DEPHOSPHORIZATION OF AGBAJA IRON ORE BY SINTERING AND BIOLEACHING PROCESSES

AUTHOR: AMEH, EBERE MONICA

DEPARTMENT: MECHANICAL ENGINEERING

AFFILIATION: NNAMDI AZIKIWE UNIVERSITY, AWKA

The reduction of phosphorus content to acceptable level (0.01 – 0.03) by sintering of Agbaja iron ore with KClO3 and NaOH as oxidants and bioleaching have been investigated. Biobeneficiation in the natural environment was used. From the result of the sinter produced with coke breeze, reduction of phosphorus to acceptable value (0.02 – 0.03%) was achieved. About 95.38%P was removed and iron was upgraded to about 99.99%. Potassium chlorate (KClO3) and NaOH successfully reduced phosphorus from 0.78% to 0.03%. For the three parameters used (leachants, time and temperature) about 96.17%P 97.62%Fe, 95.20%P 94.70%Fe, and 94.61%P 96.01%Fe respectively were successfully removed from the ore. Also, with the mixture of the two leachants (KClO3& NaOH) under the same three parameters (leachants, time and temperature) about 85.24%P, 80.83%P and 73.91%P respectively were successfully removed from the iron ore. The level of phosphorus in the ore, obtained with either of the two oxidants (KClO3 or NaOH) during sintering fell within the limit of acceptable phosphorus (0.03%P) in high quality steel. Also, the mixture of both leachants reduced phosphorus to (0.18%P) which is within the metallurgical acceptable value of (0.3%P) in pig iron production. For bioleaching, “Thiobacillus Ferrooxidans” was used on Agbaja iron ore. The organism successfully reduced phosphorus from the iron ore to the metallurgical acceptable value. From the result, it was observed that about 92.73% P (for particle size), 79.27%P (for pH) and 96.58%P(for inoculum) were removed at the fourth (4th) week for particle size (0.63mm), pH(2) and inoculums (5ml) when 2g extract in 100ml solution was analyzed. At the fourth week, the ore was also upgraded to about 97.19av%, 98.01%av and 97.01%av for PS(0.32mm), pH(2) & inoculums (5ml). The organism used, performed very well in dephosphorization & upgrading of iron content in Agbaja iron ore under the following conditions: Particle size range of 0.32 — 0.63mm, pH=2, inoculum size of 5ml (at 0.5Mc Farland standards in 300ml of experimental medium) at fourth week when 2g] extract in 100ml solution was analyzed. In sintering, the predicted model value of R correlation was slightly above the experimental value: R2 = 1 and R2 = 0.8339 respectively (time and temperature considered). In bioleaching, the predicted model value of R correlation was the same with the experimental generated value: R2 = 1 and R2 = 1 respectively (time & inoculum, time & particle size considered). Hence, the prediction indicated that the experiment was in order i.e the predicted model value was quite in agreement with the experimental generated.

TO VIEW THE FULL CONTENT OF THIS DOCUMENT, PLEASE VISIT THE UNIZIK LIBRARY WEBSITE USING THIS LINK, http://naulibrary.org/dglibrary/admin/book_directory/Metallurgical_Material_Engr/11363.pdf

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