Production of alumina from gibbsite-bearing bauxite of low reactive
silica content
    1.
    发明授权
    Production of alumina from gibbsite-bearing bauxite of low reactive silica content 失效
    从含有低活性二氧化硅含量的含三水铝矿的铝土矿生产氧化铝

    公开(公告)号:US4650653A

    公开(公告)日:1987-03-17

    申请号:US857316

    申请日:1986-04-30

    IPC分类号: C01F7/06 C01F7/46 C01F7/47

    摘要: Process for the low-temperature treatment according to the Bayer cycle of gibbsite-bearing bauxite of low reative silica content, involving desilication of the said bauxite before leaching, by a liquor of low caustic soda concentration and characterized in that this sodium liquor consists of one or more washing waters originating from the Bayer cycle, mixed or otherwise with leaching liquor, wherein the weighted reactive silica content is preferably lower than 5% of the alumina content of the bauxite and the concentration of the sodium liquor used for desilication ranges from 50 to 120 g/liter of Na.sub.2 O caustic.

    摘要翻译: 根据具有低二氧化硅含量的含三水铝矿的铝土矿的拜耳循环的低温处理方法,包括在浸出之前通过低苛性钠浓度的液体对所述铝土矿进行脱硅,并且其特征在于该钠液体由1个 或更多来自拜耳循环的洗涤水,混合或以其他方式与浸出液混合,其中加权的反应性二氧化硅含量优选低于铝土矿的氧化铝含量的5%,用于脱盐的钠液的浓度范围为50至 120克/升Na2O苛性碱。

    Process for the production of aluminum trihydroxide having a medium of
less than 4 microns, which can be varied as required
    2.
    发明授权
    Process for the production of aluminum trihydroxide having a medium of less than 4 microns, which can be varied as required 失效
    具有小于4微米的介质的三氢氧化铝的生产方法,其可根据需要变化

    公开(公告)号:US4574074A

    公开(公告)日:1986-03-04

    申请号:US622083

    申请日:1984-06-13

    摘要: A process for the production of aluminum trihydroxide having a controlled median diameter of less than 4 microns, with a unimodal distribution and minimum deviation. The process comprises grinding aluminum trihydroxide until the aluminum trihydroxide has a specific BET surface area of at least 8 m.sup.2 /g, adding the ground aluminum trihydroxide to a sodium aluminate solution, and then decomposing the solution to precipitate aluminum trihydroxide having the required median diameter.

    摘要翻译: PCT No.PCT / FR83 / 00210 Sec。 371日期1984年6月13日 102(e)日期1984年6月13日PCT提交1983年10月18日PCT公布。 公开号WO84 / 01569 日期1984年4月26日。一种具有小于4微米的受控中值粒径的三氢氧化铝的制备方法,具有单峰分布和最小偏差。 该方法包括研磨三氢氧化铝直到三氢氧化铝具有至少8m 2 / g的比BET表面积,将研磨的氢氧化铝铝酸铝加入到铝酸钠溶液中,然后分解溶液以沉淀具有所需中值直径的三氢氧化铝。

    Production of aluminum trihydroxide having median diameter of 2 to 100
microns
    3.
    发明授权
    Production of aluminum trihydroxide having median diameter of 2 to 100 microns 失效
    中间体直径为2至100微米的三氢氧化铝的生产

    公开(公告)号:US4582697A

    公开(公告)日:1986-04-15

    申请号:US624669

    申请日:1984-06-13

    摘要: A process for the production of aluminum trihydroxide having controlled median diameter of 2 to 100 microns, with a unimodal distribution and minimum deviation, by decomposing a hot supersaturated sodium aluminate solution in the presence of seed aluminum trihydroxide, separating the resultant solid and liquid phases and recovering the solid phase constituted by precipitated aluminum trihydroxide. The process comprises grinding aluminum trihydroxide until the aluminum trihydroxide has a specific BET surface area of at least 1 m.sup.2 /g, introducing the ground aluminum trihydroxide into a hot fraction of the supersaturated sodium aluminate solution to precipitate trihydroxide seed and then decomposing the remaining fraction of the supersaturated sodium alimuniate solution in the presence of the seed. This decomposition leads to the precipitation of aluminum trihydroxide having the required median diameter.

    摘要翻译: PCT No.PCT / FR83 / 00209 Sec。 371日期1984年6月13日 102(e)日期1984年6月13日PCT提交1983年10月18日PCT公布。 公开号WO84 / 01568 日本1984年4月26日。一种通过在种子三氢氧化铝存在下分解热过饱和铝酸钠溶液来生产中值粒径为2至100微米的单峰分布和最小偏差的三氢氧化铝的方法, 所得固相和液相,并回收由沉淀的三氢氧化铝构成的固相。 该方法包括研磨三氢氧化铝直到三氢氧化铝具有至少1m 2 / g的比BET表面积,将研磨的三氢氧化铝引入过饱和铝酸钠溶液的热级分中以沉淀三氢氧化钠种子,然后分解剩余部分 在种子存在下,过饱和的阿利膦酸钠溶液。 这种分解导致具有所需中值直径的三氢氧化铝的沉淀。

    Method of producing an aluminium trihydroxide with a large, even
particle size
    4.
    发明授权
    Method of producing an aluminium trihydroxide with a large, even particle size 失效
    制造具有大,均匀粒度的三氢氧化铝的方法

    公开(公告)号:US4614642A

    公开(公告)日:1986-09-30

    申请号:US747045

    申请日:1985-06-06

    IPC分类号: C01F7/06 C01F7/14

    CPC分类号: C01F7/144

    摘要: A method of decomposing a super-saturated solution of alkali metal aluminate Ld from the Bayer process, by introducing primer Sa and forming a suspension with a high content of dry material, of at least 700 g/l of alkali metal aluminate solution to be decomposed, is characterized in that, for the purpose of obtaining Al(OH).sub.3 with a large, even particle size, a zone (Zs) for separating particularly fine solid particles of Al(OH).sub.3 is formed in decomposition zone (B) comprising a cascade of n stages of the Bayer process, the separating zone being fed with at least part L(n-3)1 of the flow of suspension Ln-3 circulating in said zone (B), from which a fraction LS.sub.1 is extracted, containing at least 5% of the total number of fine particles with a maximum diameter of 40 microns present in the flow Ln-3, while the residual suspension LS.sub.2 emerging from the separating zone Zs is recycled to zone (B), then the fraction Ls.sub.1 is treated by a known means for reducing the number of fine particles by at least 50%, and is recycled to a stage in the Bayer process.

    摘要翻译: PCT No.PCT / FR84 / 00195 Sec。 371日期:1985年6月6日 102(e)日期1985年6月6日PCT提交1984年9月4日PCT公布。 出版物WO85 / 01040 1985年3月14日。一种从拜耳法中分解碱金属铝酸盐Ld的超饱和溶液的方法,通过引入底物Sa并形成至少700g / l的干物质的高含量的悬浮液 要分解的碱金属铝酸盐溶液的特征在于,为了获得具有大的甚至粒径的Al(OH)3的目的,形成用于分离特别细的Al(OH)3的细小固体颗粒的区域(Zs) 在包括拜耳方法的n级级联的分解区(B)中,分离区被供给在所述区(B)中循环的悬浮液Ln-3流的至少一部分L(n-3)1, 其中提取了一部分LS1,其含有流Ln-3中存在的最大直径为40微米的细颗粒总数的至少5%,而从分离区Zs排出的残留悬浮液LS2被再循环到区 B),则通过用于减少f的数量的已知方法来处理分数Ls1 颗粒至少50%,并被再循环到拜耳法中的一个阶段。