Flotation Tailings Research Articles

Aluminum Smelting Carbon Dust as a Potential Raw Material for Gallium and Germanium Extraction

Gallium and germanium are highly important elements used in different high-tech areas, and new secondary raw materials for its extraction are the subject of a thorough search. In this study, germanium is found in the wastes from the Hall-Heroult process for the first time. The mechanism of gallium and germanium circulation in the aluminum reduction cell is discussed. Four types of materials, namely carbon dust, flotation tailings, carbon concentrate, and ash, were examined. It was found that a temperature of 900 °C is sufficient for the complete combustion of the carbon concentrate. The gallium concentration in the ash may reach up to 4.0 kg/ton. The germanium extraction to sublimates reaches up to 90%. Carbon concentrate being the processing product of carbon dust from an aluminum reduction cell is a promising secondary raw material for germanium and gallium extraction.

Statistical investigation of flotation parameters for copper recovery from sulfide flotation tailings

This study is focused on the froth flotation reprocessing of a copper mineral from flotation tailings. The effects of flotation parameters including pulp density, collector dosage, frother dosage, and dispersant dosage were statistically examined to obtain an effective approach for concentrating copper minerals. The sample ore used in this study was mainly flotation wastes that have been stored for more than 30 years and comprised mixed sulfide minerals and partially oxidized sulfides. We conducted a 24 factorial design on the main parameters that influence flotation performance. The results showed an optimum flotation condition at dosages of 80 ​g/t, 30 ​g/t, and 150 ​g/t of collector, frother, and dispersant respectively with copper recovery and grade of more than 60% and 8% respectively. From the analysis of experimental results, we concluded that though various parameters influence the flotation performance, collector dosage and its interactions with other paramenters are the most influential factors.

Maximizing recovery, grade and throughput in a single stage Reflux Flotation Cell

The Reflux Flotation Cell (RFC) utilises the Boycott Effect to decouple the overflow water flux from the gas flux, permitting in principle high product grade and recovery at a vastly higher volumetric feed flux. This study investigated this relationship between concentrate grade, recovery, and volumetric feed throughput using a single flotation stage and feed fluxes spanning 1–9 cm/s, well beyond that used in conventional flotation. Coal flotation tailings and hydrocyclone overflow provided convenient representations of “binary” feeds for the experiments, constituting liberated hydrophobic and hydrophilic particles. The results demonstrated robust recoveries through the preservation of the gas to feed flux ratio with increasing feed flux, while minimising the gas flux strengthened the capacity to maintain high product grade using inverted fluidization water as the wash water. Remarkably, a high product grade (low product ash%) was maintained over the extreme feed flux range by ensuring a net downwards flux of wash water delivered through the upper fluidized bed of bubbles. Coal Grain Analysis (CGA), an optical imaging technique, identified the maceral composition of the feed particles and validated, with close agreement, the RFC steady state separation performance. Indeed, under continuous operation the RFC data demonstrated an overall positive shift in performance relative to that of the standard tree flotation curve. The findings showed strong preservation of product grade and recovery using a single RFC stage, over a seven-fold increase in the feed flux relative to conventional flotation systems.

Hydrometallurgical processing of technogenic finely dispersed fluorocarbon-containing raw materials of primary aluminum production

The purpose of the paper is to determine the conditions for the maximum transition of fluorine from the technogenic raw materials of primary aluminum production (mature sludge) into solution under alkaline leaching. The object of research is the mature sludge, which is formed from technogenic finely dispersed materials of aluminum production in the baths with Soderberg anodes (tailings of coal foam flotation, gas cleaning sludge, electrostatic precipitator dust) and stored close to the enterprise. Analytical studies of the initial sample and leaching products have been carried out according to the certified methods using chemical, X-ray phase and titrimetric analysis methods. It is shown that, the main percentage of the three sludge components belongs to the dust of electrostatic precipitators (~ 79.7%) and coal foam flotation tailings (~ 15.8%). It has been determined that the gas cleaning sludge features the richest composition of useful components (in the sum of F, Na and Al ~ 63%). According to the data of X-ray phase analysis, the sludge sample from the sludge storage mainly contains cryolite (up to 78.7%), carbon (11.9%), calcium-magnesium carbonate from the dolomite series (4.44%), and trace amounts of corundum and fluorite. The results of the conducted experiments on fluorine leaching from the sludge sample by the caustic soda solution allow to estimate the main process parameters: temperature - 75–80°С, duration - 60 min, NaOH concentration - 3.0% (with the W:T ratio of 10:1 and a stirrer speed of ~ 1005– 1010 rpm). According to the analytical data on the chemical composition of leaching cake, the fluorine content in the solid phase reduces by 88.1%. The experiments carried out on alkaline leaching of fluorine from the sample of mature sludge formed under primary aluminum production by the electrolysis of cryolite-alumina melts in the baths with self-baking anodes allowed to find out that the maximum decrease of fluorine content in the sample is achieved under the conditions of maintaining the process parameters including temperature, duration, reagent concentration in optimal modes.

Potentially Exploitable Reprocessing Routes for Recovering Copper and Cobalt Retained in Flotation Tailings

This research aimed at recovering metals retained in the tailings from the flotation of copper (Cu) and cobalt (Co) ores conducted at the New Concentrator in Kipushi (NCK). Metals retention in the tailings (0.73% Cu and 0.37% Co) increased due to the removal of the gravity separation section from the processing circuit together with changes arising in the feed mineralogical characteristics namely the increase in sulfide minerals. The concentrator’s feed was traditionally composed of oxidized minerals of Cu and Co from the Luiswishi deposit (DR Congo). Experiments conducted at the laboratory scale enabled identifying two exploitable routes for recovering metals retained in the tailings: firstly, the sulfuric acid leaching of tailings under reducing conditions in view of preparing a leach liquor (2.43 g/L Cu and 1.10 g/L Co) that can be utilized for cementing Cu, using iron chips and precipitating Co; secondly, the flotation of valuable minerals using xanthates in view of obtaining a rougher concentrate grading 1.43% Cu and 0.75% Co recovered at 56% and 59%, respectively, and later on, the obtaining of a cleaner concentrate assaying 3.97% Cu and 2.4% Co at the recoveries of 35% and 43%, respectively. The final concentrate enables the hydrometallurgical extraction of Cu and Co.

THE MICROWAVE IRRADIATION EFFECT ON THE FLOATABILITY OF MIXED SULPHIDE/OXIDE COPPER ORES

Pre-treatment of copper sulphide and oxide ores using microwave radiation causes a difference in their floatability through change in the surface properties of the minerals. The aim of this study is to investigate the behaviour of Sungun porphyry copper ore under the influence of microwave radiation. In this regard, the feed sample of Sungun copper flotation circuit has been subjected to microwave irradiation for 0-120 s and a radiation power of 0-600 W. The prepared samples were then subjected to flotation experiments. According to the results, the grade of sulphide and oxide Cu minerals, as well as the grade of Fe, increased by microwave irradiation in all experiments compared to the non-irradiated samples. At the same time, recovery rate has a reversed trend and decreased in all cases. Variations in the recovery rates of copper oxides and sulphides due to microwave irradiation are different. Increasing the power of irradiation resulted in a greater reduction in the recovery of copper oxides than of sulphides. On the other hand, increasing the power of microwave irradiation reduced the amount of iron recovery in the copper concentrate and with an increase in the duration of microwave irradiation, the reduction of iron recovery values is even more pronounced. Changes in the power and duration of microwave radiation have not had a significant effect on variations in oxide copper grade in flotation tailings. While the grade of sulphides in tailing is affected by the parameters of microwave irradiation and with an increase in power and duration of microwave irradiation, the grade of copper in tailing increases.

Preparation of polymeric aluminum ferric sulphate from waste residue of aluminum industry

Polymeric aluminum ferric sulphate(PAFS) was prepared from high-sulfur bauxite flotation tailings and red mud by roasting, acid leaching and polymerization. The effects of leaching temperature, leaching time, liquid-solid ratio on the leaching rate of Al3+ and Fe3+were investigated. The optimal leaching conditions are as follows: leaching temperature 100℃, leaching time 90 min, sulfuric acid concentration 4.5mol/L and liquid-solid ratio 5 mg/L. Infrared spectroscopy and X-ray diffraction analysis was carried out on the PAFS prepared under the optimum process parameters. The characterization of PAFS shows that the synthesized PAFS had polymeric aluminum, iron and hydroxyl structures. Wastewater disposal test of synthetic PAFS shows that the removal rates of COD, turbidity and chromaticity are 45.61%, 75% and 94.18%, respectively.

Studies on zinc recovery from technogenic waste

Results from laboratory experiments are presented on extraction of zinc available in waste from lead-zinc metallurgy, mixed with lead-zinc flotation tailings and some waste rock, by leaching it under atmospheric conditions with sulfuric acid (H2SO4) solutions (5 and 10 wt. %) and 30 % hydrogen peroxide in the temperature range of 25 - 80 °C, at leaching time 30 - 120 min. Material leaching with 10 % H2SO4solution at 70 °C for one hour brings into pregnant leach solution (PLS) around 80 % of zinc available. Imposing an electrochemical impact during the leaching process increases the quantity of leached zinc by around 5 %. Direct electrowinning from the PLS obtains zinc metal of grade 75-76 %. The suggested treatment removes metals-pollutants from accumulated mixed technogenic waste therefore rendering it more environmentally friendly. Experiments showed that old mixed waste from mining, mineral processing and metallurgy activities merits further studies as secondary source of metals.

ЛЕЖАЛЫЕ ХВОСТЫ ФЛОТАЦИИ МЕДНО-КОЛЧЕДАННЫХ РУД ИЗВЛЕЧЕНИЯ ЗОЛОТА И СЕРЕБРА: АНАЛИЗ РЕСУРСНОГО ПОТЕНЦИАЛА

The article analyzes the possibility and efficiency of processing stale tailings of flotation plants of the copper pyrite complex. The resource potential, material composition and technological capabilities of processing a number of technogenic objects are considered. The interrelation and influence of mineralogical and technological factors on the choice of tailings processing technology are analyzed. The results of chemical, mineral and phase analysis of stale flotation tailings of the studied pyrite ores are presented. According to the complex studies’ results, it is established that the stale flotation tailings of copper pyrite ores belong to a refractory type of geo-resources due to the high content of pyrite and low, at the level of ppm, gold and silver content, which are present mainly in the “resistant” minerals - chalcogenides, sulphides, their intergrowths. The article presents a factor analysis and conditions for the elemental composition of tailings formation: mineralogical, technological and environmental. The territorial accessibility and technological capability of the investigated technogenic formations are analyzed. In the course of experimental studies, the elemental composition of stale tailings has been revealed - the main components of which are: iron, sulfur, silicon and aluminum. According to the results of X-ray phase analysis, it has been found that the main ore mineral of the tailings is pyrite. At the same time, it is noted that the main share of gold in the stale flotation tailings is presented in the form of sulphides in the form of finely dispersed and isomorphic inclusions. The heterogeneous morphometric and mineral composition of sulphide aggregates, their difficult opening and high dispersion characterize stale tailings as a raw material that is difficult to float. The revealed features of the material composition of stale tails indicate the impossibility of extracting valuable components (gold and silver) from this resource using existing traditional technologies. It has been proved that it is possible to effectively extract precious metals from this category of raw materials only after their deep opening by chemical processing. The relevance of the research lies in the need to process gold-containing man-made waste in order to significantly expand the raw material base of mining enterprises, as well as to improve the ecological situation of the city-forming mining enterprises of the South Urals. The aim of the research is to study the material composition of stale tailings and develop a technology for selective extraction of gold and silver. The object of research is the stale flotation tailings of copper-pyrite enterprises of the Southern Urals. The subject is the mineral composition, the content of useful components of lying tailings and the technology of gold and silver selective extraction from them. Material and research methods. During the experiments, a set of physicochemical and chemical methods of analysis has been used: thermodynamic analysis, synchronous thermal analysis using a combined thermal analyzer of the Netzsch STA 449 F3 Jupiter brand, UV spectroscopy with an automated data processing system), qualitative chemical and assay analyzes

Geomechanical testing on the landslide at the Čukaru Peki flotation tailing dump

During formation of the flotation tailing dump Čukaru Peki, a landslide was activated above the mentioned location, which led to a standstill and endangerment of works. In order to obtain the geotechnical bases for designing the measures for its rehabilitation, the landslide tests were performed. Geomechanical works included the field research and testing, laboratory geomechanical testing and cabinet work

Hydrometallurgical Processing of the Wastes of Polymetallic Ore Dressing

The possibility of hydrometallurgical treatment of old flotation tailings to extract base and noble metals was investigated. Two samples of old flotation tailings samples containing 0.26% and 0.36% of copper, and 0.22% and 0.23% of zinc were the subjects of this study. Agitation and percolator leaching was performed with distilled water and sulfuric acid solutions (of 0.5 to 10% H2SO4). It was shown that under certain conditions (sulfuric acid concentration) it was possible to achieve selective leaching of non-ferrous metals and obtain solutions with relatively low concentrations of iron ions, which is necessary for further effective extraction of non-ferrous metal ions from the solution. The effect of acid leaching on further gold recovery from the first sample containing 0.7 g/t of gold by cyanidation was investigated. The sample of the tailings after leaching with a 1% sulfuric acid solution was leached with 10% sulfuric acid. After that, the tailings sample and the acid leach residues were subjected to sorption cyanidation. Two-stage acid leaching with 1 and 10% sulfuric acid provided the higher gold recovery than one-stage (49 and 65%, respectively). Also it was shown that pregnant solution obtained during leaching of the second sample with 10% sulfuric acid may be used for oxidative leaching of substandard copper-zinc concentrate that allowed to 13 and 48% of copper and zinc from the concentrate during the leaching at 80∘C.
 Keywords: flotation tailings, leaching, substandard sulfide concentrates

Optimization in the Recovery of Zinc of polymethalic minerals through the flotation process in the company Mines and Metals Trading Perú - Huancavelica

The main objective of this research work was to optimize the recovery of zinc in the second stage of flotation of polymetallic minerals of the company Mines and Metals Trading Peru where its average annual recovery of zinc is 82%. At the concentrator plant, two samplings were carried out, the first one of fresh mineral in the belt No. 01 that feeds the primary grinding and the pulp were obtained from the bulk Pb / Ag flotation tails. During the study, preliminary flotation tests were carried out in order to select the most influential independent variables in the dependent variable using the MINITAB statistical program. Flotation tests were performed varying the dosage of copper sulfate (g / TM) and regrind time (minutes). With the results obtained, the optimization with the Hexagonal Design is carried out, obtaining maximum values of copper sulfate of 351.06 gr / TM and regrinding time of 5.06 minutes. With these results a theoretical recovery of 95.54% is obtained.

Processing of the lead-zinc ore from the Pavlovsk deposit

The authors carried out a mineralogical study and substantiated a concentration process developed for the lead-zinc ores of the Pavlovsk deposit. The concentration of the valuable component in each type of concentrate is determined by the amount of pyrite contained in the ore. It was established that the main loss of lead with flotation tailings is associated with oxidized phases, which are mainly found in fine material. Lead sulphides account for 30% of the entire waste tailings. Using the results of the mineralogical study, a flotation process was developed that involves a staged separation of commercial lead and zinc concentrates, as well as waste tailings. The obtained zinc concentrate has a consistently high quality of 57–58% with an 85–90% recovery. The metal concentration in the lead concentrate 1 is 45%, with the recovery being 43%. On the basis of the experimental results, the authors propose to use an X-ray radiometric separation method for coarse ore, which will help reduce the amount of incoming ore by 30% while minimizing the loss of lead and zinc.

Исследование химического состава промышленных отходов Кадамжайского сурьмяного комбината

This article investigates the chemical composition of industrial waste (dump slag and flotation tailings). This study, in contrast to previous studies, was carried out by chemical, atomic emission, X-ray fluorescence methods. Valuable rare earth chemical elements (ytterbium, yttrium, lanthanum, scandium), valuable chemical elements (antimony, titanium, vanadium, tungsten, niobium, indium, germanium, gallium, tantalum, molybdenum, strontium, beryllium, zirconium, cobalt) and others have been determined. The oxides of elements (SiO2, Al2O3, MgO, CaO, Fe2O3, Na2O, K2O, S, FeO) have been investigated. Toxic elements (arsenic, cadmium, tin, lead). These studies were carried out with the aim of using man-made waste in various sectors of the national economy for the disposal of man-made waste and to improve the environmental situation in the region and reduce material costs for the production of new products.

Bioleaching for detoxification of waste flotation tailings: Relationship between EPS substances and bioleaching behavior

The production of large volumes of waste flotation tailings results in environmental pollution and presents a major ecological and environmental risk. This study investigates bioleaching of waste flotation tailings using Acidithiobacillus ferrooxidans. The experiments were performed with 5.00% solid concentration, pH 2.0 with 100 mL medium for 25 d in the lab. The pH, OPR, metal concentration, dissolved organic matter (DOM) in leachate and extracellular polymeric substances (EPS) were recorded. Bioleaching tailing materials were finally characterized. Results showed that microorganisms, acclimating with mine tailings, effectively accelerated the bioleaching process, achieving maximum Zn and Fe extraction efficiencies of 95.45% and 83.98%, respectively, after 25 days. Compared with raw mine tailings, bioleaching could reduce 96.36% and 95.84% leachable Zn and Pb, and Pb presented a low risk (4.13%), while Zn, Cu, and Cr posed no risk (0.34%, 0.64%, and 0%). Toxicity and environmental risk analysis revealed bioleaching process significantly reduced the environmental risk associated with mine tailings. EPS analysis indicated that the loosely-bound EPS (LB-EPS) and tightly-bound EPS (TB-EPS) fractions contained different organic substances, which played different roles in the bioleaching process. Pearson correlation analysis revealed that EPS was highly correlated with bioleaching behavior (p < 0.05), and EPS was the main factor affecting the bioleaching process, promoting bioleaching in the LB-EPS and TB-EPS fractions.

The use of carbon-containing wastes of aluminum production in ferrous metallurgy

The article discusses the prospects of recycling the most massive wastes of aluminum production (namely, used cathode blocks of electrolyzers, gas treatment dust, gas treatment residue, and flotation tailing). It have been indicated the volumes of wasteaccumulation and a special attention has been focused on the need of their disposal with a view to improve the environmental conditions of the territories adjacent to the industrial zones. Specific characteristics of the generated waste have been determined, which indicate the possibility of their secondary use and transfer from waste to by-products.Existing technical solutions relevant to the issue have been reviewed, and the reasons preventing their implementation have been explained. The most promising methods of waste processing to be carried out successfully in the current economic conditions have been identified. Spent cathode blocks can be used at ferrous metallurgy enterprises (in blast furnaces and converters) as a substitute for expensive coke and fluorspar, and finely dispersed waste can be used at cement enterprises. The areas have been determined that in the future will significantly increase the volume of processing and the demand for these wastes of the aluminum industry in technological processes of ferrous metallurgy. The possibilities for cooperation between aluminum refineries and ferrous metallurgy enterprises, as well as other related industries, were emphasized in detail.

Sequential Bioleaching of Pyritic Tailings and Ferric Leaching of Nonferrous Slags as a Method for Metal Recovery from Mining and Metallurgical Wastes

In this work, we proposed a method for biohydrometallurgical processing of mining (old pyritic flotation tailings) and metallurgical (slag) wastes to recover gold and other nonferrous metals. Since this processing allows the removal of toxic metals or at least decreases their content in the solids, this approach may reduce the negative environmental impacts of such waste. The proposed process was based on pyritic tailings’ bioleaching to recover metals and produce leach liquor containing a strong oxidizing agent (ferric sulfate) to dissolve nonferrous metal from slag. This approach also allows us to increase concentrations of nonferrous metals in the pregnant leach solution after pyritic waste bioleaching to allow efficient extraction. The old pyritic tailings were previously leached with 0.25% sulfuric acid for 10 min to remove soluble metal sulfates. As a result, 36% of copper and 35% of zinc were extracted. After 12 days of bioleaching with a microbial consortium containing Leptospirillum spp., Sulfobacillus spp., Ferroplasma spp., and Acidithiobacillus spp. at 35 °C, the total recovery of metals from pyritic tailings reached 68% for copper and 77% for zinc; and subsequent cyanidation allowed 92% recovery of gold. Ferric leaching of two types of slag at 70 °C with the leachate obtained during bioleaching of the tailings and containing 15 g/L of Fe3+ allowed 88.9 and 43.4% recovery of copper and zinc, respectively, from copper slag within 150 min. Meanwhile, 91.5% of copper, 84.1% of nickel, and 70.2% of cobalt were extracted from copper–nickel slag within 120 min under the same conditions.

Recovery of zinc and lead from Yahyali non-sulphide flotation tailing by sequential acidic and sodium hydroxide leaching in the presence of potassium sodium tartrate

The recovery of zinc and lead from Yahyali non-sulphide flotation tailing using sulfuric acid followed by sodium hydroxide leaching in the presence of potassium sodium tartrate was experimentally investigated. In the acidic leaching stage, the effects of pH, solid-to-liquid ratio and temperature on the dissolution of zinc from the tailing were explored. 82.3% Zn dissolution was achieved at a pH of 2, a temperature of 40 °C, a solid-to-liquid ratio of 20% and a leaching time of 2 h, whereas the iron and lead dissolutions were determined to be less than 0.5%. The sulfuric acid consumption was found to be 110.6 kg/t (dry tailing). The leaching temperature had no beneficial effect on the dissolution of zinc from the tailing. The acidic leach solution was subjected to an electrowinning test. The cathode product consisted of 99.8% Zn and 0.15% Fe. In the alkaline leaching stage, the Pb dissolution increased slightly in the presence of potassium sodium tartrate. More than 60% of Pb was taken into the leach solution when the leaching temperature increased from 40 to 80 °C. The final leach residue was analyzed by XRD and XRF. The XRD results indicated that the major peaks originated from the goethite and quartz while minor peaks stem from smithsonite and cerussite. The XRF analysis demonstrated that the residue contained 70.3% iron oxide. Based on the sequential leaching experiments, the zinc and lead were excellently depleted from the flotation tailing, leaving a considerable amount of iron in the final residue.

Forecasting mass and metallurgical balance at a gold processing plant using modern multivariate statistics

Knowing the quantity and the quality of products and tailings generated by a beneficiation plant, even before ore processing, can make the mining operations more sustainable, more profitable, and safer. To forecast these values, it is necessary to submit samples to batch tests which mimic the processing workflow used on an industrial scale. Then, the results need to be analysed with the aim of finding a statistical model able to comprehend how Run of Mine (ROM) characteristics impact the performance at the beneficiation. After developing a model, it is possible to apply it to blocks where the ROM characteristics are known, but the metallurgical information is not, making it possible to estimate these. With this goal, a geometallurgical model was developed with a neural network technique using 37 samples collected at two Brazilian gold mines. The Au and S grades in ROM, and the mine from where the sample was collected, were used as input variables. The model was able to forecast the following variables with a Pearson correlation coefficient on the cross validation test set equal to the value in parenthesis: mass (0.55) and metallurgical (0.54) recovery in the gravimetric concentrate, mass (0.80) and metallurgical (0.12) recovery in the flotation tailings, mass (0.77) and metallurgical (0.11) recovery in the leaching tailings, mass recovery (0.84) of gas sent to the sulphuric acid plant, and metallurgical recovery (0.65) in the leaching concentrate. The results obtained with neural networks were superior to the ones obtained when three alternative techniques were tested.

Cassiterite recovery from a sulfide ore flotation tailing by combined gravity and flotation separations

Cassiterite recovery from a sulfide ore flotation tailing by combined gravity and flotation separations