Wyniki wyszukiwania - BazTech

1

Study on gas holdup characteristics of micro-bubble countercurrent contacting flotation column

Han Jikang, Wang Weizhi, Li Ran

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 4

665--675

EN

In order to explore the gas holdup distribution of the microbubble countercurrent contact flotation column in the hematite column cationic reverse flotation process, respectively using conductance method and pressure drop method for air and water as experimental medium characteristics research of flotation column, the research group carries on the gas holdup, examines the aeration quantity, the fill medium and cation collector alkyl polyamine ether (An amine collector―GE609 which consists of four elements: carbon, hydrogen, oxygen and nitrogen)within the column on the influence of the axial and radial gas holdup. The results show that the axial gas holdup from the bottom of the column to the top of the column increases with the increase of height in the range of 0.050.07dm3/s. The radial distribution of gas holdup generally shows the distribution law of “intermediate high, low on both sides”. After the filling medium is added into the column, the radial gas holdup is evenly distributed compared with the empty column, and the gas holdup is increased. Due to the high foaming performance of GE-609, the gas holdup in the column can be increased by changing the amount of aeration and the concentration of the reagent, which can exceed 60% at the maximum. Like other alcohol foaming agents, as time passes, the effect of GE-609 weakens and the gas holdup in the column gradually decreases. The addition of quantitative HCl can improve the foaming performance of GE-609, and the gas holdup in the column is significantly improved and the stability is enhanced.

2

Study on bubble characteristics of flotation column in hematite reverse cationic flotation process

Wang Weizhi, Han Jikang

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 1

64--75

EN

In the self-designed flotation column simulation system, the foaming characteristics of the micro-bubble countercurrent contact flotation column used in the hematite cation column flotation process are systematically studied. The objective of this study is to investigate the bubble generation by a bubble generator in the flotation column. The bubble image was obtained by the high-speed camera recorder, and the bubble diameter was calculated and analyzed by image processing software. The distribution characteristics of the bubble size under different aeration conditions and with different reagent concentrations were investigated. The results show that as the aeration increases, the average diameter bubbles increases, the bubble size distribution changes from narrow to wide, and the number of small bubbles decreases. The cationic collector GE-609 can change the bubble shape. As the concentration increases, the bubble shape gradually changes from an irregular shape to a standard spherical shape. When the concentration of GE-609 exceeds 2.5 mg/dm3, the average circularity C of the bubbles in the bubble group stabilizes at 1, and the increase in concentration no longer changes the bubble shape. GE-609 also has an efficient foaming effect, as the concentration increases, the bubble diameter distribution changes significantly, the proportion of small bubbles increases, and the proportion of large bubbles decreases significantly. When the critical concentration is exceeded, the bubble diameter distribution probability density peak width no longer changes significantly. Compared with the two types of alcohol foaming agents, GE-609 produces a bubble Sauter diameter close to that of 2-octanol and slightly lower than terpineol.

3

Selection of the best route for column configuration in an existing copper circuit

Can N. Metin, Altun Okan

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 2

552--564

EN

This study was aimed to utilize column flotation to obtain much cleaner concentrate in the Cu circuit. However, the numbers of equipment and the proper streams for column application should be the key for successful operation. Therefore, the effects of some operational parameters such as wash water rate, airflow rate and froth height were investigated on the streams of namely Cu first cleaner concentrate, Cu rougher concentrate and Cu third cleaner concentrate in terms of mineral recoveries and selectivity. Distribution of wash water rate to products was also determined by a tracer test method. Optimum operating conditions and accordingly performance of the column were determined by simulation studies. According to the results, the suitable streams for industrial scale flotation column are advised as the rougher concentrate and/or first cleaner concentrate. With series installation of columns, it is possible to obtain two different concentrates which include 22% Cu, 4% Zn and 17% Cu, 8% Zn without any decrease in overall recovery of plant.

4

Column flotation performance prediction: PCA, ANN and image analysis-based approaches

Nakhaei Fardis, Irannajad Mehdi, Mohammadnejad Sima

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 5

1298--1310

EN

The flotation froth surface appearance includes remarkable information, which can be employed as a helpful index for the qualitative evaluation of the process efficiency. Image analysis is a practical technology for the sake of achieving process related information that can be employed in expert controllers in order to amend flotation performance. In this paper, the intelligent modelling of relationship between froth characteristics and the metallurgical performance in a pilot column flotation of iron ore was established. Column flotation tests were carried out at a wide range of operating conditions and the froth features along with the metallurgical performances were specified for each run. The artificial intelligence models suggested for the performance parameters prediction include (1) multi-layer back propagation neural network (BPNN), (2) hybrid BPNN with principal component analysis (PCA). The hybrid network was on the basis of the PCA employment in order to decrease the number of variables to be given as input for BPNN. The relationships between the froth features and metallurgical performance factors were successfully modelled via the use of the two methods. The simulation results revealed that the prediction precision of BPNN model on the basis of all the data was relatively higher than the estimation precision of BPNN based on PCA algorithm. The Hybrid BPNN model that was trained by the pre-processed database of measurements achieved from the PCA can be considered a robust method when training time is of paramount importance in objectives of proces control.

5

Comparison of mechanical flotation cell and cyclonic microbubble flotation column in terms of separation performance for fine graphite

Bu X., Zhang T., Chen Y., Peng Y., Xie G., Wu E.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 3

732--740

EN

Comparison of flotation performance between the flotation column and mechanical flotation was carried out to promote the grade and economic value of the graphite ore (15.40% ash content). The ash content of the concentrate of the mechanical flotation was 10.77% at the yield of 79.34%. In contrast, the yield of the concentrate of the column flotation was increased to 88.93% with 10.55% ash content. Comparative study of the Fuerstenau upgrading curves indicated that the column flotation was more efficient for cleaning the graphite ore in the presence of the centrifugal force field, nanobubbles (generated by hydrodynamic cavitation), and the thicker froth layer in comparison with the mechanical flotation.

6

A study of bubble-particle interactions in a column flotation process

Cheng G., Shi C., Yan X., Zhang Z., Xu H., Lu Y.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 1

17--33

EN

Bubble-particle interactions play an important role in flotation. This study examines the behaviour of bubble clusters in a turbulent flotation cell. Particularly, the bubble-particle interaction characteristics in flotation are investigated. The bubble size in a flotation column was measured using an Olympus i-SPEED 3 high-speed camera. Relationships between the circulating volume, bubble size and bubble terminal velocity were discussed. Probabilities of collision, attachment, detachment and acquisition between bubbles and particles in different circulating volumes were calculated based on the flotation kinetic theory. Using the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory, the relationship between the potential energy and distance in bubble-particle interaction was analysed. The results demonstrated that as the circulating volume increased, the bubble size and velocity decreased. When the circulating volume increased from 0.253 to 0.495 m3/h, the bubble diameter decreased from 511 to 462 μm, and the corresponding bubble velocity decreased from 43.1 to 37.5 mm/s. When the circulating volume remained constant as the particle size increased, probabilities of collision, attachment, detachment and acquisition increased. When the particle size remained constant as the circulating volume increased, these probabilities also increased. At a constant circulating volume as the particle size increased, the absolute value of the total potential energy between the particle and bubble increased. When the distance between the bubble and particle was 30 nm, the energy barrier appeared.

7

A study of the effect of operating parameters in column flotation using experimental design

Bedekovic G.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

523--535

EN

The effect of air flow rate, pulp density and particle size was studied using central composite design for coal samples from the Lazy mine. Evaluation of column flotation tests was based on two dependant variables such as ash content and combustible matter recovery in the concentrate. The ash content in the concentrate was from 4.61 to 9.62% with the recovery of combustible matter from 17.43 to 81.98%. The ANOVA statistical analysis showed that the main effect of air flow rate has a significant impact on the combustible matter recovery and ash content in the concentrate. The main effect of pulp density on the combustible matter recovery is significant, whereas for the ash content it is not seen. There is a strong effect of the particle size on the ash content and combustible matter recovery in the concentrate. The interaction of the effect of the pulp density and particle size has a significant impact on the ash content in the concentrate.

8

Processing of iron ore fines from alswaween Kingdom of Saudi Arabia

Ahmed H. A. M., Mahran G. M. A.

Physicochemical Problems of Mineral Processing

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2013

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Vol. 49, iss. 2

419--430

EN

Iron ores located in the Alswaween area (Saudi Arabia) are of finely disseminated nature. They require ultrafine grinding for considerable degree of liberation. In this paper, different upgrading tech-niques were tried for their processing. The applied upgrading techniques included selective flocculation and column flotation as recent efficient technologies in fines upgrading. Each technique was investigated and optimized separately. Results showed that neither selective flocculation nor column flotation can be successfully used alone to produce high quality iron concentrate especially when using iron ore of size fraction 100% -0.075 mm. The best quality concentrate was found to have 55% Fe and 57% Fe when applying selective flocculation and column flotation, respectively at their optimum operating conditions. Meanwhile, the previously obtained results can be significantly improved when grinding the ore below 45 μm and applying selective flocculation as cleaning step for the concentrate obtained from the column flotation. Thus, it is possible to obtain concentrate having iron content of 63.55% Fe with 52.3% yield, which means an iron recovery in concentrate of ~80%.

9

Porównanie flotacji klasycznej i kolumnowej na przykładzie flotacji węgla kamiennego

Fecko P., Cablik V., Havelek R, Kolomaznik H., Tora B.

Inżynieria Mineralna

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2009

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R. 10, nr 1

37-48

PL

Celem opracowania jest porównanie wyników klasycznej flotacji węgla z flotacją kolumnową. Badania przeprowadzono na próbkach węgla kamiennego z wybranych kopalń OKD (Ostrawsko-Karwinskie Duly w Czechach - kopalnie Dukla, Darkov, CSM, CSA, Doubrava) i Polski - KWK Kleofas. Uzyskane wyniki pozwalają na stwierdzenie, że zarówno w wyniku flotacji klasycznej jak i kolumnowej można uzyskać koncentraty węgla koksującego o założonej jakości.

EN

The objective of the paper was a comparison of classical and column flotation on samples of black-coal slurries from selected localities of OKR and Poland. Namely they are: Dukla Mine, Darkov Mine, CSM Mine, CSA Mine, Doubrava Mine and Kleofas Mine. The acquired results imply that the methods of classical and column flotation are suitable for flotation of the slurries in question as all the tested black-coal slurries from OKR and Poland are cokeable coals with a high flotability.

10

Factorial design for column flotation of phosphate wastes.

Abdel-Khalek N.A.

Physicochemical Problems of Mineral Processing

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2000

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Vol. 34

35-45

EN

A factorial design was used to study effects, and their interactions, of the main parameters affecting column efficiency to recover phosphates from their wastes. Three-phase experiments were performed using a mixture of fatty acid and fuel oil as a collector for phosphate while pine oil was used as a frother. Meanwhile 2-phase experiments were conducted to correlate the results of 3-phase experiments with that of bubble diameter and air holdup. The result shown that application of statistical design reveals very interesting information about the interaction between the studied parameters. For example it is shown that the interaction (X1X2) between superficial gas velocity (X1) and frother concentration (X2) has a beneficial effect on grade but aversely affect recovery.

PL

Metoda planowania czynnikowego została zastosowana do opisania wpływu i współzależności między podstawowymi parametrami procesu flotacji kolumnowej zastosowanej do odzysku fosforytu z odpadów fosforytowych. Doświadczenia flotacyjne zostały przeprowadzone z wykorzystaniem kwasu olejowego i oleju napędowego jako kolektorów oraz oleju sosnowego jako spieniacza. Planowanie typu 23 zostało przeprowadzone w celu znalezienia korelacji między wynikami eksperymentu a średnicą pęcherzyków powietrza i parametrami procesu. Dla przykładu, zostało pokazane, że X1X2, czyli między prędkością przepływu gazu (X1) a stężeniem spieniacza (X2) na korzystny wpływ na wychód a niekorzystny wpływ na uzysk procesu flotacji.