Fourier Transform Infrared Spectroscopic Studies in Flotation

Fourier transform infrared (FTIR) spectroscopy has been extensively employed In flotation research. The work done by the author and co-workers has been reported. A comparison has been made among the different FTIR specfroscopic techniques, e.g. , transmission FTIR spectroscopy, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and attenuated total reflectance (ATR) FTIR spectroscopy. FTIR spectroscopy has been used to study the mechanism of interaction between the collector and the surfaces of different minerals, the mechanism of action of the depressant in improving the selectivity of flotation, and the mechanism of adsorption of the polymeric modifying reagent on mineral surfaces. The interaction between particles in mineral suspension has also been studied by FTIR spectroscopy.     

Interactions between bubble and particles of key minerals of diasporic bauxite through the extended DLVO theory

The flotation of diasporic bauxite is to separate diaspore (valuable mineral) from aluminosilicate minerals (gangue minerals, mainly including kaolinite, illite and pyrophyllite), and the microscopic interaction force between the two types of minerals and air bubbles determines the separation efficiency. In this paper, based on the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, the van der Waals, electrostatic and hydrophobic interaction between particles of the four minerals mentioned above and air bubbles in collectorless solution were calculated first, and then diaspore and kaolinite were taken as examples to analyze the influence of various factors such as electrolyte concentration, mineral particle size, air bubble size, collector type (dodecylamine hydrochloride (DAH) and sodium oleate (NaOL)) and concentration, and pulp pH on the interactions between the particles of valuable mineral and gangue minerals and air bubbles. The results showed that the total extended DLVO interactions between the four minerals and air bubbles were repulsive in most cases in collectorless solution. The increase in electrolyte concentration reduced the interaction force or even changed the direction of the force under certain circumstances. The addition of DAH and NaOL can reduce the adhesion energy barrier of kaolinite-bubble and diaspore-bubble respectively. Each type of minerals exhibited a specific interface interaction response with air bubbles in each collector with different pH values. The research results have theoretical guiding significance for the optimization and directional control of diasporic bauxite flotation conditions.     

Flotation of copper oxide minerals: A reviewOA

Copper oxide minerals are important copper resources, which include malachite, azurite, chrysocolla,cuprite, etc. Flotation is the most widely used method for the enrichment of copper oxide minerals in the mineral processing industry. In this paper, the surface properties of copper oxide minerals and their effects on the mineral flotation behavior are systematically summarized. The flotation methods of copper oxide minerals and the interaction mechanism with reagents are reviewed in detail. Flot...     

聚合物反胶团萃取氨基酸的研究

利用德国BASF公司生产的Pluronic型和PluronicR型两类嵌段聚合物制备聚合反应胶团萃取氨基酸（L－苯丙氨酸和L－异亮氨酸）， 聚合物反胶团对氨基酸的萃取平衡特性，实验表明，聚合物反胶团对氨基酸的萃取平衡时间与纯有机溶剂的物理萃取相比差别很小，溶质在反胶团外壳部分与其内部水池间的平衡分配系数K都普遍较大，另外，当氨基酸水溶液的PH值接近等电点时，反胶团萃取达到最佳效果。通过理论分析得到如下推断，聚合物反胶团对两亲性氨基酸的增溶主要在基外壳部分，很可能是包裹在聚氧丙烯外壳内或缠绕在聚氧丙烯链之间，亲油作用和氢键作用是聚合物反胶团萃取的主要推动力。     

SYNERGISTIC EFFECT OF MINERAL SURFACE CONSTITUENTS IN DEXTRIN ADSORPTION

Abstract:As part of a systematic research on the interaction mechanismbetween polysaccharides and mineral surfaces,we extend the studies ondextrin adsorption to real minerals such as oxides and salt-type minerals,based on previous studies of model systems(surface-modified quartz).Theminerals tested include hematite,rutile,fluorite,calcite,apatite,etc.Itis obseroed that dextrin adsorption on these minerals is strongly pH-depen-dent,with adsorption maxima appearing at pH values around the isoelec-tric points of the minerals,indicating interactions with surface metal hydroxide species.X-ray photoelectron spectroscopy(XPS)measurements re-veal electronic binding energy shifts or Auger parameter changes Of miner-al surface elements after dextrin adsorption,pointing to a chemical mecha-nism of interaction.Furthermore,it is observed that the reaction of miner-als with moderate amounts of fatty acids prior to dextrin addition resultsin an increase in dextrin adsorption,whereas excessive fatty acids do theOpposite     

FLOTATION SEPARATION OF WOLLASTONITE FROM DIOPSIDE

The floatabilities of single mineral samples of wollas-tonite and diopside have been studied with addition, of a cationic collector,dodecyoamine hydrochloride (DDA·HCl) , and,modifiers. A mixture oftwo minerals was successfully separated,when DDA·HCl and tannicacid (as depressant)were used together. The interaction between tannicacid and wollastonite and diopside in the pulp and the adsorption of tannicacid on the surface of the two minerals was studide with the help of ultra-violet (UV) spectroscopy and X-ray photoelectron spectroscopy (XPS) ,re-spectively.     

湖泊沉积物的矿物组成、成因、环境指示及研究进展

湖泊沉积物是不同地质、气候、水文条件下各类碎屑、黏土、自生/生物成因矿物以及有机物质等的综合体。沉积矿物蕴含着丰富区域和全球环境演变信息,如湖水的化学组成、流域构造、气候、水文以及人类活动的相互作用等。相关信息可以赋存在矿物外部微形貌、内部微结构、化学组成、物理和化学性质、同位素组成、谱学特征、成因以及共生组合等方面。因此,湖泊科学的许多关键课题都离不开矿物学,特别是在利用湖泊沉积物进行区域及过去全球变化研究中,深入的机理研究归根到底都要涉及矿物学,如流域化学风化作用、粒度组成、生物壳体化学组成、测年材料的选择等。然而,由于湖泊沉积物中矿物的多源性、复杂性,如何有效提取和解译其中的环境信息,是一项长期困扰研究者的课题,湖泊沉积矿物学的研究往往被许多研究者所忽视,中国的相关研究也较为薄弱。笔者综述了湖泊沉积物中碎屑、黏土、自生/生物矿物的矿物组合、特征、成因在(古)环境反演中的作用及最新研究进展,提出除了继续加强对湖泊沉积物中矿物来源、成因和古环境示踪的深入研究以外,矿物相间的转变及其对湖水和孔隙水组成的响应、一些非晶质或隐晶质及低丰度矿物相在湖泊化学和动力学中的作用也是很有潜力的研究领域,最后提出了研究中存在的一些问题、面对的挑战以及对研究前景的展望。     

The Surface Groups and Active Site of Fibrous Mineral Materials

The exposed and transformed groups of fibrous bruche, wollastonite , chrysotile asbestos, sepiolite , palygorskhe , clinoptilolhe , crocidolhe and diatomaceous earth mineral materials are analyzed by IR spectra after acid and alikali etching, strong mechanical and polarity molecular interaction. The results show the active sites concentrate on the ends in stick mineral materials and on the defect or hole edge in pipe mineral materials. The inside active she of mineral materials plays a main role in small molecular substance. The shape of minerals influence their distribution and density of active she. The strong mechanical impulsion and weak chemical force change the active she feature of minerals, the powder process enables minerals exposed more surface group and more combined types. The surface processing with the small polarity molecular or the brand of middle molecular may produce ionation and new coordinate bond, and change the active properties and level of original mineral materials.     

高岭土剪切絮凝除铁机理的研究

本文对高岭石、赤铁矿－油酸钠体系的物理化学行为进行了研究，借助矿物表面电性及红外光谱的研究结果，通过计算固体微粒间的各种相互作用势能对高岭土剪切絮凝除投机理进行了探讨。     

Effect of quaternary ammonium salts on flotation behavior of aluminosilicate minerals

The electrokinetic properties and flotation of diaspore,kaolinite,pyrophyllite and illite with quaternary ammonium salts collectors were studied.The results of flotation tests show that the collecting ability of quaternary ammonium salts for the four minerals is in the order(from strong to weak)of octadecyl dimethyl benzyl ammonium chloride(ODBA),cetyl trimethyl ammonium bromide(CTAB),dodecyl trimethyl ammonium chloride(DTAC).Under the condition of alkalescence,it is possible to separate the diaspore from the silicate minerals such as kaolinite,illite and pyrophyllite using quaternary ammonium salts as collector.Isoelectric points(IEP)of diaspore,kaolinite,pyrophyllite and illite are pH=6.0,3.4,2.3 and 3.2,respectively.Quaternary ammonium salts can change ζ-potential of the aluminosilicate minerals obviously.The flotation mechanisms were explained by ζ-potential and Fourier transform infrared spectrum(FT-IR)measurements.The results demonstrate that only electrostatic interaction takes place between aluminosilicate     

煤粉中内在矿物对煤焦孔隙结构的影响

用浮沉法从4种煤粉中分选出低密度和中等密度的煤粉,进行岩相分析后分别在马弗炉和滴管炉上制焦,用SEM观察煤焦孔结构,用气体吸附仪测定煤焦比表面积和孔容.结果发现,低密度级别煤粉中壳质组和镜质组含量较高,而中等密度级别煤粉中惰质组含量较高.在马弗炉条件下,内在矿物起着增大煤焦孔隙的作用;在滴管炉条件下,随着煤变质程度降低,内在矿物由对无烟煤煤焦的增大孔隙作用变化到阻碍烟煤煤焦多孔结构形成作用.分析了矿物质与胶质体在不同条件下相互作用机理,解释了矿物对煤焦结构的影响.     

A review of flotation and selective separation of pyrrhotite: A perspective from crystal structures

Pyrrhotite is an associated mineral that exists widely in sulfide ore. The presence of pyrrhotite will affect the recovery of platinum group minerals. Therefore, researchers have paid increasing attention to the flotation separation of pyrrhotite. Pyrrhotite superstructures owning different Fe/S ratios results in various crystal structures, corresponding to different physical, chemical and electronic properties, and consequently different flotation behavior. In the present paper, a comprehensive review is conducted to discuss the influence of crystal structures on the natural floatability, mineral-reagent interaction, surface oxidation and flotation electrochemistry of pyrrhotite. The selective flotation process of pyrrhotite from its associated minerals is also reviewed in this paper. It is hoped that this review can summarize the newly published research results combined with some representative results from the past, to provide a theoretical basis for the study of the flotation mechanism of pyrrhotite and provide a new direction for future research on pyrrhotite.     

Depressing effect of phenoxyl acetic acids on flotation of minerals containing Ca^2＋/Mg^2＋ gangues

Phenoxyl acetic acids were applied to determine their depressing effect on minerals containing Ca2 /Mg2 gangues. Calcite, mixture of calcite and fluorite, and nickel ore were used in the flotation. And the depression mechanism was studied by the determination of contact angle, zeta potential, adsorptive capacity of collector, and IR analysis as well. It is found that 0.1 mmol/L of phenoxyl acetic acid derived from pyrogallol or gallic acid exhibits strong depressing ability on calcite in almost zero yields at pH value of 9.8, and calcite can be depressed in the flotation of calcite/fluorite mixture for approximate 87% yield of fluorite. The flotation result of practical nickel ore containing serpentine indicates that these two depressants may also show better depression performance to serpentine than traditional depressants such as sodium fluosilicate and carboxylmethyl cellulose. Analysis for the depression mechanism reveals that there exists strong chemical interaction between the depressants and minerals.     

驱油用“插层”聚合物表征及其溶液性能

基于X线衍射(XRD)、红外吸收光谱(IR)和透射电镜(TEM)检测技术,分析"插层"聚合物中蒙脱土硅酸盐片层间距、聚合物基体化学组成和蒙脱土结构单元分散状态,利用动态光散射系统(DLS)、描扫电镜(SEM)、布式黏度计和流变仪等检测技术,检测和对比"插层"和"高分"聚合物的分子线团尺寸、分子聚集体形态、增黏性、流变性和黏弹性.结果表明:经过插层剂处理后,蒙脱土硅酸盐片层间距有较大幅度增加,通过原位插层聚合,可形成以聚丙烯酰胺为基体,硅酸盐片层均匀分散的剥离型"插层"聚合物;在聚合物质量浓度相同条件下,与"高分"聚合物溶液相比,"插层"聚合物的增黏性、流变性和黏弹性较优,而与"高分"聚合物不同,随溶剂水矿化度升高,"插层"聚合物分子线团尺寸呈逐渐增大趋势,清水"插层"聚合物溶液中分子线团尺寸比"高分"聚合物的大,这与高矿化度水溶液中硅酸盐片层之间的相互作用和"插层"聚合物在清水溶液中的聚集体形态有关.     

胍基阳离子捕收剂反浮选磷矿的性能与机理分析

为了研究磷矿反浮脱硅过程中,胍基阳离子磷矿捕收剂的作用机理,以N-椰油基-1,3-丙撑二胺、单氰胺、乙酸为原料制得一种阳离子表面活性剂,并用于傅里叶红外光谱仪表征,测试了该药剂与3种矿物作用前后的接触角、Zeta电位、红外光谱,进行了石英、白云石、胶磷矿的纯矿物浮选试验等。结果表明:该合成药剂属胍基阳离子表面活性剂,在广泛pH值范围内,对石英的捕收能力较强,对白云石次之,对胶磷矿较弱;在弱碱性下,对白云石捕收性能有所提高;相较白云石、胶磷矿,该药剂更易与石英产生吸附作用,使矿物表面呈现疏水性;接触角、Zeta电位、红外光谱测试结果说明与3种矿物的吸附主要是物理吸附。试验结果说明该胍基阳离子表面活性剂可以作为磷矿反浮脱硅捕收剂。     

保障矿产资源安全的有效途径探讨

目前我国矿产资源安全面临严峻形势。影响我国矿产资源安全的主要原因有:矿产资源管理体制存在弊端,且管理水平低下;矿产资源价值观念淡薄;自然灾害和人为破坏时有发生等。应通过构筑新的矿产资源管理体系、建立节约型合理消费体系、确定合理的矿产资源商品的价格、建立战略矿产资源储备制度、健全矿产资料法规体系等途径保障矿产资源安全。     

Effects of extracellular polymer substances on aerobic granulation in sequencing batch reactors

The effects of extracellular polymeric substances (EPS) on aerobic granulation in sequencing batch reactors (SBR) were investigated by evaluating the EPS content, and the relationship between EPS composition and surface properties of glucose-fed aerobic granules. The results show that aerobic granular sludge contains more EPS than seed sludge, and it is about 47 mg/gMLSS. Corresponding to the changes of EPS, the surface charge of microorganisms in granules increases from -0.732 to -0.845 meq/gMLSS, whereas the hydrophobicty changes significantly from 48.46% to 73.16%. It is obviously that changes of EPS in sludge alter the negative surface charge and hydrophobicity of microorganisms in granules, enhance the polymeric interaction and promote the aerobic granulation. Moreover, EPS can serve as carbon and energy reserves in granulation, thus the growth between the interior and exterior bacteria is balanced, and the integrality of granules is maintained. SEM observation of the granules exhibits that EPS in granules are ropy; by mixing with bacteria, compact matrix structure can be formed. The distribution of EPS in granules profiles the importance of EPS storage. It can be concluded that EPS play a crucial role in aerobic granulation.     

Comparison of chemical reactivity of bauxite-tailings pre- and post-calcinations and whitening bauxite-tailing

Bauxite-tailings is aluminosilicate wastes and is used in polymer as fillers. But its intrinsic low-whiteness has limited its large-scale application in polymeric materials. Conventional methods for whitening bauxite-tailings were ineffective. A new method, which involved reactions with phosphoric acid and calcinations, was proposed to whiten bauxite-tailings. Two process routes were employed to whiten bauxitetailings, which were pre- and post-reaction calcination. While the process of pre-reaction calcination was able to achieve a whiteness of 87% from bauxite-tailings, it required high-energy post-treatment processes such as washing, milling and drying. The process of post-reaction calcination, on the other hand, resulted in an increase in whiteness of bauxite-tailings from 19% to 73%. This was achieved using 4.5% of added phosphorous, 40% acid concentration, reaction time of 2.5 hours and a calcination temperature of 600 ℃. The resultant did not require any further processing, and was therefore industrially feasible. The whitened tailings consisted of corundum, anatase, and quartz. When compared to calcined tailings, whitened tailings possessed a higher content of amorphous material, the disappearance of red iron minerals, and the emergence of a new phase of AlPO 4.     

导电高分子材料的应用研究

通过对结构型导电高分子材料的研究表明,将结构型导电高分子材料与其他聚合物进行混合,得到了如PAN/聚甲醛(POM),PPY/聚(乙烯接枝磺化苯乙烯)、PPY/聚酰亚胺(PI)等复合型导电高分子材料,从而改善了导电高分子材料的性能及应用范围.     

聚合铁和聚合铝溶液中氢离子的研究

通过对聚合铁和聚合铝溶液中氢离子的有关近似计算，进一步说明了氢离子与铁铝形态、干燥方式等之间的关系，指出了进行聚合铁理论研究时应注意其制备方法、浓度和氢离子的重要性。