溶胶-凝胶法制备硅酸锆基稀土颜料的研究

介绍了以Si（O2H5）4·8H2O及稀土化合物为原料,以Pf、Nd、Sm、Eu及Er为发色离子,采用溶胶-凝胶法经900～1000℃的低温热处理制备硅酸锆基颜料的方法。借助X衍射颜料分析手段,对硅酸锆基稀土颜料的形成机理,尤其是LiCl在低温热处理中的作用做了探讨。     

Preparation and characterization of waterborne ceramic ink with submicron-sized praseodymium-doped zirconium silicate pigment by water-based diblock polymer dispersants

Two diblock polymer dispersants (i.e., PMAA-b-AMPS and PSSS-b-GMA) were synthesized and used as water-based dispersants for dispersion and stabilization of waterborne ceramic ink with submicron-sized praseodymium-doped zirconium silicate (Pr-ZrSiO₄) pigment. The color property, dispersion, and stability of the pigment particles in aqueous suspension were determined by colorimetry, laser particle size analysis, and sedimentation test. The adsorption mechanism of carbon chains of dispersants on the particle surface was analyzed by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and electrokinetic potential measurement. Also, the viscosity, surface tension and stability of waterborne ceramic ink with the pigment particles were measured by rheometry, surface tension analysis and standing settlement. The results show that the submicron-sized pigment particles in waterborne ceramic ink show optimum dispersibility and stability at 5 wt% addition of diblock polymer dispersants PMAA-b-AMPS and PSSS-b-GMA mixed in a mass ratio of 9:1. This could be since the mixed dispersants provide the more interparticle electrostatic repulsion and steric hindrance energies due to the proper adsorption on the particle surfaces. It is indicated that adding 20 wt% of diethylene glycol monobutyl ether into the waterborne ceramic ink can effectively enhance the viscosity and reduce the surface tension, thus satisfying the applied requirements in inkjet printing. In addition, the jettability of waterborne ceramic ink on a simulated ceramic green body was also evaluated based on semi-empirical analysis.     

Microstructure and strength development of beta-dicalcium silicate pastes with and without admixtures

Microstructural developmentin hydrating $\text{beta}$-dicalcium silicate pastes was studied up to 188 days using scanning electron microscopy. The overall development is similar to that observed previously for tricalcium silicate pastes, but some unusual features were observed and are described. The calcium silicate hydrate, Type I, is larger and better developed than that which is formed in tricalcium silicate pastes; and, moreover, calcium hydroxide also forms larger crystals. Tensile strength development follows the same relationship to gel-space ratio found for tricalcium silicate pastes, and is unaffected by the presence of admixtures. Chloride and carbonate salts promote the formation of Type II calcium silicate hydrate.     

硅酸锆行业发展与锆砂消费

1我国锆砂现状和消费简述 锆砂是锆行业发展的基本原料,是我国重要的战略性矿物资源。锆砂的开发、应用和贸易与下游的硅酸锆、化学锆和金属锆产业的发展密不可分,本文将重点就硅酸锆行业与锆英砂消费作简略的讨论。     

硅酸锆放射性测试中存在的问题

简述了陶瓷行业用硅酸锆原料的放射性来源。通过试验验证了硅酸锆在放射性测试过程中的质量和体积对放射性测试结果的影响。     

Oxidative coupling of methane over sodium-chloride-added sodium zirconium phosphates

Monosodium zirconium phosphate or disodium zirconium phosphate by itself did not catalyze the oxidative coupling of methane and also the deep oxidation of methane. However, NaCl-added sodium zirconium phosphates showed markedly increased activity and high C₂₊ selectivity in the oxidative coupling of methane, which indicates that chlorine species or NaCl plays an essential role in the catalytic action. The catalytic performance became more stable with increasing content of NaCl. The primary reason for the catalyst deactivation is the loss of chlorine, and a possible secondary reason is the transformation of catalytic substance to the sodium zirconium phosphates having higher Na/Zr ratios or decomposition of sodium zirconium phosphates to zirconium oxide and sodium phosphate. Two kinds of surface chlorine species were observed, and the lower-binding-energy species is considered to be much more active than the higher-binding-energy species in methane activation, although the latter is present in a larger amount than the former.     

Synthesis and structure of cobalt layer silicate

Two cobalt layer silicates were synthesized by hydrothermal treatment at 275‡C and 54 atm from corresponding stoichiometric coprecipitate of cobalt hydroxide and silica. From IR absorption spectra and X-ray diffraction patterns, one sample was proved to be cobalt montmorillonite [Co[₃Si[₂O[_{5 2}(OH)₂, while the structure of the other was cobalt antigorite [Co₃Si₂O₅(OH)₄] of one silica layer combined with an octahedral layer of the type Co₃ ²⁺ (OH)₆.     

Development of blue ceramic dyes from cobalt phosphates

In this study the development of blue ceramic dyes from compositions based on phosphate structures have been investigated. The replacement of cobalt by copper or iron to minimize the Co content have been considered. MFeO(PO₄) (M = Co, Cu) solid solutions have been obtained with Co_1−xCu_xFeOPO₄ (0 ≤ x ≤ 1) compositions prepared from gels and fired at 1000 °C/2 h. Co_1−xCu_xFeOPO₄ compositions are not indicated to minimize the Co content in ceramic dyes because they decompose in glazed samples and pinhole defect is obtained. From FeCoOPO₄–2FePO₄ compositions, Co₃Fe₄(PO₄)₆ structure introduces the Co²⁺ ions into glassy matrix and suitable blue materials are obtained. In the conditions of this study, optimal cobalt amount is about 10 wt% Co from Co_1−xFe_1+xO_1−x(PO₄)_1+x (x ≈ 0.6) compositions.     

我国国产锆英砂现状

锆英砂是以晶体状态出现,呈四方柱结构,是优质的耐火材料。多与钛铁矿、金红石、独居石、磷钇矿等共生于海滨砂中,经水选、电选、磁选等选矿工艺分选后而得到。锆英砂其理论化学组成为：ZrO2 67．1％;SiO2 32．99,6。纯净的锆英砂为无色透明的晶体,常因产地不同、含杂质的种类与数量不同而呈黄、橙、红、褐等色,莫氏硬度为7．8,密度为4．6～4．71g／cm2,折射率为1．93～2．01,熔点为2550℃。     

溶胶凝胶自蔓延燃烧法制备钴蓝颜料

采用溶胶凝胶法制备钴蓝前体干凝胶,经自蔓延燃烧及煅烧制备钴蓝颜料,研究了柠檬酸用量、溶胶反应温度、pH值、金属离子浓度、乙二醇等对凝胶的形成、燃烧特性及对制备的钴蓝颜料晶型结构的影响,以及干凝胶热处理方式和煅烧温度对钴蓝颜料晶型的影响。研究表明:柠檬酸用量、溶胶反应温度、乙二醇对制备的钴蓝晶型结构无影响;提高溶胶反应的温度,增加金属离子的浓度(0.01～0.1mol/L),有利于凝胶的较快形成;Co2+、Al3+总浓度低至0.005mol/L,不能形成完好尖晶石结构;适宜的pH值(约6.5)有利于柠檬酸的电离及与金属离子的络合以及干凝胶的自蔓延燃烧;乙二醇的使用可以改善钴蓝颜料的团聚现象;干凝胶自蔓延燃烧不能形成完好的尖晶石结构,燃烧后再煅烧,有助于改善钴蓝颜料的晶体结构及分散性;干凝胶自蔓延燃烧后再煅烧,随着煅烧温度的提高,制备的钴蓝颜料晶型更加完整,颜色更加鲜亮。     

球磨制备超细硅酸锆分段磨的实践

对广东佛山顺德盈信超细锆微粉有限公司的生产工艺流程进行了研究,将其原有流程的分级沉砂返回再磨工艺改为分级沉砂小直径研磨介质二段磨工艺,生产试验证实,球磨效率明显提高,磨料粒度D50从3.65 μm降为2.73 μm,D97从24.10 μm降为13.82 μm,球磨时间缩短了1 h,生产成本大幅下降.     

Kinetic separation of cobalt from zirconium by cation exchange process

Zirconium-tin alloys are used as pressure tubes in Indian pressurized heavy water reactors (PHWRs). Used pressure tubes contain neutron activation products of the constituent elements. ⁶⁰Co is one of the long-lived radioisotopes of concern, for both radioactive waste management and recycling of pressure tubes. This article describes a facile cation exchange separation of Co(II) from Zr(IV) in HCl medium. Co(II) could be preferentially sorbed on the gel resin by utilizing its faster kinetics. Higher flow rates and shallow resin bed were the key steps, which prevented the loading of Zr(IV) on the resin phase.     

硅酸锆的超细粉碎及其对釉料遮盖力的影响

本文阐述了硅酸锆在釉料中产生乳浊的机理．比较了国内外几种不同粒度分布的硅酸锆在釉层中的遮盖力，并探讨了使用国产设备粉碎硅酸锆的优缺点。     

球磨超细硅酸锆湿法粉碎生产线及工艺特点

介绍了球磨超细硅酸锆湿法生产线的工艺流程、主要设备技术性能以及工艺特点.生产实践证明,该生产线工艺设计合理、设备性能优良、生产成本低,生产的超细硅酸锆达到了国内高档陶瓷釉料乳浊剂所要求的质量品级.     

Solid-state synthesis and characterization of cobalt blue core-shell pigment particles

Cobalt blue is one of the most chemically and thermally stable blue pigments. However, cobalt is scarce and expensive. To minimize the use of cobalt and reduce production costs and toxicity, cobalt blue core-shell pigments were synthesized by a solid-state method, which is cheaper than a liquid-phase reaction. Small cobalt hydroxide particles and large α-alumina particles, in various ratios, were used as the starting materials. The dry mixed powders were calcined at 1200°C for 2 hours. Elemental mappings of the surfaces and cross sections of the synthesized particles showed that the cobalt blue had a core-shell structure. X-ray diffraction patterns showed that the synthesized cobalt blue consisted of an α-alumina core and a cobalt aluminate shell. The color tone of the synthesized cobalt blue was evaluated from the lightness (L*) and chroma (C*) values. The color tone of the cobalt blue synthesized in this study was almost same as those of commercially available samples although the cobalt molar fraction was lower than the stoichiometric ratio (Co/(Co + Al) = 0.33, Co/Al = 0.5) which was calculated from the chemical reaction formula.     

2009年我国硅酸锆行业发展状况

2009年是我国硅酸锆行业大力发展的一年,1～4月份由于受到来自美国的金融危机的影响,生产和销售基本处于停滞状态,各工厂普遍开工率不足。但从5月份开始,由于中央提出了扩大内需保增长的工作要求,各地的基础建设迅速上马,