Flotation Products Research Articles

Reverse flotation process in double stage on the Algerian phosphate ore treatment

Purpose. In this work, the influence of flotation reagents on the separation yield of the phosphate-carbonate system is studied. The investigation is conducted by the reverse flotation process in double stage of the phosphate ores from the Jebel Onk deposit-Algeria. Methodology. The experimental part can be divided into three aspects, a mechanical preparation of the samples, and flotation tests in the first stage followed by a double flotation and, finally, characterization of the flotation products by different physical-chemical analysis techniques. Findings. Reverse flotation double stage process was applied on two classes of phosphate ores (C1: 40–250 and C2: 250–500 m). The samples are constituted by phosphatic elements (apatite), cemented by a mixture of a great amount of dolomite with low amounts of quartz, clay and calcite. Flotation results showed that P2O5 recovery was higher for C2 compared to C1. Thus, oleic acid and double tartrate of sodium-potassium could be considered as the best reagent since the P2O5 recovery content corresponds to 29.27 and 31.25 % for C1 and C2, respectively. Compared to the oleic acid and pine oil reagent, the recoveries of P2O5 were 28.85 and 30.55 % for C1 and C2, respectively. However, when other reagents as (oleic acid  phosphoric acid) and (oleic acid + diesel fuel) were used, the recovered amount of P2O5 was found to be less important, 27.80 and 27.10 % for class C1, and 30.14 and 29.15 % for C2, respectively. Originality. During this study two main axes were discussed: the first one was the influence of flotation reagents on flotation of the first and second stages, the second one was to study the effect of grain size on the flotation yields. The flotation process has been shown to be effective both in terms of depressed phosphate elements in the phosphate concentrates and in gangue floated in the flotation tailings. It can be seen that the concentrate contents of around 32 % is achieved in P2O5 with superior recoveries of 99 %. Practical value. The results of analyses carried out on the flotation products showed, in most cases, that the streams are richer in phosphate elements (fluorapatite, carbonate hydroxylapatite, carbonate fluorapatite) and a low amount of carbonates (dolomite and calcite), unlike floating, mainly made up of dolomite with a small amount of phosphated elements.

Study of gold-bearing ore bonification ability

The paper presents the study results on the gold benification and increase of gold extraction in the flotation cycle of ore from the Vasilkovsky deposit. The composition of the initial ores was studied. Based on mineralogical, XRF, chemical assay, atomic absorption, X-ray phase and rational analyses the following types of gold were identified: fine gold; gold associated with sulfides in chalcopyrite, pyrite and arsenopyrite; and fine-disseminated gold in silicates. It was established that the ore belongs to the gold-quartz and gold-sulfide types with free and cyanided gold. Our results allow us to optimize the ore flotation reagent mode and the crushing size class. Butyl xanthate was used as a collector; C7, aeroflot, was used as a foaming agent; sodium sulfide (Na2S) was used as a sulfidizer; dispersion mode was additionally applied. It was established that an increased pH value of the initial pulp up to 9,0 is required to boost the efficiency of flotation beneficiation. The gold extraction in the concentrate is 82,49 %. This experiment and mineralogical analysis of flotation tailings has established the optimal fineness of the fractions for flotation (0,1 +- 0,071 mm) as well as the inexpediency of additional milling, due to the fine free and quartz-embedded gold that does not pass into the concentrate during the subsequent flotation. The mineral analysis of the flotation products showed that the main sulfide mineral of the concentrates is arsenopyrite; pyrite and chalcopyrite. Flotation tailings contain host vein rock. Gold found in flotation tailings samples has round and oval shape, which is inefficient for flotation.

The distribution law of coarse particles in coal flotation and its density-size partition surface model

ABSTRACT In the process of coal preparation, large particles are often misplaced into the flotation feedings due to poor classification, and thus bring about negative effects on flotation results. In this paper, batch flotation tests of 0.5–2.5 mm were carried out at different reagent dosage to quantitatively analyze the effect of particle size and density on flotation. Flotation partition curves in corresponding conditions were plotted based on sizing analysis and float-and-sink tests of flotation products. Generalized skew-normal distribution model based on quartile was used to fit the experimental data and the variation rules of separation density, probable error and skewness, etc. with particle size and reagents were obtained, and the density-size partition surface mathematical model was established. The results show that floating ratio decreases with density and particle size. The separation density and probable error both decreases with particle size. The values of skewness were negative and tended to 0 with the decreasing of particle size. As the dosage of reagents increased, the separation density increased, the probable error increased slightly, and the difference of absolute values of skewness decreased. The research results put forward the theoretical instruction of expanding the upper limit of floatable size of particles and improving flotation efficiency.

Segmentation algorithm of coal slurry foam with double-point directional extension based on the improved FCM clustering algorithm

In flotation production, the visual surface information of the flotation foam reflects the flotation effects, which are closely related to the flotation conditions and directly reflect the degree of mineralization of the foam layer. In this study, it was proposed a novel and efficient segmentation algorithm to extract the edge information of slime bubbles, as the boundaries are typically blurred and difficult to segment, due to the slime bubbles sticking to each other in the slime flotation foam image. First, the improved clustering algorithm and image morphology operation were used to extract the edges of the foam spots. Second, the image morphological operations were used as a starting point to look around the foam edge points. The pseudo-edge points were then removed using a region and spatial removal algorithm. Finally, the foam edges were extracted using the double-point directed expansion algorithm. A new criterion was proposed for segmentation effect determination based on the particularity of the segmented object. The feasibility and effectiveness of the foam segmentation method were investigated by comparative experiments. The experimental results showed that the proposed algorithm could obtain the foam surface properties more accurately and provide effective guidance for flotation production.

Особливості коагуляції частинок та адсорбція реагентів на поверхні пінного продукту флотації .

Особливості коагуляції частинок та адсорбція реагентів на поверхні пінного продукту флотації .

Прогнозная оценка технологических показателей при обогащении железистых кварцитов

Прогнозная оценка технологических показателей при обогащении железистых кварцитов

On the flotation activity of reagents with a nitrile group in the flotation of copper-nickel ores

This paper considers the use of compounds having a nitrile group, such as Tecflote S10, S11, S12, and S13, as potential collectors in the flotation of sulfide copper-nickel ore. Tecflote S12, S10, and S13 reagents are substituted aminonitriles with one or two nitrile groups, differing by the hydrocarbon radical R, with its length in the range of C10–18. Tecflote S11 is a dimer with only two nitrile groups. Respective copper- and nickel-containing minerals were subjected to test hydrophobization when exposed to these reagents in frothless flotation using two ore samples characterized by higher chalcopyrite/pentlandite and nickel-bearing pyrotine grades. This paper shows the distribution of copper and nickel in the resulting frothless flotation products. A comparison of the results obtained when using aqueous and hexane solutions of the collector has demonstrated that Tecflote S12 is more efficient for nickel-containing minerals due to the possibility of direct interaction of the mineral particle with the collector in the volume of the solution. The formation of a Tecflote S12 complex with non-ferrous metal atoms is evidenced by the presence of broad bands corresponding to copper and nickel ions in the region of 290–360 cm–1 Raman spectrum in the compounds obtained by extraction from the aqueous solutions of copper and nickel chlorides. The flotation tests carried out using a sample of finely disseminated refractory copper-nickel ore from the Pechenga ore field have showed that feeding Tecflote S12 into the main flotation cycle, combined with xanthate and aeroflot, allows improving the yield of the finished concentrate and ensures lower nickel losses with tailings.

The impact of indigenous microorganisms on coal flotation: A new perspective on water consumption

Coal preparation plants are devoted to finding new strategies for reducing fresh water consumption, however, rarely taking consideration on slurry microorganisms. The impact of the abundant microorganisms on coal flotation, especially the isolated indigenous bacteria Bacillus sp. QX4 was systematically investigated in this study. Orthogonal experiments involved in parameters of concentration of microorganisms, collector and frother were conducted. The response surface analysis showed that the concentration of microorganisms was the main factor affecting flotation recovery and water consumption. With the amount of microorganisms increased from 105 to 108 cells/ml, clean coal yield decreased by 15 %, and water consumption increased by as high as 30 %. The characterization of the coal showed that the attachment of microorganisms increased the number of oxygen-containing functional groups onto the coal surface, and the contact angle of coal decreased from 79.5°to 56.6°. In addition, the net negative zeta potential decreased after microorganism addition, which improved the froth stability and weakened the coal’s attachment to the collector molecules. Further evaluation showed that the transfer of water reduced the calorific value of the clean coal by about 500 kcal/kg while increasing the carbon emission during combustion by about 5.9 %. This study provides a new perspective on the reverse impact of indigenous microorganisms on fresh water consumption and flotation product in coal flotation, which can potentially help efficient operation involved in optimizing water management of coal preparation plants.

A new strategy for selective recovery of low concentration cobalt ions from wastewater: Based on selective chelating precipitation-flotation process

BackgroundA significant amount of low-concentration heavy metal ion wastewater is generated daily by the mining and metallurgy industry, endangering human health and the environment. A novel method of selective chelating precipitation–floatation of copper and cobalt ions is proposed for the recovery of cobalt from wastewater. MethodsBased on the chelation of cobalt and copper ions with α-nitroso-β-naphthol (NN), the flotation process is adopted to solve the problem of fine particle separation from solution in low-concentration ions removal. Significant findingsUnder the optimized precipitation flotation conditions, the flotation recovery ratios of the copper, cobalt, and zinc ions were found to be 98.47%, 42.48%, and 9.35%, respectively, and the separation effect of cobalt and zinc showed to be outstanding, as their separation factor reached 598. Industrial wastewater also has a good flotation separation effect. Based on the mechanism studies, Co2+/Co3+ and Cu2+ were selectively chelated by NN to form hydrophobic NN-Co/Cu precipitation particles. Moreover, electrostatic attraction is the main force in the proposed flotation process. Eventually, we tried calcination to recycle the flotation products to verify the potential of the cobalt–copper composite oxides in capacitor materials. The results prove that the precipitation–flotation method has great efficiency and potential for selectively recovering low-concentration metal ions and separating fine particles from solution.

Mineralogical characteristics of copper smelting slag affecting the synchronous flotation enrichment of copper and arsenic

Synchronous enrichment of copper and arsenic has become a newly emerging and significant problem during copper smelting slag (CSS) flotation, which affects environmental safety and CSS utilization. This study on CSS and its flotation products revealed the factors that affect the flotation enrichment of copper and arsenic from a mineralogy perspective. Mineralogical characteristic studies revealed that copper existed primarily in the form of matte with excellent floatability, whereas arsenic was primarily dissolved or wrapped in glassy silicates without floatability. The second occurrence phase of copper and arsenic, copper–arsenic alloy, was closely embedded with gangue minerals, which increased the difficulty of enriching copper and arsenic. Sequential extraction and X-ray photoelectron spectroscopy analysis indicated that the floatability of copper was better than that of arsenic. Flotation tests showed that copper recovery could reach 82.79 %, whereas arsenic recovery was only 40.83 %, which further confirmed that copper and arsenic could not be enriched synchronously. Mineral phase reconstruction was proposed as a potential scheme to enhance arsenic recovery. Arsenic was released from glassy silicates and combined with a copper-bearing phase to form copper–arsenic alloy during mineral phase reconstruction, which significantly increased arsenic recovery by 39.34 % and slightly increased copper recovery. The synchronous enrichment of copper and arsenic effectively reduces the total arsenic emission during copper pyrometallurgy, thereby alleviating the pressure of environmental pollution caused by CSS flotation tailings. This work provides a scientific reference for CSS processing toward recycling and harmlessness.

Prediction model of iron reverse flotation tailings grade based on multi-feature fusion

During the production of iron in reverse flotation, obtaining real-time froth grade values helps to adjust the reagent regime to ensure the quality of the beneficiated product and save production costs. In predicting the froth grade, it is necessary to segment the froth image to extract bubble size features. In this study, an improved U-net algorithm with a focus mechanism is proposed to effectively avoid under-segmentation and over-segmentation and to extract bubble size features. Through the analysis, the bubble color features that are beneficial to the rank prediction are identified. A multi-feature fusion deep neural network model based on Resnet is established to predict the bubble grade values. The test results indicate that with sufficient accuracy, the model can be employed in reverse flotation production.

Studies into detection of amine-containing flotation agents in ore processing products as a component of technosphere safety

In mining and processing using amine-containing flotation agents (AC-F), the technosphere safety necessitates the production ecology control and monitoring, including AC-F concentration measurement using certified methods to ensure prompt adjustment of the environmental protection activities. In the absence of such methods, they must be developed, validated, verified, certified and entered into the Federal State Information System (FGIS) Arshin. When new objects appear, for instance, other amino-containing flotation reagents or other ore deposits, it is necessary to carry out validation of previously certified methods for specific application conditions, or these methods must be newly developed. In this work, the methods developed by JSC NPO RIVS and by the Mendeleev All-Russian Research Institute of Metrology were used for the specific conditions of AC-F application at Lebedinsky GOK. The methods are certified and included in the FGIS. The influence of temperature and time factors on the stability of AC-F, and on their desorbability from the solid phase of flotation products was studied. The use of the developed techniques makes it possible to determine that in the pulp tailings, the inverse AC-F desorption processes than in flotation can take place, which leads to an increase in the AC-F concentration in recycling water. However, over time, AC-F undergo chemical transformations and the content of AC-F in recycling water and in waste decreases. As the temperature increases, decomposition of AC-F intensifies. The authors appreciate participation of Candidate of Engineering Sciences O. Yu. Poperechnikova, Director of R&D Department, and B. V. Bala, a Sector Head at the R&D Department, NPO RIVS, in this study.

Joint recovery of graphite and lithium metal oxides from spent lithium-ion batteries using froth flotation and investigation on process water re-use

Spent lithium-ion batteries (LIBs) contain critical raw materials that need to be recovered and recirculated into the battery supply chain. This work proposes the joint recovery of graphite and lithium metal oxides (LMOs) from pyrolyzed black mass of spent LIBs using froth flotation. Since flotation is a water-intensive process, the quality of the aqueous phase directly impacts its performance. In pursuit of an improved water-management strategy, the effect of process water recirculation on black mass flotation is also investigated. The fine fraction (<90 µm) of the black mass from pyrolyzed and crushed spent LIBs was used. After flotation, 85% of the graphite in the overflow product and 80% of the LMOs in the underflow product were recovered. After flotation with 8 wt% solids, the process water contained about 1,000 mg/L Li and accumulated up to 2,600 mg/L Li after three cycles. The flotation with process water showed no significant impact on the recovery and grade of flotation products, suggesting the feasibility of water recirculation in black mass flotation.

Using Process Mineralogy as a Tool to Investigate Blending Potential of the Pentlandite-Bearing Ores at the Nkomati Ni Mine in South Africa

The mineralogy and texture of Ni-sulfide ores at the Nkomati nickel mine are highly variable, and this results in often erratic nickel recovery at the mine. The variability of the ore presents an opportunity to study the influence of grind size on the flotation-based recovery of Ni in highly heterogeneous sulfide ores, which would be applicable to this ore type at many other mines worldwide. In view of this, a process mineralogy investigation was conducted on thirteen mineralogically and texturally different nickel-sulfide ores from the Nkomati Nickel Mine, with a view on the influence of grind size on the flotation performance of pentlandite. Ore types presented include medium- and high-grade variants of the bleb, disseminated, massive, semi-massive, and net-textured sulfide ores of the Main Mineralized Zone (MMZ), as well as disseminated chromite-rich nickel sulfide ore and massive chromitite ore of the Peridotitic Chromitite Mineralized Zone (PCMZ). Laboratory scale metallurgical test work, comprising of sequential grinding and bench-top flotation testing of the ores, was conducted in combination with quantitative mineralogical investigation of the flotation feed and associated flotation products, using a FEI 600F Mineral Liberation Analyzer. The ore types under consideration require a variety of grind sizes (i.e., milling times) in order to attain optimal recovery of nickel through flotation. This is predominantly controlled by ore texture, and also partly by the abundance of the major constituent minerals in the ore, being pyroxenes, base metal sulfides, and chromite. Liberation of pentlandite is directly correlated with grind size (milling time), which is also positively correlated with the level of nickel recovery through flotation. A grind size of P80 at 75 µm results in the highest concentrate nickel grades of 7.5–8.1% in the PCMZ ores’ types which is the current grind for the PCMZ ores at Nkomati. A grind size of P77 at 75 µm yields the best overall pentlandite liberation, Ni recoveries of 84–88% and grades of 5.3–5.6% in the MMZ ores. This holds the potential to produce the best overall pentlandite liberation, nickel grades, recoveries from blending the MMZ and PCMZ ore types, and milling the composite ore at a target grind of P80 at 75 µm.

Soft sensor of iron tailings grade based on froth image features for reverse flotation

In the iron reverse flotation production process, the amount of flotation agent and the quality of flotation products are usually judged according to the grade of tailings, so it is essential to measure the grade of tailings froth. This research applies computer vision and image feature extraction technology to the soft sensor of tailings froth grade. An adaptive selection method for the image target region is proposed. The relationship between RGB (Red, Green, Blue), HSI (Hue, Saturation, Intensity), and Lab color space and tailings grade of reverse flotation in iron mine has been analyzed. A new image feature is proposed to characterize the degree of froth mineralization. The RGB and HSI dual color space feature values and froth mineralization degree values are determined as input, and the tailing grade soft sensor model is established by the multilayer feedforward perceptrons and VGG-19 neural network. A tailings grade soft sensor system has been developed and applied in a flotation workshop. The results of industrial tests show that this method is efficient and reliable.

Regulation of hydrogen bonding on microbubble flocs in the hybrid ozonation-coagulation (HOC) process enhances organic matter removal

The separation zone in flotation is generally considered the site of solid-liquid separation of insoluble particles. However, the residual dissolved organic matter (DOM) can be effectively removed in the separation zone of the hybrid ozonation-coagulation (HOC) process was firstly discovered. DOM removal in the separation zone was mainly attributed to the in-situ formation of microbubble flocs mediated by the interaction between ozone and flocs. Ozone can regulate the oxygen containing groups on the surface of flocs, which induces formation of multilayer reaction sites. Hydrogen bonding to polar oxygen containing groups on microbubble flocs was the dominant driver of DOM removal, and –COOH and –OH were identified as the surface hydrogen bond donors. This indicated that the hydrogen bond reaction can be enhanced by the modification of ozone for flocs in the separation zone. Furthermore, surface hydroxyl groups formed by the Al acted as active sites for the connection between ozone and flocs. Ozone accelerated the transformation of tetrahedral Al to octahedral Al in flocs, which can enhance microbubble flocs generation. Moreover, microbubble floc-HA, a flotation product, exhibited higher surface hydrophobicity than conventional flocs, which resulted in high flotation efficiency.

Study of the effect of pH, conditioning and flotation time on the flotation efficiency of phosphate ores by a soybean oil collector

The mid-low grade of phosphate ore, rich by the silicate and carbonate gangue minerals needs a special treatment using the flotation process. Where the collectors play a pivotal role. This study was conducted to enrich an untreated phosphate ore (without washing, desliming, hydrocycling, etc.), with an eco-friendly and economic collector based on soybean oil. Different analytical techniques such as UV-Visible, ATR-FTIR spectrometric and XRD were used in order to analyse and characterize the flotation products. The effects of the parameters, pulp pH, conditioning time and flotation time on gangue removal efficiency by flotation, were investigated. Flotation tests were applied for granulometric class (90 mm to 125 µm). Consequently, a good quality phosphate concentrate was obtained in an acidic medium (pH = 4.05) with 1 g of soybean oil soap collector, 20 min flotation time, 10 min conditioning time, 0.17 L×min-1 air superficial velocity, 800 rpm at 25℃ and 6% solid content. The concentrate contained 29.0% phosphorus pentoxide (P2O5), with a recovery of 94.5% from a feed sample containing about 24.5% P2O5.

CARRIER FLOTATION BY CHAR SLIME - WASHING OF ŞIRNAK ASPHALTITE SLIMES

Şırnak asphaltite slime below 200 micron size is processed. The clean coal products of the column flotation are received with mid-products and shale settlements in the modified column cell in the baffled form. The use of hydrocyclone, agglomerate thickener and wash decantation has been a suitable potential method after the driven and internal loop column flotation. With this method, ultrafine sized oily sludges with high efficiency and low solid rate coal washing are provided. It also enabled highly efficient wastewater treatment as a result of separating the oil with czar foam. Therefore, the method applied in this study can be designed as an optimum wastewater treatment technology for the treatment of oily wastewater in the oil and drilling industry. The aeration process in internal loop column flotation with air jet is widely used in lake water treatment and fresh water treatment. In this study, internal loop carrier column flotation, hydrocyclone overflows and agglomeration process are optimized for coal washing and environmental wastewater treatment. The ash and sulfur contents decreased to a level of 48% ash reduction and a 34% sulphur reduction

Enhanced flotation mechanism of coal gasification fine slag with composite collectors

In this study, different composite collectors were used to analyze the flotation separation of residual charcoal and ash materials in fine coal gasification slags. The effects of collector type, stirring speed, and conditioning time on the flotation separation were investigated. The experimental results showed that composite collectors containing dodecylamine polyoxyethylene ether (AC1201) and kerosene could effectively separate charcoal-ash when treating the fine coal gasification slags of Ningxia Coal Industry Company. The ash content of the residue carbon product was approximately 60%, and that of the ash material product was more than 95%. Compared with kerosene, AC1201-kerosene collector can be dispersed more easily and lower interfacial tension in collector-deionized water system, resulting in better selectivity of the collector. The composite collector containing 15% AC1201 has stronger adsorption on residual charcoal compared with kerosene at the same dose, owing to electrostatic mechanism. The addition of AC1201 in kerosene resulted in better adsorption on residual charcoal than ash material, the hydrophobicity difference of two materials can be further expanded, resulting in increased tailings ash and combustible recovery. The flotation products, including the concentrate and tailings of fine coal gasification slag, were evaluated by means of infrared spectrum analysis, X-ray photoelectron spectroscopy (XPS) analysis, and scanning electron microscope energy spectrometer (SEM-EDS) to characterize the different compositions and elemental distributions. The results of this study provide a reference for analyzing charcoal-ash flotation separation and its mechanism.

Prediction of coal flotation performance using a modified deep neural network model including three input parameters from feed

ABSTRACT Flotation is an effective method widely used in coal preparation. However, the complexity of the flotation process and the actual production site make the quality detection of flotation products mainly depend on manual work. This makes the automation of the flotation process and the stability of product quality difficult. Furthermore, the published literature indicates commonly using only a few dozen data sets and application of traditional machine learning methods to predict the flotation performance. In this study, a total of 641 sets of valid data were collected for training and validation of the model. On this basis, a deep neural network (DNN) model was built to predict the quality of flotation products. 80% of the total data were used for training, and 20% for testing the DNN model. To improve the prediction accuracy and generalization performance of the model, a data augmentation method was applied and a new loss function was proposed. Finally, a DNN model was obtained, which is capable of maintaining high prediction accuracy by simply adjusting the input parameters while the feed properties are changing.