WO2018233689A1 - 钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法 - Google Patents

钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法 Download PDF

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WO2018233689A1
WO2018233689A1 PCT/CN2018/092425 CN2018092425W WO2018233689A1 WO 2018233689 A1 WO2018233689 A1 WO 2018233689A1 CN 2018092425 W CN2018092425 W CN 2018092425W WO 2018233689 A1 WO2018233689 A1 WO 2018233689A1
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red mud
calcium
liquid
bayer process
carbon
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于海燕
潘晓林
吴艳
毕诗文
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Northeastern University China
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D1/00—Oxides or hydroxides of sodium, potassium or alkali metals in general
    • C01D1/02—Oxides

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  • the invention belongs to the technical field of alumina production, and particularly relates to a method for producing metallurgical grade alumina by a one-step alkali heat treatment of calcium iron garnet.
  • Red mud is the waste residue produced by alumina in the production process. It is red because it contains a lot of iron oxide, so it is called red mud.
  • the output of red mud varies with ore grade, production method and technical level. At present, for every 1 t of alumina produced, 1.0 to 1.7 tons of red mud is produced, and the accumulated red mud is currently over 300 million tons. A large amount of red mud can not be effectively utilized, and can only rely on large-area yard stacking, which not only occupies a large amount of land, but also causes serious pollution to the environment because of the high alkalinity of red mud. As of 2016, the cumulative stockpiles of more than 400 million tons have become a major environmental hazard.
  • red mud composition Due to the different production methods of alumina, the red mud composition, nature and phase of the production are different.
  • the alkali content of red mud produced by Bayer method is high; the content of CaO in red mud produced by sintering method and combined method is high, and the content of alkali and iron is low. This difference determines the different methods of red mud utilization.
  • red mud mainly includes two aspects: one is to extract useful components in red mud, and recover high-priced metals, such as iron oxide, aluminum oxide, sodium oxide, silicon oxide, calcium oxide, zinc oxide, etc. .
  • the second is to use red mud as a raw material for the manufacture of low value-added building materials, such as wall materials, cement, glass-ceramics, etc.
  • low value-added building materials such as wall materials, cement, glass-ceramics, etc.
  • Lu Guilin et al. studied the process of leaching alumina from red mud with hydrochloric acid, using secondary leaching, in which the leaching rate of alumina reached 89.0%.
  • Zheng Xiufang treated the soaked Bayer red mud and sintered silicon residue with soda lime sintering method. The dissolution rates of alumina and sodium oxide were greater than 95% and 97%, respectively.
  • the methods for removing alkali from red mud include lime de-alkali method, water-eluting alkali method, salt de-alkali method, suspension carbonization and alkali removal method, lime-sulfuric acid combined alkali removal method and other new alkali removal methods, such as ionic membrane desorption.
  • Alkaline method, bacterial de-alkali method and fire method for alkali removal all have different degrees of problems.
  • the lime de-alkali method is not ideal under normal pressure and the cost is high under high pressure; the water removal method has low removal efficiency, and only the alkali can be washed off and combined.
  • the alkali is ineffective; the chloride ion in the magnesium chloride and ammonium chloride de-alkali process will corrode the equipment and is not conducive to the subsequent application of red mud; the CO 2 suspension de-alkali process, in which CO 2 is only for Na 2 O ⁇ Al 2 in red mud O 3 , Na 2 SiO 3 and Na 2 CO 3 act but do not work for Na 2 O ⁇ Al 2 O 3 ⁇ 1.7SiO 2 ⁇ nH 2 O, while most of the sodium in the red mud is Na 2 O ⁇
  • the object of the present invention is to provide a method for producing metallurgical grade alumina by using a calcium iron garnet one-step alkali heat treatment of Bayer process red mud, and a process for de-alkali-aluminizing red mud.
  • Red mud, sodium ferrite (or calcium ferrite) and active lime are mixed and dissolved at high temperature.
  • aluminum and sodium enter the solution in the form of sodium aluminate, while silicon, iron and calcium remain in the form of calcium iron garnet. Dissolve in the slag.
  • the method of the invention not only recovers the alumina and the sodium oxide in the red mud, but also reduces the alkali content in the dissolved slag to less than 0.5%, and can digest the red mud in bulk.
  • the main technical solutions adopted by the present invention include:
  • a method for producing metallurgical grade alumina by using a calcium iron garnet one-step alkali heat treatment of Bayer process red mud comprising the following steps,
  • step S6 The carbon mother liquor obtained in the step S4 is causticized with lime milk to obtain a caustic slurry, and the caustic slurry is subjected to liquid-solid separation to obtain a polymer ratio sodium aluminate solution and calcium carbonate, and the polymer ratio is obtained.
  • the sodium aluminate solution is prepared as the circulating mother liquor in step S1.
  • the total amount of iron, aluminum, calcium and silicon present in each form is determined by the oxide, and the formulation is as follows:
  • the molar ratio of the total amount of iron oxide to the total amount of alumina is 0.5 to 1.5:1.
  • the molar ratio of the total amount of calcium oxide to the total amount of silicon oxide is 1 to 3:1.
  • the liquid-solid ratio of the raw material slurry is 2 to 5:1.
  • the concentration of caustic in the circulating mother liquor is 150 to 250 g/L, and the molecular ratio is 5 to 25.
  • the temperature of the dissolution reaction in the step S2 is 150 to 250 ° C, and the reaction time is 0.5 to 2 h.
  • step S4 carbon dioxide gas is introduced into the low molecular ratio sodium aluminate and seed crystals are added to carry out carbon, and a crude aluminum hydroxide slurry is obtained, followed by liquid-solid separation to obtain a carbon mother liquor and crude aluminum hydroxide.
  • step S4 the carbon content temperature is 60 to 90 ° C, the carbon end point is the decomposition rate of 90% or more, and the seed crystal addition coefficient is 0 to 1.0.
  • the method further includes:
  • Step S7 washing the eluted slag in step S3 and solid-liquid separation to obtain calcium garnet type slag and washing liquid;
  • Step S8 The washing liquid is used to dilute the dissolved slurry in step S3.
  • the method further comprises the step S9: calcining and decomposing the calcium carbonate obtained in the step S6 to obtain carbon dioxide gas and calcium oxide, and the obtained carbon dioxide gas is used for carbon separation in the step S4, and the obtained calcium oxide is used in the step.
  • Caustic treatment in S6 is used in the step S9.
  • the sodium ferrite in the step S1 is formed by sintering an iron-containing raw material and an industrial carbon base; the calcium ferrite is obtained by sintering the iron-containing raw material and the lime.
  • the method of the invention not only recovers the alumina and sodium oxide in the red mud, but also reduces the alkali content in the dissolution slag to less than 0.5%, and the main component of the dissolution slag is calcium iron garnet, which
  • the alkali-free calcium iron garnet is suitable for the calcium ferrite additive in the steelmaking process, the ideal aggregate for self-stressing, high-strength, quick-setting Portland cement and high-strength concrete such as highways and airport runways, and also is glass-ceramic,
  • the potential raw materials of higher value-added products such as silicon fertilizer realize the recycling of red mud and achieve the effect of green utilization of resources; the product is metallurgical grade alumina, which can be directly used as electrolytic aluminum raw material.
  • FIG. 1 is a process flow diagram of a method for producing a metallurgical grade alumina by a Bayer process red mud by a one-step alkali thermal treatment of the calcium iron garnet of the present invention.
  • the red mud used in the embodiment of the present invention is a Bayer process red mud, and the red mud contains alumina and silica.
  • the molar ratio of total iron oxide to total alumina is hereinafter abbreviated as F/A; the molar ratio of total calcium oxide to total silica is abbreviated as C /S;
  • Raw material ore slurry solid mass ratio is abbreviated as L/S.
  • one-step alkali heat method refers to the use of lye (cycle mother liquor) for alumina
  • a one-step hydrothermal stripping process produces a metallurgical grade alumina.
  • the hydraulic aluminite Bayer process red mud is used, and the main chemical components (mass percentage, wt%) are: alumina (Al 2 O 3 ) 21.62%, silicon dioxide (SiO 2 ) 16.11%, sodium oxide (Na) 2 O) 7.08%, calcium oxide (CaO) 16.50%, total iron (TFe) 14.80%, and its aluminum to silicon ratio is 1.34;
  • Sodium ferrite is sintered from iron-containing raw materials and industrial caustic soda
  • the concentration of caustic in the circulating mother liquor is 240 g / L, the molecular ratio is 25;
  • sodium aluminate is added to carbon dioxide gas at a temperature of 80 ° C and a seed crystal addition coefficient of 0.8 to carry out carbon decomposition (carbonation decomposition) to a decomposition rate of 95%, to obtain a crude aluminum hydroxide slurry, and to carry out a liquid Solid separation to obtain carbon mother liquor and crude aluminum hydroxide;
  • step S5 subjecting the crude aluminum hydroxide obtained in step S4 to a Bayer process to obtain metallurgical grade alumina
  • step S6 The carbon mother liquor obtained in the step S4 is causticized with lime milk to obtain a caustic slurry, and the caustic slurry is subjected to liquid-solid separation to obtain a polymer ratio sodium aluminate solution and calcium carbonate, and the polymer ratio is obtained.
  • the sodium aluminate solution is prepared as the circulating mother liquor in step S1;
  • the obtained polymer can be used as a circulating mother liquor to participate in other process flows after being adjusted than the sodium aluminate solution, so that the process has no efflux and no pollution;
  • step S7 washing the eluted slag in step S3 and solid-liquid separation to obtain calcium garnet type red mud and washing liquid;
  • the alkali-free calcium iron garnet type slag is obtained after treatment, so that the silicon in the red mud and the added iron and calcium remain in the dissolution slag in the form of calcium iron garnet, and the alkali in the calcium iron garnet type slag The content fell below 0.5% and the aluminum to silicon ratio dropped to 0.5.
  • alkali-free calcium iron garnet-type red mud residue is effectively utilized due to the reduction of alkali content, such as calcium ferrite additive used in the steelmaking process, Ideal aggregates of high-strength concrete such as stress, high-strength, quick-setting Portland cement and highways, airport runways, and potential raw materials for higher value-added products such as glass-ceramics and silicon fertilizers;
  • step S8 using the washing liquid for diluting the dissolved pulp in step S3;
  • the washing liquid produced in this step is waste liquid, but the washing liquid is returned to the step S3 for diluting and dissolving the pulp, which not only reduces the treatment and discharge of the waste liquid, but also achieves the effect of recycling, and achieves the recycling and reuse of the material. ;
  • step S9 calcining and decomposing the calcium carbonate obtained in step S6 at 1000 ° C to obtain carbon dioxide gas and calcium oxide, and returning the carbon dioxide gas to carbon residue in step S5, and the obtained calcium oxide returns to the causticizing step in step S6;
  • the decomposition and reuse of calcium carbonate realizes the recycling of resources, avoids waste of resources, and saves costs.
  • the resulting metallurgical grade alumina is the product.
  • the Bayer process red mud is used, and the main chemical components (mass percentage, wt%) are: alumina (Al 2 O 3 ) 23.35%, silica (SiO 2 ) 23.23%, sodium oxide (Na 2 O) 15.61 %, calcium oxide (CaO) 0.51%, total iron (TFe) 16.16%, titanium dioxide (TiO 2 ) 5.37%, its aluminum to silicon ratio is 1.01;
  • Calcium ferrite is sintered from iron-containing raw materials and industrial lime
  • the concentration of caustic in the circulating mother liquor is 240 g / L, the molecular ratio is 20;
  • the alumina extraction rate can reach 80% or more
  • step S5 subjecting the crude aluminum hydroxide obtained in step S4 to a Bayer process to obtain metallurgical grade alumina
  • step S6 The carbon mother liquor obtained in the step S4 is causticized with lime milk to obtain a caustic slurry, and the caustic slurry is subjected to liquid-solid separation to obtain a polymer ratio sodium aluminate solution and calcium carbonate, and the polymer ratio is obtained.
  • the sodium aluminate solution is prepared as the circulating mother liquor in step S1;
  • the carbon mother liquor is treated, and the obtained polymer sodium aluminate solution can be used as a circulating mother liquor to participate in other process flows, so that the process has no efflux and no pollution;
  • step S7 washing the eluted slag in step S3 and solid-liquid separation to obtain calcium garnet type red mud and washing liquid;
  • the alkali-free calcium iron garnet type slag is obtained after treatment, so that the silicon in the red mud and the added iron and calcium remain in the dissolution slag in the form of calcium iron garnet, and the alkali content in the garnet type slag Below 0.5%, the aluminum to silicon ratio drops to 0.5.
  • alkali-free calcium iron garnet type slag effectively utilized due to the reduction of the alkali content, such as calcium ferrite additive used in the steelmaking process, self-stressing, high strength, speed Ideal aggregates for high-strength concrete such as condensed Portland cement and highways and airport runways, and as potential raw materials for higher value-added products such as glass-ceramics and silicon fertilizers;
  • step S8 using the washing liquid for diluting the dissolved pulp in step S3;
  • the washing liquid produced in this step is waste liquid, but the washing liquid is returned to the step S3 for diluting and dissolving the pulp, which not only reduces the treatment and discharge of the waste liquid, but also achieves the effect of recycling, and achieves the recycling and reuse of the material. ;
  • step S9 calcining and decomposing the calcium carbonate obtained in step S6 at 1000 ° C to obtain carbon dioxide gas and calcium oxide, and returning the carbon dioxide gas to carbon residue in step S5, and the obtained calcium oxide returns to the causticizing step in step S6;
  • the decomposition and reuse of calcium carbonate realizes the recycling of resources, avoids waste of resources, and saves costs.
  • the resulting metallurgical grade alumina is the product.
  • the method of the invention not only recovers the alumina in the red mud, but also reduces the alkali content in the red mud, realizes the recycling of the solid waste, and achieves the effect of green utilization of resources.

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Abstract

提供一种钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，包括下述步骤，S1：将赤泥、铁酸钠或铁酸钙、活性石灰及循环母液混合制备成原料矿浆；S2：将原料矿浆进行碱热溶出反应，反应后得到溶出矿浆；S3：将溶出矿浆进行稀释并将稀释液进行液固分离，得到溶出渣和溶出液；S4：向溶出液中通入二氧化碳气体进行碳分，得到粗氢氧化铝和碳分母液；S5：将粗氢氧化铝进行拜耳法处理，得到冶金级氧化铝；S6：将碳分母液采用石灰乳进行苛化，得到高分子比铝酸钠溶液后再调整成循环母液用于溶出。该方法回收了赤泥中的氧化铝，降低了赤泥中的碱含量，实现了固体废弃物的回收利用，达到了资源绿色利用的效果。

Description

钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法 技术领域
本发明属于氧化铝生产的技术领域，具体涉及一种钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法。
背景技术
赤泥是氧化铝在生产过程中产生的废渣，因含有大量氧化铁而呈红色，故被称为赤泥。赤泥的产出量，因矿石品位、生产方法、技术水平而异。目前，每生产1t氧化铝，伴随着就会产生1.0～1.7t的赤泥，目前累积堆存的赤泥超过三亿吨。大量的赤泥不能得到有效利用，只能依靠大面积的堆场堆放，不但占用了大量土地，同时因为赤泥的高碱性，也对环境造成了严重污染。截止到2016年，累计堆存量达4亿吨以上，成为一大环保隐患。
由于氧化铝的生产方法不同，其生产的赤泥成分、性质、物相各异。拜耳法产生的赤泥中碱金属含量高；烧结法和联合法产生的赤泥CaO含量高，碱和铁含量较低。这种差异决定了赤泥利用的不同方法。
现在在赤泥的综合利用方面，主要包括两个方面：一是提取赤泥中的有用组分，回收高价金属，如回收氧化铁、氧化铝、氧化钠、氧化硅、氧化钙、氧化锌等。二是将赤泥作为原材料用于制造低附加值的建筑材料，如做墙体材料、水泥、微晶玻璃等。但是由于赤泥中的碱含量较高，不利于赤泥在建筑材料中的应用。
目前关于从赤泥中回收铝的方法主要有浮选，石灰烧结法及浸出等工艺。范先锋等人对拜耳法赤泥进行了浮选工艺研究。小型闭路浮选试验表明，可以丢弃45.74％的赤泥，回收65.52％的Al 2O 3，其中铝硅比为7.53的占62.01％，可直接返回拜尔法溶浸，而铝硅比4.78的占2.86％， 可作为烧结法的原料。周秋生等采用烧结法处理拜耳法高铁赤泥回收其中的氧化铝，熟料中的Al 2O 3回收率可达85％～90％。鲁桂林等研究了采用盐酸浸出赤泥中的氧化铝的工艺，采用二次浸出，其中氧化铝的浸出率可达89.0％。郑秀芳用碱石灰烧结法处理泡合的拜耳法赤泥和烧结法硅渣，氧化铝和氧化钠溶出率分别大于95％和97％。
关于赤泥脱碱的方法主要有石灰脱碱法、水洗脱碱法、盐类脱碱法、悬浮碳化脱碱法、石灰-硫酸联合脱碱法及其他新型脱碱方法，如离子膜脱碱法、细菌脱碱法和火法脱碱。然而，上述脱碱方法均存在不同程度的问题，在常压下石灰脱碱法效果不理想而在高压下则成本较高；水洗法脱除效率较低，仅能洗掉附着碱而对结合碱无效；氯化镁和氯化铵脱碱法中的氯离子会腐蚀设备并不利于后续赤泥的应用；CO 2悬浮脱碱法，其中的CO 2仅对赤泥中的Na 2O·Al 2O 3、Na 2SiO 3和Na 2CO 3起作用，却对Na 2O·Al 2O 3·1.7SiO 2·nH 2O不起作用，而赤泥中大部分的钠是以Na 2O·Al 2O 3·1.7SiO 2·nH 2O的形态存在，因此该方法脱除效率不高；石灰一硫酸联合脱碱法中，酸法与碱法并存，易浪费原料，同时工艺较复杂，且使用了高压釜，成本较高。
发明内容
(一)要解决的技术问题
为了解决现有技术的上述问题，本发明的目的在于提供一种钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，对赤泥进行脱碱提铝的工艺，即将赤泥、铁酸钠(或铁酸钙)及活性石灰混合后高温溶出，高温溶出过程中铝和钠以铝酸钠形式进入溶液，而硅、铁和钙以钙铁榴石的形式留在溶出渣中。本发明的方法不仅回收了赤泥中的氧化铝和氧化钠，使溶出渣中的碱含量降低到0.5％以下，可大宗消化赤泥。
(二)技术方案
为了达到上述目的，本发明采用的主要技术方案包括：
一种钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方 法，包括下述步骤，
S1：将赤泥、铁酸钠或铁酸钙、活性石灰及循环母液混合制备成原料矿浆；
S2：将原料矿浆进行碱热溶出反应，反应结束后得到溶出矿浆；
S3：将溶出矿浆进行稀释得到稀释液，将稀释液进行液固分离，得到溶出渣和溶出液，其中：溶出液为铝酸钠溶液；
S4：向铝酸钠溶液中通入二氧化碳气体进行碳分，得到粗氢氧化铝和碳分母液；
S5：将所述粗氢氧化铝进行拜耳法处理，得到冶金级氧化铝；
S6：将步骤S4中得到的碳分母液采用石灰乳进行苛化，得到苛化料浆，将苛化料浆进行液固分离，得到高分子比铝酸钠溶液和碳酸钙，将高分子比铝酸钠溶液进行调制，作为步骤S1中的循环母液。
优选地，在赤泥、铁酸钠或铁酸钙、活性石灰组成的原料矿中，各形态存在的铁、铝、钙、硅总量分别以氧化物计，配料配方如下：
氧化铁的总量与氧化铝的总量的摩尔比为0.5～1.5∶1
氧化钙的总量与氧化硅的总量的摩尔比为1～3∶1
优选地，步骤S1中，原料矿浆的液固比为2～5∶1。
优选地，步骤S1中，循环母液中的苛碱浓度为150～250g/L，分子比为5～25。
优选地，步骤S2中溶出反应的温度为150～250℃，反应时间为0.5～2h。
优选地，步骤S4中，向低分子比铝酸钠内通入二氧化碳气体并加入晶种进行碳分，得到粗氢氧化铝料浆后进行液固分离，得到碳分母液和粗氢氧化铝。
步骤S4中碳分温度为60～90℃，碳分终点为分解率达到90％以上，晶种添加系数为0～1.0。
优选地，所述方法还包括：
步骤S7：将步骤S3中的溶出渣进行洗涤并固液分离，得到钙铁榴石型渣和洗涤液；
步骤S8：将所述洗涤液用于步骤S3中稀释所述溶出矿浆。
优选地，所述方法还包括步骤S9：将步骤S6中得到的碳酸钙进行焙烧分解，得到二氧化碳气体和氧化钙，得到的二氧化碳气体用于步骤S4中碳分处理，得到的氧化钙用于步骤S6中苛化处理。
优选地，步骤S1中的铁酸钠是含铁原料与工业碳碱烧结而成；铁酸钙是含铁原料与石灰烧结而成。
(三)有益效果
与现有技术相比，本发明的方法不仅回收了赤泥中的氧化铝和氧化钠，还使溶出渣中的碱含量降低到0.5％以下，溶出渣的主要成分为钙铁榴石，这种无碱钙铁榴石适合炼钢过程的铁酸钙添加剂、做自应力、高强度、速凝硅酸盐水泥和高速公路、机场跑道等高强度混凝土的理想骨料，也是微晶玻璃、硅肥等附加值较高产品的潜在原料，实现了赤泥的回收利用，达到了资源绿色利用的效果；产品为冶金级氧化铝，可直接做电解铝原料。
附图说明
图1为本发明钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法的工艺流程图。
具体实施方式
下面结合具体实施例，进一步阐述本发明。应理解，这些实施例仅用于说明本发明，而不用于限制本发明的范围。
本发明实施例所用的赤泥为拜耳法赤泥，赤泥中含有氧化铝和二氧化硅。赤泥、铁酸钠或铁酸钙和石灰组成的原料矿中，总氧化铁与总氧化铝的的摩尔比以下简写为F/A；总氧化钙与总氧化硅的摩尔比以下简写为C/S；原料矿浆液固质量比以下简写为L/S。
钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，是指溶出渣为钙铁榴石型渣，一步碱热法是指利用碱液(循环母液)对氧化铝进行一步水热溶出处理的方法，生产的产品为冶金级氧化铝。
实施例1
本实施例采用水硬铝石拜耳法赤泥，主要化学成分(质量百分比，wt％)为：氧化铝(Al 2O 3) 21.62％，二氧化硅(SiO 2) 16.11％，氧化钠(Na 2O) 7.08％，氧化钙(CaO) 16.50％，全铁(TFe) 14.80％，其铝硅比为1.34；
铁酸钠为含铁原料与工业烧碱烧结而成；
循环母液中的苛碱浓度为240g/L，分子比为25；
F/A＝0.6∶1；
C/S＝2.5∶1。
按照本图1所示的本发明钙铁榴石一步碱热法处理拜耳法赤泥生产铝酸钠的方法：
S1：将赤泥、铁酸钠和活性石灰混合后，按照L/S＝4∶1的比例与循环母液混合制备成原料浆；
S2：将原料矿浆进行碱热溶出反应，溶出反应温度为200℃，溶出反应时间为1h，反应结束后得到溶出矿浆；
S3：将溶出矿浆稀释得到稀释液，将稀释液进行液固分离，得到溶出渣和溶出液，其中溶出液为铝酸钠溶液；
S4：将铝酸钠在80℃、晶种添加系数为0.8的条件下，通入二氧化碳气体进行碳分(碳酸化分解)至分解率达到95％，得到粗氢氧化铝料浆，并进行液固分离，得到碳分母液和粗氢氧化铝；
S5：将步骤S4中得到的粗氢氧化铝进行拜耳法处理，得到冶金级氧化铝；
S6：将步骤S4中得到的碳分母液采用石灰乳进行苛化，得到苛化料浆，将苛化料浆进行液固分离，得到高分子比铝酸钠溶液和碳酸钙，将 高分子比铝酸钠溶液进行调制，作为步骤S1中的循环母液；
本步骤中，将碳分母液进行苛化处理后，得到的高分子比铝酸钠溶液调整后能够作为循环母液参与其他工艺流程，使得工艺流程无外排无污染；
S7：将步骤S3中的溶出渣进行洗涤并固液分离，得到钙铁榴石型赤泥和洗涤液；
本步骤中，经过处理得到了无碱钙铁榴石型渣，使赤泥中的硅与加入的铁和钙以钙铁榴石的形式留在溶出渣中，钙铁榴石型渣中碱含量降至0.5％以下，铝硅比降至0.5。不仅回收了赤泥中的氧化铝和氧化钠，还使得无碱钙铁榴石型赤泥渣，因碱含量的降低得到了有效利用，如用于炼钢过程的铁酸钙添加剂、做自应力、高强度、速凝硅酸盐水泥和高速公路、机场跑道等高强度混凝土的理想骨料，以及作为微晶玻璃、硅肥等附加值较高产品的潜在原料；
S8：将洗涤液用于步骤S3中稀释所述溶出矿浆；
本步骤产生的洗涤液为废液，但将洗涤液返回到步骤S3中用于稀释溶出矿浆，既减少了废液的处理和排放，又达到了重复利用的效果，达到了物料的回收再利用；
S9：将步骤S6中得到的碳酸钙在1000℃下进行煅烧分解，得到二氧化碳气体和氧化钙，二氧化碳气体返回步骤S5中碳分处理，得到的氧化钙返回步骤S6中苛化工序；
本步骤中，碳酸钙的分解再利用，实现了资源的回收利用，避免了资源的浪费，节约了成本。
得到的冶金级氧化铝即为产品。
实施例2
本实施例采用拜耳法赤泥，主要化学成分(质量百分比，wt％)为：氧化铝(Al 2O 3) 23.35％，二氧化硅(SiO 2) 23.23％，氧化钠(Na 2O)  15.61％，氧化钙(CaO) 0.51％，全铁(TFe) 16.16％，二氧化钛(TiO 2) 5.37％，其铝硅比为1.01；
铁酸钙为含铁原料与工业石灰烧结而成；
循环母液中的苛碱浓度为240g/L，分子比为20；
F/A＝1∶1；
C/S＝3.0∶1。
按照如图1所示的本发明钙铁榴石一步碱热法处理拜耳法赤泥生产铝酸钠的方法：
S1：将赤泥、铁酸钙和石灰混合后，按照L/S＝5∶1的比例与循环母液混合制备成原料浆(注意：配石灰时应考虑到原料中的TiO 2与石灰反应生成钛酸钙的影响)；
S2：将原料矿浆在反应釜中进行溶出反应，溶出反应温度为250℃，溶出反应时间为1h，反应结束后得到溶出矿浆；
经过本步骤的溶出反应，氧化铝提取率能够达到80％以上；
S3：将溶出矿浆稀释得到稀释液，将稀释液进行液固分离，得到溶出渣和溶出液，其中溶出液为低分子比铝酸钠溶液；
S4：将低分子比铝酸钠在80℃、晶种添加系数为0.8的条件下，通二氧化碳并加入晶种进行碳分，碳分终点为分解率95％以上。碳分得到粗氢氧化铝料浆后进行液固分离，得到碳分母液和粗氢氧化铝；
S5：将步骤S4中得到的粗氢氧化铝进行拜耳法处理，得到冶金级氧化铝；
S6：将步骤S4中得到的碳分母液采用石灰乳进行苛化，得到苛化料浆，将苛化料浆进行液固分离，得到高分子比铝酸钠溶液和碳酸钙，将高分子比铝酸钠溶液进行调制，作为步骤S1中的循环母液；
本步骤中，将碳分母液进行处理，得到的高分子铝酸钠溶液调整后能够作为循环母液参与其他工艺流程，使得工艺流程无外排无污染；
S7：将步骤S3中的溶出渣进行洗涤并固液分离，得到钙铁榴石型赤 泥和洗涤液；
本步骤中，经过处理得到了无碱钙铁榴石型渣，使赤泥中的硅与加入的铁和钙以钙铁榴石的形式留在溶出渣中，铁榴石型渣中碱含量降至0.5％以下，铝硅比降至0.5。不仅降低了赤泥中的碱含量，还使得无碱钙铁榴石型渣因碱含量的降低得到了有效利用，如用于炼钢过程的铁酸钙添加剂、做自应力、高强度、速凝硅酸盐水泥和高速公路、机场跑道等高强度混凝土的理想骨料，以及作为微晶玻璃、硅肥等附加值较高产品的潜在原料；
S8：将洗涤液用于步骤S3中稀释所述溶出矿浆；
本步骤产生的洗涤液为废液，但将洗涤液返回到步骤S3中用于稀释溶出矿浆，既减少了废液的处理和排放，又达到了重复利用的效果，达到了物料的回收再利用；
S9：将步骤S6中得到的碳酸钙在1000℃下进行煅烧分解，得到二氧化碳气体和氧化钙，二氧化碳气体返回步骤S5中碳分处理，得到的氧化钙返回步骤S6中苛化工序；
本步骤中，碳酸钙的分解再利用，实现了资源的回收利用，避免了资源的浪费，节约了成本。
得到的冶金级氧化铝即为产品。
本发明的方法不仅回收了赤泥中的氧化铝，还降低了赤泥中的碱含量，实现了固体废弃物的回收利用，达到了资源绿色利用的效果。

Claims (9)

  1. 一种钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，其特征在于：包括下述步骤，
    S1：将赤泥、铁酸钠或铁酸钙、活性石灰及循环母液混合制备成原料矿浆；
    S2：将原料矿浆进行碱热溶出反应，反应结束后得到溶出矿浆；
    S3：将溶出矿浆进行稀释得到稀释液，将稀释液进行液固分离，得到溶出渣和溶出液，其中溶出液为铝酸钠溶液；
    S4：向所述铝酸钠溶液中通入二氧化碳气体进行碳分，得到粗氢氧化铝和碳分母液；
    S5：将所述粗氢氧化铝进行拜耳法处理，得到冶金级氧化铝；
    S6：将步骤S4中得到的碳分母液采用石灰乳进行苛化，得到苛化料浆，将苛化料浆进行液固分离，得到高分子比铝酸钠溶液和碳酸钙，将高分子比铝酸钠溶液进行调制，作为步骤S1中的循环母液。
  2. 根据权利要求1所述的钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，其特征在于：赤泥、铁酸钠或铁酸钙、活性石灰组成的原料矿浆中，各形态存在的铁、铝、钙、硅总量分别以氧化物计，配料配方如下：：
    氧化铁的总量与氧化铝的总量的摩尔比为0.5～1.5∶1；
    氧化钙的总量与氧化硅的总量的摩尔比为1～3∶1。
  3. 根据权利要求1所述的钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，其特征在于：步骤S1中，原料矿浆的液固比为2～5∶1。
  4. 根据权利要求1所述的钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，其特征在于：步骤S1中，循环母液中的苛碱浓度为150～250g/L，分子比为5～25。
  5. 根据权利要求1所述的钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，其特征在于：步骤S2中溶出反应的温度为 150～250℃，反应时间为0.5～2h。
  6. 根据权利要求1所述的钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，其特征在于：
    步骤S4中，向低分子比铝酸钠内通入二氧化碳气体并加入晶种进行碳分，得到粗氢氧化铝料浆后进行液固分离，得到碳分母液和粗氢氧化铝，
    步骤S4中碳分温度为60～90℃，碳分终点为分解率在90％以上，晶种添加系数为0～1.0。
  7. 根据权利要求1所述的钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，其特征在于：所述方法还包括：
    步骤S7：将步骤S3中的溶出渣进行洗涤并固液分离，得到钙铁榴石型渣和洗涤液；
    步骤S8：将所述洗涤液用于步骤S3中稀释所述溶出矿浆。
  8. 根据权利要求1所述的钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法，其特征在于：所述方法还包括步骤S9：将步骤S6中得到的碳酸钙进行焙烧分解，得到二氧化碳气体和氧化钙，得到的二氧化碳气体用于步骤S5中碳分处理，得到的氧化钙用于步骤S6中苛化工序。
  9. 根据权利要求1所述的钙铁榴石一步碱热法处理拜耳法赤泥生产铝酸钠的方法，其特征在于：步骤S1中的铁酸钠是含铁原料与工业碳碱烧结而成；铁酸钙是含铁原料与石灰烧结而成。
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WO2025256134A1 (zh) * 2024-06-11 2025-12-18 中铝检测科技(郑州)有限公司 一种赤泥的处理方法

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CN107298452A (zh) * 2017-06-23 2017-10-27 东北大学 钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法
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CN117865195A (zh) * 2023-12-27 2024-04-12 东北大学 一种钙化碱溶全碳化及钠钙碳循环生产氧化铝方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2992893A (en) * 1957-01-15 1961-07-18 Pechiney Prod Chimiques Sa Process for treating aluminum ores
CN101054626A (zh) * 2007-05-31 2007-10-17 中国铝业股份有限公司 一种一水硬铝石型铝土矿的溶出方法
CN101117230A (zh) * 2007-07-12 2008-02-06 中国铝业股份有限公司 一种拜耳法溶出方法
CN101289211A (zh) * 2008-06-12 2008-10-22 中国铝业股份有限公司 一种拜耳法赤泥中氧化钠和氧化铝的回收方法
CN102328943A (zh) * 2011-06-21 2012-01-25 中国铝业股份有限公司 一种含铝矿物的综合利用方法
CN104445310A (zh) * 2013-09-25 2015-03-25 贵阳铝镁设计研究院有限公司 一种全湿法碱性体系下处理中低品位铝土矿的新工艺
CN107298452A (zh) * 2017-06-23 2017-10-27 东北大学 钙铁榴石一步碱热法处理拜耳法赤泥生产冶金级氧化铝的方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1235802C (zh) * 2003-04-18 2006-01-11 中国铝业股份有限公司 一种拜尔法溶出方法
CN100390307C (zh) * 2006-07-18 2008-05-28 中国铝业股份有限公司 一种拜尔法溶出添加剂的制备方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2992893A (en) * 1957-01-15 1961-07-18 Pechiney Prod Chimiques Sa Process for treating aluminum ores
CN101054626A (zh) * 2007-05-31 2007-10-17 中国铝业股份有限公司 一种一水硬铝石型铝土矿的溶出方法
CN101117230A (zh) * 2007-07-12 2008-02-06 中国铝业股份有限公司 一种拜耳法溶出方法
CN101289211A (zh) * 2008-06-12 2008-10-22 中国铝业股份有限公司 一种拜耳法赤泥中氧化钠和氧化铝的回收方法
CN102328943A (zh) * 2011-06-21 2012-01-25 中国铝业股份有限公司 一种含铝矿物的综合利用方法
CN104445310A (zh) * 2013-09-25 2015-03-25 贵阳铝镁设计研究院有限公司 一种全湿法碱性体系下处理中低品位铝土矿的新工艺
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