微生物技术在低品位铁矿中的应用研究

生物浮选技术(Bioflotation)具有效果好、工艺简单、生产成本低和不污染环境等优点。本研究以新分离的一株芽孢杆菌(Bacillus sp.)为选矿微生物,在研究细菌生长特性和吸附性能基础上,利用多种铁矿石开展浮选试验,为开发新型微生物浮选药剂提供理论基础。结果表明,该菌可吸附于赤铁矿表面,导致矿物形成疏水的团聚物而絮凝,而石英体系中却未观察到明显变化,这一现象是由该菌和不同矿物的表面Zeta电位决定的。生物吸附实验进一步证明该菌对不同矿物的吸附作用不同,赤铁矿对该菌的吸附作用明显大于石英矿物,从显微图中可以看出,该菌大量聚集于赤铁矿周围形成强烈吸附,而在石英体系中,并未观察到明显吸附现象。生物浮选实验表明该菌对四种铁矿都有一定捕收作用,但对鲕状赤铁矿和褐铁矿的效果较小,而对赤铁矿具有较好的生物浮选作用,由此可见,该菌在以石英为主要脉石的赤铁矿中可用作生物捕收剂使用。     

2，4-二羟基苯甲酸对赤铁矿和石英的抑制性能

通过单矿物试验比较了2,4-二羟基苯甲酸对赤铁矿和石英的抑制性能,结果显示,该药剂对石英有较强的的抑制作用,而对赤铁矿的抑制作用弱得多。在矿浆pH=8.4条件下,以30.4 mg/L油酸钠为捕收剂、40.2 mg/L 2,4-二羟基苯甲酸为抑制剂分选赤铁矿与石英的人工混合矿（配比为32）,可取得精矿铁品位64.03%、铁回收率90.66%的分选指标。动电位测试和红外光谱分析结果表明,2,4-二羟基苯甲酸在石英表面发生吸附时,依靠的是氢键作用。     

微细粒级赤铁矿对反浮选的影响

通过现场浮选产品特性分析、人工混合矿浮选试验及显微动态吸附量测定,并借助于SEM及EDS等分析手段,系统研究了微细粒级赤铁矿恶化反浮选指标、造成浮选尾矿铁品位偏高的机制。现场浮选产品特性分析结果表明,浮选尾矿-0.010mm粒级的产率为23.11%、铁矿物的单体解离度为80.43%,金属分布率达31.08%,是导致浮选尾矿品位偏高的主要部分。-0.010mm粒级赤铁矿与不同粒度、不同质量分数石英的人工混合矿浮选试验结果表明,当-0.010mm赤铁矿质量分数为40%时,赤铁矿粒度对浮选指标恶化影响最小。显微动态吸附量测定结果表明,当赤铁矿与石英粒度相近、含量相差很大,或者两者粒度相差很大、赤铁矿含量为40%时,赤铁矿与石英间的吸附较小,对反浮选的影响较小。     

十二烷基磺酸钠浮选赤铁矿的研究

研究了十二烷基磺酸钠(SDS)作捕收剂的时,赤铁矿的可浮性。考察了pH值、钙离子、氟化物和六偏磷酸钠对赤铁矿浮选的影响。研究结果表明:当SDS做捕收剂时,赤铁矿浮选的最佳pH=3～4,加入氟化钠有利于浮选。而钙离子、六偏磷酸钠对赤铁矿浮选起到抑制作用。氟硅酸钠对浮选有一定的效果。红外光谱分析显示,SDS的捕收作用是静电力吸附。     

六偏磷酸钠在磷矿浮选中的应用及作用机理

磷矿石是磷化工生产的重要原料,在国民经济的发展中占有重要地位。磷矿石入选品位的降低、有用矿物与脉石矿物性质相似、矿物嵌布粒度过细等不利因素影响着磷矿选矿技术的发展。通过研究药剂与矿物之间的相互作用机理有助于改善矿物的选别效果,综述了磷矿石的重要性和浮选现状,着重研究了六偏磷酸钠在中低品位磷矿石浮选中的应用及作用机理。研究发现六偏磷酸钠在磷矿石浮选中有两个主要作用:一是六偏磷酸钠的加入会与捕收剂在磷灰石矿物表面形成竞争吸附,抑制捕收剂在磷灰石矿物表面的吸附,从而改变矿物的亲疏水性;二是六偏磷酸钠的加入会引起矿物表面电荷发生改变,使得矿物颗粒间相互作用力随之发生改变,增加矿物颗粒的分散性,从而优化矿物浮选条件。      

用阳离子型捕收剂DYP反浮选铁矿物

采用脂肪酸类阴离子捕收剂反浮选铁矿物,需要通过加温矿浆来保证其捕收性,不仅造成了能源的大量消耗,而且会对环境造成危害,为此东北大学研发了新型常温阳离子捕收剂DYP。为了研究其对铁矿物反浮选的分选效果,进行了石英、赤铁矿、磁铁矿单矿物及人工混合矿的浮选试验。结果显示：在捕收剂DYP体系中,3种单矿物的可浮性由强到弱依次为石英>赤铁矿>磁铁矿;DYP的用量为50 mg/L时,石英的回收率达到了97.33%,而赤铁矿和磁铁矿的回收率分别为6.50%、4.33%,说明捕收剂DYP具有很好的选择性,适合铁矿物反浮选。对捕收剂DYP在溶液中化学平衡、DYP对石英表面动电位及可浮性影响的分析表明,DYP对石英的捕收作用是静电吸附和氢键吸附协同作用的结果,且氢键作用强于静电吸附。     

Gemini型捕收剂对石英和磁铁矿的浮选性能

通过单矿物浮选试验,考察了Gemini型捕收剂Gemini-31503和十二胺对石英和磁铁矿的浮选特性,结果表明,Gemini-31503在较宽的pH范围里对石英具有很强的捕收能力,并且对石英具有良好的选择性,其性能明显优于十二胺。用Gemini-31503对石英和磁铁矿的人工混合矿进行反浮选,在不需再添加其他任何药剂的情况下取得了良好的分选指标。动电位测定和红外光谱分析结果显示,Gemini-31503在两种矿物表面的吸附主要为静电吸附,且在相同条件下,Gemini-31503在石英表面的吸附量比在磁铁矿表面的吸附量大。     

Interaction mechanism of miscible DDA–Kerosene and fine quartz and its effect on the reverse flotation of magnetic separation concentrate

In this study, a modification of oil assisted flotation processes of quartz particles has been proposed, which is based on introduction of miscible Dodecylamine (DDA)-Kerosene as collector with DDA cationic surfactant coated on kerosene to the hydrophilic quartz particles in the pulp. The property of miscible DDA–Kerosene emulsion was investigated. Due to the adsorption of DDA at kerosene/water interface, a smaller and uniform kerosene emulsion formed. Addition of cationic surfactant to the kerosene emulsion changed the zeta potential value from negative to positive, which resulted in enhancing the adhesion of the oil droplets to negatively charged quartz. The results showed that agglomeration and flotation process can be realized simultaneously with DDA–Kerosene. The agglomeration of fine quartz minerals in the presence of miscible DDA–Kerosene led to the formation of very large compact agglomerates resulting in increasing hydrophobicity of the particles and inducing a higher probability of collision and adhesion to air bubble. Experimental data indicated that miscible DDA–Kerosene had better selectivity and stronger collectability to quartz than DDA–HCl, which can be used as an efficient collector in the reverse flotation of magnetic separation concentrate of TISCO. At the same DDA dosage (60 g/t), separation efficiency got to 18.53% when using DDA–HCl as collector; while a better result was obtained with DDA–Kerosene, the efficiency of separation reached 59.07% which was identical with 120 g/t DDA–HCl.     

Influence of bromine modification on collecting property of lauric acid

Bromine atom with strong electronegativity was introduced to α-carbon position of lauric acid (LA) by solvent-free method (Hell–Volhard–Zelinski reaction) at ambient pressure in laboratory, and the synthesized product α-Bromolauric acid (CH₃(CH₂)₉CHBrCOOH, α-BLA) was used as a new type collector for the flotation of quartz mineral. The flotation properties of pure quartz using α-BLA as a collector were investigated by single mineral flotation tests. The adsorption mechanism of α-BLA collector on quartz surface was established by zeta potential measurements, Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS), in conjunction with the results of quartz micro-flotation tests. Pure mineral flotation results showed that the collector α-BLA exhibited an excellent performance at alkaline conditions (pH ⩾ 11.50), activator CaCl₂ concentration 1.0 × 10⁻⁴ mol/L, and collector concentration 1.5 × 10⁻⁴ mol/L in a relatively lower temperature 15 °C, where about 99.8% of the quartz could be floated out. Compared with collector LA, the new synthesized collector α-BLA is more tolerant to lower pulp temperature and fluctuations of the reagents dosages. The study revealed that the α-BLA collector had adsorbed on the surface of pure quartz in the forms of chemical interaction, electrostatic adsorption and hydrogen bonding adsorption based on the results of zeta potential measurements, FT-IR spectra, and XPS.     

N,N-二羟乙基十二胺对赤铁矿和石英的浮选性能研究

以赤铁矿反浮选脱硅体系为载体,通过单矿物浮选试验和人工混合矿分选试验考察了N,N-二羟乙基十二胺对赤铁矿和石英浮选行为的影响。单矿物浮选试验结果表明,N,N-二羟乙基十二胺对石英具有很好的捕收能力,在矿浆自然pH、N,N-二羟乙基十二胺用量大于13.33 mg/L时,石英回收率保持在90%以上;N,N-二羟乙基十二胺对赤铁矿的捕收能力较弱,在考察的捕收剂用量范围内,赤铁矿回收率不超过70%。人工混合矿分选结果表明,在矿浆自然pH、N,N-二羟乙基十二胺用量为20 mg/L、淀粉用量为3.33 mg/L条件下,可获得精矿铁回收率为86.86%、铁品位为65.28%的分选指标;N,N-二羟乙基十二胺可应用于石英和赤铁矿矿物的浮选分离。动电位测试结果表明,N,N-二羟乙基十二胺在石英表面发生了静电吸附。     

Preparation and performance of 4-alkyl-4,4-bis(hydroxycarbamoyl) carboxylic acid for flotation separation of diaspore against aluminosilicates

The existed collector for the flotation of diasporic bauxite in China is poor in selectivity. To look for a collector with high selectivity and strong collecting capacity on the diaspore flotation, novel 4-alkyl-4,4-bis(hydroxycarbamoyl) carboxylic acids (ABHC) including 4,4-bis(hydroxycarbamoyl) dodecanoic acid (HCDA), 4,4-bis(hydroxycarbamoyl) tetradecanoic acid (HCTA), and 4,4-bis(hydroxycarbamoyl) hexadecanoic acid (HCHA) were designed and synthesized for the beneficiation of diasporic bauxite by selective flotation. The results of flotation experiments for the single minerals showed that by using these compounds as collectors, the pulp pH value has significant influence on their collecting performance as the floatability of diaspore varies sharply with its change. The appropriate pH value for the flotation of diaspore gets close to neutral condition at which diaspore presents good floatability while kaolinite and illite exhibit poor floatabilities. HCDA, HCTA, and HCHA, especially HCDA, show good selectivity for the flotation between diaspore and aluminosilicate around pH 7. A satisfactory mass ratio of Al₂O₃ to SiO₂ (A/S) and recovery of Al₂O₃ were obtained from the flotation separation of artificially mixed minerals and the flotation desilication of diasporic bauxite by using HCDA as a collector, proving that the selectivity of HCDA is better than that of the traditional collector oleate. Moreover, adsorption amount, zeta-potential, DFT calculation, XPS, and FTIR were performed to study the mechanisms. The results indicated that the adsorption of HCDA on the surface of diaspore is dominantly chemisorption in the form of three chelate rings. The oxygen atoms contained in carboxyl and hydroxycarbamoyl of the polar group have the highly negative charges and stereo conditions to form five- to eight-membered ring, resulting in the coordination of carboxyl and hydroxycarbamoyl to the metal aluminum atoms to form chelate rings. By contrast, the adsorption of HCDA on the surface of kaolinite or illite is mainly physical adsorption.     

细粒赤铁矿对淀粉与石英吸附特性影响及机理研究

通过不同粒度赤铁矿、石英单矿物及两者混合矿与淀粉抑制剂的吸附作用试验,结合FT-IR、AMF检测分析及表征,旨在分析细粒赤铁矿对石英与淀粉作用影响,为鞍山式细粒赤铁矿浮选过程的优化提供理论指导。试验结果表明:当吸附温度为35℃、矿浆p H值为11.5、淀粉浓度为3 g/L、吸附时间为5 min时,淀粉与赤铁矿、石英作用差异最大;随着淀粉浓度的增加,-0.037 mm粒级的细粒赤铁矿与其吸附作用强度明显增强;淀粉在赤铁矿表面发生了以范德华力为主的多分子层物理吸附,在石英表面的发生了多分子层的物理吸附,且存在吸附滞后现象。-0.045 mm的细颗粒赤铁矿含量为34.6%～88.4%时会削弱淀粉的抑制作用,导致铁精矿进入尾矿,降低浮选指标。     

新型常温捕收剂DX-1对石英的浮选性能研究及机理分析

为解决赤铁矿阴离子反浮选脱硅过程中矿浆加热引起的能耗高等问题, 以月桂酸和液溴为原料, 采用催化加成法合成了一种新型常温阴离子捕收剂DX-1。通过石英单矿物浮选试验、石英和赤铁矿的人工混合矿浮选试验, 考察了DX-1的捕收性能, 试验结果表明:在常温条件下, DX-1对石英的捕收能力较强, 当pH=11.5时, 石英单矿物浮选试验可以取得石英回收率99.49%的指标, 人工混合矿浮选试验可得到精矿TFe品位65.91%、回收率98%的选别指标。并通过红外光谱及动电位等测试分析方法探讨了其作用机理, 结果表明:捕收剂DX-1与石英表面主要发生了化学吸附, 除此以外可能还存在静电吸附。这说明DX-1是一种可用于铁矿反浮选的新型高效常温阴离子捕收剂。      

Amine flotation of fine quartz and glass beads

The effect of pH on the n-dodecylamine flotation of −20 μm quartz and glass beads was studied. A microflotation cell suitable for use with very fine particles was used in the flotation experimentation. The amount of agglomeration of particles at different pH values was compared using 80% passing sizes (P₈₀) estimated from size distribution data.Results obtained show that in such flotation systems agglomerates, instead of individual particles, are generally present and floated. The presence and flotation of agglomerates suggests that low recoveries in very fine particle systems may have little to do with single particle — bubble contact, but rather are related to other problems associated with such systems.     

某新型脂肪羧酸类捕收剂的浮选性能试验研究

通过药剂结构修饰,制备了一种新型脂肪羧酸类捕收剂CM-5。在pH调整剂、淀粉、CaCl₂、CM-5或油酸钠的浮选体系下进行了石英、绿泥石、赤铁矿单矿物浮选试验。结果表明:高碱条件下,相对于油酸钠,CM-5对经淀粉、CaCl₂作用后的绿泥石具有更好的选择捕收作用,对同条件下的赤铁矿捕收效果较弱。温度试验表明,CM-5在15~35 ℃的范围内都具有良好的选择性捕收效率。Zeta电位测定结果表明,在pH=11.5条件下,CM-5的吸附使经淀粉、CaCl₂作用后的绿泥石、赤铁矿动电位分别下降约15、10 mV,而油酸钠的吸附使同条件下的绿泥石、赤铁矿动电位分别下降8、11 mV,说明CM-5能选择性地吸附到绿泥石上。综合分析,CM-5可作为一种高效的铁矿反浮选捕收剂。      

四种阳离子捕收剂对赤铁矿和石英浮选行为的影响

以赤铁矿和石英为试验原料,探究了十二胺、十二烷基三甲基氯化铵、GE-609与N-十二烷基乙二胺四种阳离子捕收剂对两种矿物浮选行为的影响。结果表明,四种阳离子捕收剂对石英和赤铁矿均有一定的捕收作用,且对石英的捕收能力均强于赤铁矿;在四种捕收剂体系中,淀粉对赤铁矿均有明显的抑制作用,对于石英,淀粉除在N-十二烷基乙二胺体系中对石英一定抑制作用外,在其他三种捕收剂体系中淀粉对石英浮选影响较小。混合矿浮选试验表明,与十二胺和N-十二烷基乙二胺相比,十二烷基三甲基氯化铵和GE-609作为捕收剂时,精矿Fe品位和Fe回收率指标相对较优,与单矿物浮选结果一致。      

一种高效的脱硅浮选捕收剂

系统地研究了Ｎ－烷基－β氨基丙酸甲酯（ＳＦ８）的结构与性能，对其紫外光谱特性，等电点，表面一及起泡性能进行了检测，浮选试验结果表明，在自然ＰＨ条件下，ＳＦ６对石英和石榴子石具有较镪捕收能力，而对萤石和赤铁矿捕收能力很弱；对萤石－石英－石榴子石及郝铁矿－我工混膈矿进行浮选分离，获得满意结果，表明ＳＦ６是一咱高选择的性的脱硅硅浮选捕收剂，机理研究表明，ＳＦ６在硅酸盐矿物表面的吸附，是以静电力为主并附有     

偕氨肟捕收剂对石英和磁铁矿的浮选性能

采用羟胺法合成了3-十二烷基氨基丙偕氨肟（简称DAPA）作为铁矿反浮选捕收剂。通过单矿物浮选试验,考察了DAPA和十二胺对石英和磁铁矿的浮选特性,结果表明,在矿浆pH为4~6.5的条件下,DAPA捕收剂对石英的回收率可达到85%以上,同时在此条件下对磁铁矿的回收率均不超过20%,选择性能明显优于十二胺。用DAPA对石英和磁铁矿的人工混合矿进行反浮选,在不添加抑制剂的情况下,浮选精矿中TFe品位可达68.78%,可以应用于磁铁矿的脱硅浮选中。Zeta电位测试和红外光谱分析结果显示,DAPA在石英和磁铁矿表面的吸附主要为物理吸附。      

十二烷基胺类捕收剂的取代基基因特性对其浮选性能的影响研究

为考察取代基种类和数量对十二烷基胺类阳离子捕收剂浮选性能的影响，通过浮选试验研究了含不同取代基的捕收剂对石英、赤铁矿单矿物的捕收性能，以及对石英/赤铁矿人工混合矿的分选能力。研究结果表明，甲基取代基的引入不利于阳离子捕收剂对石英和赤铁矿的捕收，随着甲基取代基数量的增加，石英和赤铁矿的浮选回收率均逐渐降低，但赤铁矿回收率降低速率更快；甲基的引入，有助于提升阳离子捕收剂的浮选选择性；随着取代基数量的增加，人工混合矿的分选效率逐渐增大。向阳离子捕收剂分子结构中引入含羟基（-OH）或胺基（-NH2）的官能团有利于其对石英的捕收，但引入含胺基的取代基以后，赤铁矿回收率也相应提高；向十二胺极性基中引入含羟基或胺基的取代基，能够提高人工混合矿分选效率，但引入含胺基的取代基后，人工混合矿分选效率增加效果不如引入含羟基取代基时明显。对试验捕收剂分子进行量子化学计算表明：随着引入甲基数量的增加，捕收剂极性基团的横截面尺寸增加，增大了药剂与矿物表面作用的空间位阻，导致药剂的捕收能力减弱，选择性增强；含胺基取代基的引入，可以增加极性基团的总电荷量，捕收剂与矿物表面的静电引力增强；引入含羟基的取代基后，能够在增强药剂与矿物表面氢键吸附作用的同时，增加药剂极性基横截面尺寸，从而在提高药剂捕收能力的同时提高了浮选选择性。在后续研究中，结合有机化学的相关知识来提取取代基的相关参数，以定量这种影响规律，从而明确取代基参数与阳离子捕收剂浮选性能之间的基因特性，可为构建一种基于取代基效应的阳离子捕收剂设计方法奠定基础。     

十二胺与十二烷基磺酸钠组合捕收剂对赤铁矿浮选的优化及其泡沫性能调控北大核心

采用十二胺进行微细粒级赤铁矿反浮选时具有泡沫产品黏、难消泡的问题。选取赤铁矿和石英两种纯矿物,分别在十二胺(DDA)以及十二胺与十二烷基磺酸钠(SDS)的组合捕收剂体系下,研究了pH值、捕收剂用量及其配比、淀粉用量等对赤铁矿和石英单矿物和混合矿浮选的影响,并进行了泡沫稳定性试验。研究表明,不加入矿物颗粒时,十二胺溶液的气泡平均尺寸小于组合捕收剂(DDA∶SDS=2∶1)的气泡平均尺寸;采用十二胺作捕收剂浮选赤铁矿和石英时,泡沫量更多,气泡小且密集,气泡破裂速度较慢,泡沫更黏更稳定。与单一十二胺捕收剂相比,十二胺和十二烷基磺酸钠组合捕收剂在浮选指标和泡沫性能均体现出了优势。在适宜的药剂制度条件下,十二胺与十二烷基磺酸钠在一定比例条件下组合使用,不仅能够提高浮选指标,还能优化泡沫性能,大幅度降低泡沫黏性。研究对克服阳离子浮选工艺存在的泡沫问题和微细粒级赤铁矿石的浮选具有一定的参考价值。