发明名称 METHOD OF MANUFACTURING HIGH PURITY CALCIUM CARBONATE
摘要 Flue gases exhausted from a lime kiln (10) containing lime kiln dust are treated to produce a high purity calcium carbonate precipitate. This is accomplished by passing the flue gases from the lime kiln (10) through a kil n dust separator (12) so that lime kiln dust containing calcium oxide is remov ed from the remaining flue gas (15). The lime kiln dust is mixed with water so that an aqueous suspension of the lime kiln dust is formed. Quicklime or calcium oxide in the lime kiln dust is thus hydrated to form calcium hydroxide. The solids within the suspension are then allowed to settle in settling tank (14) so that a clear, saturated solution of calcium hydroxide having a pH of about 12.4 is formed. This solution is then contacted with carbon dioxide gas in reaction tank (16) so that the calcium hydroxide react s to form a high purity calcium carbonate precipitate. This high purity calciu m carbonate precipitate is then allowed to settle from supernatant water of th e solution in thickener tank (20). The high purity calcium carbonate is separated from the supernatant water, while the supernatant water is recycle d through conduit (24) and used as the water mixed with the lime kiln dust to form the aqueous suspension.
申请公布号 CA2232302(C) 申请公布日期 2001.07.31
申请号 CA19962232302 申请日期 1996.01.30
申请人 CHEMICAL LIME COMPANY 发明人 HUEGE, FRED R.
分类号 B01D53/73;C01F11/18;(IPC1-7):C01F11/18 主分类号 B01D53/73
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