Ind. Eng. Chem. Res. 1992, 31, 2642-2647
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At the conditions under which the oxidation reaction of copper sulfide to sulfur was studied, complete conversion of copper sulfide to cupric ion and sulfur could not be achieved. Since complete conversion is necessary in order for the overall process to be succeesful, different conditions or a different oxidation reaction scheme would be needed to make the proposed process feasible. Acknowledgment This work was supported in part by the Morgantown Energy Technology Center, Assistant Secretary for Fossil Energy, office of Coal Utilization, Advanced Research and Technology Department, Division of Surface Coal Gasification, through the U.S. Department of Energy under Contract No. DE-AC03-76SF00098. Registry No. ZnS04, 7733-02-0; CuSO,, 7758-98-7; HzS, 7783-06-4; CUS,1317-40-4. Supplementary Material Available: Chapters 6 and 7 (text, figures, and tables) and bibliography from the M.S. Thesis of D.J.K., "Absorption of hydrogen sulfide using metal sulfate solutions" (33 pages). Ordering information is given on any current masthead page.
Coulson, J. M.; Richardson, R. F.; Sinnott, R. K. Chemical Engineering; Pergamon: Oxford, 1983; Vol. 6, p 354. Crudwell, F. K.Kinetics and Mechanism of the Oxidative Diseolution of a Zinc Sulphide Concentrate in Femc Sulphate Solutions. Hydrometallurgy 1987, 19, 227. Danckwerte, P. V. Gas-Liquid Reactionu; McGraw-Hilk New York, 1970.
Doyle, B. N.; Mastere, I. M.; Webster, I. C.; Veltman, H. Acid Pressure Leaching of Zinc Concentrates with Elemental Sulfur as a By-product. Proceedings of the 11th Commonwealth Mining and Metallurgical Congress, Hong Kong;IMM: London, 1978; p 645. Doyle, F. M.; Arauco, H.; Feng, L. M. Iron Removal During Oxidative, Acid Pressure Leaching of a Zinc Sulphide Concentrate. Znt. J. Miner. Process. 1989,25, 241. Dutrizac, J. E.; MacDonald, R. J. C. Ferric ion a~ a leaching medium. Miner. Sci. Eng. 1974, 6, 59. Koch, D. J. Absorption of Hydrogen Sulfide Using Metal Sulfate Solutions. M. S. Thesis, University of Calfomia at Berkeley, 1992. Mulak, W. Kinetics of diesolving polydispersed covellite in acidic solutions of ferric sulphate. Rocz. Chem. 1971,45, 1417. Swift, Ernest H.A System of Chemical Aanulysis; Prentice-Hall: New York, 1949. Thomas, G.;Ingraham, T. R. Kinetics of dissolution of synthetic covellite in aqueous acidic ferric sulphate solutions. Can Metall.
Q. 1967,6, 153. Uchida, S.; Wen, C. Y.Gas Absorption by Alkaline Solutions in a Venturi Scrubber. Znd. Eng. Chem. Process Des. Dev. 1973,12, 437.
Literature Cited Chmielewski, T.; Charewin, W. A. The oxidation of Fe(I1) in aqueow sulphuric acid under oxygen pressure, Hydrometallurgy 1984, 12, 21.
Weast, R. C., Ed. CRC Handbook of Chemistry and Physics, 65th ed.; CRC Press: Boca Raton, FL, 1984; p D-51. Received for review May 20, 1992 Accepted August 10,1992
In Situ Formation of MgC12 Support and Internal Donor during Preparation of Propylene Polymerization Catalystst Dong-ho Lee* Department of Polymer Science, Kyungpook National University, Taegu 702- 701, Korea
Young-tae Jeong Department of Research and Development, Korea Petrochemical Indwtrial Co., Ltd., Ukan 680-10, Korea
Kazuo Soga Research Laboratory of Resources Utilization, Tokyo Institute of Technology, Yokohama 227, J a p a n
Mg(OEt)2/benzoyl chloride (BC)/TiC14and Mg(OEt)2/phthaloyl chloride (PC)/TiC1, catalysts have been prepared by a chemical reaction method, and the chemical composition and polymerization behaviors were examined for various conditions of catalyst preparation and propylene polymerization. During the in situ preparation of catalysts, Mg(OEt), is converted to MgC12 and BC or PC is changed into the corresponding organic ester, ethyl benzoate (EB) or diethyl phthalate, respectively. With retreatment of the catalysts with T i c 4 ,the catalyst activity and isospecificity were improved. The obtained catalysts were found to have efficiencies comparable to the usual MgC12-supportedcatalyst. For Mg(OEt)2/EB/TiC14 catalyst, it has also been found that BC is formed by the chlorination of EB with TiC14 and remains in the prepared catalyst. Introduction The ZieglerNatta catalysts for stereospecific olefin polymerization employ a high surface area support for active transition metal catalyst sites. There have been many reports about the various supports for Tic&catalyst including such magnesium compounds as Mg(OH)Cl, MgSO,, Mg(OHI2 (Boor, 1979), MgO (Invanchev et al., 1980), MgC1, (Kashiwa et al., 1976), Grignard compounds (Yano et al., 1988),and Mg-alkyls (Haward et al., 1973). 'Dedicated to Prof. Dr. Tae-om Ahn on the occasion of his 60th birthday. 0888-5885/92/2631-2642$03.00/0
Among these supports, it has been discovered that MgC12 is a good support for stereospecific catalysts, and the preparation and characterization of MgC12-supported highly active titanium catalysts have been studied intensively (Barbe et d., 1987; Keii and Soga, 1990) in which MgC12 is activated by a physical milling method or a precipitation method. In addition, magnesium alkoxides were reported to be efficient supports in some patents (Goodall and Job, 1985). Recently, Mg(0Et)2-supportedTiCL catalysts including an organic chloride and/or an internal donor were studied. It has found that Mg(OEt)2is converted to MgC12 by the reaction with Tic4, and the organic chloride is necessary 0 1992 American Chemical Society
Ind. Eng. Chem. Rea., Vol. 31, No. 12, 1992 2643 to promote the conversion of Mg(OEtI2 to MgCl, (Jeong and Lee, 1990). The polymerization activity and isospecificity of polypropylene for the catalyst prepared by a chemical reaction method were similar to those for the catalyst obtained with the physical milling method. In addition, it was also found that ethyl benzoate forms as internal donor during the preparation of Mg(OEt)2/ benzoyl chloride/TiC14 catalyst by the chemical reaction method (Jeong et al., 1991a). In this paper, Mg(OEt),/benzoyl chloride/TiCl, and Mg(OEt),/phthaloyl chloride/TiC14 catalysts were prepared by the chemical reaction method, and the chemical composition of catalysts was examined in detail. The catalyst behaviors for propylene polymerization were also studied.
Experimental Section Materials. Propylene of polymerization grade, 99.5% purity, was supplied by the Korea Petrochemical Industrial Co. and dried by passing through two columns of preactivated molecular sieve 4A. Neat triethylaluminum (TEA) was supplied by the Tosoh Akzo Corp., Japan, and used without further purification. n-Hexane (Tokyo Kasei Co., Japan) was dried over preactivated molecular sieve 4A for at least 24 h and contained
