WO2019019844A1 - 钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法 - Google Patents

钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法 Download PDF

Info

Publication number
WO2019019844A1
WO2019019844A1 PCT/CN2018/092421 CN2018092421W WO2019019844A1 WO 2019019844 A1 WO2019019844 A1 WO 2019019844A1 CN 2018092421 W CN2018092421 W CN 2018092421W WO 2019019844 A1 WO2019019844 A1 WO 2019019844A1
Authority
WO
WIPO (PCT)
Prior art keywords
red mud
zeolite
calcium
producing
bayer process
Prior art date
Application number
PCT/CN2018/092421
Other languages
English (en)
French (fr)
Inventor
潘晓林
于海燕
吴艳
毕诗文
Original Assignee
东北大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 东北大学 filed Critical 东北大学
Publication of WO2019019844A1 publication Critical patent/WO2019019844A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
    • C01B39/02—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof
    • C01B39/14—Type A
    • C01B39/145—Type A using at least one organic template directing agent

Definitions

  • the invention belongs to the technical field of comprehensive utilization of red mud, and particularly relates to a method for producing 4A zeolite by the Bayer process red mud 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. Now, for every 1 t of alumina produced, 1.0 to 1.7 tons of red mud will be produced, and the accumulated red mud is more than 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 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 and zinc oxide.
  • 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 Bayer process red mud and the 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 zeolite A has a tetragonal structure similar to that of sodium chloride, and its chemical formula is Na 2 O ⁇ Al 2 O 3 ⁇ 2SiO 2 ⁇ 4.5H 2 O, and its internal pore diameter is 4.2 angstroms, so it is simply referred to as 4A zeolite.
  • 4A zeolite is a non-toxic, odorless, tasteless and fluid white powder with strong calcium ion exchange capacity, no pollution to the environment, non-toxic to fish and algae, and ideal for replacing sodium tripolyphosphate. Phosphorus-free detergent builder. It has excellent surface adsorption capacity and is an ideal adsorbent and desiccant.
  • the sodium ion in the zeolite can effectively exchange the calcium ions in the water, so that the degree of softening of the water is greatly improved, so that the sodium ions released from the synthetic zeolite remain in the washing solution without causing precipitation to adhere to the fabric, and the high exchange capacity of the zeolite It also prevents the precipitation reaction of the calcium and magnesium ions with the surfactant in the detergent, thereby improving the activation of the surfactant in the detergent, that is, improving the cleaning effect.
  • 4A zeolite As a phosphorus-free detergent builder which replaces phosphorus-containing detergent builders such as sodium tripolyphosphate, 4A zeolite is inevitably increased in its amount. As the amount of non-phosphorus detergent increases, the production of 4A zeolite is expected to increase rapidly.
  • the raw materials for the production of 4A zeolite are chemical raw materials and natural aluminosilicate minerals.
  • the chemical raw materials are mainly Al(OH) 3 , Na 2 SiO 3 and NaOH.
  • the natural aluminosilicate minerals mainly include kaolin and coal gangue. The production methods are as follows:
  • Kaolin method using kaolin (Al 2 Si 2 O 5 (OH) 4 ) as a raw material, chlorination calcination at 600 ° C ⁇ 800 ° C, followed by alkali dissolution, gelation and crystallization to obtain 4A zeolite.
  • the characteristics are wide source of raw materials, simple process and low production cost.
  • the problem is that the kaolin raw materials are inferior, the product quality is unstable, often the density is high, the particle size and whiteness are unqualified, and the chlorination technology is difficult, which is easy to cause environmental pollution, and the product market competitiveness is not strong.
  • hydrothermal method melting method
  • alkali dissolution method There are three main methods for synthesizing 4A zeolite from coal gangue, namely hydrothermal method, melting method and alkali dissolution method.
  • the hydrothermal synthesis of zeolite has the characteristics of convenient operation, but because of the high content of impurities, the crystallinity is low, and the product particles are greatly affected by the ore particles. At present, this method has been gradually replaced by the melting method and the alkali dissolution method.
  • the products synthesized by the melt method have higher crystallinity and relatively less impurity content than the hydrothermal synthesis products.
  • the alkali-soluble synthetic zeolite has a step of filtering and dissolving silicon-aluminum than the hydrothermal method and the melting method, the synthesized product has the characteristics of high crystallinity, high whiteness, low impurity content, and large cation exchange capacity.
  • the object of the present invention is to provide a method for producing 4A zeolite by using a calcium iron garnet one-step alkali heat treatment of Bayer process red mud, which uses a one-step alkali heat method to use red mud produced by alumina industry as a raw material, with iron-rich material and active lime. After mixing, it is dissolved at a high temperature, so that aluminum and sodium in the red mud mainly enter the solution in the form of sodium aluminate, and silicon, iron and calcium remain mainly in the form of calcium garnet in the dissolution slag.
  • the method of the invention uses the waste red mud as a raw material to prepare a 4A zeolite product with large market value and high added value, thereby realizing the high added value utilization of the solid waste and achieving the effect of resource green utilization.
  • the main technical solutions adopted by the present invention include:
  • the polymer is prepared by a sodium aluminate solution to prepare a circulating mother liquid used in the step S1.
  • the total amount of iron, aluminum, calcium and silicon present in each form is respectively determined by the oxide, and the formulation formula is as follows:
  • the molar ratio of the total amount of iron oxide to the total amount of alumina is 1 to 2:1;
  • the molar ratio of the total amount of calcium oxide to the total amount of silicon oxide is 1.5 to 2.5:1;
  • the amount of calcium oxide does not include the amount of calcium oxide used to react with titanium dioxide in red mud to form calcium titanate.
  • the raw material slurry has a liquid to solid ratio of 2 to 5:1.
  • the polymer is prepared by reacting a caustic alkali concentration with a sodium aluminate solution to obtain a circulating mother liquor, wherein the concentration of the caustic in the circulating mother liquor is 150 to 250 g/L, and the molecular ratio is 10 to 30.
  • the temperature of the dissolution reaction in the step S2 is 180 to 300 ° C, and the reaction time is 0.5 to 2 h.
  • the method further includes:
  • Step S6 washing the eluted slag in step S3 and solid-liquid separation to obtain calcium garnet type slag and washing liquid;
  • Step S7 The washing liquid is used to dilute the dissolved ore slurry in step S3.
  • the sodium carbonate solution and the sodium silicate solution are mixed, the sodium oxide concentration is 50-150 g/L; the alumina concentration is 8-25 g/L; and the silica concentration is 9-30 g/ L; the silica to alumina molar ratio is 1.5 to 2.5, and the crystallizing agent is added in an amount of 1 to 5 Torr (volume fraction).
  • the crystallization temperature is 70 to 99 ° C, and the crystallization time is 0.5 to 10 h.
  • the iron-rich material is hematite, goethite, iron concentrate, sodium ferrite or calcium ferrite.
  • the sodium silicate solution in step S4 is prepared from water glass.
  • the method of the invention recovers the alumina and the sodium oxide in the red mud, so that the alkali content in the dissolution slag is reduced to less than 0.5%, and the main component of the dissolution slag is calcium iron garnet, and the alkali-free calcium iron garnet is suitable for refining.
  • the calcium ferrite additive in the steel 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 high value-added products such as glass-ceramics and silicon fertilizers.
  • this method can greatly reduce the red mud, realize the recycling of red mud; at the same time, it can prepare 4A zeolite products with large market value and high added value, realizing the high added value utilization of solid waste. The effect of green utilization of resources.
  • 1 is a process flow diagram of a method for producing 4A zeolite by Bayer process red mud by a one-step alkali thermal treatment of 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 the total amount of iron oxide to the total amount of alumina is abbreviated as F/A;
  • the amount of calcium oxide (when calcium titanate is formed, a certain amount of The molar ratio of calcium oxide, the amount of calcium oxide written in the examples does not include the amount of calcium oxide used to form calcium titanate in the red mud, and the total amount of silica is abbreviated as L/S.
  • Iron-rich materials include, but are not limited to, hematite, goethite, sodium ferrite, calcium ferrite, and the like.
  • the sodium silicate solution can be used as an industrial raw material such as water glass.
  • the ratio of silicon to aluminum is the molar ratio of silicon oxide to aluminum oxide in the solution.
  • one-step alkali heat method refers to the use of lye (circulation mother liquor) to carry out one step of water on alumina
  • the hot stripping treatment method produces a target product of 4A zeolite.
  • the 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;
  • the iron-rich material is iron concentrate, and the iron oxide content in the iron concentrate is 85%;
  • the concentration of caustic in the circulating mother liquor is 240 g / L, the molecular ratio is 25;
  • the concentration of the caustic alkali and the molecular ratio in the sodium aluminate solution produced in this step need to be adjusted to meet the parameter requirements of the circulating mother liquor, and is used for formulating the raw material slurry and performing the dissolution reaction;
  • step S6 washing the eluted slag in step S3 and solid-liquid separation to obtain calcium garnet type dissolution slag and washing liquid;
  • the alkali-free calcium iron garnet type slag is obtained after treatment, so that the silicon in the raw red mud and the added iron and calcium remain in the dissolution slag in the form of calcium iron garnet, and the calcium iron garnet type slag
  • the alkali content falls below 0.5% and the aluminum to silicon ratio drops to 0.5.
  • the alkali-free calcium iron garnet type slag is effectively utilized due to the reduction of the alkali content, such as calcium ferrite additive used in the steel making process, self-stressing, high Ideal aggregates for high-strength concrete such as strength, quick-setting Portland cement and highways, airport runways, and as potential raw materials for higher value-added products such as glass-ceramics and silicon fertilizers;
  • step S7 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 of the material. use.
  • the obtained 4A zeolite is a product.
  • the filtered slag is an alkali-free calcium iron garnet type slag, and the rest of the materials are recycled, which meets the requirements for comprehensive utilization of resources.
  • 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;
  • the iron-rich material is calcium ferrite, and the calcium ferrite is sintered from iron-containing raw material and lime;
  • the concentration of caustic in the circulating mother liquor is 240 g / L, the molecular ratio is 25;
  • the alumina extraction rate can reach 80% or more
  • the concentration of the caustic alkali and the molecular ratio in the sodium aluminate solution produced in this step need to be adjusted to meet the parameter requirements of the circulating mother liquor, and is used for formulating the raw material slurry and performing the dissolution reaction;
  • step S6 washing the eluted slag in step S3 and solid-liquid separation to obtain calcium garnet type slag and washing liquid;
  • the alkali-free calcium iron garnet-type red mud residue 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 red garnet type red mud
  • the sodium content in the slag was reduced to 0.11% and the aluminum to silicon ratio was reduced to 0.5. It not only reduces the alkali content in the red mud, but also makes the alkali-free calcium iron garnet-type red mud residue effectively utilized due to the reduction of the alkali content, such as calcium ferrite additive used in the steelmaking process, self-stressing, high strength.
  • Ideal aggregates for high-strength concrete such as quick-setting 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 S7 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 of the material. use.
  • the obtained 4A zeolite is a product.
  • the filtered slag is an alkali-free calcium iron garnet-type red mud slag, and the rest of the materials are recycled, which meets the requirements for comprehensive utilization of resources.
  • the method of the invention not only recovers the alumina in the red mud to prepare the high value-added 4A zeolite product, but also reduces the alkali content in the red mud, realizes the recycling of the solid waste, and achieves the effect of resource green utilization.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Silicates, Zeolites, And Molecular Sieves (AREA)
  • Treatment Of Sludge (AREA)

Abstract

提供一种钙铁榴石一步碱热法处理拜耳法赤泥生产4A沸石的方法，包括下述步骤，S1：将赤泥、富铁料、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，溶出液为铝酸钠溶液；S4：将铝酸钠溶液与硅酸钠溶液混合后加晶型导向剂进行晶化反应并固液分离，得到4A沸石和高分子比铝酸钠溶液；S5：将高分子比铝酸钠溶液进行调制，制成用于步骤S1中的循环母液。该方法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，制备出市场需求量大、附加值高的4A沸石产品，实现了固体废弃物的高附加值利用，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4A沸石的方法 技术领域
本发明属于赤泥综合利用的技术领域，具体涉及一种钙铁榴石一步碱热法处理拜耳法赤泥生产4A沸石的方法。
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。现在每生产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。
现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。
A型沸石具有类似氯化钠四方结构，其化学式为Na 2O·Al 2O 3·2SiO 2·4.5H 2O，其内部孔径为4.2埃，因此简称其为4A沸石。4A沸石是一种无毒、无臭、无味且流动性较好的白色粉末，具有较强的钙离子交换能力，对环境无污染，对鱼类、藻类无毒，是替代三聚磷酸钠理想的无磷洗涤助剂。表面吸附能力强，是理想的吸附剂和干燥剂。沸石中的钠离子能有效交换水中的钙离子，使水的软化程度大大提高，这样从合成沸石中释放出的钠离子便留在了洗涤溶液中不致沉淀附着在织物上，沸石的高交换容量还防止了钙镁离子与洗涤剂中的表面活性剂发生沉淀反应，从而提高了洗涤剂中的表面活性剂的活化作用，即提高了清洗效果。
4A沸石作为替代三聚磷酸钠等含磷洗涤助剂的无磷洗涤助剂，其用量的迅速增加是必然的。随着无磷洗涤剂用量的增加，预计4A沸石的产量会迅猛增加。
目前，4A沸石的生产原料有化工原料和天然铝硅酸盐矿物。化工原料主要是Al(OH) 3、Na 2SiO 3和NaOH，天然铝硅酸盐矿物主要有高岭土和煤矸石等，生产方法大致有以下几种：
①化工原料法：以Al(OH) 3、Na 2SiO 3和NaOH为原料水热合成4A沸石的工艺路线简单，产品纯度高，质量稳定。最大缺点是原料成本高由于原料价格一再上涨，所以4A沸石的生产成本昂贵。
②高岭土法：以高岭土(Al 2Si 2O 5(OH) 4)为原料，在600℃～800℃下进行氯化焙烧后进行补碱溶出、成胶和结晶后得4A沸石。特点是原料来源广，工艺简单，生产成本较低。存在的问题是对高岭土原料要求刻薄，产品质量不稳定，往往是密度高，粒度和白度不合格，且氯化技术难度大，易造成环境污染，产品的市场竞争力不强。
③煤矸石合成4A沸石的方法主要有3种，即水热法、熔融法和碱溶法。水热法合成沸石具有操作方便的特点，但是因为杂质含量多，结晶度低，而且产品颗粒受原矿颗粒的影响较大，目前，这种方法已经逐渐被熔融法和碱溶法取代。熔融法合成的产品比水热法合成产品结晶度高，杂质含量相对较少。碱溶法合成沸石虽然比水热法以及熔融法增加了过滤溶出硅铝的步骤，但是合成出来的产品具有结晶度高、白度高、杂质含量低和阳离子交换容量大等特点。
发明内容
(一)要解决的技术问题
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4A沸石的方法，利用一步碱热法，将氧化铝工业产生的赤泥作为原料，与富铁料及活性石灰混合后高温溶出，使赤泥中的铝和钠主要以铝酸钠形式进入溶液，而硅、铁和钙主要以钙铁榴石的形式留在溶出渣中。本发明的方法以废弃赤泥为原料，制备市场用量大、附加值高的4A沸石产品，实现了固体废弃物的高附加值利用，达到了资源绿色利用的效果。
(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4A沸石的方法，包括下述步骤，
S1：将赤泥、富铁料、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：将铝酸钠溶液与硅酸钠溶液混合后加晶型导向剂进行晶化反应，晶化反应完成后将产物固液分离，得到4A沸石和高分子比铝酸钠溶液；
S5：将所述高分子比铝酸钠溶液进行调制，制成步骤S1中所用的循环母液。
优选地，所述原料矿浆中，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1～2∶1；
氧化钙的总量与氧化硅总量的摩尔比为1.5～2.5∶1；
其中：所述氧化钙的量不包括与赤泥中二氧化钛反应生成钛酸钙所使用氧化钙的用量。
优选地，所述原料矿浆的液固比为2～5∶1。
优选地，步骤S5中所述高分子比铝酸钠溶液进行苛碱浓度调制后得到循环母液，其中，循环母液中的苛碱浓度为150～250g/L，分子比为10～30。
优选地，步骤S2中溶出反应的温度为180～300℃，反应时间为0.5～2h。
优选地，所述方法还包括：
步骤S6：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S7：将所述洗涤液用于步骤S3中稀释所述溶出矿浆。
优选地，步骤S4中，铝酸钠溶液和硅酸钠溶液混合后的溶液中，氧化钠浓度在50～150g/L；氧化铝浓度在8～25g/L；氧化硅浓度在9～30g/L；氧化硅和氧化铝摩尔比在1.5～2.5，结晶导向剂加入量为1～5‰(体积分 数)。
优选地，步骤S4中，晶化温度为70～99℃，晶化时间为0.5～10h。
优选地，所述富铁料为赤铁矿、针铁矿、铁精矿、铁酸钠或铁酸钙。
优选地，步骤S4中的硅酸钠溶液由水玻璃调配而成。
(三)有益效果
本发明的方法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，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，此方法可对赤泥进行大宗消纳，实现了对赤泥的回收利用；同时可制备市场用量大、附加值高的4A沸石产品，实现了固体废弃物的高附加值利用，达到了资源绿色利用的效果。
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4A沸石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、富铁料和石灰组成的原料矿中，氧化铁的总量与氧化铝的总量的摩尔比简写为F/A；氧化钙的量(生成钛酸钙时，需要消耗一定量的氧化钙，实施例中所写的氧化钙的量不包括与赤泥中二氧化钛生成钛酸钙所使用氧化钙的用量)与氧化硅总量的摩尔比简写为L/S。
富铁料包括但不限于赤铁矿、针铁矿、铁酸钠、铁酸钙等。
硅酸钠溶液可用水玻璃等工业原料。
铝酸钠溶液和硅酸钠溶液混合后的溶液中，硅铝比为溶液中氧化硅 与氧化铝摩尔比。
钙铁榴石一步碱热法处理拜耳法赤泥生产4A沸石的方法，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，生产的目标产品为4A沸石。
实施例1
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)  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；
富铁料采用铁精矿，铁精矿中氧化铁含量为85％；
循环母液中的苛碱浓度为240g/L，分子比为25；
F/A＝1.5∶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4A沸石的方法：
S1：将赤泥、富铁料和活性石灰混合后，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250℃，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2.5‰结晶导向剂加入到铝酸钠和硅酸钠的混合溶液中，混合溶液中，氧化钠浓度在70g/L；氧化铝浓度在11.5g/L；氧化硅浓度在13.5g/L；氧化硅和氧化铝摩尔比在2。并在90℃进行晶化反应8h，得到4A沸石浆料，然后将4A沸石浆料进行液固分离，得到高分子比铝酸钠溶液和固体4A沸石；
S5：将高分子比铝酸钠溶液进行调制，制成步骤S1中所用的循环母液；
本步骤中产生的高分子比铝酸钠溶液中的苛碱浓度及分子比均需调整以达到循环母液的参数要求，用于配制原料浆并进行溶出反应；
S6：将步骤S3中的溶出渣进行洗涤并固液分离，得到钙铁榴石型溶出渣和洗涤液；
本步骤中，经过处理得到了无碱钙铁榴石型渣，使原料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；
S7：将洗涤液用于步骤S3中稀释所述溶出矿浆；
本步骤中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。
得到的4A沸石即为产品。滤出渣为无碱钙铁榴石型渣，其余物料均实现了循环利用，符合资源绿色化综合利用的要求。
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；
富铁料为铁酸钙，铁酸钙为含铁原料与石灰烧结而成；
循环母液中的苛碱浓度为240g/L，分子比为25；
F/A＝1.5∶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4A沸石的方法：
S1：将赤泥、铁酸钠和石灰混合后，按照L/S＝5∶1的比例与循环母液混合制备成原料浆；
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，其中溶出液为铝酸钠溶液；
S4：将2‰结晶导向剂加入到铝酸钠和硅酸钠的混合溶液中，混合溶液中，氧化钠浓度在90g/L；氧化铝浓度在15g/L；氧化硅浓度在17.5g/L；氧化硅和氧化铝摩尔比在2。并在90℃进行晶化反应8h，得到4A沸石浆料，然后将4A沸石浆料进行液固分离，得到高分子比铝酸钠溶液和固体4A沸石；
S5：将高分子比铝酸钠溶液进行调制，制成步骤S1中所用的循环母液；
本步骤中产生的高分子比铝酸钠溶液中的苛碱浓度及分子比均需调整以达到循环母液的参数要求，用于配制原料浆并进行溶出反应；
S6：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；
本步骤中，经过处理得到了无碱钙铁榴石型赤泥渣，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，铁榴石型赤泥渣中钠含量降至0.11％，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；
S7：将洗涤液用于步骤S3中稀释所述溶出矿浆；
本步骤中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。
得到的4A沸石即为产品。滤出渣为无碱钙铁榴石型赤泥渣，其余物料均实现了循环利用，符合资源绿色化综合利用的要求。
本发明的方法不仅回收了赤泥中的氧化铝制备高附加值4A沸石产品，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 (10)

  1. 一种钙铁榴石一步碱热法处理拜耳法赤泥生产4A沸石的方法，其特征在于：包括下述步骤，
    S1：将赤泥、富铁料、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：将铝酸钠溶液与硅酸钠溶液混合后加晶型导向剂进行晶化反应，晶化反应完成后将产物固液分离，得到4A沸石和高分子比铝酸钠溶液；
    S5：将所述高分子比铝酸钠溶液进行调制，制成步骤S1中所用的循环母液。
  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4A沸石的方法，其特征在于：所述原料矿浆中，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1～2∶1；
    氧化钙的量与氧化硅总量的摩尔比为1.5～2.5∶1；
    其中：所述氧化钙的量不包括与赤泥中二氧化钛反应生成钛酸钙所使用氧化钙的用量。
  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4A沸石的方法，其特征在于：所述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4A沸石的方法，其特征在于：步骤S5中所述高分子比铝酸钠溶液进行苛碱浓度调制后得到循环母液，其中，循环母液中的苛碱浓度为150～250g/L，分子比为10～30。
  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4A沸石的方法，其特征在于：步骤S2中溶出反应的温度为180～300℃，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 4A沸石的方法，其特征在于：所述方法还包括：
    步骤S6：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S7：将所述洗涤液用于步骤S3中稀释所述溶出矿浆。
  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4A沸石的方法，其特征在于：步骤S4中，铝酸钠溶液和硅酸钠溶液混合后的溶液中，氧化钠浓度在50～150g/L；氧化铝浓度在8～25g/L；氧化硅浓度在9～30g/L；氧化硅和氧化铝摩尔比在1.5～2.5，结晶导向剂加入量按体积分数为1～5‰。
  8. 根据权利要求7所述的钙铁榴石一步碱热法处理拜耳法赤泥生产4A沸石的方法，其特征在于：步骤S4中，晶化温度为70～99℃，晶化时间为0.5～10h
  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4A沸石的方法，其特征在于：所述富铁料为赤铁矿、铁精矿、针铁矿、铁酸钠或铁酸钙。
  10. 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4A沸石的方法，其特征在于：步骤S4中的硅酸钠溶液由水玻璃调配而成。
PCT/CN2018/092421 2017-07-26 2018-06-22 钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法 WO2019019844A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201710619960.X 2017-07-26
CN201710619960.XA CN107311192A (zh) 2017-07-26 2017-07-26 钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法

Publications (1)

Publication Number Publication Date
WO2019019844A1 true WO2019019844A1 (zh) 2019-01-31

Family

ID=60174942

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2018/092421 WO2019019844A1 (zh) 2017-07-26 2018-06-22 钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法

Country Status (2)

Country Link
CN (1) CN107311192A (zh)
WO (1) WO2019019844A1 (zh)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107311192A (zh) * 2017-07-26 2017-11-03 东北大学 钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法
CN109437217A (zh) * 2018-10-30 2019-03-08 东北大学设计研究院（有限公司） 一种赤泥处理及氧化铝生产的方法
CN111170330B (zh) * 2020-01-02 2021-06-22 淮阴工学院 以高岭土和赤泥为原料制备磁性4a沸石的方法

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
CN102320620A (zh) * 2011-06-20 2012-01-18 太原理工大学 一种用氧化铝赤泥制备4a沸石的方法
CN102530978A (zh) * 2011-08-09 2012-07-04 中国环境科学研究院 一种利用赤泥制备钠型沸石分子筛的方法
CN107311192A (zh) * 2017-07-26 2017-11-03 东北大学 钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1699171A (zh) * 2005-05-12 2005-11-23 山东铝业股份有限公司 低堆比4a型分子筛原粉的制造工艺
CN105236443B (zh) * 2015-09-16 2017-10-13 山东磊宝锆业科技股份有限公司 Azs固体废料制备4a沸石的工艺

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
CN102320620A (zh) * 2011-06-20 2012-01-18 太原理工大学 一种用氧化铝赤泥制备4a沸石的方法
CN102530978A (zh) * 2011-08-09 2012-07-04 中国环境科学研究院 一种利用赤泥制备钠型沸石分子筛的方法
CN107311192A (zh) * 2017-07-26 2017-11-03 东北大学 钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法

Also Published As

Publication number Publication date
CN107311192A (zh) 2017-11-03

Similar Documents

Publication Publication Date Title
WO2018233689A1 (zh) 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
WO2018233690A1 (zh) 钙铁榴石一步碱热法处理拜耳法赤泥生产铝酸钠的方法
CN103030160B (zh) 一种从拜耳法赤泥回收氧化铝和氧化钠的方法
WO2012151767A1 (zh) 高铝粉煤灰生产氧化铝联产活性硅酸钙的方法
CN104445311B (zh) 高含量二氧化硅质粉煤灰多联产洁净制备方法
CN100441708C (zh) 一种一水硬铝石型铝土矿的溶出方法
CN100582009C (zh) 一种石灰烧结-拜耳法联合生产氢氧化铝的方法
WO2018233688A1 (zh) 钙铁榴石一步碱热法处理中低品位铝土矿生产氢氧化铝的方法
WO2019019844A1 (zh) 钙铁榴石一步碱热法处理拜耳法赤泥生产4a沸石的方法
CN101117230A (zh) 一种拜耳法溶出方法
WO2018233687A1 (zh) 钙铁榴石一步碱热法处理中低品位铝土矿生产铝酸钠的方法
CN101289211A (zh) 一种拜耳法赤泥中氧化钠和氧化铝的回收方法
WO2020206831A1 (zh) 一种钙化-碳化高铁赤泥回收铁及尾渣水泥化的方法
CN109110788A (zh) 一种盐湖卤水中锂镁资源综合利用的方法
CN108950212B (zh) 一种赤泥中综合回收钠、铝、铁的方法
CN107022681A (zh) 一种铝硅废料中稀土、铝和硅的综合回收方法
CN102659559B (zh) 一种从稀土抛光粉废渣中制取草酸镧铈的方法
WO2018233686A1 (zh) 钙铁榴石一步碱热法处理中低品位铝土矿生产冶金级氧化铝的方法
CN104340994B (zh) 一种循环流化床锅炉粉煤灰综合利用的方法
CN109694092A (zh) 一种含氯固废的综合治理方法
CN113441519A (zh) 一种拜耳法赤泥脱碱及碱回收工艺
CN103408050B (zh) 一种煤矸石中高效提取铝铁钛的方法
CN108285163A (zh) 一种脱硅粉煤灰的制备方法和应用
CN107792870B (zh) 一种铝土矿的综合利用方法
CN105219957A (zh) 一种从石煤焙烧料中选择性浸出钒的方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18838425

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18838425

Country of ref document: EP

Kind code of ref document: A1