Flotation Operation Research Articles

Design and Development of a 0.012 m<sup>3</sup> Froth Flotation Machine from Locally Sourced Materials

The desire to design and develop machine with high versatile method of physically separating mineral particles based on differences in the ability of air bubbles to selectively adhere to specific mineral surfaces in mineral/water slurry using indigenous materials is constantly evolving to meet specific requirements of specific industrial plant. Therefore, the aim of this study was to design and construct a 0.012 m³ capacity laboratory froth flotation machine using locally sourced materials with the view to promoting indigenous technology in Nigeria. The construction was based on parameters established from literatures. The design was done using Auto-Cad version 7 software. The machine was built of different components which are corrosion resistant, easy to access and can be assembled and disassembled when the need arises. The machine was constructed such that its height can be adjusted to suite flotation characteristics of different materials. The machine was of height 1.5 m and designed to operate at batch condition. A flotation tank of capacity 0.012 m³ holds the pulverized pulp mixture for flotation operation. The flotation tank was equipped with regulated speed agitator shaft and stirrer assembly to condition the pulverized pulp mixture. Regulated air flow from a 0.02 m³/min compressor was also applied to the mixture in the cell for effective hydrophobicity and hydrophilicity.

Improvement of reagent flotation modes of sphalerite and pyrite from deposits of copper-zinc pyrite, polymetallic copper-zinc pyrite and polymetallic ores

Copper-zinc pyrite (Sulphide) and polymetallic ores of Russia are complex and difficult to process mineral raw materials. The main technology for the enrichment of this ores are flotation. Currently, the improvement of the flotation technology of this mineral raw materials is carried out in several way. It has been established by the practice of beneficiation of copper-zinc ores that obtaining high-quality zinc and pyrite concentrates is impossible without adding flotation modifiers of sphalerite and pyrite to various flotation operations. This reagent are copper (II) sulfates, zinc and iron (II) sulfates in an alkaline calcareous medium. Therefore, studies on the flotation of sphalerite and pyrite in an alkaline calcareous medium with the addition of one of these metal sulfates to the mineral flotation operation were performed. The effect of each copper (II) sulfates zinc, and iron (II) on the flotability of sphalerite and pyrite was studied during flotation of the mineral and xanthate and dithiophosphate at pH = 8, 10, and 12. The aim of this work was to study the effect of the flotation size class (- 0.074 + 0.044 mm) sphalerite and pyrite of one of the Russian deposits by sulfhydryl collectors in the presence of copper, zinc and iron sulfates in the liquid phase of flotation pulp

Thermodynamic and experimental studies on removal of calcium and sulfate ions from recycling water of complex sulfide flotation operations

A chemical method for removing calcium sulfate saturated solutions (0.016 mol/L CaSO4) using barium chloride (BaCl2·2H2O) and sodium phosphate (Na3PO4) was experimentally studied. The main interest is to remove these ions from the solution through the precipitation of two solid species: sulfate (SO42−) as barite (BaSO4), and calcium (Ca2+) as hydroxyapatite (Ca5(PO4)3OH). Additionally, a solid/liquid separation method (i.e., flotation) was explored, using oleic acid and dodecylamine as collectors. The results show that, the chemical treatment of saturated solutions at 60 °C, pH 11.5 and using 3.9 g/L BaCl2·2H2O and 1.6 g/L Na3PO4, promotes the precipitation of barium sulfate and calcium-deficient hydroxyapatite (Ca10–x(HPO4)x(PO4)6–x(OH)2–x), with residual concentrations of calcium and sulfate below 0.10 and 5 mg/L, respectively. The residual calcium concentration increases to 28 mg/L when using the same amount of reactants, at temperature and pH values below those quoted. The highest flotation recovery of hydroxyapatite with oleic acid at pH 9.5 was about 80%, while that of barite floated with dodecylamine at pH 6.5 was about 90%.

A dynamic flotation model for predictive control incorporating froth physics. Part II: Model calibration and validation

Modelling for flotation control purposes is the key stage of the implementation of model-based predicted controllers. In Part I of this paper, we introduced a dynamic model of the flotation process, suitable for control purposes, along with sensitivity analysis of the fitting parameters and simulations of important control variables. Our proposed model is the first of its kind as it includes key froth physics aspects. The importance of including froth physics is that it improves the estimation of the amount of material (valuables and entrained gangue) in the concentrate, which can be used in control strategies as a proxy to estimate grade and recovery.In Part II of this series, experimental data were used to estimate the fitting parameters and validate the model. The model calibration was performed to estimate a set of model parameters that provide a good description of the process behaviour. The model calibration was conducted by comparing model predictions with actual measurements of variables of interest. Model validation was then performed to ensure that the calibrated model properly evaluates all the variables and conditions that can affect model results. The validation also allowed further assessing the model’s predictive capabilities.For model calibration and validation purposes, experiments were carried out in an 87-litre laboratory scale flotation tank. The experiments were designed as a randomised 32 full factorial design, manipulating the superficial gas velocity and tailings valve position. All experiments were conducted in a 3-phase system (solid-liquid–gas) to ensure that the results obtained, as well as the behaviour of the flotation operation, are as similar as possible to those found in industrial flotation cells.In total, six fitting parameters from the model were calibrated: two terms from the equation for overflowing bubble size; three parameters from the bursting rate equation; and the number of pulp bubble size classes. After the model calibration, simulations were performed to validate the predictions of the model against experimental data. The validation results revealed good agreement between experimental data and model predictions of important flotation variables, such as pulp level, air recovery, and overflowing froth velocity. The high accuracy of the predictions suggests that the model can be successfully implemented in predictive control strategies.

Grade prediction of zinc tailings using an encoder-decoder model in froth flotation

Accurate grade prediction is conducive to proper flotation operation or control. Different from grade monitoring, grade prediction needs to obtain the target grade in advance. However, there is usually a time delay between the flotation cell and the predicted grade in froth flotation. This time delay makes it difficult to match the features of the observed flotation cell with the predicted grade. To solve this problem, this article studies the method of zinc tailings grade prediction using encoder-decoder models. The proposed model considers the feature time series of the first rougher and the previously measured tailings grades. First, according to the sample ratio between froth video and X-ray fluorescence (XRF) analyser, the feature time series of the first rougher can be automatically extracted by finding the nearest available feature vectors. Next, the feature time series of the first rougher is fed into the encoder to generate a context vector, and then the context vector and previously measured grades are sent into the decoder to predict the current tailings grade. The proposed model effectively captures the dynamic consistency between the feature time series and previously measured grades. The effectiveness of the proposed model in the froth flotation has been verified by experiments. Compared with the traditional recurrent neural network (RNN)-based models, the root mean squared error (RMSE) and mean absolute percentage error (MAPE) of the proposed model decrease by about 17.8% and 1.9%. respectively, and the R-squared (R2) score of the proposed model increases by about 13.8%.

Pilot tests of gravity-flotation technology for processing industrial waste from alluvial gold mining

Large-scale development of technogenic resources with low recoverable value is constrained by the lack of technologies that ensure their break-even development. Most of the gold from dumps can be extracted using the least costly gravity methods. In the pilot industrial processing of this raw material, screw separators were used in the main metal concentration operation. The finishing of their heavy fractions was carried out on concentration tables. With the light fraction of gravitational apparatus, 28.7% of the gold was lost. The light fraction material (with gold in the form of thin leaves and scales) has a low contrast in density. Gold of hard-to-recover morphotype was isolated from light fractions of gravitational apparatus by flotation. It was found that with an increase in the content of gold in the feedstock, its recovery into concentrate by flotation increases. In the practice of flotation, the required increase in the metal content in the separation operation is achieved through the turnover of middlings. However, in this case, the gold content of the resulting mixture increases and the separability decreases. This result is due to the fact that grains with reduced flotation properties are returned with the middlings. During flotation, the rough concentrate separated from 1/2 part of the initial feed is mixed with another 1/2 part of the initial feed. As a result, in the main flotation operation, the metal content and the ability of the material to be separated by flotation increase. In this case, the pulp is aerated with a mixture of air with hot steam. Condensation of steam in bubbles is the reason for the increase in completeness of gold recovery and selectivity of the flotation process. The technological efficiency of the developed technology has been proven by the results of its pilot tests. The assessment of economic efficiency was carried out by extraction of metal from the waste of alluvial gold mining and by the amount of capital costs and operating costs associated with its production. When processing man-made raw materials with a low gold content and switching from gravity to gravity-flotation technology due to the profit from additionally obtained gold, the payback period for the discounted cash flow decreases by one year, the value of the net discounted income increases by more than an order of magnitude, and the profitability index by 12.5% (rel.), EBITDA margin — from 31.4 to 42.5%.

Combined gravitation-flotation technology for technogenic gold placer concentration

Gold recovery from placer washing waste was carried out using a flotation method where circulating rough concentrate is used to increase the recovered metal content in the rougher flotation operation. Moreover, flotation is carried out with a mixture of air with hot steam. Pressure in bubbles drops and their sizes decrease as a result of vapor condensation at the first moment of time under conditions of vapor-air flotation. Heat exchange between the phases worsens when the bubble is compressed, and mass transfer stops at the minimum bubble size, while temperature and vapor pressure in the bubble reach their maximum. As the bubble grows in size, superheated steam becomes saturated and pressure in the bubble decreases resulting in resumed condensation. The bubble surface undergoes damped oscillations. When the bubble surface vibrates, the motion of a slowly developing concentration-capillary Marangoni flow to the center of the interphase film cannot compensate for its thinning by the counter thermocapillary flow with a high hydrodynamic stability potential from the film center to its periphery. The vapor-air flotation results obtained can be interpreted in the context of this mechanism of wetting film stability changes during the vapor-liquid phase transition. Pilot tests of gravity and gravity-flotation technologies for gold extraction from a technogenic placer of gold have been carried out. It has been proved that the main effect of using the developed configuration of the scheme and the mode of flotation with a vapor-air mixture is a decrease in the concentrate yield by ~ 25% rel. while maintaining the achieved level of recovery and concentrate quality. When using the combined technology, the added value of marketable products provides an increase in the value of net discounted income and the return on investment index, and a decrease in their payback period.

Surface chemistry of oxidised pyrite during grinding: ToF-SIMS and XPS surface analysis

In the processing of minerals, the ore is ground to small particles to liberate the valuable minerals which are then separated from the ore waste material by froth flotation. The conditions of the grinding process have an impact on the surface chemistry of the minerals which is critical for the subsequent flotation process. This study aims to investigate the effect of different grinding conditions on the evolution of the surface chemistry of pyrite during the grinding process. The hydrophobicity of the ground pyrite is determined using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and the surface chemistry speciation is characterized by X-ray Photoelectron Spectroscopy (XPS). The results show that when grinding with forged steel media, the new surfaces produced on pyrite particles during grinding are oxidised or react rapidly in the mill, resulting in low surface hydrophobicity. In contrast, when grinding with high chrome steel media under nitrogen gas atmosphere, the reaction rate of fresh surfaces can be markedly reduced, hence, increasing the natural hydrophobicity of pyrite. This paper provides a comprehensive understanding of how surface chemistry of pre-oxidised pyrite changes during grinding. This knowledge is critical for devising control strategies to optimise grinding and flotation operations in mineral processing plants.

Effects of Operating Parameters on the Froth and Collection Zone Recovery in Flotation: An Industrial Case Study in a 10 m3 Cell

The effects of flotation operation parameters, including froth depth, air flowrate, and frother dosage, on the froth and collection zone recovery and the flowrate of particles into the froth phase were investigated in a 10 m3 industrial cell. The results showed that froth recovery increases upon increasing air flowrate and frother dosage, as well as reducing froth depth. While all tested parameters affected the particles that entered into the froth phase, air flowrate and frother dosage showed the most and least significance, respectively. When the air flowrate, frother dosage, and froth depth were 146 m3/h, 150 mL/min, and 5 cm, respectively, froth recovery was found to be above 84%. Also, the effect of the parameters studied on collection zone recovery was different from their effect on the froth zone, with air flowrate having the greatest impact on the former.

A dynamic flotation model to infer process characteristics from online measurements

A dynamic flotation model incorporating fundamental and phenomenological relationships, information from froth images and steady-state models is described. Model outputs correspond with online measurements commonly available on flotation circuits, and the model parameters are estimated from industrial data. Simulation results are presented, highlighting important non-linearities that need to be taken into account for optimal flotation operation. Observability and controllability analyses are performed, proving that key flotation parameters can theoretically be estimated from online process measurements, and that the set of modelled inputs can control all the model outputs. This model can be used in advanced model-based control and optimisation applications. The ability to estimate key flotation parameters opens up opportunities for improved optimisation of operating variables such as aeration rates, froth depth and the reagent recipe.

ПРИМЕНЕНИЕ СТРУЙНОЙ СХЕМЫ И РЕЖИМА ФЛОТАЦИИ ПАРОВОЗДУШНОЙ СМЕСЬЮ ПРИ ОБОГАЩЕНИИ ЗОЛОТОСОДЕРЖАЩИХ РУД

Increasing the economic efficiency of enrichment of refractory gold-bearing ores is possible by reducing the cost of opening sulphide gold-bearing concentrates by reducing the yield of flotation concentrate sent to pyro- or hydrometallurgical processing. It is important to maintain the achieved level of gold recovery into concentrate with a lower concentrate yield. In order to achieve this goal, the gold content in the main flotation operation is increased by mixing the rough concentrate separated from ½ part of the ore feed with another ½ part of it. Mixing in the flotation operation of products with a high level of wash ability (ability to separate) – initial feed and rough concentrate – is identical to an increase in the content of the extractable component in the original ore. In accordance with the new regime of flotation, the process is carried out in cold slurry with bubbles filled with hot steam. The physical basis of the new flotation regime is the dependence of the surface properties of air bubbles and surface forces that determine the stability of the liquid film separating the bubble and the particle on the temperature, which increases due to the heat of the vapor-liquid phase transition. Radial oscillations of the bubble surface as a result of pressure pulsations during condensation and vapor evaporation and surface thermal flows of liquid in the wetting film are factors that provide an increase in the completeness of gold recovery and the selectivity of flotation adhesion obtained in ore flotation experiments. In laboratory conditions, a comparison was made of the indicators obtained during the dressing of gold-bearing ores according to the factory and new schemes. It was revealed that the use of the developed technology allows, with a lower concentrate yield, to obtain an increase of 7.06% abs. extraction of gold into a concentrate of the best quality. A decrease in gold losses with flotation tailings is a consequence of an increase in the number of particles reaching the bubble surface due to radial oscillations of its surface and a weakening of the stability of the wetting film by the thermo-capillary mechanism. An increase in adhesion selectivity can be interpreted using the concept of surface forces of structural origin – an increase in the forces of hydrophobic attraction and hydrophilic repulsion with increasing temperature. The interaction of vapor bubbles with nanobubbles on the surface of the solid phase (wetting by the Cassie-Baxter mechanism) ensures efficient particle recovery by the coalescence mechanism of flotation.

Enhancing flotation separation of chalcopyrite and magnesium silicate minerals by surface synergism between PAAS and GA

Separation effects of sodium polyacrylate (PAAS) and gum Arabic (GA) on flotation of chalcopyrite and magnesium silicate minerals using potassium butyl xanthate (PBX) as collector were investigated by micro-flotation experiments, zeta potential, Infrared spectral (IR), SEM–EDS, XPS analysis and copper sulphide ore beneficiation test. The micro-flotation experiments and zeta potential measurements showed that combined depressant consisting of PAAS and GA could efficiently reduce the recoveries of mixed minerals of serpentine and talc more than 25%, while that of chalcopyrite remained above 70% at pH 9.2. Infrared spectral (IR), SEM–EDS and XPS analysis showed that PAAS chemically reacted with Mg on the surface of serpentine, while GA adsorbed on talc surface mainly via physical interaction and hydrogen bond may also play a role. Surface synergism between PAAS and GA was investigated by turbidity test and its depression mechanism was proposed. The technology feasibility of using PAAS and GA to improve the copper sulphide ore flotation performance was verified through artificial mixed ore flotation and laboratory closed-flotation operation.

The Effect of Hydrothermal Treatment on Structure and Flotation Characteristics of Lignite and a Mechanistic Analysis.

Lignite is difficult to obtain highly efficient indexes by conventional flotation due to its poor surface hydrophobicity. Although the modification of flotation reagents has made some progress in improving the flotation performance, they all remain at the stage in the laboratory. Here, we proposed to improve the flotation performance by hydrothermal treatment dewatering (HTD) for lignite. Combined with the 13C NMR and FT-IR analysis, the impact of the HTD process on lignite’s chemical structural evolution and flotation performance was investigated. The results showed that the HTD process is an effective means for dehydration and deoxygenation to increase lignite quality and the metamorphic degree of coal. The content of oxygen-containing functional groups generally decreases during the HTD process, especially carboxyl acid and ether groups. Therefore, surface properties and wettability of HTD coal samples were changed, and the contact angle gradually increases with the HTD temperature increased, which enhance the hydrophobicity and decrease hydrophilia of the lignite surface. The HTD process effectively improves the flotation performance of lignite during the conventional flotation operation condition, even if the coal pulp after HTD was directly used as a flotation feedstock. Specifically, the coal oil and capryl alcohol were used as collector and forming agents, respectively, and the pulp concentration was adjusted to 60 g/L. The yield of the cleaned coal increased from 12.14% of the raw coal to 55.58% of HTD310, and combustible matter recovery increased from 13.83% of the raw coal to 65.17% of HTD310 by raw coal basis.

Modelling of coal flotation responses based on operational conditions by random forest

Coal consumption is one of the critical factors in the economy of China. Flotation separation of coal from its inorganic part (ash) can reduce environmental problems of coal consumption and improve its combustion. This investigation used random forest (RF) as an advanced machine learning method to rank flotation operations by variable importance measurement and predict flotation responses based on operational parameters. Fifty flotation experiments were designed, and performed based on various flotation conditions and by different variables (collector dosage, frother dosage, air flowrate, pulp density, and impeller speed). Statistical assessments indicated that there is a significant negative correlation between yield and ash content. Experiments indicated that in the optimum conditions, yield and ash content would be 80 and 9%, respectively. Variable importance measurement by RF showed that frother has the highest effectiveness on yield. Outcomes of modelling released that RF can accurately be used for ranking flotation parameters, and generating models within complex systems in mineral processing. [Received: May 20, 2020; Accepted: July 19, 2020]

СОВЕРШЕНСТВОВАНИЕ РЕАГЕНТНЫХ РЕЖИМОВ ФЛОТАЦИИ СФАЛЕРИТА И ПИРИТА ИЗ МЕСТОРОЖДЕНИЙ КОЛЧЕДАННЫХ МЕДНО-ЦИНКОВЫХ И ПОЛИМЕТАЛЛИЧЕСКИХ РУД

Pyrite copper-zinc (sulfide) and polymetallic ores in Russia are complex and refracto-ry mineral raw materials. The main processing technology for such ores is flotation. Currently, the improvement of the flotation technology of such mineral raw materials is carried out in several directions. It has been established by the practice of enrichment of copper-zinc ores that obtaining high-quality zinc and pyrite concentrates is impossible without the use of various modifiers in the practice of flotation of sphalerite and pyrite. Such reagents are copper (II), zinc and iron (II) sulfates in an alkaline lime environment. Therefore, studies were carried out to float sphalerite and pyrite in an alkaline lime medium with the addition of one of the indicat-ed sulfates to the mineral flotation operation. The effect of each of the sulfates of copper (II), zinc and iron (II) on the flotation of sphalerite and pyrite was studied during flotation of the mineral with butyl xanthate and dithiophosphate at pH = 8, 10, and 12. The aim of this work was to study the effect of sulfhydryl collectors in the presence of copper sulfates , zinc and iron for flotation of sphalerite and pyrite with a size class (-0.074 + 0.044 mm) from one of the Rus-sian deposits.

Modelling of coal flotation responses based on operational conditions by random forest

Coal consumption is one of the critical factors in the economy of China. Flotation separation of coal from its inorganic part (ash) can reduce environmental problems of coal consumption and improve its combustion. This investigation used random forest (RF) as an advanced machine learning method to rank flotation operations by variable importance measurement and predict flotation responses based on operational parameters. Fifty flotation experiments were designed, and performed based on various flotation conditions and by different variables (collector dosage, frother dosage, air flowrate, pulp density, and impeller speed). Statistical assessments indicated that there is a significant negative correlation between yield and ash content. Experiments indicated that in the optimum conditions, yield and ash content would be 80 and 9%, respectively. Variable importance measurement by RF showed that frother has the highest effectiveness on yield. Outcomes of modelling released that RF can accurately be used for ranking flotation parameters, and generating models within complex systems in mineral processing. [Received: May 20, 2020; Accepted: July 19, 2020]

Development of a flotation recovery model with CFD predicted collision efficiency

In this study, a novel flotation recovery model based on a first-order kinetics is proposed. The collision efficiency in the recovery model was directly obtained from 3D computational fluid dynamics (CFD) simulations involving a single-bubble-multi-particle aggregate system with typical flotation operating conditions (bubble diameter of 1 mm and particles diameter of 30 μm). The effect of the fluctuating flow field on collision was accounted using a large eddy simulation (LES) turbulence model for two turbulence intensity cases namely 4% and 20%, respectively. It was noted that the collision efficiency decreased in the radial direction away from the symmetry axis of the bubble. The normalized equivalent critical radius K1 for the overall collision efficiency, was found to be optimum at the lower turbulence intensity of 4%. A maximum bubble surface loading, 0.142 was determined by fitting the model-predicted bubble velocity with available experimental data. With this maximum bubble surface loading constraint, the recovery model predicted two regimes namely a loading regime in the early flotation period and a saturated regime wherein the bubble loading capability was entirely exhausted. Simulation of a batch flotation system suggested that loss in bubble surface loading capacity occurred faster in a dense pulp compared to a dilute pulp system and the predicted recovery decreased with increasing solids concentration for the same gas volume fraction. Similar to the collision efficiency, the optimum recovery was obtained at Ti = 4%. Further, the model predicted recovery was compared to a lab scale coal flotation test and reasonable agreement was obtained.

A Study on the Electric Surface Potential and Hydrophobicity of Quartz Particles in the Presence of Hexyl Amine Cellulose Nanocrystals and Their Correlation to Flotation

In this work, the study of hexyl amine cellulose nanocrystal (HAC) as a renewable and environmentally-friendly reagent for the flotation of quartz (QRZ) is expanded with a focus on the changes of electrical states at the solid-liquid interface, the range of solid-gas interactions, and their impact on flotation operations under a turbulent regime. Furthermore, particle-bubble attachment probabilities were measured with the recently engineered automated contact timer apparatus (ACTA), a versatile technique used to deduce the wettability of microparticles and potentially predict their floatability. Therefore, the findings of the ACTA proved that, with sufficiently hydrophobic QRZ (i.e., HAC concentration ≥ 0.667 mgHAC/m2QRZ), stable particle-bubble attachments occur at particle-bubble distances in the range of tens of micrometres. The distances for the successful attachment of HAC-coated QRZ particles exceed the range of interactions reported in literature so far and imply the existence of structural or hydrodynamic phenomena acting between particle and bubble surfaces. The occurrence of so-called non-compressive particle-bubble attachments is shown to correlate with a significant increase in the floatability of QRZ, where recoveries up to 90% were obtained. Based on the experimental results, some insights on the nature of the long-range interactions responsible for the particle-bubble attachment of hydrophobic particles are provided.

Statistical Modelling of Oil Removal from Surfactant/Polymer Flooding Produced Water by Using Flotation Column

The objective of this study was to investigate the effect of polymer (GLP-100) and surfactant (MFOMAX) towards the efficiency of oil removal in a flotation column by using the Response Surface Methodology (RSM). Various concentrations of surfactant (250, 372 and 500 ppm) and polymer (450, 670, and 900 ppm) produced water were prepared. Dulang crude oil was used in the experiments. Flotation operating parameters such as gas flow rate (1–3 L/min) and duration of flotation (2–10 min) were also investigated. The efficiency of oil removal was calculated based on the difference between the initial concentration of oil and the final concentration of oil after the flotation process. From the ANOVA analysis, it was found that the gas flow rate, surfactant concentration, and polymer concentration contributed significantly to the efficiency of oil removal. Extra experiments were conducted to verify the developed equation at a randomly selected point using 450 ppm of polymer concentration, 250 ppm of surfactant concentration, 3 L/min gas flowrate and duration of 10 min. From these extra experiments, a low standard deviation of 1.96 was discovered. From this value, it indicates that the equation can be used to predict the efficiency of oil removal in the presence of surfactant and polymer (SP) by using a laboratory flotation column.

Recovery of clean coal from blast furnace dusts by flotation column

The paper presents the results of the study on recovery of clean coals from blast furnace dusts of the Cao Bang Iron Steel plant. The study has explored the effects of the most important operating parameters on the coal flotation performance including flotation reagent dosage, solid concentration, froth wash-water rate, flotation time and the froth thickness. The results of the study showed that using a combination of a rougher and a cleaning flotation operations at respectively collector dosage, solid concentration, flotation time, froth wash-water rate and froth thickness of 1000 g/t, 100 g/l, 10 minutes and 1.5 l/minute and 450 mm, has obtained a clean coal product with the yield, ash content and combustible matter recovery respectively of 44.90%, 19.15% and 77.63%. The clean coal has met the quality strandards requirements of the fuel for sintering.