TESTING THE ISGS FROTH WASHER ON A STREAM OF COAL PREP PLANT FINES
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Title
TESTING THE ISGS FROTH WASHER ON A STREAM OF COAL PREP PLANT FINES
ICCI Project ID
97-1/2.1A-5
Investigator
Khan
Institution
Illinois State Geological Survey
ICCI Abstract
The purpose of this project was to continue the development of the ISGS froth washer for producing clean coal from fines rejected from an operating coal processing plant and to test the washer on a packed column using IBC-112. The washer has been developed at the ISGS to increase the throughput and improve the grade of clean coal from a froth flotation circuit using a subaeration cell or column. In this washer, the froth goes through several wash stages. The opportunity for removing contaminants from the froth is increased in four ways: 1) the area over which the froth is exposed to clean wash water can be increased providing an opportunity for multiple stage washing; 2) the amount of wash water and the force or intensity of washing can be increased; 3) the wash water carries the contaminants down through froth only a short distance quickly separating the contaminants from the froth; and 4) the total depth of the froth is decreased, decreasing the tendency for the weight of upper levels of froth to crush the froth underneath.
During the first phase (1996-1997), the ISGS washer was adapted to a subaeration cell and was tested under various conditions. Tests were conducted on IBC-112 from the Illinois Basin Coal Sample Program. The results were compared to an advanced flotation washability curve, a float/sink curve and the results from packed column tests. Tests indicate that the subaeration cell equipped with the ISGS washer can consistently produce a cleaner product than the packed column at a similar throughput. Particularly good results (especially in pyrite rejection) were obtained when the inclined washer was run under water saturated conditions.
During the second phase (1997-1998) a representative sample of prep plant fines was collected, homogenized, and subdivided into smaller lots. Sink-float and advanced flotation washability tests were carried out to establish what type of product may be generated out of this coal under ideal conditions. This was followed by qualitative tests in a subaeration cell to determine dosages of the reagent that may be required to float the coal. The impact of variables such as the dosage of frother, aeration rate and feed rates on the quality and quantity of material produced were carried out in the subaeration cell equipped with the ISGS washer. These tests indicate that the modified subaeration cell can produce results approaching the advanced flotation washability curve at feed rates of 50 lb/hr/ft3. The maximum throughput tested without significant detrioration of cell performance was 61 lb/hr/ft3. The yield from the packed column retrofitted with the ISGS froth washer increased with decreased wash water and increased pulp level for both IBC-112 and plant fines.
During the first phase (1996-1997), the ISGS washer was adapted to a subaeration cell and was tested under various conditions. Tests were conducted on IBC-112 from the Illinois Basin Coal Sample Program. The results were compared to an advanced flotation washability curve, a float/sink curve and the results from packed column tests. Tests indicate that the subaeration cell equipped with the ISGS washer can consistently produce a cleaner product than the packed column at a similar throughput. Particularly good results (especially in pyrite rejection) were obtained when the inclined washer was run under water saturated conditions.
During the second phase (1997-1998) a representative sample of prep plant fines was collected, homogenized, and subdivided into smaller lots. Sink-float and advanced flotation washability tests were carried out to establish what type of product may be generated out of this coal under ideal conditions. This was followed by qualitative tests in a subaeration cell to determine dosages of the reagent that may be required to float the coal. The impact of variables such as the dosage of frother, aeration rate and feed rates on the quality and quantity of material produced were carried out in the subaeration cell equipped with the ISGS washer. These tests indicate that the modified subaeration cell can produce results approaching the advanced flotation washability curve at feed rates of 50 lb/hr/ft3. The maximum throughput tested without significant detrioration of cell performance was 61 lb/hr/ft3. The yield from the packed column retrofitted with the ISGS froth washer increased with decreased wash water and increased pulp level for both IBC-112 and plant fines.
Start Date
9/1/1997
End Date
9/30/1998
Year Funded
1997
Collection
Citation
“TESTING THE ISGS FROTH WASHER ON A STREAM OF COAL PREP PLANT FINES,” ICCI Reports, accessed May 23, 2024, https://isgswikis.web.illinois.edu/icci_reports/items/show/519.