红土镍矿综合利用制备尖晶石铁氧体基础及工艺研究

发布时间：2018-04-25 02:06

本文选题：红土镍矿 + 酸浸-共沉淀法　；参考：《北京科技大学》2016年博士论文

【摘要】：随着硫化镍矿资源的匮乏以及日益增长的镍需求,占世界镍资源储量72%的低品位红土镍矿将成为提取镍的主要资源。本文针对红土镍矿的组成及结构特点,提出了酸浸-共沉淀-煅烧法和碱熔-水浸-固相烧结法综合利用红土镍矿制备尖晶石铁氧体的新型工艺路线；阐明了各流程阶段红土镍矿中元素的分布及走向规律；揭示了选择性浸出及分离富集过程对于制备尖晶石铁氧体材料的组成、结构及磁性能的微观影响机制。新型工艺流程不仅能够高效回收红土镍矿中的Ni、Co、Mn、Mg、Fe等有价金属元素,同时制备得到了高附加值铁氧体磁性材料,实现了红土镍矿资源的高效综合利用。采用水热酸浸-水热共沉淀-煅烧法,从单一腐泥土型红土镍矿制备合成了Co-Mn-Al共掺杂铁酸镍(NiFe2O4)。系统研究了水热酸浸过程中水热反应温度和初始盐酸溶液浓度对于金属选择性浸出和金属摩尔比RFe/Ni勺影响;阐明了水热共沉淀法实现溶液中Ni、Co、Mn、Fe金属元素与Mg的分离机理；探讨了选择性浸出分离过程对于制备共掺杂铁酸镍微观结构及磁性能的影响规律。结果表明：当浸出温度控制在200℃,盐酸浓度为2.0 mol-L-1,液固比为6：1 mL·g-1时,Fe和Ni的浸出率可控制为17.0%和85.0%,此时得到的浸出液中Fe与Ni、Co、Mn的摩尔比约为2.0;调节酸浸液pH值为7.0,在水热温度为200℃,水热反应2 h,溶液中的Ni、Co、Mn、Fe和Al发生共沉淀反应而实现与溶液中Mg离子的完全分离：将沉淀在1000℃煅烧2 h可以获得高纯度和结晶度、性能良好的尖晶石共掺杂NiFe204.采用常压酸浸-共沉淀-煅烧法,从腐泥土型和褐铁矿型红土镍矿混合矿制备合成了Ni-Co-Mn或者Mn-Al-Cr共掺杂铁酸镁(MgFe2O4)。系统研究了常压酸浸过程中初始盐酸溶液浓度、液固比和浸出时间对于金属浸出的影响规律；探讨了共沉淀过程中沉淀剂、溶液pH值、沉淀过程加料方式以及酸浸液中金属离子浓度对于共沉淀过程金属离子的沉淀行为、分离和富集的影响机理;研究并揭示了不同沉淀剂和初始酸浓度对于制备单一铁氧体结构和磁性能的影响机制。结果表明：采用100℃冷凝回流法,当初始HCl溶液浓度为2.75 mol·L-1,液固比为10 mL·-g-1,浸出时间为60 min时,Fe、Ni、Co、 Mn、Mg的浸出率分别为94.6%、96.1%、81.5%、83.2%和71.8%；在沉淀过程中,分别以氨水溶液和氢氧化钠溶液为沉淀剂,控制反应终了溶液的pH值为11.0和12.0,采用反向加料方式,反应时间为30 min,搅拌速度为300rpm时,Ni、Co、Al和Cr的回收率分别达到了93.0%、92.0%、92.0%和90.0%,同时得到的沉淀可以用于制备尖晶石铁氧体材料；在煅烧过程中,以氨水溶液和氢氧化钠溶液作为沉淀剂时,制备合成单一尖晶石铁氧体相的最佳MS/L分别为9：1和7：3 g·g-1,煅烧温度和时间为1000℃和2 h时,分别制备得到了Mn-Al-Cr共掺杂MgFe2O4和Ni-Co=Mn共掺杂MgFe204.采用共沉淀-煅烧法,从腐泥土型和褐铁矿型红土镍矿混合矿酸浸液中分别制备合成了不同Zn掺杂量和Ni掺杂量的尖晶石铁氧体。系统研究了Zn掺杂和Ni掺杂对于Ni-CO-Mn-Mg铁氧体结构和磁性能的影响。结果表明：随着Zn掺杂量的增加,铁氧体的晶胞参数、平均粒径和X-ray密度都在增大；随着Ni掺杂量的增加,晶胞参数在减小。磁性能测试结果表明：当Zn掺杂量为0.4时,产物饱和磁化强度Ms最大为55.6 emu.g-1,矫顽力Hc约为40 Oe；Ni掺杂量为0.9时,产物饱和磁化强度Ms为41.0 emu·-1,矫顽力约为62 Oe。通过对比发现,适量的Zn掺杂(0.4)更有利于铁氧体磁性能的改善。采用固相烧结法,从碱熔-水浸预处理的腐泥土型和褐铁矿型红土镍矿混合矿中制备合成了Ni-Co-Mn共掺杂MgFe2O4.系统研究了碱熔-水浸过程中碱熔温度、时间和矿碱比对于杂质元素Si、Al和Cr去除的影响；探究了MTSL/TLL、煅烧温度及杂质SiO2对于制备铁氧体结构和磁性能的影响规律。结果表明：在碱熔温度和时间为550℃和30 min,矿碱质量比为1：1、1：1.25和1：1.5时,分别得到了Si02含量约为5%、3%和2%的预处理混合矿,同时Al2O3和Cr2O3的含量分别从0.65%和0.18%降低到0.43%和0.12%；MTSL/TLL为6：4的预处理混合矿在1000℃煅烧2 h可以制备得到单一尖晶石铁氧体相；随着Si02含量从2%增加到3%,样品的饱和磁化强度从45.4 emu·g-1略微减小到43.0 emu·g-1当SiO2含量继续增加到5%时,饱和磁化强度急剧下降到31.5 emu·g-1;随着尖晶石铁氧体中Si02含量从2%增加到5%,样品的矫顽力从120 Oe减小到75 Oe.针对建立的新型工艺中各元素分布走向及相应综合利用率进行了定量计算。结果表明：腐泥土型和褐铁矿型红土镍矿混合矿处理工艺的金属综合回收率可以达到89.2%、85.4%和99.5%.
[Abstract]:With the shortage of nickel sulfide mineral resources and the increasing demand for nickel, the low grade laterite nickel ore, which accounts for 72% of the world's nickel reserves, will be the main resource of nickel extraction. In this paper, the composition and structure characteristics of the laterite nickel ore are made, and the comprehensive utilization of the nickel ore nickel ore by the acid leaching co precipitation calcination and the alkali melting water immersion solid sintering method is put forward in this paper. A new process for the crystallization of the ferrite is introduced, and the distribution and trend of elements in the laterite deposits at various stages are clarified, and the microcosmic influence mechanism of selective leaching and separation and enrichment on the composition, structure and magnetic properties of spinel ferrite materials is revealed. The new technological process can not only efficiently recover the laterite and nickel ores. The valuable metal elements such as Ni, Co, Mn, Mg, Fe and other valuable metal elements were prepared, and the high added value ferrite magnetic materials were prepared. The high efficiency and comprehensive utilization of the laterite and nickel ore resources were realized. By the hydrothermal acid leaching and hydrothermal coprecipitation calcination method, the Co-Mn-Al Co Doped Nickel ferrites (NiFe2O4) were synthesized from the single clay type laterite nickel ore, and the hydrothermal acid leaching was systematically studied. The effect of hydrothermal reaction temperature and initial hydrochloric acid solution concentration on metal selective leaching and metal molar ratio RFe/Ni spoon, and the separation mechanism of Ni, Co, Mn, Fe metal elements and Mg in solution by hydrothermal coprecipitation method, and the microstructure and magnetic properties of Co Doped Nickel ferrites were discussed. The results show that when the leaching temperature is controlled at 200, the concentration of hydrochloric acid is 2 mol-L-1 and the liquid to solid ratio is 6:1 mL. G-1, the leaching rate of Fe and Ni can be controlled to 17% and 85%, and the molar ratio of Fe to Ni, Co, Mn is about 2 in the leaching solution; the pH value of the acid leaching solution is 7, the hydrothermal temperature is 200, the hydrothermal reaction 2 h, solution Ni, Co, Mn, Fe and Al have coprecipitation reaction to complete the complete separation of Mg ions from the solution: high purity and crystallinity can be obtained by calcining 2 h at 1000 C. The good properties of the spinel Co doped NiFe204. are prepared by the normal pressure acid leaching co precipitation calcination method, and the preparation of Ni-Co-M from the humic and limonite laterite nickel ore is made. N or Mn-Al-Cr Co doped magnesium ferrites (MgFe2O4). The influence of initial hydrochloric acid solution concentration, liquid solid ratio and leaching time on metal leaching in the process of atmospheric acid leaching was systematically studied. The precipitator, pH value of solution, feeding mode of precipitation process and metal ion concentration in the acid leaching process were discussed. The influence mechanism of precipitation, separation and enrichment of ions is studied. The influence mechanism of different precipitants and initial acid concentration on the structure and magnetic properties of single ferrite is studied and revealed. The results show that when the concentration of the initial HCl solution is 2.75 mol. L-1, the liquid to solid ratio is 10 mL. -g-1, the leaching time is 60 min. The leaching rates of Fe, Ni, Co, Mn, Mg are 94.6%, 96.1%, 81.5%, 83.2% and 71.8%, respectively. In the process of precipitation, the pH value of the solution is 11 and 12, respectively, and the reaction time is 30 min and the stirring speed is 300rpm, Ni, Co, Al and Cr. 93%, 92%, 92% and 90% were reached, and the precipitates obtained at the same time could be used to prepare spinel ferrite materials. In the process of calcination, the best MS/L for preparing single spinel ferrite phase was 9:1 and 7:3 G. G-1 respectively, when the calcined temperature and time were 1000 and 2 h, when the ammonia solution and sodium hydroxide solution were used as precipitant. Mn-Al-Cr Co doped MgFe2O4 and Ni-Co=Mn Co doped MgFe204. were prepared by co precipitation calcining method. The spinel ferrite with different Zn doping content and Ni doping content was prepared from the acid leaching solution of soil type and limonite laterite nickel ore respectively. The Zn doping and Ni doping for Ni-CO-Mn-Mg ferrite junction were studied systematically. The effect of structure and magnetic properties shows that with the increase of Zn doping, the cell parameters, average particle size and X-ray density of ferrite are all increasing. With the increase of Ni doping, the cell parameters are reduced. The magnetic energy test results show that when the doping amount of Zn is 0.4, the maximum saturation and magnetization of the product is 55.6 emu.g-1, and the coercive force Hc is about Hc. When the amount of Ni doping is 40 Oe, the saturation magnetization of the product is 41 EMU. -1 and the coercive force is about 62 Oe. by contrast, and a proper amount of Zn doping (0.4) is more beneficial to the improvement of the ferrite magnetic properties. The solid phase sintering method has been used to synthesize Ni-Co-M from the soaking soil type and the limonite nickel ore and nickel ore mixture. N Co doped MgFe2O4. system has studied the effect of alkali melting temperature, time and ore base ratio on the removal of impurity elements Si, Al and Cr during the alkali melt water leaching process. The influence of MTSL/TLL, calcining temperature and impurity SiO2 on the structure and magnetic properties of ferrite was investigated. The results showed that the alkali melting temperature and time were 550 and 30 min, and the mineral alkali content was at the alkali melting temperature and time. When the quantity ratio is 1:1,1:1.25 and 1:1.5, the pretreated mixed ore with Si02 content of 5%, 3% and 2%, respectively, the content of Al2O3 and Cr2O3 decreased from 0.65% and 0.18% to 0.43% and 0.12%, respectively, and the pre treated mixed ore with MTSL/TLL for 6:4 can be prepared by calcining 2 h at 1000 C, and with the Si02 content from 2. % increase to 3%, the saturation magnetization of the sample decreases slightly from 45.4 EMU. G-1 to 43 EMU. G-1 when SiO2 content continues to increase to 5%, the saturation magnetization drops sharply to 31.5 EMU. G-1; with the increase of Si02 content in the spinel ferrite from 2% to 5%, the coercive force of the sample decreases from 120 Oe to 75 Oe. for each element in the new technology established. The results show that the comprehensive recovery of the metal in the mixed ore of the humic and limonite laterite nickel ores can reach 89.2%, 85.4% and 99.5%..

【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TM277;TD98

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