Influence of copper ions and calcium ions on adsorption of CMC on chlorite

The effects of copper ions and calcium ions on the depression of chlorite using CMC（carboxymethyl cellulose） as a depressant were studied through flotation tests,adsorption measurements,ζ potential tests and co-precipitation experiments.The results show that the electrostatic repulsion between the CMC molecules and the chlorite surfaces hinders the approach of the CMC to the chlorite while the presence of copper ions and calcium ions enhances the adsorption density of CMC.The action mechanisms of these two types of ions are different.Calcium ions can not adsorb onto the mineral surfaces,but they can interact with the CMC molecules,thus reducing the charge of the CMC and enhancing adsorption density.Copper ions can adsorb onto the mineral surfaces,which facilitates the CMC adsorption through acid/base interaction.The enhanced adsorption density is also attributed to the decreased electrostatic repulsion between the CMC and mineral surfaces as copper ions reduce the surface charge of both the mineral surfaces and the CMC molecules.

Chlorite cement and its effect on the reservoir quality of sandstones from the Panyu low-uplift,Pearl River Mouth Basin

Based on porosity and permeability measurements, mercury porosimetry measurements, thin section analyses, SEM observations, X-ray diffraction （XRD） analysis and granulometric analyses, diagenetic features of reservoir sandstones taken from the Zhuhai formation in the Panyu low-uplift of the Pear River Mouth Basin were examined. This study shows that chlorite cements are one of the most important diagenetic features of reservoir sandstones. The precipitation of chlorite was controlled by multiple factors and its development occurred early in eo-diagenesis and continued till Stage A of middle diagenesis. The precipitation of chlorite at the early stage was mainly affected by the sedimentary environment and provenance. Abundant Fe- and Mg-rich materials were supplied during the deposition of distributary channel sediments in the deltaic front setting and mainly in alkaline conditions. With the burial depth increasing, smectite and kaolinite tended to be transformed into chlorite. Smectite cements were completely transformed into chlorite in sandstones of the studied area. Volcanic lithics rich in Fe and Mg materials were dissolved and released Fe2＋ and Mg 2＋ into the pore water. These cations precipitated as chlorite cements in middle diagenesis in an alkaline diagenetic environment. Chlorite coatings acted as porosity and permeability, thus helping preserve cements in the chlorite cemented sandstones. The reservoir quality of chlorite cemented sandstones is much better than sandstones without chlorite cements. Chlorite cements play an important role in the reservoir evolution that was mainly characterized by preserving intergranular porosity and forming better pore-throat structures of sandstones.

Investigation of methane adsorption on chlorite by grand canonical Monte Carlo simulations

In this paper, the methane adsorption behaviours in slit-like chlorite nanopores were investigated using the grand canonical Monte Carlo simulation method, and the influences of the pore sizes, temperatures, water, and compositions on methane adsorption on chlorite were discussed. Our investigation revealed that the isosteric heat of adsorption of methane in slit-like chlorite nanopores decreased with an increase in pore size and was less than 42 kJ/mol, suggesting that methane adsorbed on chlorite through physical adsorption. The methane excess adsorp- tion capacity increased with the increase in the pore size in micropores and decreased with the increase in the pore size in mesopores. The methane excess adsorption capacity in chlorite pores increased with an increase in pressure or decrease in pore size. With an increase in temperature, the isosteric heats of adsorption of methane decreased and the methane adsorption sites on chlorite changed from lower- energy adsorption sites to higher-energy sites, leading to the reduction in the methane excess adsorption capacity. Water molecules in chlorite pores occupied the pore wall in a directional manner, which may be related to the van der Waals and Coulomb force interactions and the hydrogen bonding interaction. It was also found that water molecules existed as aggregates. With increasing water content, the water molecules occupied the adsorption sites and adsorption space of the methane, leading to a reduction in the methane excess adsorption capacity. The excess adsorption capacity of gas on chlorite decreased in the following order： carbon dioxide 〉 methane 〉 nitrogen. If the mole fraction of nitrogen or carbon dioxide in the binary gas mixture increased, the mole fraction of methane decreased, methane adsorption sites changed, and methane adsorption space was reduced, resulting in the decrease in the methane excess adsorption capacity.

Formation mechanisms and sequence response of authigenic grain-coating chlorite: evidence from the Upper Triassic Xujiahe Formation in the southern Sichuan Basin, China

Authigenic grain-coating chlorite is widely distributed in the clastic rocks of many sedimentary basins around the world. These iron minerals were mainly derived from flocculent precipitates formed when rivers flow into the ocean, especially in deltaic environments with high hydrodynamic conditions. At the same time, sandstone sequences with grain-coating chlorites also tend to have relatively high glauconite and pyrite content. EPMA composition analysis shows that glauconites with ‘‘high Al and low Fe’’ content indicate slightly to semi-saline marine environments with weak alkaline and weakly reducing conditions. By analyzing the chlorite-containing sandstone bodies of the southern Sichuan Xujiahe Formation, this study found that chlorite was mainly distributed in sedimentary microfacies, including underwater distributary channels, distributary channels, shallow lake sandstone dams, and mouth bars. Chlorite had a tendency to form in the upper parts of sandstone bodies with signs of increased base level, representing the influence of marine（lacustrine）transgression. This is believed to be influenced by megamonsoons in the Middle and Upper Yangtze Region during the Late Triassic Epoch. During periods of abundant precipitation, river discharges increased and more Fe particulates flowed into the ocean（lake）. In the meantime,increases or decreases in lake level were only affected byprecipitation for short periods of time. The sedimentary environment shifted from weakly oxidizing to weak alkaline, weakly reducing conditions as sea level increased, and Fe-rich minerals as authigenic chlorite and glauconite began to form and deposit.

Origin and controlling factors of chlorite coatings—an example from the reservoir of T_3x Group of the Baojie area,Sichuan Basin,China

The study of the chlorite coatings always attracts scholars in China and other countries because the chlorite coatings play an important role in the preservation of residual primary pores in sandstone reservoirs.At present,the study of the origin and the controlling factors is relatively few.The occurrence,time of formation,genesis,controlling factors,and the mechanism of chlorite coatings inhibiting quartz overgrowths were studied in detail with thin section and SEM analysis.Samples were from the sandstone reservoirs of the T3x Group in the Baojie area,the transitional zone from the middle to the south of Sichuan Basin.The results indicate that the chlorite coatings on the walls of the pore spaces are oriented perpendicular to grain surfaces in the form of isopachous(even-thickness) grain-coating,while the chlorite coatings at the contacts between adjacent detrital grains are arranged with a preferred orientation tangential to the surface of detrital grains.The chlorite coatings were formed in the eogenetic stage.They were formed by recrystallization of Fe-rich clay films during the syndepositional period,and chlorite cements would be recrystallized after the coatings’ formation.The formation of chlorite coatings was mainly controlled by the depositional environment,provenance conditions,and diagenetic environment.The presence of chlorite coatings could result in the preservation of primary pores in deeply buried sandstone reservoirs by effectively inhibiting quartz overgrowths and the development of compaction and pressure solution.

Selective depression action of taurine in flotation separation of specularite and chlorite

Chlorite,as the most representative gangue mineral associated with specularite,of which the separation of these two minerals is difficult.This paper investigated the depression effect of taurine on specularite/chlorite separation via flotation experiments,adsorption tests,contact angle measurements,Zeta potential detection,FT-IR measurements,and XPS analyses.The results of single mineral flotation indicated that chlorite could be depressed selectively by taurine with the recovery of less than 30%,but the floatability of specularite remains high with recovery rate of 81.77%at pH 10.The artificial mixed mineral flotation results confirmed the effectiveness of taurine as a depressant.Surface adsorption,contact angle,and Zeta potential detection revealed taurine primarily adsorbs on the chlorite surface,which hampered the DDA’s subsequent adsorption and results in the chlorite’s poor floatability.The FT-IR spectra and XPS analyses provided further proof that taurine adsorbed on chlorite surface as an electron donor,and part of the electrons transferred from the sulfonic acid group of taurine to metal ions during the adsorption process.In addition,the hydrogen bond between amino-group of taurine and O ions in chlorite surface was also formed in the adsorption process.Finally,optimized adsorption configurations of taurine on chlorite surfaces were proposed.

Effect of solution conditions on depression of chlorite using CMC as depressant

The effect of solution conditions on the depression of chlorite using CMC (carboxymethyl cellulose) as depressant was studied through flotation tests and adsorption measurements. Flotation and adsorption tests were first studied as a function of initial solution conditions. The results show that electrostatic repulsion between CMC molecules and chlorite surface hinders the approach of the CMC molecules to the chlorite surface and CMC adsorbs to a great extent at high ionic concentration (10-4 mol/L ions as opposed to 0 mol/L ions) or low pH (3 as opposed to 9). The enhanced adsorption density is attributed to the decreased electrostatic repulsion between CMC and mineral surface. The solution condition that yielded the lowest initial adsorbed amount (0 mol/L ions, pH 9) was used as a reference to investigate the response of the adsorbed CMC layer to a switch in solution conditions after adsorption. The two kinds of solution switches (reducing the solution pH or increasing ionic concentration) result in an increased depression effect of CMC on chlorite flotation, as a result of conformational change of CMC pre-adsorbed layer. The change in the flotation recovery of the CMC-coated chlorite following the solution switches is reversible.

A novel, simple and sensitive resonance scattering spectral method for the determination of chlorite in water by means of rhodamine B

A new resonance scattering method was proposed for the determination of chlorite, basing on the resonance scattering effect of rhodamine dye. In HCl-sodium acetate buffer solution, chlorite oxidizes 1- into 12 and the reaction of 12 and excess 1- results in If. It is respectively combined with rhodaminc dyes, including rhodamine B （RhB）, butyl rhodamine B （b-RhB）, rhodamine G （RhG） and rhodamine S （RhS）, to form association complex particles, which exhibit stronger resonance scattering （RS） effect at 400 nm. The chlorite concentration of ClO2 in the range of 0.00726-0.218 μg/ml, 0.0102-0.292 μg/ml, 0.00726-0.145 μg/ml and 0.0290- 0.174 μg/ml is respectively linear to the RS intensity of association complex particle systems at 400 nm for the RhB, b-RhB, RhG and RhS. The detection limits of the four systems were respectively 0.00436, 0.00652, 0.00580 and 0.01450μg/ml ClO2^-. In the four systems, the RhB system possesses good stability and high sensitivity. It has been applied to the analysis of chlorite in wastewater with satisfactory results.

Ordinary Toxicity of Chlorine Dioxide and By-products Chlorite and Chlorate in Water

Acute toxicity and accumulated toxicity of chlorine dioxide (ClO2) and by-products chlorite (ClO2-) and chlorate (ClO3-) in water acted on mice are studied by the method of Horn and accumulation coefficient. Subchronic toxicity of the mixture of ClO2 and ClO2-and ClO3- in water acted on rat is studied though feeding test for 90 days, including statistical analysis of variance on weight gaining, food utilization efficiency,index of blood and serum,liver (or kidney) to body weight ratio, and histopathological examination on liver and kidney. The results show that aqueous solution of ClO2, NaClO2 and NaClO3 ( with the concentration of 276.5 mg/L, 200 mg/L and 200 mg/L respectively) and the mixed aqueous solution of ClO2 with the concentration of 553 mg/L are actually non-poisonous , and non-cumulative aqueous solution as well.

Geochemistry and Tectonic Significance of Chlorite Amphibolite in Nanfen BIF, Benxi Area, Northeastern China

Benxi area, Northeastern China, is the main distribution area of Archean BIF-hosted iron deposits in China. In this area, Nanfen iron deposit is well known as the largest open-pit iron deposit not only in China but also in Asia. So far, the tectonic nature during Archean BIF formation period in Benxi area has been long disputed and the tectonic setting of Nanfen BIF had not been found. In this study, the geochemical characters of chlorite amphibolites closely associated with BIF have been investigated for the tectonic environment of Nanfen BIF. Chlortie amphibolites show the geochemical affinity to the back-arc basin basalt (BABB), indicating that the tectonic environment of Nanfen BIF is the back-arc basin. In conjunction with geological evidence of other BIFs at Benxi area, it is identified that BIF in Benxi area might be formed in the subduction-related back-arc basin, which provides a favorable sedimentary environment of Algoma-type BIF.

Antimicrobial Activity of Acidified Sodium Chlorite and Cell Free Culture Supernatent of Lactic Acid Bacteria against <i>Salmonella</i>Typhimurium

Most methods used by food industries to decontaminate eggs involve washing of egg surface with various chemicals. In this study, the effectiveness of two organic decontaminants viz., acidified sodium chlorite (ASC) and cell free culture supernatant (CFCS) of two lactic acid bacteria (Lactobacillus plantarum and Pediococcus cerevisiae) was evaluated for the decontamination of spiked Salmonella Typhimurium on chicken egg shell surface. Acidified sodium chlorite at 100 μl/L concentration with the contact time of 20 min completely inhibited S. Typhimurium on egg shell surface while at 50 μl/L concentration 1 - 2 log10 units reduction was observed in counts of S. Typhimurium as compared to control group. Likewise, CFCS of P. cerevisiae completely inhibited the growth of S. Typhimurium on 30 min contact, whereas L. plantarum and combination of both were revealed significant reduction in the counts of S. Typhimurium counts.

Preparation of porous silica from natural chlorite via selective acid leaching and its application in methylene blue adsorption

In this study,porous silica with high surface area was prepared through selective leaching of thermally activated chlorite in HCl solution.In the process,chlorite was activated by pre-calcining treatment,then activated components(MgO,Al_(2)O_(3),and Fe_(2)O_(3))were selectively leached by acid solution,resulting in the formation of nanopores in situ.The morphology,structure,surface area and pore-size distribution of the material were characterized by XRD,TG/DSC,^(27)Al MAS NMR,SEM,TEM and N2 adsorption−desorption isotherms.The highest specific surface area(SBET=333 m^(2)/g)was obtained by selectively leaching the 600℃ calcined chlorite from 3 mol/L HCl at 90℃ for 2 h.The pore sizes and specific surface areas can be controlled by calcination and leaching conditions.The ^(27)Al MAS NMR spectra of the samples revealed the relationship between structural transformation and the selective acid leaching properties of thermal-activated chlorite,demonstrating that AlVI transfers into AlV when chlorite changes into activated chlorite during thermal activation,and the coordinations of Al has a significant effect on acid solubility of chlorite.The as-prepared porous silica showed favorable adsorption abilities with capacity of 148.79 mg/g for methylene blue at pH of about 7 and temperature of 25℃,indicating its promising potential in adsorption application.

Mineralogical Characteristics and Short-wave Infrared Spectra of Chlorite as Indicators of Hydrothermal Centers: A Case Study of the Giant Porphyry Copper-Molybdenum Deposit at Qulong, Tibet

The Qulong deposit in Tibet is one of the largest porphyry copper-molybdenum deposits in China. We used short-wave infrared(SWIR) spectroscopy to examine the spectral characteristics of the extensively developed chlorite in this deposit. X-ray diffraction and electron microprobe analyses were used for phase identification and to obtain the chemical composition, ion substitution relationships, and formation environment of the chlorite. SWIR spectral parameters were applied to detect the hydrothermal centers. The results indicate that the wavelength of the absorption feature for Qulong chlorite Fe-OH(Pos2250) range from 2240 to 2268.4 nm;the chlorite substitution relationships are dominated by Mg-Fe substitution at the octahedral sites together with Al;-Si substitution at the tetrahedral sites;the chlorite formation temperatures range within the medium-low temperature hydrothermal alteration range from 164 to 281°C, with an average value of 264℃;the wavelength of the chlorite peak position for Fe-OH(2250 nm) absorption and its chemical composition are positively correlated with Al^(Ⅵ), Fe + Al^(Ⅵ), Fe/(Fe + Mg), Fe, and Fe + Al^(Ⅳ)but negatively correlated with Mg and Mg/(Fe + Mg);and the wavelength associated with the chlorite Fe-OH(2250 nm) absorption feature is positively correlated with the temperature at which the chlorite formed. These correlations indicate that more Fe and Al^(Ⅵ) ions and fewer Mg ions at the octahedral sites of chlorite lead to a longer the wavelength of the chlorite Fe-OH(2250 nm) absorption feature and a higher chlorite formation temperature. The wavelength of the Qulong chlorite Fe-OH(2250 nm) absorption feature(>2252 nm) can thus serve as an exploration indicator to guide the detection of hydrothermal centers in porphyry copper deposits. The results of the study indicate that the mineralogical and SWIR spectral characteristics of chlorite are significant indicators for locating hydrothermal centers within porphyry deposits.

新型抑制剂木质素磺酸钙在赤铁矿和绿泥石浮选分离中的应用

绿泥石属于层状含铁硅酸盐脉石矿物,与赤铁矿性质接近难以分离,通过单矿物浮选及人工混合矿浮选、吸附量测试、接触角测量、Zeta电位测试、红外光谱(FTIR)和X射线光电子能谱(XPS)探究了木质素磺酸钙(CLS)作为赤铁矿/绿泥石浮选抑制剂的可行性和产生吸附的主要机制。浮选试验结果证明,在pH=10、CLS用量为60 mg/L情况下能有效选择抑制绿泥石,但对赤铁矿的抑制效果不明显,CLS可作为赤铁矿与绿泥石分离的抑制剂。CLS吸附在绿泥石表面,使绿泥石表面显著亲水,同时阻碍了捕收剂十二胺(DDA)在绿泥石表面的吸附。在浮选过程中,CLS的大量磺酸基团吸附在绿泥石表面,改变了绿泥石的表面环境,Ca离子也吸附在绿泥石表面并促进了反应的进行。

X射线荧光光谱(XRF)法测定绿泥石中镁、铝、硅、磷、钾、钙、钛、铁元素含量

以标准物质及标准物质与基准试剂氧化镁、氧化钙人工混合配制标样的方法建立标准工作曲线,探讨了各元素测定的仪器条件、标准工作曲线的配制方案、理论α系数校正基体效应,建立了用X射线荧光光谱(XRF)法测定绿泥石中镁、铝、硅、磷、钾、钙、钛、铁8种元素含量的快速分析方法。通过熔剂和脱模剂的选取,最终得出最佳熔样条件为采用8.0 g四硼酸锂和偏硼酸锂混合熔剂(质量比67∶33)+0.8 g样品,并添加溴化锂作为脱模剂,熔样温度1100℃,熔样时间10 min。与传统的重量法、容量法、分光光度法相比,X射线荧光光谱法具有能同时测定多种元素,并且具有测量范围广、精密度及准确度高、分析速度快等特点,方法的相对标准偏差(n=12)均小于5.6%,实际绿泥石样品测定结果与化学法一致,硅酸盐标准物质GBW03131滑石、GBW07103花岗岩、GBW07301a水系沉淀物、GBW07309水系沉淀物、GBW07107页岩测定结果均满足不确定度要求。X-射线荧光光谱熔片法成本低、流程短、测定结果可靠,为绿泥石成分检测提供了一种快速的分析方法。

真空紫外活化亚氯酸盐降解酸性红G的机理

采用真空紫外(VUV)活化亚氯酸盐(ClO_(2)^(-)),研究其对偶氮染料酸性红G(ARG)的氧化降解机理,考察不同体系、ClO_(2)^(-)浓度、初始pH值、ARG初始浓度、无机阴离子和印染助剂对ARG降解效能的影响。结果表明:在ARG初始质量浓度为50 mg/L、ClO_(2)^(-)投加浓度为0.4 mmol/L的条件下,反应10 min时,VUV/ClO_(2)^(-)体系中ARG去除率可达98.3%。ARG去除速率随pH值的增大而降低,Cl-会促进ARG氧化分解,HCO_(3)^(-)有微弱的抑制作用,NO_(3)^(-)、SO_(4)^(2-)影响较小,柠檬酸钠和十二烷基苯磺酸钠抑制作用显著。VUV/ClO_(2)^(-)体系中主要氧化物质为·OH、1O_(2)、Cl·和ClO·,ARG降解机理为偶氮键断裂和萘环被破坏。

粤北书楼丘矿床绿泥石成分特征及其指示意义

绿泥石化是诸广南部长江岩体内书楼丘矿床中典型的成矿早期中低温热液蚀变类型。本文利用光学显微镜、电子探针和扫描电镜等手段对矿体外围水平蚀变带内绿泥石进行了综合研究,根据绿泥石的岩相学特征和成因等,将其划分为裂隙充填型绿泥石、黑云母蚀变型绿泥石、长石蚀变型绿泥石、白云母蚀变型绿泥石和球粒状绿泥石5种类型。这5种绿泥石结构类型相同,均为三八面体富铁型绿泥石,分别属于蠕绿泥石、铁镁绿泥石、鲕绿泥石3个种属。5种类型的绿泥石可能形成于成矿早期同一期流体作用之中,形成温度在219~282℃之间,成矿系统的log f_(O2)值为-47.74~-43.69。综合区域上前人研究成果,认为成矿早期流体是以幔源物质为主的壳幔混合流体,其形成与区域上基性岩脉的侵入作用有关,同时,成矿早期流体具有强还原性,为成矿系统提供了还原性化学障,致使主成矿期流体中携带的U6+被还原沉淀成矿。

青礞石治疗癫痫的作用机制及临床应用研究进展

青礞石作为矿物类中药,味甘、咸,性平,归肺、心、肝经,具有坠痰下气、平肝镇惊之功,用于顽痰胶结、咳逆喘急、癫痫发狂、烦躁胸闷、惊风抽搐。研究结果表明,青礞石能够减少海马神经元凋亡,抑制炎症因子过度表达,抑制兴奋性神经递质从而减少大脑异常放电,干预肠道微生态的重建、降低变形菌门的丰富度从而通过“脑肠轴”抑制癫痫样放电。临床研究结果证实,青礞石抗癫痫疗效显著。笔者通过查阅相关文献,探讨了青礞石治疗癫痫的作用机制及临床应用,以期为临床中药新药的研发提供参考。

川西南峨眉山玄武岩中蚀变绿泥石的成分特征及其地质意义

在火山岩和碎屑岩储层中普遍发育大量绿泥石,影响着物性。为查明火山岩中蚀变绿泥石的成因及其对储层物性的影响,本次工作选取川西南峨眉山典型剖面、ZG1井、ZG2井以及YT1井等系列玄武岩样品进行岩相学研究和电子探针微区成分分析。结果显示:玄武岩中绿泥石大致可分为显晶质、隐晶质和微晶3种结晶类型,总体上属于富铁种属的铁斜绿泥石(辉绿泥石)和铁镁绿泥石,形成于富铁的还原环境;隐晶质与微晶和显晶质绿泥石分别受到岩浆期后热液和来自深部的多期次构造热液叠加蚀变的控制,形成主要表现为Fe^(2+)对Mg^(2+)的成分置换,反映流体具有从碱性向弱酸性-中酸性过渡的变化规律。绿泥石的形成过程对火山岩储集空间的影响具有双重作用:岩浆期后热液的充填结晶充填减少了火山岩原生孔隙并降低储层物性,对火山岩储层起到破坏性作用;多期次构造热液的溶蚀迁移沉淀则产生了新的微孔,对火山岩储层起到建设性作用。

亚甲基蓝共振散射光谱法测定地下水中亚氯酸根

在CH3COONa-HCl缓冲溶液中,ClO_(2)-氧化过量的I-生成I3-,I3-与带正电荷的亚甲基蓝在静电引力作用下形成缔合物微粒,使体系的共振散射强度增强,据此建立测定水中痕量NaClO_(2)的共振散射光谱新方法。以提高共振散射强度为目标对该方法的测定条件进行了优化,获得了测定时CH3COONa-HCl缓冲溶液、KI溶液、亚甲基蓝溶液的最佳用量及最佳的反应时间和测定波长。在最佳测定条件下,共振散射强度在ClO_(2)-质量浓度0.0182~0.3640 mg/L范围内随其增大而增强,二者呈现良好的线性关系,检出限为0.0048 mg/L。该方法用于测定地下水中ClO_(2)-的含量时,测定结果的相对标准偏差为1.5%~2.9%,回收率为96%~99%。