Persistent froth is becoming more and more common in coal and mineral flotation plants and presents safety and operational challenges.No effective method has been developed to destabilise persistent froth.As a new ini...Persistent froth is becoming more and more common in coal and mineral flotation plants and presents safety and operational challenges.No effective method has been developed to destabilise persistent froth.As a new initiative,this study examined the structural difference between persistent foam and coal froth,based on which a solution was developed to maximumly destabilise coal froth.Destabilisation test,oscillatory rheology measurement and scanning electron microscopy(SEM) analysis indicated that the coal froth was more stable than the foam due to the formation of thin capillaries and tightly arranged coal particles on bubble surfaces.Although 107 μm silicone oil droplet could completely destabilise the foam at 2 mmol/L concentration,it only destabilised less than 50% coal froth even at 6 mmol/L concentration.To maximumly destabilise the coal froth formed by-38 and-20 μm particles,24 and 18 μm silicone oil droplets were required to pass through the thin capillaries and enter the bubble films,respectively.However,smaller silicone oil droplets could not bridge the bubble films to destabilise coal froth and therefore a critical droplet size occurred depending on the size of particles stabilising the froth.展开更多
This paper presents a methodology for evaluating the water purification process efficiency attained by 1) jar tests, which are commonly used to determine the treatability of water, and 2) waterworks performance in dif...This paper presents a methodology for evaluating the water purification process efficiency attained by 1) jar tests, which are commonly used to determine the treatability of water, and 2) waterworks performance in different phases of the purification process as well as in its entirety. This methodology provides an important tool for the following: 1) determination of optimised reaction conditions under which water is treatable to its best attainable quality;2) evaluation of the purification process efficiency attained by waterworks during different periods and under different operational conditions;3) comparisons of performance efficiency of different waterworks;and 4) comprehensive commissioning of waterworks and identification of bottlenecks if any exist in process and plant design. This paper describes procedures for pre-processing of water samples to be analysed as well as mathematical formulas for processing of the results obtained. A few examples of the practical application of the methodology are included and the potential to obtain the optimization of waterworks’ purification processes is herein illustrated.展开更多
基金ACARP (Australian Coal Association Research Program) project C24040 for financial supportscholarship provided by the University of QueenslandChina Scholarship Council。
文摘Persistent froth is becoming more and more common in coal and mineral flotation plants and presents safety and operational challenges.No effective method has been developed to destabilise persistent froth.As a new initiative,this study examined the structural difference between persistent foam and coal froth,based on which a solution was developed to maximumly destabilise coal froth.Destabilisation test,oscillatory rheology measurement and scanning electron microscopy(SEM) analysis indicated that the coal froth was more stable than the foam due to the formation of thin capillaries and tightly arranged coal particles on bubble surfaces.Although 107 μm silicone oil droplet could completely destabilise the foam at 2 mmol/L concentration,it only destabilised less than 50% coal froth even at 6 mmol/L concentration.To maximumly destabilise the coal froth formed by-38 and-20 μm particles,24 and 18 μm silicone oil droplets were required to pass through the thin capillaries and enter the bubble films,respectively.However,smaller silicone oil droplets could not bridge the bubble films to destabilise coal froth and therefore a critical droplet size occurred depending on the size of particles stabilising the froth.
文摘This paper presents a methodology for evaluating the water purification process efficiency attained by 1) jar tests, which are commonly used to determine the treatability of water, and 2) waterworks performance in different phases of the purification process as well as in its entirety. This methodology provides an important tool for the following: 1) determination of optimised reaction conditions under which water is treatable to its best attainable quality;2) evaluation of the purification process efficiency attained by waterworks during different periods and under different operational conditions;3) comparisons of performance efficiency of different waterworks;and 4) comprehensive commissioning of waterworks and identification of bottlenecks if any exist in process and plant design. This paper describes procedures for pre-processing of water samples to be analysed as well as mathematical formulas for processing of the results obtained. A few examples of the practical application of the methodology are included and the potential to obtain the optimization of waterworks’ purification processes is herein illustrated.
