 42%, respectively. The identified silver phases in super-hot acid leach residue may correspond to silver sulfide, silver chloride, and elementary silver, where silver sulfide was the most commonly occurring silver phase. After leaching this selectively for lead with triethylenetetramine, similar silver phases were identified, but silver sulfide and silver chloride occurred to a similar extent. Additionally, silver copper sulfide was detected. The presence of different silver phases might pose a challenge to reaching high silver recovery during leaching as the optimum leaching conditions differ somewhat. Furthermore, elemental sulfur, with a tendency to coat gold and silver particle surfaces, which is indicated to be present in all materials except the silver flotation tailings, may hinder metal extraction.

Experimental Study on Activated Sulfur Selection from High Alkalinity Lead Zinc Flotation Tailings

This article takes the flotation tailings of a high sulfur lead-zinc mine in Inner Mongolia as the research object. XRD and BPMA automatic process mineralogical analysis systems are used to analyze the mineral composition of the tailings, and experimental research is conducted on the comprehensive recovery of pyrite through activated flotation. The results showed that using concentrated sulfuric acid as an activator, ethyl xanthate and isoamyl xanthate as a combination collector, and adopting a flotation process of “one coarse, one sweep, and two fine”, a concentrate product with a yield of 9.31% and a sulfur grade of 37.78% can be obtained, and the sulfur recovery rate in the concentrate can reach 77.13%; The comprehensive recovery and utilization of sulfur in the original flotation tailings have been achieved.

Project solution of intervention measures at the dam of the "Šaški potok" tailing dump

There was an increase in the groundwater level and increased waterlogging of the terrain at the "Šaški potok" flotation tailing dump in Majdanpek, due to a damage of drainage collector. The stability of man-made materials of the landfills is directly dependent on the position of the free water surface in the body of the landfill. The rise of the underground water level leads to a decrease in the strength parameters of the materials from which the dam is built, which reduces the safety factor of the outer slope. For the purpose of interventional lowering the high level of underground water in the main dam body of the landfill, a hydrodynamic terrain model was created and various conceptual solutions were evaluated, using the hydrodynamic analysis. A group of wells was selected as the most optimal technical solution for lowering the groundwater level below the designed elevation.

Pollution indices as useful tools for comprehensive evaluation of the soil contamination degree in the vicinity of mining and metallurgical complexes

Soil pollution levels in the copper mining and metallurgical area were evaluated at 14 sampling sites in the City of Bor and its surroundings in regard to Al, As, Cu, Fe, Pb and Zn contents, as well as single and integrated pollution indices. The significance of single pollution indices provides information about pollution by a specific element, while integrated pollution indices offer an insight into cumulative pollution by the examined elements. The mean soil concentrations of As, Cu, Pb and Zn were several times higher than the world average values. The exceedances of soil remediation values were most pronounced for As (at seven sites) and Cu (at eleven sites), more than 3 and 13 times, respectively. According to the geoaccumulation index, the enrichment factor and the contamination factor, the highest soil contamination was with As and Cu, especially at the urban-industrial site. Pollution load index, Nemerow pollution index and the improved Nemerow index confirmed that the most contaminated soils were from the sites in the vicinity of the metallurgical complex and flotation tailing ponds, as well as from the sites in the prevailing wind directions compared to the less polluted soils affected by the ore mining processes. The areas affected by the serious cumulative contamination from the pyrometallurgical copper production need continuous pollution prevention, monitoring and remediation measures.

Microbial processes with the potential to mobilize As from a circumneutral-pH mixture of flotation and roaster tailings

The Northwest Tailings Containment Area at the inactive Giant Mine (Canada) contains a complex mixture of arsenic-containing substances, including flotation tailings (84.8 wt%; with 0.4 wt% residual S), roaster calcine wastes (14.4 wt% Fe oxides), and arsenic trioxide (0.8 wt%) derived from an electrostatic precipitator as well as As-containing water (21.3 ± 4.1 mg L−1 As) derived from the underground mine workings. In the vadose zone the tailings pore water has a pH of 7.6 and contains elevated metal(loid)s (2.37 ± 5.90 mg L−1 As); mineral oxidizers account for 2.5% of total 16S rRNA reads in solid samples. In the underlying saturated tailings, dissolved Fe and As concentrations increase with depth (up to 72 and 20 mg L−1, respectively), and the mean relative abundance of Fe(III)-reducers is 0.54% of total reads. The potential for As mobilization via both reductive and oxidative (bio)processes should be considered in Giant Mine remediation activities. The current remediation plan includes installation of an engineered cover that incorporates a geosynthetic barrier layer.

ENERGY EFFICIENCY INCREASING OF ORE ENRICHMENT WASTES’ PROCESSING BY ELECTRICAL DISCHARGE METHOD

A promising and accessible raw material, comparable in terms of gold and silver content to natural ore deposits, is the lying tailings of ore flotation. Currently, billions of tons of ore tailings have been accumulated, the content of valuable components in which sometimes exceeds those in natural deposits. The processing of ore tailings from tailings for the extraction of non-ferrous metals in most cases requires complex beneficiation schemes, and in terms of technical and economic indicators and the quality of concentrates, they are uncompetitive compared to products of natural raw materials. An electric discharge method of disintegration of ore beneficiation waste to increase the number of available target components, based on the rational organization of crushing and grinding processes in relation to beneficiation tasks, was experimentally investigated. The pressure values of the compression waves generated by the electric discharge were determined to calculate the radius of effective selective influence on the studied waste samples of flotation beneficiation of copper-zinc ores. The necessary conditions for the effective operation of the technological part of the equipment are established: in the volume of the disintegrator, the pressure, created by the electric discharge, should not be less than the tensile strength of the processed material and at the same time should not exceed the strength of the disintegrator’s material. The use of the electric discharge method ensures the selectivity of disintegration of the material along the interphase boundary "dead rock - mineral inclusion", this circumstance allows to achieve a significant increase in the amount of mined valuable metals and simultaneously reduction of energy consumption by 2 - 4 times. Increasing energy efficiency is considered by the way of example with copper-zinc ore concentration’s waste. The increase in the number of target metals available in wastes of flotation concentration of copper-zinc ore after their electric discharge treatment is shown. The increase in the amount of copper extracted from copper-zinc ore enrichment waste was from 40 to 93% by mass, extracted zinc - from 39 to 94% by mass, silver extracted - from 16 to 50% by mass.

Mineral Weathering and Metal Leaching under Meteoric Conditions in F-(Ba-Pb-Zn) Mining Waste of Hammam Zriba (NE Tunisia)

Mining waste is an obvious source of environmental pollution due to the presence of heavy metals, which can contaminate soils, water resources, sediments, air, and people living nearby. The F-(Ba-Pb-Zn) deposit of Hammam Zriba located in northeast Tunisia, 8 km southeast of Zaghouan was intensively exploited from 1970 to 1992. More than 250,000 m3 of flotation tailings were produced and stored in the open air in three dumps without any measure of environmental protection. Thus, in this paper, mineralogical and chemical characterization, especially the sulfide and carbonate phases, were carried out to evaluate the potential for acid mining drainage (AMD) and metal leaching (ML). Conventional analytical methods (XRD, XRF, SEM) have revealed that this mining waste contains on average 34.8% barite–celestine series, 26.6% calcite, 23% quartz, 6.3% anglesite, 4.8% fluorite, 2.1% pyrite, and 0.4% sphalerite. The content of sulfides is less important. The tailing leaching tests (AFNOR NFX 31-210 standard) did not generate acidic leachate (pH: 8.3). The acidity produced by sulfide oxidation was neutralized by calcite present in abundance. Furthermore, the leaching tests yielded leachates with high concentrations of heavy metals, above the authorized thresholds. This high mobilization rate in potential toxic elements (PTE) represents a contamination risk for the environment.

Degradation of residual xanthate in flotation tailing wastewater by activated H2O2 with natural ilmenite: A heterogeneous fenton-like reaction catalyzed at natural pH

Efficient treatment of residual xanthate from tailing wastewater has attracted soaring interesting recently. Herein, effect of activated H2O2 by natural ilmenite (FeTiO3) as a catalyst on sodium butyl xanthate (SBX) degradation was systematically investigated. More than 98 % SBX degradation efficiency was achieved by the method under optimal conditions (a natural pH = 8.7, [FeTiO3]0 = 4.0 g/L, [H2O2]0 = 2.0 mM, and [SBX]0 = 40.0 mg/L), and chemical oxygen demand (COD) removal rate was 85.41 %. Kinetic studies indicated that SBX degradation efficiency in FeTiO3-H2O2 system conformed with a pseudo first order kinetic equation. Also, comparative experiments indicated that this system degraded SBX was superior to the H2O2 alone and FeTiO3 alone systems. Reactive oxygen species (ROS) were determined by quenching experiments and electron paramagnetic resonance (EPR) tests, suggesting that OH and O2− were the primary reactive radicals in FeTiO3-H2O2 system. Cycling experiments and leaching metal ion tests suggested that FeTiO3 still exhibited high catalytic activity and excellent stability after five times of recycling. Finally, possible degradation pathways and mechanism of SBX in this system were proposed. Consequently, this study promotes the application of natural iron-based minerals as a catalyst in wastewater treatment, and provides new insights into the effective treatment of organic pollutants in tailing wastewater.

SWRC interpretation of iron ore tailings blends focusing on saturation assessment of dry stacking

ABSTRACT The study addresses challenges in dry stacking of fine-grained materials by blending itabirite iron ore slime tailings with coarser flotation tailings. It focuses on flow dynamics, capillary saturation, and the necessity to prevent large, saturated volumes. Geotechnical tests were conducted on various blends, deriving unsaturated hydraulic conductivity functions using Fredlund and Xing’s methodology. The Soil-Water Retention Curve data, combined with transient 1D analysis, assesses capillary rise. Results show capillary rise up to 50 meters with over 80% saturation, and also influenced by weather conditions penetrating up to 20 meters. Integrating up to 30% slime content in flotation tailings mitigates saturation issues. Empirical and numerical findings enable inferring saturation tendencies in distinct iron ore tailings mixtures, establishing a procedural framework for practical field applications.

Natural Pyrite as a Catalyst for a Fenton Reaction to Enhance Xanthate Degradation in Flotation Tailings Wastewater

The efficient treatment of mineral-processing wastewater has attracted soaring interest recently. This study’s objective was to degrade xanthate from flotation tailings wastewater using a pyrite-catalyzed Fenton system. A sodium butyl xanthate (SBX) removal rate of more than 96% was achieved via the method under optimal conditions (a H2O2 concentration of 0.5 mM, a FeS2 concentration of 0.5 g/L, an initial SBX concentration of 100 mg/L, and a natural pH of 9.36 ± 0.5), which is 12.85% higher than with a H2O2 system. An appropriate concentration of natural pyrite can act as a catalyst to significantly improve the oxidation capacity of H2O2. Additionally, the results of electron paramagnetic resonance and quenching measurements suggest that hydroxyl radicals (•OH) are the main active species in the H2O2-FeS2 system. The possible reaction mechanism is proposed. The H2O2 adsorbs onto the pyrite surfaces and reacts with Fe2+, triggering the formation of •OH and Fe3+. The •OH most likely attacks the SBX that adsorbs on the pyrite surface or exists in the solution and promotes the transformation of the SBX anion (C4H9OCS2−) into the intermediate butyl xanthate peroxide (BPX, C4H9OCS2O−). Finally, BPX intermediates are likely further oxidized to smaller products such as SO42−, CO2, and H2O under the ongoing attack of •OH.

Preparation of Fly Ash of Ekibastuz Coals for Subsequent Production of Alumina

Pre-processing of ash from coal power plants were carried out, which consists of its decarbonization and iron removal to produce a carbon concentrate with a carbon content of 71 % for reuse in the power sector and magnetite concentrate from flotation tailings as an additional raw material in ferrous metallurgy. The optimal consumption of flotation reagents and flotation duration were identified. To increase the concentration of iron intended for magnetic separation, desliming of flotation tailings was recommended.

Insights into the design of polymetallic ore flotation circuits, including tailing desulfurization

Flotation is a main mineral concentration technology, which is why the design of flotation circuits has been extensively studied in the literature. However, studies on flotation circuit designs for polymetallic ores have rarely been reported in the literature. On the other hand, sulfide mineral flotation tailings are potential generators of acid mine drainage (AMD), which is one of their main environmental drawbacks. Although there are several strategies to prevent and control AMD, the most proactive attitude is to generate tailings without sulfur species. This paper investigates the circuit design of polymetallic ores, including desulfurization within the flotation process. Three types of circuit designs are analyzed: fractional flotation with the generation of a bulk concentrate and its subsequent separation, fractional flotation using selective flotation, and integrated flotation with combined bulk and selective flotation. Various aspects are analyzed, such as the effect of stage recovery uncertainty on the design; the impact of the design type on costs, energy use, and environmental effects; and the influence of the design strategy applied. Additionally, the design of a Cu–Ni plant that includes desulfurization is employed to deepen the research. The results show that it is useful to design these separation systems holistically to obtain more efficient designs. It is also concluded that the most traditional way of processing polymetallic ores consumes more energy, water, and materials, resulting in a more significant environmental impact. Finally, based on these results, a methodology for designing these complex systems is outlined.

Research and development of gold ore processing technology

This paper presents the results of technological studies of two samples of gold-bearing ore from the gold-bearing deposit of Kazakhstan deposits 1 and 2. A comprehensive analysis of ore samples by X-ray fluorescence, X-ray phase, chemical, and mineralogical methods was carried out. The calculated initial gold content was determined, and X-ray fluorescence analysis showed that the main elements that make up the ore are oxygen up to 51% and silicon up to 33%. X-ray phase analysis showed the presence of more than 95% quartz and muscovite in the samples. The form of finding gold in the ore, according to the results of mineralogical analysis, is defined as free gold and gold in iron hydroxide. Silver is present in the studied samples in the form of various types of halides. An ore beneficiation scheme has been developed and presented, including gravity and flotation. Gravity enrichment was carried out in two stages, with the production of concentrate and tailings, with the maximum recovery of gold in concentrate up to 91%, flotation enrichment using butyl xanthate reagents and a blowing agent, was carried out in two stages with the production of main and control concentrates and final flotation tailings. The subsequent hydrometallurgical study of the ore was carried out to assess the effect of sodium cyanide on the extraction of gold, tests were performed on the leaching of the initial samples of the ore and the obtained flotation and gravity concentrates in the agitation mode, it was found that cyanide leaching is an effective method for processing the mineral raw materials of the gold-bearing deposit of Kazakhstan, and the obtained flotation concentrates, with the recovery of gold into solution under optimal conditions up to 98%. The results obtained make it possible to predict the effectiveness of the main technological stages in the ore processing scheme, technology optimization, and maximum gold recovery.

Effect of excitation parameters on the motion characteristics of the tailings slurry during vibration dewatering

Fine flotation tailings slurry (FFTS) are potential mines rich in a large number of useful minerals, and the large-scale stockpiling of tailings slurry have caused serious resource waste and environmental pollution. High efficiency dewatering is urgent demand of the FFTS disposal and utilization. In this work, the influence of excitation parameters on the FFTS motion characteristics and dewatering performance was explored during the continuous dewatering by the vibration screen. The results showed that the slurry concentration along the screen surface showed a trend of increasing in steps, and a typical three-region differential dewatering phenomenon appeared. The increase of vibration intensity was conducive to speeding up the motion velocity of the FFTS and avoiding the accumulation of the tailings particles on the screen surface. And the layer thickness on the screen was reduced, which was beneficial to shorten the percolation distance of the liquid. There was a competitive coordination mechanism between percolation distance and dewatering time on the dewatering performance. When the velocity was less than 0.07 m/s, the moisture was reduced by the reduction of the layer thickness, and the dewatering time was not the main factor. When the velocity exceeded 0.07 m/s, the influence of the layer thickness on the dewatering was weakened, the material could not obtain sufficient dewatering time. The dewatering results showed that with the optimal conditions of f = 16 Hz, A = 5 mm and α = 45°, the product moisture reached 19.37 % and the discharge speed was 4.69 t/m2·h. A case study indicated that dewatering for 6000 t FFTS could be completed by 3 vibration screens working 7.67 h per day, and the volume of FFTS was reduced from 2125 m3 to 831.25 m3. The work might provide theoretical and technical support for efficient dewatering of FFTS with environmental benefits.