The application of enhanced gravity separation as a fine coal cleaning technique
- Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mining Engineering
- Illinois Clean Coal Inst., Carterville, IL (United States)
Past research and current industrial practice have found that froth flotation is a very efficient technique for separating well liberated hydrophobic coal particles from the hydrophilic particles of mineral matter. However, for coal suspensions containing a significant portion of mixed-phase particles, commonly referred to as middlings, the separation is not as effective since particles containing very little coal can be floated. A more efficient method of treating fine coals containing a large amount of middling particles is to use a gravity-based process which can exploit the large density differences between coal and its associated mineral matter. To achieve this on fine coal, an enhanced gravity field must be supplied to achieve the centrifugal force needed to increase particle inertia and, thus, provide an efficient separation. A commercial-scale centrifugal washing unit capable of treating a mass flow rate of 5 tph continuously has been used to evaluate its feasibility for treating fine coal as an alternative to froth flotation. A {minus}28 mesh flotation feed sample was used in this investigation. The critical process parameters were identified by conducting exploratory tests. Then, a statistically-designed experimental program was carried out which led to the development of empirical expressions which describe the effect of the process parameters on the response variables. The response variables considered in this study include ash and sulfur rejection, combustible recovery, and separation efficiency. Next, the process parameters were optimized based on the maximum values of the response variables. The results of this study are presented in this publication.
- OSTI ID:
- 51990
- Report Number(s):
- CONF-940930--
- Country of Publication:
- United States
- Language:
- English
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