卤水-碳铵法制备特级轻质氧化镁的新工艺技术研究

【作者】 王犇；

【导师】 任保增；

【作者基本信息】 郑州大学 ， 化学工艺， 2004， 硕士

【摘要】 氧化镁（MgO）是镁化合物的核心，因为它产量大，应用面广，品种规格多，并且还是其他高纯镁化合物的原料。我国是一个产镁大国，仅菱镁矿资源贮量约占世界总贮量的1／3，也是一个镁盐出口大国，但主要是以出口低值镁矿为主，这种只顾眼前利益，长期廉价出卖资源，不符合我国经济持续发展的政策。 我国有漫长的海岸线，有取之不尽的海水资源，又是世界上生产海盐最多的国家，每年约副产卤水2000万m³。卤水是浓缩了的海水，其中可溶性无机盐浓度是海水的40～50倍，其主要成分是镁，以卤水为原料生产镁产品，不仅价格便宜，而且卤水含杂质少，成分均匀，易处理，容易制备高纯镁制品。同时又减少了卤水中Mg²⁺给制盐工业带来的二次污染，是一举两得的事，但是长期以来未能引起重视，90％以上的卤水没有被利用，大量镁资源白白浪费了，实在可惜! 随着科学技术的飞速发展，镁产品的用途日益广泛，特别是高新科技领域内的应用，就需要高品质的镁产品。我国的镁产品工业，生产工艺落后，生产成本高，能耗大，产品品种单一，无法同工业发达国家竞争，失去了市场竞争力。 本研究就是根据我国国情（有大量碳酸氢铵的生产）以卤水（或地下卤水）为原料，以碳酸氢铵和氨水为沉淀剂生产特级轻质氧化镁的新工艺研究。这种生产工艺技术在国外很少有报道，国内近年来虽有些试验研究，但大多停留在试验阶段，在山东省虽有些小厂用碳酸氢铵作沉淀剂（以期代替纯碱）生产轻质氧化镁，但工艺不合理，能耗高，经济效益差，大多处于开开停停的困境中。所以研究高附加值的特级轻质氧化镁及其新工艺技术，节能降耗，增大经济效益和社会效益就是本研究的目的。 本研究所述的工艺是采用卤水、碳酸氢铵和氨水为原料，生产特级轻质氧化镁的方法。首先，将部分碳酸氢铵和氨水配成一定浓度的溶液，并将该溶液逐滴加入到卤水中，并在一定温度下反应。反应后，分批添加固体碳酸氢铵，直到沉淀完全。然后经陈化、热解、过滤、洗涤、干燥、粉碎、煅烧等工序制成轻质氧化镁。通过对碳酸氢铵和氨水的消耗量，反应温度对视比容、回收率的影响等工艺条件的研究和探讨，找到其最佳工艺条件。从而达到节能降耗并生产出特级轻质氧化镁产品的目的。在此基础上进行了工业放大试验，效果也非常理想。此方法的优点是工艺简单、易于操作控制、产品质量稳定、附加值高、经济效益显著。 尽管卤水杂质含量少，为确保产品质量，本研究对其进行了净化处理。加入少量次氯酸钠和与5042一等摩尔的氯化钙以去掉铁、锰、50扩等杂质。并按反应原理，实验中紧紧抓住碳酸氢钱的离解式反应中生成的HCO3.或放出的CO:的利用和循环利用这一关键，进行了实验条件的探索。通过试验找出了:氨水的用量与卤水（浓度一定）用量，以及碳酸氢按用量与氨水之间的用量比。选出了最佳的三者之间用量关系，为:卤水用量:氨水用量=卜0.221（质量比）;氨水用量:碳酸氢馁用量=1:0.61（质量比）。 按此用量比，可使碳酸氢馁的耗量（生产一吨轻质氧化镁）由原来的4一6吨降低到2吨左右，从而大大降低了生产成本。 通过对反应温度、热解温度对轻质氧化镁的产率与视比容关系的试验，得出在反应温度较低时，尽管热解温度较高，轻质氧化镁的视比容和产率都较低，随着反应温度的升高，视比容和产率也相应升高。综合考虑得到了较适宜工艺条件:反应温度为:60士5℃;热解温度为:70士5℃;热解时间为1小时。 在小试、重复试验及放大试验的基础上，在山东潍坊地区天盛氧化镁厂进行了工业试生产，制备出特级轻质氧化镁产品，同时大大降低了生产成本，改善了操作环境。本工艺具有工艺简单，流程短，改善了操作环境，Mg2+回收率高等特点，特别适合中小规模生产，另外减少了原料消耗，降低了生产成本，生产出高附加值的特级轻质氧化镁，达到了节能降耗，增加经济效益的目的。更多还原

【Abstract】 MgO is the core of magnesium compounds because of its high output, wide use, lots of kinds, mainly MgO is the materials of the other pure magnesium compounds.Magnesium compounds are mass-produced in China, the reserves of magnesite resources account for 1/3 in the world. China is a country which exports largely magnesian salts.China has a long coastline, so it has large amounts of seawater. The most briny salt is produced in China, so it has about 2000m3 haloid water as outgrowth. Haloid water is the concentrated seawater, in which, the consistence of solubrlrty salt is 40-50 times of seawater, its main component is magnesium. If we use haloid water to produce magnesian compounds, the products is not only more cheaper, but also less impurities, equality components, easily preparated high pure magnesian products. With this method, we can decrease the twice pollution. But in a long time, people don’t focus on this instance and more than 90% haloid water is not fully used.With the quick development of technology, the use of magnesian products are more widely, specially in the fields of advanced technology, we need high quality magnesian products. But the technics of magnesian industry is draggle, high economic costs, high energy costs, less kinds of products. So we can not compete with the developed countries and lose much of markets.This paper about the technics is according to the situation of our country, using the material of haloid liquid, ammonium bicarbonate and ammonia to prepare the super light MgO. Few of this technics is reported hi foreign. There are some experiment researches in China, but they only stay experiment stage. In Shangdong, even though some small industries use ammonium bicarbonate as precipitator to produce the super light MgO, but the technics is not reasonable ,in high energy, badly economic benefit. So they are all in bad status. So the main purposes of this paper is to research high appendice super light MgO and its new technics, lessen energyconsume, large economic benefits and society benefits.This paper about the technics is to use the material of haloid liquid, ammonium bicarbonate and ammonia to preparate the super light MgO. First, we use ammonium bicarbonate and ammonia to have the prescriptive consistency solution, then add the solution into haloid liquid drop by drop and reaction each other in the fixed temperature. After reaction we add ammonium bicarbonate solid into the solution in batches until deposited completely. Secondly, we use the methods of aging, pyrolysis, filtration, lavation, desiccation, shiver, calcinations, finally, the super light MgO is obtained. From the amount of ammonium bicarbonate and ammonia, reaction temperature, specific votume, recycle rate, we can find the excellent technics condition. So we can produce the super light MgO under the condition of less material and less energy. On this base, we have a magnified experimentation. It means that the result is very good. The virtues of this technics is simple, controllable, steady quality, high annex and more economic benefits.Although there are few of impurities in haloid water, in order to ensure the quality of the products, we have to purify it. We add little NaCIO and a little CaCk which molar scalar is same with the SO42" to dispose of the impurities, such as iron, manganese, SO42". According with the principle of reaction, in experimentation, we grasp the sticking point which in reaction of ammonium bicarbonate, there it creates HCOs" and COi, and both of the two can be used circularly to search after the conditions of the experiment. Through the experiment, we can confirm the ratio of dosage of ammonia and haloid wate, the ration of dosage of ammonium bicarbonate and ammonia. The best rations of the three are: Haloid water: Ammonia=l:0.221, Ammonia : Ammonium bicarbonate=l:0.61 by mass, respectively.With the rations of them, we can make the consuming of ammonium bicarbonate decrease from 4-6 tons to about 2 tons, and reduce the production costs.Through the experiment of the relations更多还原