EFFECT OF ALKALI-HALIDES AND SILVER-NITRATE ON CRYSTALLIZATION OF SILICA POWDERS
EFFECT OF ALKALI-HALIDES AND SILVER-NITRATE ON CRYSTALLIZATION OF SILICA POWDERS
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DOI：
10.1007/bf00574929
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发表时间：
1972-01-01
影响因子：
4.5
通讯作者：
ZETTLEMOYER, AC
中科院分区：
文献类型：
--
作者：
BASSETT, DR;BOUCHER, EA;ZETTLEMOYER, AC
本文研究了碱金属卤化物对无定形二氧化硅粉晶化的影响。通常在1000°C以下不会发生结晶，但在约20重量%氯化锂存在下，α-石英在700°C下2小时内形成。在钠盐和钾盐的存在下，α-方石英在约800至850°C下形成。似乎石英是在锂盐存在下形成的，因为Li+可以进入石英晶格，而Na+和K+可以渗透更膨胀的多晶型形式方石英。在所有情况下，阳离子都可能伴随有氧离子，以保持电中性。无定形颗粒的有限渗透足以使新相成核。综述了盐处理后的白炭黑产品的其它性能。
The effect of alkali halides on the crystallization of amorphous silica powders has been investigated. Normally crystallization does not occur below 1000°C, but in the presence of about 20% by weight of lithium chloride, α-quartz forms within 2 h at 700°C. In the presence of sodium and potassium salts, α-cristobalite forms at about 800 to 850°C. It appears that quartz is formed in the presence of the lithium salt because Li+can enter the quartz lattice, whereas Na+and K+can penetrate the more expanded polymorphic form, cristobalite. It is possible that the cations are accompanied by oxide ions in all cases to maintain electrical neutrality. Limited penetration of the amorphous particles is sufficient to nucleate the new phase. Other properties of silica products treated with salts are reviewed.