Taking the saline lake bischofite and NH4Cl that was removed with the ammonia method and continuously followed by filtration as raw materials with a molar ratio of 1∶1 of MgCl2 to NH4Cl, ammonium carnallite was synth...Taking the saline lake bischofite and NH4Cl that was removed with the ammonia method and continuously followed by filtration as raw materials with a molar ratio of 1∶1 of MgCl2 to NH4Cl, ammonium carnallite was synthesized. And then the ammonium carnallite was dehydrated to some extent at 160℃ for 4 h. Ammonium carnallite reacted with ammonia at 240℃ for 150 min and the ammonation ammonium carnallite was produced. Finally, the ammonation ammonium carnallite was calcined at 750℃ into anhydrous magnesium chloride containing only 0.1%（mass fraction） of MgO. On the other hand, dehydrated ammonium carnallite was mixed with the solid ammonium chloride at mass ratio 1∶4 at high temperature and with the differential pressure of NH3 above 30.5kPa. The dehydrated ammonium carnallite of mixture was dehydrated at 410℃, and then calcined at 700℃ into anhydrous magnesium chloride with only 0.087%（mass fraction） of MgO. X-ray diffraction and electron microscopy analysis results prove that anhydrous magnesium chloride obtained by both methods hasn’t mixed phases, the particle is large and even has good dispersion, which is suitable for preparation of metal magnesium in the electrolysis.展开更多
Online control of the ratio of carnallite to water is a key to achieve a fully continuous and automatic potash produc tion. By monitoring carnallite cold decomposition process using online conductivity meter, the rela...Online control of the ratio of carnallite to water is a key to achieve a fully continuous and automatic potash produc tion. By monitoring carnallite cold decomposition process using online conductivity meter, the relationship between the conduc tivity and the control parameters was analyzed based on the data collected online. The results show that the conductivity regu larly varies with a general trend of decrease after an initial increase when the ratio of mineral to water is adjusted. There are certain rules satisfying cubic polynomial regression equation. When the ratio of mineral to water is larger than 0. 6, with the a mount of carnallite increased by 10%, the conductivity decreases by 0. 28%-0. 45% accordingly and the relative deviation is less than 0. 5%. The value of electrical conductivity has stabilized when the density of liquid increased to 1.27 g/cm3, namely, the solution reaches saturation. It has proved that the methods can be employed for online monitoring the ratio of carnallite to water during carnallite cold decomposition and the precise control has an important value for reference and application.展开更多
The relationship between sylvinite and carnallite is important in the potash mine body contained carnallite,especially sylvinite overlies carnallite,the reverse of a normal depositional sequence.Trace elements are more
Mixing brine method,which founded on the commonion effect,is widely used for low-sodium carnallite production.Compared with traditional carnallite preparation techniques,the mixing brine method possess a
目前,工业上广泛采用“分解-浮选”工艺生产KCl,但是在光卤石分解过程中NaCl对KCl晶体的影响尚不明确。在光卤石的分解结晶阶段,由于KCl和NaCl的明显聚集,使得两种颗粒在浮选阶段的分离效率较差。以NaCl掺杂光卤石为原料,开展了分解-浮...目前,工业上广泛采用“分解-浮选”工艺生产KCl,但是在光卤石分解过程中NaCl对KCl晶体的影响尚不明确。在光卤石的分解结晶阶段,由于KCl和NaCl的明显聚集,使得两种颗粒在浮选阶段的分离效率较差。以NaCl掺杂光卤石为原料,开展了分解-浮选制备KCl实验。以NaCl的粒径和含量为变量,结合扫描电子显微镜-能谱仪(scanning electron microscope-energy dispersive spectrometer,SEM-EDS)图像,研究了NaCl的粒度和含量对精矿中KCl品位的影响。研究结果显示,掺杂的NaCl粒径对精矿中KCl的影响较大。当NaCl粒径在40~60目时,随着光卤石中NaCl含量的升高,浮选后精矿品位基本不变,K^(+)平均含量为44.39%;当NaCl粒径在60~80目和100目下时,随着光卤石中NaCl含量的升高,浮选后精矿中K^(+)含量明显降低,K^(+)含量分别降低至36.08%和35.48%,而Na+含量分别升高至6.27%和8.36%。此外,SEM和EDS结果表明精矿中的杂质NaCl是以黏附或者嵌入的方式生长在KCl晶体上,从而导致浮选KCl的同时NaCl一起选出,使得精矿中K^(+)含量降低。该研究结果成功揭示了盐田低钾光卤石矿生产钾肥过程中NaCl和KCl难分离的主要原因,为盐湖钾资源的高效利用提供了研究基础。展开更多
基金Project(2000 G 101) supported by the Key Science and Technology Research Project of Qinghai Province
文摘Taking the saline lake bischofite and NH4Cl that was removed with the ammonia method and continuously followed by filtration as raw materials with a molar ratio of 1∶1 of MgCl2 to NH4Cl, ammonium carnallite was synthesized. And then the ammonium carnallite was dehydrated to some extent at 160℃ for 4 h. Ammonium carnallite reacted with ammonia at 240℃ for 150 min and the ammonation ammonium carnallite was produced. Finally, the ammonation ammonium carnallite was calcined at 750℃ into anhydrous magnesium chloride containing only 0.1%（mass fraction） of MgO. On the other hand, dehydrated ammonium carnallite was mixed with the solid ammonium chloride at mass ratio 1∶4 at high temperature and with the differential pressure of NH3 above 30.5kPa. The dehydrated ammonium carnallite of mixture was dehydrated at 410℃, and then calcined at 700℃ into anhydrous magnesium chloride with only 0.087%（mass fraction） of MgO. X-ray diffraction and electron microscopy analysis results prove that anhydrous magnesium chloride obtained by both methods hasn’t mixed phases, the particle is large and even has good dispersion, which is suitable for preparation of metal magnesium in the electrolysis.
文摘Online control of the ratio of carnallite to water is a key to achieve a fully continuous and automatic potash produc tion. By monitoring carnallite cold decomposition process using online conductivity meter, the relationship between the conduc tivity and the control parameters was analyzed based on the data collected online. The results show that the conductivity regu larly varies with a general trend of decrease after an initial increase when the ratio of mineral to water is adjusted. There are certain rules satisfying cubic polynomial regression equation. When the ratio of mineral to water is larger than 0. 6, with the a mount of carnallite increased by 10%, the conductivity decreases by 0. 28%-0. 45% accordingly and the relative deviation is less than 0. 5%. The value of electrical conductivity has stabilized when the density of liquid increased to 1.27 g/cm3, namely, the solution reaches saturation. It has proved that the methods can be employed for online monitoring the ratio of carnallite to water during carnallite cold decomposition and the precise control has an important value for reference and application.
基金the West Light Foundation of CAS (2011-180)the National Program on Key Basic Research Project of China (973 Program) (2011CB403004) for financial support
文摘The relationship between sylvinite and carnallite is important in the potash mine body contained carnallite,especially sylvinite overlies carnallite,the reverse of a normal depositional sequence.Trace elements are more
基金Project supported by the Sichuan Youth Science and Technology Innovation Research Team Funding Scheme(2013TD0005)Innovation Team of CDUT(KYTD201405)
文摘Mixing brine method,which founded on the commonion effect,is widely used for low-sodium carnallite production.Compared with traditional carnallite preparation techniques,the mixing brine method possess a
基金STS Regional key projects of CAS(KFJ-STS-QYZD-2-21-06-002)Qinghai province science and technology department Key R&D and transformation plan(2021-GX-C04).
文摘目前,工业上广泛采用“分解-浮选”工艺生产KCl,但是在光卤石分解过程中NaCl对KCl晶体的影响尚不明确。在光卤石的分解结晶阶段,由于KCl和NaCl的明显聚集,使得两种颗粒在浮选阶段的分离效率较差。以NaCl掺杂光卤石为原料,开展了分解-浮选制备KCl实验。以NaCl的粒径和含量为变量,结合扫描电子显微镜-能谱仪(scanning electron microscope-energy dispersive spectrometer,SEM-EDS)图像,研究了NaCl的粒度和含量对精矿中KCl品位的影响。研究结果显示,掺杂的NaCl粒径对精矿中KCl的影响较大。当NaCl粒径在40~60目时,随着光卤石中NaCl含量的升高,浮选后精矿品位基本不变,K^(+)平均含量为44.39%;当NaCl粒径在60~80目和100目下时,随着光卤石中NaCl含量的升高,浮选后精矿中K^(+)含量明显降低,K^(+)含量分别降低至36.08%和35.48%,而Na+含量分别升高至6.27%和8.36%。此外,SEM和EDS结果表明精矿中的杂质NaCl是以黏附或者嵌入的方式生长在KCl晶体上,从而导致浮选KCl的同时NaCl一起选出,使得精矿中K^(+)含量降低。该研究结果成功揭示了盐田低钾光卤石矿生产钾肥过程中NaCl和KCl难分离的主要原因,为盐湖钾资源的高效利用提供了研究基础。
