Purification of specularite by centrifugation instead of flotation to produce iron oxide red pigment

This study used specularite, a high-gradient magnetic separation concentrate, as a raw material in reverse flotation.An iron concentrate with a grade of 65.1 wt% and a recovery rate of 75.31% were obtained.A centrifugal concentrator served as the deep purification equipment for the preparation of iron oxide red pigments, and its optimal rotating drum speed, feed concentration, and other conditions were determined.Under optimal conditions, a high-purity iron oxide concentrate with a grade of 69.38 wt% and a recovery rate of 80.89% were obtained and used as a raw material for preparing iron oxide red pigment.Calcining with sulfuric acid produced iron red pigments with different hues.Simultaneously, middlings with a grade of 60.20 wt% and a recovery rate of 17.51% were obtained and could be used in blast furnace ironmaking.High-value utilization of specularite beneficiation products was thus achieved.

Research and Development of Cadmium Sulphoselenide Red Pigment

Cadmium sulphoselenide was synthesized continuous substitution solid solution and the only known pigment to yield bright red color on ceramic decoration. Encapsulated cadmium sulphoselenide pigments could yield abundant hues from yellow to red with high opacity at high temperature. The color generation has a linear function relation with the substitution rate. The encapsulation formation process of zirconium silicate encapsulated cadmium sulphoselenide was shown. Insuffi cient encapsulation effi ciency and potential hazard to human and environment had limited the industrial application of cadmium sulphoselenide red pigment. Ink-jet printing decoration required fi ne size cadmium sulphoselenide red pigment on ceramic decoration. The review mainly focused on the synthesis techniques and industrial application of cadmium sulphoselenide red pigment.

Preparation of SiO_2 coated Ce_2S_3 red pigment with improved thermal stability

SiO2 coated Ce2S3 red pigment was prepared in ethanol/H2O system via sol-gel method and TEOS were used as silica sources. X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDX）, UV-visible spectro-photometer and automatic colorimeter were used to investigate the properties of the samples. The results showed that the compact SiO2 film formed on the surface of Ce2S3 pigment at a cerium silicon molar ratio of 2. The thermal stability temperature of Ce2S3 pigment was improved to 450 oC after SiO2 coating. In addition, the color of Ce2S3 pigment was not affected significantly through coating colorless and transparent SiO2 and it could be used as safe red pigment in higher temperature fields.

Novel environmentally friendly inorganic red pigments based on calcium bismuth oxides

Novel environmentally friendly inorganic red pigments based on calcium bismuth oxide Ca3(Bi1-xREx)8O15(0≤x≤0.09;RE=Sc^(3+),Er^(3+),Y^(3+),Ho^(3+)and Dy^(3+)),were successfully synthesized and the color properties were characterized.The color of these pigments depended on the composition and the synthesis condition,and the most vivid red color was obtained for the Ca3(Bi0.93Y0.07)8O15 sample calcined thrice at 800℃for 2 h.The L*and a*values corresponding to brightness and red chromaticity for this pigment were 45.6 and+30.6,respectively,which were greater than those of a commercially available Fe2O3 pigment(L^(*)=38.4,a^(*)=+29.5).Since the present pigment is composed of nontoxic and safe elements,it should be an attractive alternative to the conventional Fe2O3 pigment.

Effect of Sr^2+ and Dy^3+ co-doping on coloration and temperature stabilization of a γ-Ce2S3 red pigment

In this paper,a Sr^2+and Dy^3+co-doped γ-Ce2S3 red pigment was synthesized via a combination of coprecipitation and sulfurization processes.Mixed oxide was prepared by presintering the coprecipitates,(Ce,Sr,Dy)CO3,followed by high-temperature sulfurization under a CS2 atmosphere.The effects of the sulfurization temperature,time,and doped proportion on the phase composition,color performance and temperature stability of γ-Ce2S3 were systematically studied.The results show that a stable γ-Ce2S3 red pigment can be obtained through Sr^2+and Dy^3+co-doping at 730℃ for 200 min.The diffraction peaks of all the samples shift to higher 2θ values with increasing doping proportion,indicating that part of the Dy^3+species enter the lattice and form a solid solution.The band gap of the samples remains practically constant at 2.01-2.04 eV,which causes their red color.The best red-color quality(L*=37.13,a*=34.77,b*=29.44) is achieved when the pigment has a Dy^3+/Ce^3+molar ratio of 0.15,and the material maintains its excellent red color(L*=31.49 a*=30.94 b*=25.33) after being heated at 410℃ for 30 min.

Determination and thermal stability experiments of red pigment from large-scale silver deposit hosted in the Sinian strata in South China and their significance

Over the past years a kind of red organic pigment was found in various strata in Chi-na. Recently, the authors have discovered the similar red pigment in a large-scale sil-ver deposit hosted in the Sinian black shale, and confirmed that the pigment is an

Preparation of Cr-Doped YAlO3 Red Ceramic Pigment and the Coloration Mechanism

The red ceramic pigment is widely used in industrial production, but the pigments with pure color and bright red performance are rare. Therefore, it is important to study and develop new red ceramic pigment with perfect color performance. This paper reports the preparation of Cr-doped YAlO_3 red ceramic pigment rendering by sol-gel method with high temperature resistance, good color and proposed color mechanism. The prepared samples were characterized by XRD, SEM, EDS and UV-vis, and the effects of Cr on the crystal structure, color rendering properties and color mechanism were discussed. The results showed that the optimum concentration of coloring agent（Cr） in Cr：YAlO_3 red ceramic pigment was 3 at.%. The main color mechanism was also discussed. Compared with the solid phase sintering and precipitation methods for the synthesis of red ceramic pigment, the sol-gel method possessed obvious advantages, such as perfect mixing of the raw materials, uniform dispersion of doping ions and the pure color.

High-Efficiency Synthesis and Properties of Latent Pigment Red 272DPP-BOC by Microwave Irradiation

A high-efficiency synthesis method for a latent pigment of red pigment diketo-pyrrolo-pyrrole (Pig. Red 272:272DPP), which is important as a functional organic pigment, was investigated, and the investigation results revealed that irradiation of microwaves (MWs) for several seconds to 272 DPP in NMP (N-methyl-2-pyrrolidone) solvent yielded DPP latent pigment (272DPP-BOC) at a high yield of 86.2%. Two kinds of latent-pigment crystals, namely, red and yellow, were obtained by recrystallization, and it was found that the fluorescence-emission properties of the two kinds differ significantly. Single-crystal X-ray structural analysis showed that the difference in the fluorescence-emission properties of the two types is derived from the difference in their crystal structures.

前体物和诱导剂对红曲霉液态发酵产红曲红色素的影响

为了提高红曲霉(Monascus)GN01液态发酵产红曲红色素(MRPs)的产量,文章采用单因素实验法考察前体物和诱导剂的种类,以及添加量对红曲霉产MRPs的产量的影响。研究结果表明,前体物和诱导剂都有利于促进MRPs的产生,但促进程度存在一定的差异。作为前体物,CH3COONH(41 g/L)和CH3COOK(3 g/L)的处理分别将MRPs的产量提升了2.96倍和1.54倍;作为诱导剂,ZnSO(40.2 g/L)和曲拉通X-100(7%v/v)的处理分别将MRPs的产量提升了6倍和3倍,但曲拉通X-100的处理不利于红曲霉的生长。因此,CH3COONH4(1 g/L)和ZnSO(40.2 g/L)的处理更有助于进一步提高MRPs的产量。

Study on the Stability of Pigment in Red Pulp Plum

The stability was studied of the pigment in red pulp plum (Prunus salicina Lindl). The results showed that the pigment had a high resistance to heat and it′s stability seemed to be affected greatly by pH, and red pulp plum was suitable to be applied for making acid food. Several kinds of metallic ions including Na + 、Zn 2+ had an effect of reinforcement on its tone, however Fe 3+ had a disruptive effect. Sucrose had no undesirable effect, but vitamin C had a significant undesirable effect. Also the preservative of sodium benzoate had a definite undesirable effect. The pigment showed strong resistance to reducer sodium sulfite but was very weak in resistance to oxidizer hydrogen peroxide.

改性蚕丝织物的胭脂虫红染色工艺探析

为使胭脂虫红上染蚕丝织物效果好,采用壳聚糖季铵盐(HACC)对蚕丝织物改性后,用胭脂虫红色素直接染色,探讨改性工艺。研究表明,最佳改性工艺条件为改性温度70℃,改性时间40 min,pH=5,HACC质量浓度4%。胭脂虫红对改性蚕丝织物进行直接染色,得出优化的染色工艺条件为染色温度80℃,染色时间40min,pH=7,染液质量浓度6%。在最佳的工艺条件下,对未改性及改性蚕丝织物进行直接染色和后媒染,用环保的氯化镧稀土为媒染剂,对染色织物的染色性能、色牢度进行测试。结果表明,HACC改性试样经过后媒染法染色,其染色性能、色牢度最好,对生态染整技术发展提供积极的意义。

索氏抽提法制备裂果枣红色素及其理化性质分析

以裂果枣粉为原料,采用索氏抽提法对裂果枣红色素进行提取,分别采用单因素试验和响应面试验进行提取条件的优化,并对裂果红枣色素进行理化性质研究(抗氧化活性及色素稳定性)。结果表明:索氏抽提法提取最佳条件为裂果枣粉添加量2.0 g/100 mL、乙醇体积分数69%、加热温度89℃、浸提时间26 min、抽提时间1.5 h,裂果枣红色素提取率4.540 mg/g,裂果枣红色素提取率较高。通过研究裂果枣红色素对DPPH自由基,·NO_(2)^(-)和ABTS+自由基的清除能力,结果显示裂果枣红色素浓度达到1.2 mg/mL时,DPPH自由基清除率可达67.8%,当裂果枣红色素浓度达到2.0 mg/mL时,NO_(2)^(-)清除率为69.4%,当裂果枣红色素浓度达到1.5 mg/mL时,ABTS^(+)自由基清除率达到63.5%。裂果枣红色素稳定性试验结果表明,索氏抽提法提取的裂果枣红色素具有良好的热稳定性,光照对其稳定性有一定的影响,pH值对裂果枣红色素稳定性的影响较大。

超高压物理改性处理提高甜菜红的热稳定性及应用

目的:甜菜红易在碱性、高温等条件下发生褪色,分别采用超高压技术(UHP)、脉冲电场(PEF)、动态高压微射流(DHPM)技术对甜菜红进行物理改性,以吸光度值为考察指标,确定合适的提高甜菜红热稳定性的物理改性技术。方法:通过扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)及高效液相色谱(HPLC)分析揭示了超高压处理提高甜菜红热稳定性的机制;以未经超高压处理的甜菜红作对照组、超高压处理的甜菜红为原料制作曲奇饼干,验证超高压处理提高甜菜红热稳定性作用。结果:在400 MPa、保压时间30 min、室温的处理条件下,甜菜红的热稳定性显著高于其他条件下的样品;超高压处理提高了甜菜红的热稳定性,对甜菜红的特征官能团没有显著影响,但使其组分比例发生了改变;以超高压处理的甜菜红色素制作的饼干与未处理的相比,烘烤前后饼干色差变化幅度小。结论:超高压处理是提高甜菜红色素热稳定性的有效方法。

Culture medium optimization for pigment production with RSM method

Response surface methodology was used to optimize a medium for a red-pigmented marine bacterium S-9801 strain （Flavobocterium sp.）. In the first optimization step the influence of yeast extract, peptone, glucose and sodium chloride on pigment production was evaluated using a fractional factorial design. Pigment production was positively influenced by glucose and sodium chloride while other components had no significant effect. In the second step the path of steepest ascent was used to approach the optimal region of the medium composition. In the third step the optimal concentration of glucose and sodium chloride was determined by a central composite design and response analysis. The optimized medium allowed pigment production （A 535-650） to be increased from 0.137 to 0.559, being 320% higher than the original medium.

火龙果果皮红色素抑菌活性及对鳙鱼肉新鲜度的指示效应

本研究通过超声波辅助乙醇浸提法提取火龙果果皮红色素,采用药敏试纸抑菌圈检验法、DPPH自由基清除法比较两种果皮红色素的抑菌活性和总抗氧化能力,同时结合果皮红色素提取物对pH变化的响应和色差值评估指标,优选红色素提取物浓度制作指示卡。通过检测常温放置过程中鱼肉的pH、脂质过氧化值变化评估指示卡对鳙鱼鱼肉新鲜度的指示效果。结果表明,红肉红皮火龙果果皮红色素对大肠杆菌(Escherichia coli)和金黄色葡萄球菌(Staphylococcus aureus)的抑菌活性和总抗氧化能力均显著高于白肉红皮火龙果果皮红色素(P<0.05),且其红色素提取物水溶液对pH2~13具有较灵敏的呈色变化反应。应用10 g/L红肉火龙果果皮红色素提取物制备的指示卡,评估鳙鱼鱼肉变化可知,25℃常温放置12 h过程中鱼肉的pH先微降后上升,TBA脂质过氧化值持续升高为0 h的1.96倍,揭示鱼肉的新鲜度下降;同期,放置鱼肉的指示卡色差值ΔE也从起始时1.40(0 h)上升到18.30(12 h),指示卡外围呈色从淡红色向玫红色及土黄色转变,对放置的鲜切鳙鱼肉新鲜度的衰减表现出较为直观的指示效应。本研究为火龙果果皮天然红色素的综合利用提供前期的科学依据,也为水产类预制菜行业的新型食品包装应用提供初步参考。

高颜色稳定红色PA6材料的制备与性能

通过双螺杆挤出机制备了红色尼龙6(PA6)材料,采用万能试验机、冲击试验机、分光测色仪和电子天平研究了在吸湿过程中不同种类红色颜料和增塑剂对PA6材料综合性能的影响。结果表明:红色PA6材料的吸湿变色严重,红色颜料对PA6材料的吸湿率影响很小。不同红色颜料所得红色PA6材料的吸湿变色色差变化方向不同。有机红178与溶剂红52复配使用明显改善了红色PA6材料的吸湿变色问题。增塑剂用量越多,红色PA6材料吸湿变色的改善效果越好。增塑剂的加入使得PA6材料的刚性降低、韧性增加、吸湿率轻微下降。

香樟树红叶色素的提取及稳定性研究

以香樟树红叶为原料,采用溶剂浸提法提取香樟树红叶色素。以色素特征吸光度为指标,研究红叶色素的提取工艺和稳定性。结果表明:最佳提取工艺为料液比1:40(g/mL)、乙醇体积分数40%、提取温度70℃、提取时间2.5h。稳定性试验得出,在较低温度(20~60℃)、避光条件下,红叶色素的稳定性较好;红叶色素在酸性、中性和弱碱性(pH1~9)条件下稳定,在强碱性(pH10~14)条件下不稳定;红叶色素具有较好的抗氧化性和抗还原性;冰醋酸对红叶色素的稳定性影响不大,而葡萄糖对其有一定影响;金属离子Fe^(2+)、Fe^(3+)、Cu^(2+)Pb^(2+)对红叶色素的稳定性影响明显。通过显色反应得出香樟树红叶色素主要含有二氢黄酮醇类物质。

Construction of high-density genetic linkage map of Pyropia yezoensis(Bangiales,Rhodophyta)and identifi cation of red color trait QTLs in the thalli

Pyropia yezoensis is an important macroalga because of its extensive global distribution and economic importance.Color is an important trait in the thalli of P.yezoensis,it is also an effective marker to identify the hybridization in genetic breeding.In this study,a high-density genetic linkage map was constructed based on high-throughput single nucleotide polymorphism(SNP)markers,and used for analyzing the quantitative trait loci(QTLs)of red color trait in the thalli of P.yezoensis.The conchospore undergoes meiosis to develop into an ordered tetrad,and each cell has a haploid phenotype and can grow into a single individual.Based on this theory,F1 haploid population was used as the mapping population.The map included 531 SNP markers,394.57 cM long on average distance of 0.74 cM.Collinear analysis of the genetic linkage map and the physical map indicated that the coverage between the two maps was 79.42%.Furthermore,QTL mapping identified six QTLs for the chromosomal regions associated with the red color trait of the thalli.The value of phenotypic variance explained(PVE)by an individual QTL ranged from 4.71%-63.11%.And QTL qRed-1-1,with a PVE of 63.11%,was considered the major QTL.Thus,these data may provide a platform for gene and QTL fine mapping,and marker-assisted breeding in P.yezoensis in the future.

“微电解+芬顿氧化法”在红曲色素废水处理中的应用与研究

采用“微电解+芬顿氧化法”对红曲色素废水中的高浓度压滤废水进行预处理,通过两组试验找出最佳投药量及验证对废水可生化性提高的效果。第一组试验(最佳投药量试验)过程及结果:取200 mL压滤废水水样,经0.5 h曝气微电解反应后,投加芬顿试剂,在投药量30%双氧水5 mL,亚铁盐1.2 g,氧化时间1 h时,COD从24520 mg/L降至18231 mg/L,去除率为25.6%;色度从7500(倍)降至3680(倍),去除率为50.9%。第二组试验(可生化性提高效果试验)过程及结果:原废水B/C比(可生化性)为24%,经0.5 h曝气微电解后提升至36%,再经芬顿氧化后(芬顿试剂投药量:30%双氧水5 mL,亚铁盐1.2 g,氧化时间1 h),B/C比可提升至58%,试验证明B/C比提升效果非常显著,废水中的有机污染物具备了易于生化降解的特性。以上试验及其结果,可为红曲色素废水处理达标排放工程设计时,在工艺流程选择、工艺参数设计及运行费用分析上,提供非常重要的参考依据。