摘要:

This is a critical review of the research on the collector mechanism carried out during the last ten years. The work has been reviewed in three parts. The first part is concerned with the studies on the collector mechanism in sulfide minerals. The discussion centers on the collector action of xanthates and dixanthogens. The nature of the adsorbed film is discussed in the light of recent studies by infrared spectroscopy, electron diffraction, adsorption and calorimetric measurements. The influence of oxygen on the adsorption of xanthate on sulfide minerals is discussed and a critical evaluation made of the evidence for and against the theory that the presence of oxygen is crucial to the formation of a hydrophobic film at the sulfide mineral surface conditioned with xanthate. Recent studies on the stability of the adsorbed collector film are reviewed and correlated with the theories of the collector action of xanthates. The influence of modulating agents, activators, and depressants on the collector action of xanthates on pyrite, pyrrhotite, and marmatite are discussed. Finally, the collector action of xanthates on oxidized lead and zinc minerals has been reviewed and the known basic differences between the nature of the adsorbed species on these minerals and that on sulfide minerals is discussed. The collector mechanism in nonsulfide minerals is reviewed for the following groups of minerals: oxides, silicates, and alumino-silicates, polar salt-type minerals containing alkaline earth metal cations and soluble salts. The collector mechanism of anionic as well as cationic reagents is reviewed in conjunction with the action of modifying agents. The possibilities of employing chelating agents as mineral collectors for nonsulfide minerals are examined. The recent electrokinetic studies on nonsulfide systems in relation to the electrical double layer and nature of the adsorbed species is discussed in detail. In the third part certain new aspects of the collector mechanism, namely the role of impurities and nonstoichiometry of the mineral samples, are discussed. The possibility of controlling the floatabilities of minerals by incorporating impurity centers is examined. Finally, the kinetic factors affecting the collector mechanism are discussed.

ISSN:0037-2366    

DOI:10.1080/01496396908052266

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The fundamental chemical entity in any equilibrium chemical system is thepartition state, which is the state formed by the reversible physical or chemical reaction between a componentiand an environments.Such a state represents a unifying concept for the description of partitioning chemical systems, phase equilibria, and chemical equilibria. It is defined thermodynamically and applied to a chemical system containing five different components and three chemical equilibria.

ISSN:0037-2366    

DOI:10.1080/01496396908052267

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

The feasibility of virtually any commercial-scale ion flotation (foam separation) process depends on the recovery and reuse of the surfactant used as the flotation agent. For aqueous solutions of acid chromate complexed with a cationic quaternary ammonium salt, ethylhexadecyl-dimethylammonium bromide, a variety of paths are investigated to split the complex and to separate and recover the surfactant. These include acid chromate reduction with NaHSO3or SnCl2followed by sorption of the surfactant by and elution from a polymeric resin, Rohm and Haas Amberlite XAD-2. The most promising path is reduction of the acid chromate with NaHSO3at pH 2–3, extraction with isopropanol—chloroform in a 1:1 ratio, vacuum distillation of the solvents, and redissolution of the surfactant in aqueous solution. The minimum HSO3/Cr ratio is established, distribution coefficients for the extraction are determined, and the recovered surfactant is tested in several ion flotation experiments, making a comparison with fresh surfactant.

ISSN:0037-2366    

DOI:10.1080/01496396908052268

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

In an attempt to set up a simple laboratory experiment for illustrating and assessing thermal diffusion in solutions we were surprised to find that, owing to the arrangement used, the solute became more concentrated at the hot end instead of at the cold end as is almost always the case. However, once again it turns out that what appears to be a negative result can serve a useful purpose.

ISSN:0037-2366    

DOI:10.1080/01496396908052269

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0037-2366    

DOI:10.1080/01496396908052265

出版商:Taylor & Francis Group    

年代:1969

数据来源: Taylor