INORGANICCHEMICALSINDUSTRY ›› 2010, Vol. 0 ›› Issue (5): 0-0.

   

Thermodynamic analysis on preparation of zinc oxide precursor by carbonation method and characterization of its products

Tong Zhifang,Li Yanlong,Yang Guanghua,Kang Liwu   

  • Online:2010-05-10 Published:2010-10-01

Abstract: <SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">Thermodynamics in preparation process of zinc oxide precursor by carbonation method was analyzed.Influences of the amounts and addition ways of ammonium bicarbonate,concentration of zinc sulfate solution and temperature on precursor were studied and the product was characterized by TG-DTA-DTG,XRD,and SEM.Results showed that Gibbs free energy of generation of basic zinc carbonate [Zn<SUB>5</SUB>(CO<SUB>3</SUB>) <SUB>2</SUB>(OH) <SUB>6</SUB>] calculated by thermodynamics was the smallest,which was-170.429 9 kJ/mol;precursor was obtained under the processing conditions as follows:ammonium bicarbonate and zinc sulfate solutions were added with paralled flow, n (NH<SUB>4</SUB>HCO<SUB>3</SUB>)</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">∶</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">n (Zn<SUP>2+</SUP>)=2.4</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">∶</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">1,concentration of Zn<SUP>2+ </SUP>was 0.4 mol/L and reaction temperature was 40 </SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">℃</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">.From the analysis of TG-DTA-DTG and XRD,precursor was existing in the form of basic zinc carbonate;decomposition temperature of precursor was 170</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">~</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">330 </SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">℃</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">;decomposition directly emitted carbon dioxide and water and activated zinc oxide was formed finally.SEM showed the precursor was flake-like solid with the average size of about 0.4 </SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">μ</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">m.</SPAN>