SciELO - Scientific Electronic Library Online

 
vol.110 issue4Optimizing yield of metallic zinc tapped from a zinc smelter by studying factors causing zinc losses to drossImproving the quality of tinplated steel using a novel technique to study the effect of industrial process parameters author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Journal of the Southern African Institute of Mining and Metallurgy

On-line version ISSN 2411-9717

J. S. Afr. Inst. Min. Metall. vol.110 n.4 Johannesburg Apr. 2010

 

JOURNAL PAPERS

 

A novel approach to reagent selection for coal flotation

 

 

M. Kruger

Department of Materials Science and Metallurgical Engineering, University of Pretoria, Pretoria, South Africa

 

 


SYNOPSIS

Considerable amounts of fine particles (smaller than 150 micron) are produced during the processing of coal. Significant value can be realized if this fraction can be economically beneficiated, disregarding the negative environmental impact of fine coal. Flotation is a very common worldwide beneficiation process to recover ultra-fine coal material and has been implemented in many oversees operations. However, flotation in South Africa has not fully matured-difficult coal types, high operating cost, inexperience of plant personnel and cell design are only a few of the reasons for flotation not being widely implemented. Reagent cost is by far the largest single contributor to the operating cost. The challenge with reagent selection, however, is that reagents are very selective and very sensitive to a change in ore characteristics-a new reagent combination is required when there is a drastic change in the ore characteristics. Frother selection is crucial due to the fact that the coal has a froth carrying capacity constraint. However, frother test work is notoriously difficult on a laboratory scale. Therefore, the aim was to develop a fast, effective and reliable method of choosing flotation reagent combinations and to verify this combination on a pilot scale. Laboratory scale froth characterization techniques (froth height, froth breakdown rate, froth carrying capacity, froth water recovery, selectivity and solids concentration in froth) were conducted in a 3 litre Leeds cell and Bikerman flotation column, whereas the pilot-plant scale tests were conducted at Kangra coal in a Dual Cell from ENPROTEC. The results have indicated that the froth characterization tests can be very successfully implemented to select a reagent combination that realizes significant value during pilot campaign runs. The pilot-plant results showed that by changing the reagent regime to the lab-predicted suite, a reagent cost saving of 43%, an increase in yield of 5%, with a decrease in product ash of 3%, can be realized.


 

 

“Full text available only in PDF format”

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License