Recycling and Treatment of Settling Pond Fines - A challenge to Industry and Environment

Abstract

About 3.0 Million tonness of coking coal fines (-0.5mm) generated from various coal preparation plants are lying in the lagoons/settling ponds in the vicinity of these plants for quite some time . In addition, 60,0001t of slurries are being bled every month to these waste basins. These discarded coal fines which contain significant amount of vitrinite enriched coking materials, are not being properly utilised due to the following reasons. (i)Inability of existing coal washing circuit to benef- iciate these coal fines from the slurry economically ii) Environmental restrictions regarding waste disposal were not stringent; (iii) Non-availability of suit- able technology to recover the coal fines at desired quality. To use these coal slurry fines, CFRI through decades long R&D efforts have developed an improved process technology, which can recover finest cleans (ash < 15%) from the said high ash (30-35%) coal slurry. Based on CFRI to Tech-nology, three mini flotation plants have been commissioned of throughput capacity 5 to 10 tph in small scale sector, which are successfully producing cleans (Yield 50-60%, and Moisture < 20%) from high ash coal slurry and dispatching the low ash cleans to M/s IISCO. Burnpur as one of their coking blend constituents for metallurgical coke making. Many irety mini flotation plants are coming into picture based upon this technology. This paper summarises data, concerning slurry pond quality estimate, floatability, material recovery, etc.