LLC “Institute “Gipronikel”, Saint Petersburg, Russia:
A. B. Portov, Researcher
S. S. Ozerov, Engineer, e-mail: ssoze@nikel.spb.ru
Yu. A. Savinova, Junior Researcher
L. Sh. Tsemekhman, Head of Pyrometallurgy Laboratory

Technology of partial oxidation roasting of ore copper-nickel concentrate, mixed with silt of technogenic Nyud-Yavr Lake deposit, was carried out on aggregative-laboratory unit of boiling layer. There was studied the influence of various parameters (charge fluid bed furnace capacity; feed rate of blow gas and their oxygen content in layer temperature) on roasting indicators (cinder output, its size and cyclone dust size; content of residual sulfides in this cinder and cyclone dust, structure and material composition of roasting products). There was found that the roasting-formed dust is very fine, its material composition is unstable, and it is non-condition product for subsequent electrical melt. Organization of complete dust recycling is not possible with low-temperature roasting (720–740 ^oC). At the same time, dust removal is reached by 40–53%, if roasting is carried out at the temperature of 820–840 ^oC. The maximum extraction of silt into cinder is 95–98%. Increasing of roasting temperature leads to a deeper sulfur removal from cinders and transfer of main part of non-ferrous metals in the deep oxidized (spinel and ferrite) components. There were defined the parameters, which require the process of obtaining of optimal composition roasting products (cinder) in maximum amount. Process adjustment and maintaining at the given parameters is achieved by varying of oxygen content in blow gases and the time of material presence in a fluidized bed (sector gates opening frequency). Feed of concentrate as a slurry sludge injection into the fluid bed furnace through nozzles is possible as well as furnace operation for complete dust removal. However, for the purpose of maintaining of required sulfur content of dust, it is necessary to decrease the roasting temperature of 600–610 ^oC, leading predominantly to sulfates’ formation in cinder

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