离子型稀土矿渗流溶浸行为研究

离子型稀土矿性质复杂,当前所采用的原地溶浸工艺适应性不强、影响因素较多,为揭示离子型稀土矿原地溶浸过程影响机制,探寻溶浸过程优化调控方法,本文以江西龙南足洞风化离子型稀土矿为研究对象,采用室内柱式溶浸法模拟原地溶浸工艺过程,开展离子型稀土矿溶浸过程影响规律研究,考察浸出过程各工艺因素对离子型稀土矿浸出效率的影响以及稀土原矿浸出前后的物质变化。研究结果表明,调控离子型稀土矿浸出过程原矿含水量4%、矿层高度43 mm,浸出剂浓度4%、浸出剂溶液p H值5.0、浸取过程固液比1.0∶0.8、浸取剂流速5 ml·min-1为最佳浸出条件参数,在原矿REO总量为0.078%的情况下,可获得浸出率为92.87%的稀土母液,母液中稀土平均浓度为1.73g·L-1,效果良好。稀土离子在浸出过程中与浸出剂的电解质NH+4发生了离子交换反应,稀土离子被交换浸出,而阳离子电解质NH+4则保留在浸渣中,整个浸出过程未生成其他新的物质,没有改变离子型稀土矿原有的晶型结构,不会影响稀土离子的渗流溶浸,有利于离子型稀土矿的绿色高效提取。     

离子吸附型稀土矿再吸附试验研究

针对离子型稀土矿原地浸矿中的再吸附问题,进行了实验室条件试验,探讨了离子型稀土矿再吸附存在的条件,提出避免离子型稀土矿浸出再吸附的措施。结果表明稀土母液与稀土矿相互接触越充分,再吸附效果就越好;母液稀土离子浓度升高或母液液固比增大,会使稀土矿再吸附量增大;母液中阳离子离子交换能力大于稀土离子,会抑制稀土矿再吸附,交换能力小于稀土离子,会促进稀土矿再吸附;pH值升高再吸附量先增大后减小。同时,为避免浸出过程再吸附,应该选择合适的浸取剂浓度与液固比。     

离子型稀土浸矿过程中渗透性变化规律的试验研究

离子型稀土矿体的渗透性对浸矿工艺和浸矿引起边坡稳定变化具有重要影响,为此,采用室内柱浸试验研究渗流过程离子型稀土渗透性变化规律,通过对比原矿和筛分样的渗透系数变化,探讨了浸矿过程渗透系数的变化机理.研究结果表明:在清水渗流过程中,微颗粒迁移引起渗流稳定时间增长.渗流变化幅度增大,随着水力梯度的增大,流场稳定时间减小.流量变化幅度增加;浸矿过程中,离子吸附和离子交换使渗透系数减小,微颗粒迁移引起渗透系数增加,两种相反的作用同时存在,当水力梯度小于某一临界值时,引起渗透系数变化的主要原因是离子吸附和离子交换,当水力梯度大于某一临界值时,引起渗透系数变化的主要原因是微颗粒迁移,水力梯度增大,微颗粒迁移对渗透系数的变化影响增大;由于原矿级配良好,粒径大小相差悬殊,导致原矿比筛分样流场稳定时间更长.      

某离子型稀土矿浸出试验

以中国南方地区某离子型稀土矿为研究对象,采用搅拌浸出和柱浸的方式,研究不同条件下矿样中稀土及杂质元素的浸出情况,为离子型稀土矿产资源的绿色高效开采提供参考。结果表明,浸出液固比对离子相稀土浸出率影响较大,浸出时间影响较小,离子相稀土浸出过程时间短,反应迅速;柱浸过程中离子相稀土流出速率最快,达到平衡时间短,杂质元素前期浸出浓度高,后续拖尾严重;离子相稀土浸出率随着样品深度的增加不断降低,符合南方离子型稀土成矿规律;硫酸铵浸出过程中铵根离子损失量较大,最低损失率超过11.31%,硫酸根不参与金属离子的交换反应过程,回收率最高可达99.22%。     

浸矿液对离子型稀土矿孔隙影响机制研究

为了研究浸矿液对离子型稀土矿孔隙的影响机制,通过柱浸试验,借助CT扫描图像处理技术及扫描电镜手段,分析了颗粒重配比下稀土矿渗透性,浸出前后矿体孔隙率变化以及颗粒表面微观形貌变化情况,试验结果显示:离子型稀土矿浸出液渗流速率随浸出时间不断下降直至稳定,浸出前后矿体孔隙率呈时空差异性变化,浸出后矿体高度下降了8. 66 mm,孔隙率减小了4. 47%,矿物颗粒表面孔裂隙增大增多并呈贯通趋势。提出并探讨了浸矿液对离子型稀土矿孔隙4种影响机制:颗粒迁移、扩散双电层作用、化学反应作用和压力溶解。分析表明,4种机制的作用结果不同,其中颗粒迁移、扩散双电层作用和压力溶解导致矿体孔隙率减小,而化学反应作用导致矿体孔隙率变大; 4种机制的作用效果室内试验和现场实际不一样,室内试验:颗粒迁移化学反应作用扩散双电层作用压力溶解,现场实际:化学反应作用扩散双电层作用颗粒迁移压力溶解。浸出后矿体孔隙率增大或减小最终取决于矿体自身条件和物理化学综合作用结果。     

一种离子型稀土矿的浸矿方法与系统

正一种离子型稀土矿的浸矿方法,其特征在于,以无氨电解质作为浸矿剂,对矿物进行渗滤浸出,使浸矿剂中的阳离子与被吸附在载体矿物表面上的"离子相"稀土发生交换,形成可溶性的稀土化合物而进入到溶液中。将离子型稀土矿装入浸矿交换柱     

硫酸镁浸出离子型稀土矿动力学研究

为提高硫酸镁作为浸矿剂浸出稀土时的稀土浸出效率,对其浸出动力学进行研究.采用搅拌浸出的方式进行动力学实验,明晰浸出过程动力学控制步骤,并结合Arrhenius方程求取反应的表观活化能及动力学方程,此外,考察了浸出温度、硫酸镁浓度、搅拌速度以及矿石粒径对稀土浸出过程的影响.结果 表明:硫酸镁浸出离子型稀土矿动力学符合未反...     

浸出母液后处理工艺影响稀土回收率和产品质量因素研究

离子型稀土矿浸出母液后处理过程中,除杂会导致部分稀土随同杂质沉淀进入除杂渣、沉淀分离不完全会导致部分稀土仍然以溶液状态残留在沉淀上清液中,造成后处理过程的稀土化学损失;除杂过程杂质离子沉淀不完全或不生成沉淀而仍以离子形态存在于稀土溶液中,沉淀过程除杂后净化母液中的一些残留杂质与稀土离子共同沉淀,会造成沉淀分离后的稀土矿产品含有杂质。本文研究了某火山岩型离子型稀土矿浸出母液后处理过程影响稀土回收率和产品质量的因素,并提出了浸出母液后处理提高稀土回收率和产品质量的措施。     

离子型稀土矿浸出前后工艺矿物学研究

为了研究离子型稀土矿浸出前后的工艺矿物学,以柱浸实验为基础,通过X射线衍射仪(XRD),矿物解离分析仪(MLA),傅利叶交换-红外分析仪(FT-IR), X射线荧光分析仪(XPS),扫描电镜(SEM)等多种测量手段对稀土原矿与浸出尾矿的表面组成和结构进行对比分析。研究结果表明:离子型稀土矿主要由高岭石、钾长石、石英、金云母、褐铁矿等矿物组成,稀土含量仅含0.12%左右;浸出过后Al, RE, Fe, O元素相对含量下降, K, Si元素含量相对上升; Al减少的主要原因是高岭石、褐铁矿、金云母等矿物与浸出剂发生溶解反应造成的,浸出后矿体结构遭到破坏; Fe减少的主要原因是部分氧化铁胶体被溶解以及浸出过后离子型稀土矿中的水合铁离子进入到了溶液中。钾长石、石英等矿物在浸出过程中基本不参与反应;元素N在稀土原矿中主要以有机物的形式存在,浸出后稀土矿中发生了离子交换反应,大量N元素以-NH_2键存在于尾矿中,有机态N大量减少,有机态N的减少会破坏矿体的胶结体结构,使矿体中团聚体的稳定性降低,进而使矿体的整体稳定性下降。Al, Fe等元素随着矿体的部分溶解而进入到溶液中,使浸出液含有杂质。本实验进一步完善了稀土浸出理论,并为稀土浸出以及矿山防护提供了理论依据。     

离子型稀土矿控速淋浸工艺研究

针对离子型稀土矿浸出液固比大，浸出液稀土浓度低，浸出率低，资源浪费十分严重的状况，利用矿石结构疏松，稀土呈阳离子状态吸附在铝硅酸盐类粘土矿物上的特点，通过科学布液和加液的控速淋浸装置，将浸出剂均匀分散在矿石上，强化浸出过程，使离子相稀土得到有效浸出。     

聚乙二醇对风化壳淋积型稀土矿浸出的影响

针对氯化铵作为浸取剂浸取风化壳淋积型稀土时,稀土浸取速率较低和浸出周期长等问题,使用聚乙二醇(PEG)为添加剂,通过柱浸试验模拟工业生产中的原地浸出工艺,探究不同聚合度的聚乙二醇对稀土矿渗透性和稀土浸出的影响。结果表明,聚乙二醇400、聚乙二醇1000和聚乙二醇4000溶液在稀土浸出过程中表现出较好的渗透效果。采用质量分数2.00%的聚乙二醇400、聚乙二醇1000、聚乙二醇4000分别与0.20mol/L的氯化铵复配,复配浸取剂溶液在稀土矿样中的渗透速率随着水力梯度的增大呈线性增大,符合达西定律。PEG400+NH_4Cl、PEG1000+NH_4Cl、PEG4000+NH_4Cl以及NH_4Cl溶液的稀土浸出率分别为82.61%、89.12%、70.67%和88.06%,且当聚乙二醇1000作为助浸剂时,渗流速率最大,渗透效果最佳。添加了聚乙二醇1000的复配浸取剂溶液,在浸取风化壳淋积型稀土矿中稀土的反应过程符合内扩散动力学模型。研究结果对提升复配浸取剂溶液在稀土矿体中的渗流速率有重要意义。     

非离子型表面活性剂对风化壳淋积型稀土矿浸出过程的影响

为了缓解风化壳淋积型稀土矿浸取过程存在的浸取周期长、浸出剂用量大和稀土拖尾等问题,以非离子型表面活性剂为助浸剂,氯化镁为浸出剂,对稀土浸出过程进行研究,研究复配浸出剂溶液性质,分析浸矿前后矿物粒径分布,探讨表面活性剂的促渗机理。研究结果显示,加入表面活性剂后,稀土浸出率提高,渗透速度加快,溶液的表面张力和接触角均减小,黏度增大,矿物颗粒的中值粒径明显减小,矿物表面Zeta电位增大,其中加入吐温40后稀土浸出率提高至86.38%,表面张力减小19.00%,接触角减小53.19%,溶液黏度减小4.29%,溶液性质变化最大。加入表面活性剂后可使溶液更容易润湿矿物,进入孔隙的阻力变小,扩散层厚度减小,黏土矿物的膨胀受到抑制,使得溶液浸出稀土的效果更好,其中吐温40对溶液浸出稀土的渗流效果影响最大,助渗效果最好。     

Recovery of rare earths from ion-absorbed rare earths ore with MgSO4-ascorbic acid compound leaching agent

The magnesium sulfate leaching technology for the ion-absorbed rare earths ore can solve the ammonia pollution problem existing in ammonium sulfate leaching process. However, the leaching capacity of magnesium sulfate is slightly weaker than that of ammonium sulfate, resulting in a bigger consumption of magnesium sulfate. In this paper, the MgSO_4-ascorbic acid compound leaching agent had been demonstrated to deal with the ion-absorbed rare earths ore. The ascorbic acid could form a stable coordination with rare earth ions, so that it can strengthen the leaching of ion-exchangeable phase.Moreover, ascorbic acid has a strong reductive property, it can leach the colloidal sediment phase rare earth as well. The present study investigates the effect of the initial pH and the composition of leaching agent on the rare earth leaching. It is determined that the rare earth leaching efficiency is 107.5% under the condition of pH 2.00,0.15 mol/L magnesium sulfate and 1.0 g/L ascorbic acid in leaching agent. In this case, the content of the ion-exchangeable phase and colloidal sediment phase rare earth in the leaching residues are both only 0.02‰. The leaching efficiency of colloid sediment phase rare earth can be 85.7%,so that the Ce partition in the leaching liquor increases to be 5.77%. The magnesium-ascorbic acid compound leaching agent is proposed to be a promising choice to deal with the ion-absorbed rare earths ore, which can realize the efficient leaching, low consumption of MgSO_4 and environmentally friendly leaching.     

离子型稀土不同浸出剂柱浸对比试验

针对离子型稀土原地浸出工艺现有氨氮污染问题,考察镁盐、铝盐等非铵浸出剂对稀土浸出过程的影响。以赣州稀土矿样为研究对象,选择硫酸镁与硫酸铵通过柱浸的方式进行对比试验,同时考察铝盐与铵盐、镁盐联合浸出效果的影响,测定浸出液成分,分析不同浸出剂浸出效果的差异。结果表明：相同质量分数的硫酸铵和硫酸镁浸出效率相当,硫酸铵可达91.37%,硫酸镁可达89.22%;添加铝盐后的稀土浸出率仅76%左右,铝盐的添加不能促进稀土浸出效率的提升;铵盐柱浸顶水洗涤后铵根离子可降低至76 mg/L,镁盐柱浸顶水洗涤后镁离子可降低至27 mg/L,镁离子比铵根离子更容易洗涤去除。硫酸镁作为浸出剂能够从根本上解决离子型稀土矿山氨氮污染问题。     

Insight into leaching of rare earth and aluminum from ion adsorption type rare earth ore: Adsorption and desorption

Clay minerals are inferred to be the primary host materials for ion-exchangeable rare earth in ion adsorption type rare earth ore(IAREO).During the rare earth leaching process,the adsorption and desorption reactions of the cations controlling the leaching process continue to occur at the clay minerals-leaching agent solution interface.In order to understand the leaching mechanism and behavior of rare earth and co-leached aluminum,adsorption,competitive adsorption,and desorption experiments were ...     

渗流作用下风化壳淋积型稀土矿细观孔隙结构演化特征

为研究风化壳淋积型稀土矿浸出过程中溶液渗流作用对孔隙结构的影响,以去离子水为溶浸液开展浸矿实验。对浸出前后矿样进行显微CT扫描,获取了试样内部结构图像,利用阈值分割算法得到了浸出前后稀土矿样的孔隙结构图像。进而,研究了溶液渗流作用下试样孔隙结构的变化特征,分析了渗流作用对试样孔隙率、孔隙体积、孔隙长度、孔隙宽度和孔隙方位角等参数的影响。结果表明:稀土矿孔隙形状和尺寸在渗流作用下发生显著变化,且在粗细颗粒接触区最为明显;溶液渗流作用使得稀土矿孔隙率增大,孔隙总数量减少,孔隙总体积增大。渗流作用下矿样中小孔隙数量减少,大孔隙数量增多,各尺寸区间的孔隙数量变化率随孔隙尺寸的增大呈现先增大后减小的趋势。溶液渗流作用下孔隙长宽比分布更加集中,孔隙方位角在各角度区间的分布更加均匀,孔隙各向异性增强。      

Reduction leaching of rare earth from ion-adsorption type rare earths ore with ferrous sulfate

The practice of in-situ leaching of the ion-adsorption type rare earths ore with ammonium sulfate could only leach most of rare earth in ion-exchangeable phase,but not the colloidal sediment phase.Therefore,the reduction leaching of rare earth from the ion-adsorption type rare earths ore with ferrous sulfate was innovatively put forward.The soak leaching process and the column leaching process were investigated in the present study.It was determined that ion-exchangeable phase could be released,and part of colloidal sediment phase rare earth could be reduction leached by the cations with reduction properties.The mechanism of reduction leaching was discussed with the Eh-pH diagram of cerium.Moreover,the stronger reduction of reductive ions,the greater acidity of leaching agent solution,and the higher reductive ion concentration,could result in the higher rare earth efficiency and the bigger cerium partition in the leaching liquor.In the ferrous sulfate column leaching process,the rare earth leaching rate and the rare earth efficiency were a little higher than with(NH_4)_2SO_4 agent,and the rare earth efficiency and the partitioning of cerium in leaching liquor could be about 102% and 5.31%,respectively.However,the ferrous sulfate leaching process revealed some problems,so compound leaching with magnesium sulfate and a small amount of ferrous sulfate was proposed to an excellent alternative leaching agent for further studies,which may realize efficiency extraction and be environment-friendly.     

A two-parameter model for ion exchange process of ion-adsorption type rare earth ores

The establishment of a mathematical model for the ion exchange process is key to creating a theoretical basis for the mining of ion-adsorption type rare earth ores. Ore samples from Xinfeng, Xunwu and Anyuan were used as the test ore samples in the present study and equilibrium batch tests of ore sample leaching using various ammonium sulfate concentrations were performed. The results show that, after leaching, there is a negative exponential relationship between the ratio of the solid-phase rare earth ion concentration to the aqueous-phase rare earth ion concentration and the initial ammonium ion concentration. However, there is a linear relationship between the natural logarithm of the ratio of the solid-phase ammonium ion concentration to the aqueous-phase ammonium ion concentration and the initial ammonium ion concentration. Based on the above two functional relationships, a two-parameter model for the equilibrium ion exchange process of ion-adsorption type rare earth ores was established. Using the established model to analyze the test data the model error for the Xunwu ore sample is found to be less than 5%. The proposed model is more accurate compared with the Kerr model. The two-parameter model proposed in this study provides theoretical support for the numerical simulation of column leaching (in-situ leaching) of ion-adsorption type rare earth ores.     

离子吸附型稀土矿除铝技术研究进展

赣南离子吸附型稀土矿富含中、重稀土元素,具有极高的经济价值及重要的战略意义.在对大量文献资料进行查阅及分析的基础上,介绍铝在离子吸附型稀土矿中的赋存形态、浸出行为以及对稀土工业生产的影响,系统地阐述离子吸附型稀土矿浸取过程中除铝技术的研究和实践进展,并对现有技术进行分析总结,提出未来离子吸附型稀土矿除铝技术应向环境友好型发展,并实现除铝产物资源化、商品化.