菜单
  
    摘要:碳酸钙(Calcium carbonate)是一种无机化合物,俗称灰石、石灰石、石粉、大理石、方解石,是石灰石的主要成分,其分子式为CaCO3。呈中性,基本上不溶于水,溶于酸。碳酸钙是一种重要的粉体材料,也是重要的化工原料之一,因其无毒和使用性能良好而被广泛应用应用于塑料、橡胶、造纸、油墨、涂料等行业,是一种附加值高、经济效益好、应用范围广的产品。我国每年的碳酸钙耗量巨大。31616
    造纸黑液的主要成分是木质素和聚糖等,木质素是一种含有各种生物学稳定的复杂键型的高分子有机化合物,难以直接进行生物降解,黑液中的木质素多数是由数个苯丙烷单元组成。所以本论文采用先碱化黑液的方法,在黑液中加入Ca(OH)2溶液,调节PH=12左右,然后提取碳酸根,制备碳酸钙,通过无水甲醇、二氯甲烷、乙酸乙酯、石油醚打浆纯化和水洗等方法尽量去除碳酸钙中的杂质,再测定其中碳酸钙,杂质的含量。最后酸析滤液,调节PH=1左右使苯丙烷单元转变成不溶性的游离酚的状态从黑液中析出,再经过沉淀、过滤,进而沉淀提取木质素。
    毕业论文关键词:碳酸钙,打浆,钙含量,酸析
    The research of preparing CaCO3 by papermaking black liquor
    Brief:Calcium carbonate is an Inorganic compound.Generally speaking,it is the main ingredient of limestone,known as greystone、limestone、mountain flour、marble and calcite.The molecular formula is CaCO3 which is presented neutral ph value.And it almost insoluble in water but soluble in acids.CaCO3 is created by calcium ion and carbanion,so it’s not only called calcium salt but also carbonate.Calcium carbonate are widespread in the earth,exist in aragonite、calcite、chalk、limestone and so on.Besides that,it’s also the major ingredient of animals’ bones and shells.In addition to that,Calcium carbonate is an important powder material and a part of chemical materials.It’s ulitized in many aspects because of its characteristics of non-toxic and well usability,commonly used in plastic、rubber、papermaking、printing ink、painting and so on.High value、good economic benefits and wide range of application are all advantages of the product.So there is a great amount of annual consumption of calcium carbone in China.
    The main components of black liquor are lignin and glycan etc.Lignin is a water-soluble polymer that contains all kinds of stable and complicated bond types in biology. Most of lignin is composed of so many phenylpropane-units that it’s difficult to adopt biodegradation.
    So the paper adopt a way that alkalify the black liquor firstly,that is add moderate Ca(OH)2 to the black liquor and adjust PH=12 or so.Then extract the carbonate to prepare calcium carbonate.At the same time,to wipe off the impurities from the calcium carbonate by beating、purification and washing with absolute ethyl alcohol、dichloromethane、ethyl acetate and petroleum ether.The next step is to assay the content of calcium carbonate and impurities respectively.Finally,to acid out filtrate,adjust PH=1 to convert the phenylpropane-unit into the insoluble free phenol and separate out it from the black liquor.Then extract lignin by precipitating、filtrating and precipitating again.
    Keywords:Calcium carbonate,beating,The calcium content,acidification
    目录
    1、绪论    1
      1.1开题依据    1
      1.2碳酸钙的概况    1
      1.3碳酸钙的性质    2
      1.3.1碳酸钙的物理性质(25℃,100KPa)    2
      1.3.2碳酸钙的化学性质    3
      1.4碳酸钙的分类    4
      1.4.1按微观排列分类    4
      1.4.2按生产方法分类    5
      1.4.4纳米碳酸钙Nano Calcium Carbonate    7
  1. 上一篇:比值控制在氨氧化炉生产氧化炉温度控制中的应用
  2. 下一篇:1-(2-吡啶基)-3-甲基-4-三氟甲基-吡唑酮与各种金属的配合物溶液的光谱学性质
  1. O2存在下cis-CF3CH=CHCl与OH自由基反应机理的研究

  2. 大气中ISOPOOH与OH自由基反应机制的研究

  3. CHF2CH2OH与OH自由基气相反应动力学的研究

  4. O2存在下(Z)-CF3CH=CHCF3与OH自...

  5. 原位生成磺酰基自由基诱...

  6. 光催化还原二氧化碳

  7. 自由基环合反应制备氟代3,3-二取代-2-吲哚酮

  8. 大众媒体对公共政策制定的影响

  9. 乳业同业并购式全产业链...

  10. 酸性水汽提装置总汽提塔设计+CAD图纸

  11. 电站锅炉暖风器设计任务书

  12. 中考体育项目与体育教学合理结合的研究

  13. 河岸冲刷和泥沙淤积的监测国内外研究现状

  14. java+mysql车辆管理系统的设计+源代码

  15. 杂拟谷盗体内共生菌沃尔...

  16. 当代大学生慈善意识研究+文献综述

  17. 十二层带中心支撑钢结构...

  

About

751论文网手机版...

主页:http://www.751com.cn

关闭返回