公开(公告)号：US06203773B1

公开(公告)日：2001-03-20

申请号：US09351968

申请日：1999-07-12

申请人： Michael A. Easley ,  Alan Pearson ,  Dinesh Moorjani ,  John E. Marhanka

发明人： Michael A. Easley ,  Alan Pearson ,  Dinesh Moorjani ,  John E. Marhanka

IPC分类号： C01F702

CPC分类号： C01F7/46 ,  C01F7/021 ,  C01P2004/61 ,  C01P2006/11 ,  C01P2006/12 ,  C01P2006/60 ,  C01P2006/62 ,  C01P2006/80

摘要： Alpha alumina particles are made by heating particles of alumina with an aqueous solution containing a dissolved fluorine-containing compound and an acid; separating the particles from the solution and then calcining the particles at a temperature not greater than about 1025° C. The alumina particles preferably have an LOI in the range of about 1-20 wt. %; more preferably about 1-6 wt. %. Alpha alumina particles of the invention are more readily ground into smaller particles than alpha alumina particles made by calcining at higher temperatures. The remaining soda in the alpha alumina is found to be highly soluble in hot water. The process produces low soda content (0.01 wt. % Na2O or less) alpha alumina crystals from alumina feedstocks with 0.5 wt. % or more initial soda levels. The alpha alumina crystals produced are as large as 30-40 microns. Most typically; the size range is between 2 and 8 microns. Because of the low mineralization temperature, the particles require significantly less grinding time to separate the component alpha crystals.

摘要翻译： 通过用含有溶解的含氟化合物和酸的水溶液加热氧化铝颗粒来制备α-氧化铝颗粒; 将颗粒与溶液分离，然后在不大于约1025℃的温度下煅烧颗粒。氧化铝颗粒优选具有约1-20重量％的LOI。 ％; 更优选约1-6wt。 ％。 本发明的α氧化铝颗粒比通过在较高温度下煅烧制备的α氧化铝颗粒更容易研磨成较小的颗粒。发现α氧化铝中的剩余苏打在高温下可溶于热水。 该方法从0.5重量％的氧化铝原料产生低苏打含量（0.01重量％Na 2 O或更少）的α氧化铝晶体。 初始苏打水平的百分比以上。 产生的α氧化铝晶体大至30-40微米。 最典型的 尺寸范围在2到8微米之间。 由于矿化温度低，颗粒需要明显较少的研磨时间来分离组分α晶体。