摘要:

The demineralization of coal by selective agglomeration using pentane as an agglomerant which has been called the “T-process”involves two steps: first, the raw coal is reduced to some particle size smaller than 0.5 mm. And secondly, the fine coal is recovered from a dilute raw coal water slurry by the dispersion of pentane in the slurry. The pentane envelopes the coal particles which allows the formation of liquid bridges between the coal particles that results in a water immiscible mass of coal and pentane. The latter is separated from the dispersed mineral matter in the water phase by some simple mechanical procedure. The coal recovery from very fine raw coals is normally in excess of 95%. The pentane is recovered by evaporation/condensation for reuse in the process leaving the demineralized coal for utilization either as a slurry or as dry pellets. Pilot operations using this process have produced over 125 tons of pyrite-free product coal with an average ash content in the range of 0.8 wt%.

ISSN:0734-9343    

DOI:10.1080/07349349008905169

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

An advanced packed column (or static tube) flotation system developed at Michigan Technological University offers the potential for sharp separation of fine coal particles from mineral matter and can be readily incorporated into practice for efficient coal processing at reduced costs. The essential element of the system is the packed-bed cell design in combination with a controlled dispersion reagent scheme.

ISSN:0734-9343    

DOI:10.1080/07349349008905170

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

An economic analysis revealed that the new packed-bed flotation column is superior to conventional flotation cells for reduction of ash and pyritic sulfur. Furthermore, commercial packed-bed flotation columns can be designed on a direct scale-up basis.

ISSN:0734-9343    

DOI:10.1080/07349349008905171

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Recovery of fine coal is becoming an important and integral part ofcoal cleaning plants. The froth flotation technique is widely used for recovery of fine coals; however, the technique becomes inefficient when excessive amounts of ultra-fine clay material is present. The counter-current column addresses this problem by providing a stream of wash water to remove fine clays from the froth. The experimental results reported herein examine the effect of column operational parameters (feed rate, frother concentration, airflow, column height, pulp density and wash water) on cleaning of fine coal. The study was conducted using the Plackctt-Burman experimental design followed by a 23factorial design. The study identifies frother concentration, column height and airflow as the most significant parameters and enabled characterization of the magnitude and interaction of the effects. In general, for the same amount of frother concentration column flotation provided a lower ash clean coal product compared to the conventional flotation. The paper describes the test procedure, results and conclusions obtained.

ISSN:0734-9343    

DOI:10.1080/07349349008905172

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Laboratory tests had been carried out to clean pulverized coal in air streams using a process known as high gradient magnetic separation. Encouraging preliminary separability results were obtained for a British coal; most or the pyrites and greater than 70% of the ash were removed from the pulverized coal. The effects of some operating parameters such as gas velocity and matrix loading on coal cleanability were reported.

ISSN:0734-9343    

DOI:10.1080/07349349008905173

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A study based on a statistically designed set of experiments (central composite design) has been made to determine the optimum conditions for grinding of coal/water slurries. The dependent variable in these experiments was fineness of the product while the independent variables were percent solids, ball size, dispersant dosage and mill speed. The optimum conditions found from a response surface analysis not only predicted an increase in grinding efficiency but the product obtained in the region of the optimum showed other desirable slurry properties, especially improved slurry rheology. This analysis has helped to establish the significance and relative importance of the independent variables examined and has been useful in defining the interactions between the operating variables and their effect on the grinding response.

ISSN:0734-9343    

DOI:10.1080/07349349008905174

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0734-9343    

DOI:10.1080/07349349008905175

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0734-9343    

DOI:10.1080/07349349008905176

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0734-9343    

DOI:10.1080/07349349008905177

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor