多层流化床制备活性氧化镁中试实验研究

发布时间：2018-04-30 16:24

  本文选题：活性氧化镁 + 动态煅烧　； 参考：《河北科技大学》2015年硕士论文

【摘要】：活性氧化镁作为重要的无机化工产品,因其可具有不同的活性,在氯丁橡胶、胶黏剂、轮胎、输送带、医药、硅钢、荧光粉等不同行业中得到了广泛的应用。目前,活性氧化镁的制备方法主要是通过煅烧菱镁矿、水氯镁石、水镁石、碱式碳酸镁和氢氧化镁得到,工业上煅烧反应器主要是回转煅烧炉和旋流动态煅烧炉。但是这两种煅烧设备在生产活性氧化镁时存在着产品活性不均匀、活性不可控的缺点:回转煅烧炉设备直径较大,加热时容易造成内部温度低,炉壁温度高等现象;而旋流动态煅烧炉则是瞬间煅烧,煅烧时间短,造成煅烧不完全。本论文提出采用多层流化床煅烧炉作为氢氧化镁煅烧设备,以实现活性氧化镁活性的可控性和均匀性,并通过冷模实验和热态实验对其流化现象、煅烧结果进行分析研究,以探索适宜的结构形式和操作参数。本论文首先对来自南风集团的氢氧化镁在马弗炉中进行静态煅烧,探讨其在不同煅烧温度、煅烧时间、升温速率等条件下,影响活性氧化镁活性的因素。结果表明:在煅烧温度450℃,煅烧时间1h,升温速率20min条件下煅烧制备得到的氧化镁活性最高,其吸碘值最高可达到127 mg I2/g MgO,纯度达到92%,BET为57m2/g。设计了冷态的多层流化床结构,实验研究了不同分布板形式及溢流管形式对氢氧化镁流态化效果的影响。结果表明:分布器采用风帽式,正方形排列方式,孔间距为22mm,风帽高度为22mm,分布板为百叶窗式单旋导向层间分布板,溢流管为直管型溢流管,实验用氢氧化镁具有较好的流化效果。根据冷态实验结果,设计制造了热态多层流化床煅烧装置,并对氢氧化镁进行不同温度下的煅烧,探讨产品活性氧化镁活性变化以及在空气中的吸潮性。结果表明,在热态多层流化床中高温流体介质分布均匀,床层内部温度分布均匀,氢氧化镁呈现流化状态,颗粒表面受热均匀。在实际操作中通过调节进料量和各层的煅烧温度,多层流化床煅烧装置可以实现氧化镁产品的活性可控,较好地解决了工业回转煅烧炉和旋流动态煅烧炉中产品活性不可控的问题。与静态煅烧制备的活性氧化镁相比,多层流化床煅烧制备的氧化镁具有较高的活性,吸碘值、比表面积值均较高。其中吸碘值可达到142 mgI2/g Mg O,纯度可达到92%,而BET值则高达147m2/g。
[Abstract]:As an important inorganic chemical product, active magnesium oxide has been widely used in many industries, such as neoprene, adhesive, tire, conveyor belt, medicine, silicon steel, phosphor and so on. At present, the preparation of active magnesium oxide is mainly obtained by calcining magnesite, hydrochlorite, brucite, basic magnesium carbonate and magnesium hydroxide. However, these two kinds of calcinations have the disadvantages of uneven product activity and uncontrollable activity in the production of active magnesium oxide: the rotary calciner has a large diameter, which can easily lead to low internal temperature and high furnace wall temperature when heated; The swirl dynamic calciner is instantaneous calcinations, short calcination time, resulting in incomplete calcination. In this paper, the multilayer fluidized bed calciner is used as the calcining equipment of magnesium hydroxide to realize the controllability and uniformity of the activity of active magnesium oxide, and the fluidization phenomenon and the calcination result are analyzed through cold model experiment and hot state experiment. In order to explore the appropriate structure and operational parameters. In this paper, the magnesium hydroxide from Nanfeng Group was first calcined in a muffle furnace, and the factors affecting the activity of active magnesium oxide were discussed under different calcination temperature, calcination time and heating rate. The results show that under the conditions of calcination temperature 450 鈩，

本文编号：1825281