Titanium Dioxide Pigment Research Articles

The effects of particle size distribution on the optical properties of titanium dioxide rutile pigments and their applications in cool non-white coatings

The particle size distributions of three commercially available titanium dioxide pigments were measured, and their effects on the optical properties of the pigments were investigated. The Altiris 550 and 800 pigments possess larger median particle size and wider size distributions than those of the conventional titanium dioxide rutile. The visible (VIS) reflectance, the solar reflectance and the lightness of the films and coatings singly pigmented with any of these three pigments decrease as the pigment particle size increases. The VIS transmittance and near-infrared (NIR) reflectance both increase as the pigment particle size increases. The main reflection band of the coatings shifts farther into the NIR region with increasing pigment particle size. The partially VIS-transmitting Altiris pigments enable the NIR and the solar reflectance of cool non-white coatings to be improved, thereby yielding metameric matches to the desired colors.

Theoretical analysis of light scattering properties of encapsulated rutile titanium dioxide pigments in dependent light scattering regime

Using numerical simulation, we study and compare the optical properties of model systems representing three types of scatterer: (a) standard TiO2 pigments, (b) standard TiO2 pigments encapsulated by a hard polymer shell and (c) standard TiO2 pigments encapsulated by a layer of air and a polymer shell. Calculations are performed taking into account multiple and dependent light scattering regimes. Assuming an equivalent amount of TiO2 in each system, results show that a standard TiO2 pigment particle encapsulated by air could be a better opacifier than a standard un-encapsulated TiO2 pigment because the presence of air could provide: (a) additional volume to the existing particle to scatter light; (b) better redistribution of the scattered field in the backward hemisphere; (c) a scattering cross-section less affected by crowding and (d) spacing effects due to the presence of the thin hard polymer shell which is required to encapsulate the air layer. Nonetheless, results also suggest that such benefits could probably not be exploited in real paint systems as encapsulated TiO2 would only be more efficient than standard TiO2 in a range of pigment volume filling fractions (PVC) that would not generate enough scattering efficiency to yield complete hiding as required by international standards.

Preparation of nanosized powders of calcium hydrosilicates for the use in composite materials

Nanosized powders of calcium hydrosilicates with a high granulometric uniformity have been synthesized from water-soluble calcium- and silicon-containing raw materials in the presence of structure-forming agents using the sol-gel method. The possibility of their application as the main components in the manufacture of acrylic paints has been demonstrated. The process of the formation of CaSiO3/TiO2 composite nanoparticles using freshly precipitated calcium hydrosilicate gel using the extraction-pyrolysis method has been investigated. A method of preparing composite titanium pigments based on calcium silicates has been elaborated and the possibility of using them in paint compositions as a substitute for titanium dioxide has been found out. A method of producing a white water-dispersion acrylic paint based on synthetic calcium hydro-silicates in the form of pastes of high humidity from calcium chloride and liquid glass has been developed.

Alumina Surface Treated Pigmentary Titanium Dioxide with Suppressed Photoactivity

The aim of the optimization of the technological process was to coat the surface of the pigment in a controlled manner and to supress photoactivity in the titanium dioxide (TiO2) pigment. As part of this research, a systematic approach to TiO2 pigment surface treatment with alumina was conducted. Surface treatment with alumina plays a significant role in the improvement of TiO2 properties (e.g. weather resistance and photostability). This research encompasses a raw material analysis and process conditions study. Sodium aluminate and aluminium sulphate were used as a source of alumina hydroxide. The effectiveness of surface treatment was determined using scanning-transmission (STEM) and transmission (TEM) electron microscopy. The photoactivity of pigmentary TiO2 was determined before and after surface treatment. A controlled surface treatment process resulted in pigmentary TiO2 particles with uniform amorphous layers, which supressed the photoactivity of the pigment.

Production of Nanosized Synthetic Rutile from Ilmenite Concentrate by Sonochemical HCl and H2SO4 Leaching

Titanium dioxide is widely used in the manufacturing of paints, varnishes, lacquer, paper, paperboard, printing inks, rubber, floor covering, and ceramics and so on. White titanium dioxide pigment has been produced by two main processes. The sulfate and the chloride processes. Each of these two routes requires different feedstocks. However, economic and environmental pressures are shifting the world balance of titanium dioxide production away from sulphate based manufacture towards the more cost effective and cleaner chloride route. According to usage of titanium dioxide, the nano sized TiO 2 was produced by the sulfuric acid and hydrocholoric acid leaching by using Sonochemical technique during the leaching process. No adding extra materials and no milling after precipitate, no vaporization during the leaching are advantages of this work which reduced the processes of leaching. All of determination techniques of particle size (Zeta Sizer, XRD, SEM, and TEM) prove this matter. The particles sizes of nano TiO 2which was leached by HCl and H 2SO 4 are 83 and 85 nm respectively.

Determination of optimal conditions for technology main waste processing titanium production

Suggested a radical solution for the recycling accumulated iron sulphate - waste production of titanium dioxide pigment in the APM "Sumyhimprom." The algorithm is constructed and identified the main physical and chemical processes of the technology being developed. The conditions for ammonolysis of the process, the oxidation process and the resulting filter cake, it was found that the precipitate obtained is magnetite, which can be used in metallurgy.

Organizing the Production of Pigmentedtitanium Dioxide as Part of the Formation of the Far-East Metallurgical Cluster

The reserves of titanium-bearing raw materials in the Far East and the prospects for their use are examined. The article examines the conditions needed to create and grow companies that produce titanium dioxide pigment as part of the nascent metallurgical cluster.

Cristal rationalizes brand names for TiO2 products

Titanium dioxide (TiO2) pigment firm Cristal has announced that all TiO2 products manufactured at its Yanbu facility in Saudi Arabia have transitioned from the Cristal product name to the TiONA® brand name, effective from October 2013. Packaging is also being changed as a result.

A Review of the Production Cycle of Titanium Dioxide Pigment

Titanium is a very important element for several industrial applications, being one of the ninth most abundant elements in the Earth’s crust (0.63% wt). In this work it will discuss the different mining and industrial activities involved in the production of titanium dioxide. The first step analyzed will treat about the beneficiation mining process of titanium mineral, and secondly, it will discuss the two main processes of the TiO2 manufacturing (sulphate and chloride routes). In addition, we will show different uses of the titanium dioxide pigment as filler in paper, plastics and rubber industries and as flux in glass manufacture, etc. Finally, we will show that the old wastes are currently called co-products since they were valorized, being commercialized by the Spanish industry of TiO2 production in different fields such as agriculture, civil engineering, or cement manufacturing.

Cerium Oxide Coating of Titanium Dioxide Pigment to Decrease Its Photocatalytic Activity

The use of cerium oxide coating of titanium dioxide pigments to decrease photocatalytic activity was studied. A large decrease in the photocatalytic activity of titanium dioxide particles coated with cerium oxide was obtained even with a tiny coating amount of 0.2 wt %, and these particles were more stable than those with the conventional 2.0 wt % film coating of silicon dioxide or 1.5 wt % aluminum oxide. The combination film coatings of cerium oxide and silicon or aluminum oxide showed smaller decreases in photocatalytic activity. Both Ce(III) and Ce(IV) oxide coatings gave highly decreased photocatalytic activity, even when the cerium oxide coating did not completely cover the surface. It was inferred that the efficient decrease of photocatalytic activity was because the unpaired electrons in the 4f orbital of cerium enabled the coating film to capture electrons and holes that were produced when titanium dioxide was exposed to ultraviolet irradiation.

Preparation of magnesium hydroxide from leachate of dolomitic phosphate ore with dilute waste acid from titanium dioxide production

A novel method for the removal of magnesium from dolomitic phosphate ores by using dilute waste acid (DWA) from titanium dioxide pigment production was experimentally studied in this work. The pH of liquid phase and particle size of granulized phosphate ore have been found to be crucial to the efficient removal of magnesium from phosphate ore. Operating under the optimum leaching conditions, a 98.31% removal of Mg with 0.02% P2O5 loss was obtained. It was demonstrated that dolomite can be selectively dissolved by H+ in the DWA and the ability of H+ to attack the apatite is inhibited by the strong interionic strength of DWA. By using the solubility differences of corresponding elements, a two-step precipitation process was presented to remove Fe selectively from Mg. A process for further purifying the synthetic leachate by a precipitation/leaching method and oxidation was also investigated. Subsequently, magnesium hydroxide (Mg(OH)2) was prepared by precipitation from the refined solution with ammonia as the precipitant and sodium dodecyl sulfate (SDS) as the modifier. The phase structure and morphology of Mg(OH)2 were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The prepared nanoparticles of Mg(OH)2 were found to exhibit a column-shaped structure, demonstrating that the anions of DS− adsorbed onto the surface of Mg(OH)2 nucleus contribute to the stacking of Mg(OH)2 regular-hexagon platelets along the c-axis perpendicular to the [001] plane. The adsorption of SDS on the surface of Mg(OH)2 was supported by Fourier transform infrared spectroscopy (FTIR).

Influence of titanium dioxide pigments on the optical properties of polycarbonate and polypropylene for diode laser wavelengths

ABSTRACTIn laser transmission welding of polymers, additives and colorants could influence the welding result. In this work, polypropylene and polycarbonate probes colored with titanium dioxide (TiO2) pigments of various concentrations are investigated. The probes are produced using an extrusion process to obtain a homogeneous distribution of colorants. The TiO2 pigments change the optical properties of the polymers considerably. The measured reflectance increases with increasing pigment load while the transmittance decreases. From the measured data of transmittance, reflectance, and collimated transmittance, the scattering, the absorption coefficient, and the anisotropy factors are calculated. It is shown that the scattering coefficient at 1530 nm (laser) wavelength is smaller than for 968 nm, while the absorption coefficient is negligible for both wavelengths. Scattering coefficient and anisotropy factor are used to simulate the propagation of the laser radiation in the polymers. The influence of the scattering process on the beam propagation is represented by the change of the power density distribution. It is shown that the maximum intensity of the distribution is reduced more than the transmittance with increasing pigment concentration. The effect is higher for 968 than for 1530 nm wavelength making the larger wavelength more favorable for transmission welding. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40073.

Study on required energy to deagglomerate pigmentary titanium dioxide in water

The dispersion process is used in various industries, including coatings, paper manufacturing, and food processing. All of these industries base their developments and technology of particle dispersion on theories that consider spherical particles in simple systems. The objective of this study was to improve understanding of the impact of these theories when applied to nonspherical/nonideal particles. Effective dispersion allows for a reduction in the use of the powder to achieve the specified final properties. This paper reports experimental results on the required energy (RE) used to disperse five different titanium dioxide (TiO2) samples into liquids with different values of surface tension [deionized (DI) water and DI water containing surfactants]. The selection of the TiO2 samples was based on different particle sizes with the same surface properties, and similar sizes with different surface properties. The results showed that the particle shape is fundamental in determining the RE for dispersion, once it defines the number of interactions among the particles. The larger the number of interactions, the more energy is required to deagglomerate the particles. An empirical equation was developed to describe the energy required for pigment dispersion as a function of the ratio between the liquid and the particle surface tensions and the particle shape factor.

Wettability study for pigmentary titanium dioxide

Wetting is the first step in the dispersion process of any powder. Understanding how the powder surface and the liquid properties affect the speed and intensity of the wetting process provides a set of tools to determine the dispersion efficiency as a whole, and an effective dispersion allows the reduced use of the powder to achieve the specified final properties. This article reports experimental results on the wetting behavior of five different TiO2 samples by liquids with different values of surface tension [deionized (DI) water and DI water containing surfactants] and its effect on the dispersion process. The selection of the TiO2 samples was based on different particles sizes with similar surface properties, and similar sizes with different surface properties. The samples were characterized in terms of their specific surface area and particle size distribution. The wetting behavior was evaluated by a capillary rise technique (Washburn) to measure liquid penetration height and rate, and the time evolution of the particle size distribution. The results show that larger particles presented faster wettability and that liquids with lower surface tension facilitate the wetting of the powder. The energy required to deagglomerate the powder is inversely proportional to the wetting speed: the faster the wetting the easier it will be to disperse the particles, with less energy required.

Huntsman Takes A Spin With TiO

Continuing a shake-up in the titanium dioxide pigment industry, Huntsman Corp. has agreed to acquire Rockwood Holdings’ business in TiO2 and several other chemicals. Huntsman plans to combine the Rockwood businesses with its own TiO2 operation and then unload the combination in a public stock offering by 2016. The purchase will cost Huntsman $1.1 billion plus $225 million in Rockwood pension obligations. The businesses employ about 3,300 people worldwide and had sales last year of $1.5 billion. The deal includes operations in iron oxide pigments, wood preservatives, water treatment chemicals, and elastomers; but titanium dioxide, at 66% of sales, is clearly the focus. By combining the Rockwood titanium dioxide business with its own, Huntsman will create the world’s second-largest TiO2 producer after DuPont. TiO2, a white pigment added to almost every can of paint, has become something of a hot potato for Huntsman, Rockwood, and DuPont. It’s a commodity chemical ...

Application of Mathematical Programming Method for Water Supply and Recycle Network in Titanium Pigment

Water integration method is widely used in water minimization. Water minimization has great benefits to environmental and industrial sustainability. Both freshwater consumption and wastewater discharge can be minimized by practicing water system integration. Sulfate process (SP) is an important and mature method to produce titanium dioxide (TiO2) pigment. A large amount of water is consumed and a large quantity of effluent is discharged, which may cause water resource waste and serious environmental pollution. The paper presents Mathematical Optimization Method for water minimization of a titanium pigment plant event in China. The result of this study shows that mathematical optimization method has been effectively applied for the titanium pigment plant, and the freshwater consumption is reduced by 45.97 %.

Integration of thermal insulation coating and moving-air-cavity in a cool roof system for attic temperature reduction

Cool roof systems play a significant role in enhancing the comfort level of occupants by reducing the attic temperature of the building. Heat transmission through the roof can be reduced by applying thermal insulation coating (TIC) on the roof and/or installing insulation under the roof of the attic. This paper focuses on a TIC integrated with a series of aluminium tubes that are installed on the underside of the metal roof. In this study, the recycled aluminium cans were arranged into tubes that act as a moving-air-cavity (MAC). The TIC was formulated using titanium dioxide pigment with chicken eggshell (CES) waste as bio-filler bound together by a polyurethane resin binder. The thermal conductivity of the thermal insulation paint was measured using KD2 Pro Thermal Properties Analyzer. Four types of cool roof systems were designed and the performances were evaluated. The experimental works were carried out indoors by using halogen light bulbs followed by comparison of the roof and attic temperatures. The temperature of the surrounding air during testing was approximately 27.5°C. The cool roof that incorporated both TIC and MAC with opened attic inlet showed a significant improvement with a reduction of up to 13°C (from 42.4°C to 29.6°C) in the attic temperature compared to the conventional roof system. The significant difference in the results is due to the low thermal conductivity of the thermal insulation paint (0.107W/mK) as well as the usage of aluminium tubes in the roof cavity that was able to transfer heat efficiently.

Resource-saving electrochemical processes in manufacture of pigment titanium dioxide

Development directions of the sulfate method for manufacture of titanium dioxide are considered, and alternative solutions for improving its cost efficiency and ecological advisability are suggested. A high-efficiency technology for electrochemical synthesis of a strong reducing agent, Ti2(SO4)3·nH2O, used instead of waste iron and powdered aluminum is suggested.

Investigation on Preparation of Micro-Sized Hematite Powder from Hydrous Ferrous Sulfate Using Microwave and Conventional Heating

AbstractMicrowave and conventional heating were employed to synthesize micro-sized hematite powder from hydrous ferrous sulfate, a by-product in the process of titanium pigment manufacture. The TG/DTG analysis was used to study thermal behavior of the industrial ferrous sulfate. Therefore the temperature which was significant to product was defined. The calcination experiments were carried out to assess the effect of calcination temperature covering three different temperatures (650°C, 750°C and 850°C, respectively). X-ray powder diffraction (XRD) was used to characterize the structure of the product, while the scanning electron microscopy (SEM) was utilized to characterize the morphology of the product. Microwave calcination process resulted in a mixture of hematite and minor magnetite while a considerable amount of magnesium sulfate was detected with the conventional calcination process. The transformation from periclase to magnesium was discussed during the calcinations as well. The conventional heating resulted in porous product while the microwave heating resulted in smaller particle size.

Study on the Silicone Coating with Heat Insulation and Resistance

Experimental choose methyl-trichlorosilane, di-methyl-dichlorosilane and phenyl trichlorosilane synthetic organic silicon resin, add white mica powder, aluminum silicate, titanium pigment, zinc phosphate as packing, system high temperature insulation coating. For after high temperature resistant coating surface coating of tin model coating physical mechanical properties and high temperature resistant, heat insulation temperature difference of performance test, the results indicate that the system of high temperature resistant coating resistant to 400 ~ 500 °C high temperature, and has good high temperature resistance, heat insulation performance, etc.