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A study of the optimal model of the flotation kinetics of copper slag from copper mine Bor

Stanojlovic R. D., Sokolovic J. M.

Archives of Mining Sciences

2014

Vol. 59, no. 3

821--834

In this study the effect of mixtures of copper slag and flotation tailings from copper mine Bor, Serbia on the flotation results of copper recovery and flotation kinetics parameters in a batch flotation cell has been investigated. By simultaneous adding old flotation tailings in the ball mill at the rate of 9%, it is possible to increase copper recovery for about 20%. These results are compared with obtained copper recovery of pure copper slag. The results of batch flotation test were fitted by MatLab software for modeling the first-order flotation kinetics in order to determine kinetics parameters and define an optimal model of the flotation kinetics. Six kinetic models are tested on the batch flotation copper recovery against flotation time. All models showed good correlation, however the modified Kelsall model provided the best fit.

W pracy badano wpływ mieszanin żużla miedziowego i odpadów poflotacyjnych w kopalni miedzi Bor na efektywność odzysku miedzi na drodze flotacji oraz parametry kinetyki flotacji w urządzeniu do flotacji pracującego w trybie cyklicznym. Poprzez równoczesne wprowadzenie starych odpadów poflotacyjnych rozdrobnionych w młynie kulowym w ilości 9%, możliwe jest podniesienie poziomu odzysku miedzi o około 20%. Wyniki te porównać można z poziomem odzysku miedzi z czystego żużla. Wyniki badań flotacji porcji wsadu zostały dopasowane przy użyciu oprogramowania MatLab do modelowania kinetyki flotacji (model pierwszego rzędu) w celu określenia parametrów kinetycznych i dla zdefiniowania optymalnego modelu kinetyki procesu flotacji. Przebadano sześć modeli kinetyki, analizując wielkość odzysku miedzi ze wsadu w stosunku do czasu flotacji. Wszystkie modele wykazywały dużą korelację, a najlepsze dopasowanie wykazywał zmodyfikowany model Kelsalla.

Activation of oxidized surface of anthracite waste coal by attrition

Sokolovic J. M., Stanojlovic R. D., Markovic Z. S.

Physicochemical Problems of Mineral Processing

2012

Vol. 48, iss. 1

5-18

In this paper the activation of oxidized surface of anthracite waste coal was investigated. Coal weathering leads to physical and chemical changes on the coal surfaces and a reduction of its hydrophobicity and floatability. The changes and the presence of oxygen functional groups in the structure and surfaces coal was confirmed by the FTIR study on the raw and waste coal. The groups have remarkable impacts on surface charge and thus flotation kinetics. The floatability of oxidized coal may be improved by the creation of fresh, unoxidized surfaces on coal by attrition at high solid concentration prior to introducing coal to the froth flotation process. This paper presents the results of the effects of attrition on the floatability of the oxidized surface of waste coal, coal pyrite and alumino-silicate minerals through electrokinetics and microflotation experiments. The results show that the attrition, in the viscous pulp with the solid content of 50%, lead to the mechanical cleaning of oxidized surface and activation of the surface of coal particles, which agrees with the change of zeta potential and increasing floatability of coal by 10%. Obviously that the mechanical scrubbing may be able to restore the natural floatability of superficially oxidized coal by removing the thin oxidation layer from the coal surface. The results show that attrition time is an important parameter from the point of view of activating the oxidized coal surface, and positive changes in zeta potential and floatability. The change of zeta potential, as a measure surface charge state of coal particles, from -15 mV to about 0 mV, after attrition for 30 minutes, confirms positive application of attrition. Zeta potential approaching 0 mV resulted in increasing floatability down to the real possibilities of the attrition process prior the coal flotation.