Structure and Properties of Copper-Zinc

Structure and Properties of Copper-Zinc Superoxide Dismutases Ivano Bertini, Stefano Mangani, and Maria Silvia Viezzoli... 

Bertini I, Magnani S, Viezzoli M-S. (1998) Structure and properties of copper-zinc superoxide dismutases. In Advances in Inorganic Chemistry, Sykes AG. (ed.), pp. 127-250, Academic Press New York. 

STRUCTURE AND PROPERTIES OF COPPER-ZINC SUPEROXIDE DISMUTASES... 

Bems B, et al. Relations between synthesis and micro structural properties of copper/zinc hydroxycarbonates. Chem Eur J. 2003 9(9) 2039-52. 

Flotation has been used for more than 100 years to separate sulphides, oxides and other salts from ores, as well as to obtain phosphates, barite, chromite and other materials. Up to 90% of copper, lead, nickel, zinc are extracted using flotation in the USA [152 - 153]. In Russia, flotation is widely used to additionally obtain apatite, barite and phosphates. Flotation of iron oxides is not used in practise yet, but the number of experiments carried out in this direction is rather large. The main physicochemical principles of flotation have been discussed above [59 -74]. Here, only some practical problems will be discussed. In [153], requirements are pointed out which apply to three-phase flotation foams, and the main components of the process are defined, i.e. surfactant - collector surfactant - frother activator, depressants, colligend, gangue. The peculiarities of flotation and foam separation in batch and continuous modes are outlined as well as the structure and properties of the main types of flotation agents described. As surfaces of the majority of mineral particles are hydrophilic in nature, hydrophobisation of particles is necessary for a selective separation. 

The /3-alloys are different in nature from the 7-alloys and the a-manganese and /3-manganese structures discussed above, in that they are not complex structures, but are simple, being based upon the body-centered arrangement. /3-Brass, for example, has either a disordered structure, above 480°K, the copper and zinc atoms in essentially equal number being distributed largely at random over the points of a body-centered cubic lattice, or an ordered structure, below 300°K, with copper and zinc at the positions 000 and, respectively, of the cubic unit. Moreover, the physical properties of /3-brass are not those that indicate a filled zone structure. 

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