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Role of calcium and magnesium cations in the interactions between kaolinite and chalcopyrite in seawater

Uribe L., Gutierrez L., Laskowski J. S., Castro S.

Physicochemical Problems of Mineral Processing

2017

Vol. 53, iss. 2

737--749

A number of flotation plants around the world have increased the use of seawater due to limited sources of fresh water. The aim of this research work is to study the role that Mg2+ and Ca2+ ions play in the interactions between kaolinite and chalcopyrite in seawater. In order to achieve this objective, the effect of kaolinite on flotation of chalcopyrite is studied over the pH range from 8 to 11, when flotation is carried out in seawater and in a 0.01M NaCl solution. The influence of calcium, magnesium, sodium, and potassium ions on the extent of depression by kaolinite is evaluated. The micro-flotation results indicate that chalcopyrite is depressed by kaolinite in both 0.01 NaCl solution and seawater. In the 0.01 NaCl solution, the depressing effect of kaolinite decreases as the pH increases from 8 to 11. However, the results obtained using seawater show that the depressing effect of kaolinite is similar to what is observed in a 0.01 NaCl solution only at pH values below 9, but above this pH kaolinite significantly affects the recovery of chalcopyrite. The results from experiments with using solutions containing individual cations show that the depressing action of kaolinite in the presence of Mg2+ and Ca2+ is more obvious at pH values of 9 and 10, respectively, which correlates with the pH values at which the first hydroxy-complexes of these divalent cations start forming. This seems to indicate that depressing effect of kaolinite on chalcopyrite in seawater may be related to formation of hydrolyzed species of calcium and magnesium. These species can induce heterocoagulation between kaolinite and chalcopyrite. The trends observed in the micro-flotation experiments are in good agreement with the results of the induction time measurements and slime coating tests.

Structural weight estimation of a flying wing with a pressurized wing box

Rodriquez C., Martinez-Val R., Gutierrez L.

Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics

2000

nr 10

177-182

The present paper will introduce a prediction method that will allow for estimation of the structural weight of a transport flying with an approximate capacity of 300 passengers. The flying wing payload will be located between the front and rear spars, and up to half the span approximately, which implies that the study of the wing structure will have two different parts; i.e., the external structure that will be of conventional architecture apart from its dimensions that will be bigger and the internal structure, no conventional, where the torsion box will be pressurized and with all the equipment required for passenger and, cargo transportation.