Integrally formed heavy media pulping column

#The present invention is directed generally toward coal preparation plants and, more particularly, toward an improved integrally formed heavy media pulping column for mixing raw coal particles with a slurry of media and water.

#Coal preparation plants separate organic and non-organic solid particles by their specific gravities. The coal preparation plant receives a feed of raw mined coal, and separates the raw mined coal into clean coal and refuse. These plants typically utilize two basic processing methods for separating raw coal from rock and varying proportions of striated rock and coal from the higher quality coal. The two processing methods include heavy media and water based separation methods. Heavy media, utilizing a slurry of media, e.g., water and magnetite or ferrosilicon, to separate the coal from the refuse according to their specific gravity of dry solids, is the most common separation process for larger size (Plus 1 mm-0.5 mm) particles. Whereas, water based separation processes are more commonly used for the “cleaning” of the finer sized particles, as that term is commonly understood in the coal processing art. One type of heavy media circuitry used in the coal preparation plants includes a heavy media cyclone.

#Coal preparation plants using heavy media cyclones operate with three separate types of screens for coal processing, namely, a deslime screen, a refuse screen and a clean coal screen. A common screening assembly used in many coal preparation plants today is known as a vibratory banana screen. The deslime screen receives the raw coal feed particles and separates them into coarse and fine sized fractions. The coarse or larger sized particles discharged from the deslime screen surface are directed to the heavy media separation section of the coal preparation plant, while the finer sized particles passing through the deslime screen are directed toward the water based separation section of the coal preparation plant.

#FIG. 1 is a side view of a pulping column according to the present invention in association with deslime, refuse and clean coal screens in a coal preparation plant;

#FIG. 2 is a combination top view and block diagram of the pulping column according to the present invention associated with deslime, refuse and clean coal screens in a coal preparation plant; and

#FIG. 3 is a combination top view and block diagram of a pulping column according to an additional embodiment of the present invention in association with deslime, refuse and clean coal screens in a coal preparation plant.

#Referring to FIGS. 1 and 2, a pulping column according to the present invention is shown at 10 in association with a deslime screen 12 in a coal preparation plant, shown generally at 14. The deslime screen 12 receives a feed of raw coal 16 which is to be processed by the coal preparation plant 14. The deslime screen 12, with the addition of water, separates the raw coal 16 into coarse and fine sized fractions. The deslime screen 12 includes screens 18 and 20 which size the coarse or larger raw coal particles from the finer particles, with the finer particles and water passing to an underpan 22 of the deslime screen 12.

#The raw coal particles 16 screened by the deslime screen 12 are received directly at a coal inlet 24 of the pulping column 10. The pulping column 10 is integrally formed with discharge chutework 25 of the deslime screen 12, such that the raw coal particles 16 from the deslime screen 12 feed directly to the pulping column 10. These raw coal particles 16 are mixed with a slurry of media and water in the pulping column 10, as will be hereinafter described, and fed, via a pump 26, to a conventional heavy media separating device 28 to produce clean coal 30 and refuse 32. Typically, these coal processing techniques will utilize a media, such as magnetite, and water to separate the clean coal particles 30 from the refuse particles 32 according to their specific gravities.

#The clean coal particles 30 are fed to a clean coal screen 34 and, similarly, the refuse particles 32 are fed to a refuse screen 36. The clean coal particles 30 screened by the clean coal screen 34 are passed to a conventional clean coal handling section (not shown) of the coal preparation plant 14, while the refuse particles 32 screened by the refuse screen 36 are passed to a conventional refuse handling section (not shown) of the coal preparation plant 14.