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公开(公告)号：US5030424A
公开(公告)日：1991-07-09
申请号：US381537
申请日：1989-07-18
申请人： George D. Fulford , Gordon Lever , Taichi Sato
发明人： George D. Fulford , Gordon Lever , Taichi Sato
CPC分类号： C01F17/0006 , C01F17/0043 , C01F7/066 , C22B59/00 , Y02P10/234
摘要： A process for the recovery of rare earth elements from Bayer Process red mud includes the following steps: (a) digesting red mud containing rare earth elements with a dilute acid solution, e.g. sulphur dioxide dissolved in water, to selectively dissolve the rare earth elements while leaving iron in the red mud substantially undissolved; (b) separating the solution obtained from the solid residue and (c) recovering the rare earth elements from the solution.
摘要翻译： 从拜耳法红泥中回收稀土元素的方法包括以下步骤：（a）用稀酸溶液（例如稀土元素）消化含有稀土元素的红泥。 溶解在水中的二氧化硫，选择性地溶解稀土元素，同时使赤泥中的铁基本上不溶解; （b）从固体残渣中分离出溶液，（c）从溶液中回收稀土元素。
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2.发明授权Recovery of rare earth elements from sulphurous acid solution by solvent extraction 失效通过溶剂萃取从亚硫酸溶液中回收稀土元素
公开(公告)号：US5015447A
公开(公告)日：1991-05-14
申请号：US381577
申请日：1989-07-18
申请人： George D. Fulford , Gordon Lever , Taichi Sato
发明人： George D. Fulford , Gordon Lever , Taichi Sato
CPC分类号： C01F17/0006 , C22B3/0067 , C22B3/0068 , C22B59/00 , Y02P10/234 , Y10S423/14
摘要： A process is described for the recovery of rare earth elements from a sulphurous acid solution containing them. The rare earth elements can be successfully separated and recovered by solvent extraction from the sulphurous acid solution, being an organo-phosphorus compound as extraction agent. Di-2-ethylhexyl phosphoric acid or 2-ethylhexyl phosphonic acid mono-ethylhexyl ester is preferred as extraction agent.
摘要翻译： 描述了从含有它们的含硫酸溶液中回收稀土元素的方法。 可以通过溶剂萃取从作为萃取剂的有机磷化合物的亚硫酸溶液中成功地分离和回收稀土元素。 作为提取剂，优选二-2-乙基己基磷酸或2-乙基己基膦酸单乙基己酯。
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公开(公告)号：US5286472A
公开(公告)日：1994-02-15
申请号：US800880
申请日：1991-11-27
申请人： George D. Fulford
发明人： George D. Fulford
摘要： A process for producing alumina is described in which the efficiency of calcination is greatly improved by utilizing a total heat exchange system in which alumina hydrate is heated stepwise in a plurality of heat exchange stages to sequentially higher temperatures approaching calcining temperatures and is then fed to a calciner for final conversion to alumina, and the calcined alumina is cooled in a plurality of heat exchange stages, with sensible heat being transferred from the calcined alumina cooling stages to the alumina hydrate heating stages at a temperature in each stage only slightly higher than the temperature of a heating stage or at which the heat is consumed in that stage. Further efficiency in the system may be obtained by predrying the alumina hydrate to remove superficial moisture using air from the system. Furthermore, exhaust gases from the calciner may be used to preheat combustion and fluidizing air for the calciner.
摘要翻译： 描述了一种生产氧化铝的方法，其中通过使用全部热交换系统大大提高煅烧效率，其中将氧化铝水合物在多个热交换阶段逐步加热到接近煅烧温度的较高温度，然后进料到 煅烧炉用于最终转化为氧化铝，并且煅烧的氧化铝在多个热交换阶段中被冷却，显热在煅烧氧化铝冷却阶段中转移到氧化铝水合物加热阶段，每个阶段的温度仅略高于温度 或在该阶段消耗热量的加热阶段。 通过使用来自该系统的空气来预处理氧化铝水合物以除去表面水分，可以获得系统中的进一步的效率。 此外，来自煅烧炉的废气可用于预热煅烧炉的燃烧和流化空气。
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公开(公告)号：US5051243A
公开(公告)日：1991-09-24
申请号：US447158
申请日：1989-12-07
申请人： George D. Fulford , Anwer M. Khan
发明人： George D. Fulford , Anwer M. Khan
CPC分类号： C09K17/08 , C01F7/066 , C09K8/145 , C09K8/5045
摘要： This invention provides an improved process for increasing the specific gravity of red mud. The process comprises mixing red mud in an acidic solution, such as sulfur dioxide solution, having a pH of between about 1.5 and about 3.0 to form an insoluble red mud residue. The specific gravity of the red mud residue can also be increased by heating the residue in air to a temperature of 250.degree. C. to about 300.degree. C. This process enables recovery of a treated red mud derivative having an increased specific gravity in excess of 4.0, which makes the product particularly useful as a weighting agent for drilling fluid, and as the solid phase of slurries used to fill crevices and fissures exposed by drilling or excavation.
摘要翻译： 本发明提供了一种用于提高红泥比重的改进方法。 该方法包括在酸性溶液（例如二氧化硫溶液）中混合红泥，pH在约1.5至约3.0之间以形成不溶性红泥残留物。 通过将空气中的残余物加热至250℃至约300℃的温度，也可以提高赤泥残渣的比重。该方法使得能够回收具有提高的比重超过 4.0，这使得该产品特别有用作钻井液的加重剂，以及用于填充通过钻孔或挖掘暴露的裂缝和裂缝的浆料的固相。
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公开(公告)号：US5118484A
公开(公告)日：1992-06-02
申请号：US568989
申请日：1990-08-17
申请人： Kwat I. The , George D. Fulford
发明人： Kwat I. The , George D. Fulford
CPC分类号： C01F7/47 , C01F7/0606
摘要： A process is described for removing dissolved silica from process solutions or slurries formed in the Bayer process for producing alumina from bauxite. In the novel process, a Bayer process solution or slurry is contacted with porous agglomerates of a material containing Bayer process desilication product and bonded together by a polymer resin which is resistant to chemical degradation by high concentrations of caustic present in Bayer process liquors. The desilication product is essentially complex hydrated sodium aluminum silicates and typical bonding resins are polyvinylchloride or polypropylene.
摘要翻译： 描述了从用于从铝土矿生产氧化铝的拜耳法中形成的工艺溶液或浆料中除去溶解的二氧化硅的方法。 在新型方法中，拜耳法溶液或浆料与含有拜耳法脱除产物的材料的多孔附聚物接触，并通过聚合物树脂粘合在一起，该聚合物树脂通过高浓度的拜耳法处理液中存在的高浓度苛性碱而耐化学降解。 脱硅产物基本上是复合水合硅酸铝钠，典型的粘结树脂是聚氯乙烯或聚丙烯。
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公开(公告)号：US5027891A
公开(公告)日：1991-07-02
申请号：US175046
申请日：1988-03-30
CPC分类号： F28D15/0233 , C01F7/06 , C01F7/0606 , C01F7/147 , F28D15/0266 , Y10S165/909
摘要： A method of transferring heat between process liquor streams such as streams of caustic liquor in the Bayer process for producing alumina from bauxite, utilizing a heat pipe arrangement for heat exchange. The process streams respectively pass in contact with one surface of a first heat-exchange wall and one surface of a second heat-exchange wall while being isolated from the second surfaces of the two walls; these second walls are exposed to a closed volume (also isolated from both process streams) containing a heat transfer fluid that vaporizes below the temperature of the hotter process stream and condenses above the temperature of the cooler process stream. The heat transfer fluid vaporizes at the exposed surface of the wall contacted by the hotter stream, and condenses at the exposed surface of the wall contacted by the cooler stream, thereby transferring heat (as heat of vaporization) from the former stream to the latter.
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公开(公告)号：US4994244A
公开(公告)日：1991-02-19
申请号：US462777
申请日：1990-01-10
IPC分类号： C01F7/06
CPC分类号： C01F7/062 , C01F7/0646
摘要： A process for producing alumina from bauxite by the Bayer process. Bauxite slurry is pressure digested in caustic soda solution to dissolve aluminum hydroxides in the bauxite as sodium aluminate while leaving most of the remaining constituents of the bauxite in solid form as red mud. The red mud is separated from the digested slurry to obtain a caustic-aluminate pregnant liquor, alumina hydrate is precipitated from the pregnant liquor and the alumina hydrate is calcined to obtain the alumina. The separation of the red mud from the digested slurry is carried out at a temperature above the boiling atmospheric temperature of the liquor phase of the slurry.
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