添加剂促进锌铝尖晶石生成机理研究

Study on the Formation Mechanism of Zinc Aluminate Spinel Promoted by Additives

以氧化铝和氧化锌为原料,采用固相反应法合成锌铝尖晶石,将试样在800～1500℃进行烧结,研究了添加剂对矿物组成和微观结构的影响,采用XRD、SEM和EDS等手段对烧后试样的物相组成和显微结构进行表征。结果表明:在800℃时,空白样的主晶相为氧化锌,次晶相为锌铝尖晶石,添加ZrO_2的试样主晶相为锌铝尖晶石,次晶相为氧化锌和氧化锆,添加TiO_2的试样,主晶相为锌铝尖晶石,次晶相为钛酸锌,两种添加剂均有促进锌铝尖晶石生成的作用,添加TiO_2和ZrO_2的试样晶粒尺寸均比空白样大; 1500℃时,氧化钛与氧化铝反应生成钛酸铝,当TiO_2含量在1%～5%之间时,随着TiO_2含量增加,锌铝尖晶石晶粒尺寸增大。

Zinc oxide and alumina sources were used to develop zinc aluminate spinel by solid-state reaction sintering technique.The effects of additives on mineral composition and microstructure were studied.The product was sintered in the temperature range of 800℃to 1500℃.The phase composition and microstructure of the burned samples were characterized by means of XRD,SEM and EDS.The XRD results indicated that main crystal of blank samples is zinc oxide,secondary crystal is zinc aluminate spinel.Main crystal is zinc aluminate spinel,secondary crystal is zinc oxide and zirconia when additives zirconia is added into samples.Main crystal is zinc aluminate spinel,secondary crystal is zinc titanate when additives titanium oxide is added into samples at 800℃.Both additives have the effect of promoting the formation of zinc aluminate spinel.The grain size is larger than blank samples.But the microstructure was influenced greatly by TiO 2 addition at 1500℃sintering temperature.Titanium oxide reacts with aluminum oxide to form alumimum titanate.When the content of titanium oxide is between 1%and 5%,The grain size of zinc aluminate spinel increases with the increase of titanium oxide content.