TECHNOLOGICAL STATUS OF THE ORE TREATMENT-PLANT AT RAJHARA MINES (BSP) AND SUGGESTIONS ON IMPROVEMENT OF CRUSHING AND SCREENING EFFICIENCY

Investigations had been carried out some years ago at Rajhara. Mines o f Bhilai Steel Plant, BSP, at the instance of the plant, with a view t o effect improvement in the existing crushing and screening system. Th e industrial trials primarily concerned with a diagnostic study of the then existing ore handling circuit and was directed towards achieving better granulometry of lump ore and increased productivity. Stabilisa tion of the granulometry of lump and attendant reduction in the percen tage undersize in it was the prime concern of the plant.The investigat ions revealed that the crushing efficiency of the jaw crusher was good , but that of the cone crusher was poor. This was primarily due to the fact that -40 mm size fraction of the ore was inadvertently being fed to the secondary crusher. This in turn resulted in overcrushing of th e finished product as well as generation of higher proportion open-hea rth variety lump ore. The paper, based on data analysis and generated information, describes remedial measures for improving granulometric c omposition of BF lump and sinter fines and, more importantly, lays str ess on increasing productivity of the existing circuit. The salient re commendations on improvement in granulometry envisaged second phase of trial investigations for fixing up of the operational regime of the p lant and making firm recommendations. Further trial investigations val idated the findings and subsequent changes made in the circuit by the plant themselves vindicated the RDCIS stance.