Titanium dioxide production

Titanium Tetrachloride. The major use for titanium tetrachloride [7550 5-0] is in titanium dioxide production, and titanium dioxide [13463-67-7] is enjoying strong growth for use as a filler in pulp and paper manufacture and as a pigment in paint and plastic manufacture. Annual growth for this product is forecasted at between 2.5 and 3.0% through 1992. 

Because sulfur suppHes, either as elemental sulfur or by-product sulfuric acid, have grown owiag to iacreased environmental awareness, demand for sulfur has decreased ia some consuming iadustries for the same reason. Industries such as titanium dioxide productions, which traditionally utilized sulfuric acid, have concerted to more environmentally friendly processes. In addition, many consumers who contiaue to use sulfuric acid are puttiag an emphasis on regenerating or recycling spent acid. 

An excellent example of the differing energy requirements of competing processes is provided by titanium dioxide production. There are two competing processes ... 

In the titanium dioxide production plant where the chlorine process is employed, the wastewater from the kiln, the distillation column, bottom residue, and those from other parts of the plant first settle in a pond. The overflow from this pond is neutralized with ground calcium carbonate in a particular reactor, while the scrubber wastewater is neutralized with lime in another reactor. The two streams are sent to a settling pond before being discharged. 

A typical wastewater treatment process flow diagram in a titanium dioxide production plant (the chlorine process) is shown in Figure 22.19. 

The process was developed by Du Pont in the 1940s and its first plant started operating in 1958. It has progressively replaced the older Sulfate Process because it produces less effluent in 1998, 56 percent of the world capacity for titanium dioxide production used the Chloride Process. See also ICON. 

Sulfate-resisting cement, 5 498 Sulfate surfactants, 24 145 Sulfate titanium dioxide production process, 29 388-391 Sulfathiazole, 28 684 Sulfation, 23 513, 514, 536-538 higher aliphatic alcohols, 2 4 in higher olefins, 27 713 Sulfation operations, industrial changes affecting, 23 515-516 Sulfation processes, general overviews of, 23 555... 

The raw titanium dioxide product generally is neutralized by washing in an aqueous solution of piopei pH. 

The chief mined ore of titanium is ilmenite (iron titanium oxide, FeTiC>3) and it occurs as vast deposits of sand in Western Australia, Canada and the Ukraine. Large deposits of rutile (titanium dioxide, TiO ) are known in North America, and South Africa. World production of the metal itself is around 90,000 tonnes per year, small compared to titanium dioxide production which is 4.3 million tonnes per year. Reserves of titanium amount to more than 600 million tonnes and while there is an abundance of this element it is extremely costly because it has to be extracted by a complicated process, and yet it could be so much more useful if it was cheaply available. 

Meng. X.G. et al.. Methods of preparing a surface-activated titanium dioxide product and of using same in water treatment processes, U.S. Patent 6 919 029, 2005, cited in [2110]. 

Kemira Pigments pigments, including titanium dioxide production. 

EfQuents may be affecting the environment by the amounts of suspended solids such as effluents from phosphate fertilizer or titanium dioxide production or may contain one or, more usually, many chemicals with varying environmental impact. For example, 30 years ago, effluent from phosphorus production contained yellow phosphorus and caused spectacular kills of schools of herring that swam through the contaminated area, turned red by hemorrhaging, and died miles away from the exposure area [179]. Such surprises are much less Hkely now, but unanticipated chemicals or effects are Hkely to be encountered. 

The other important process for production of titanium dioxide is termed the chloride process [7]. The raw material used in this process is natural rutile, which is first heated at 9S0°C in the presence of carbon (in the form of coke) and chlorine. This produces crude TiC, and this product is heated at l(XX) C in the presoice of oxygen to produce the final titanium dioxide product. Under these conditions, the final product is the rutile phase. 

There are two crystalline forms widely used in papermaking applications, anatase and rutile. The major difference between the two is crystal uniformity and size, which yields a slightly higher index of refraction in the rutile crystal (Fig. 6.8). There are two chemical processing manufacturing routes commercially viable for titanium dioxide production, the sulphate and the chlorine process. The older sulphate method may be used to produce both anatase and rutile, while the more recent chlorine process is utilised only for rutile crystal production. 

Low-Residue Process for Titanium Dioxide Production (Example from Kronos International)... 

Standard Classification for Dry Pigmentary Titanium Dioxide Products Standard Specification for Zinc Yellow (Zinc Chromate) Pigments Standard Test Methods for Sampling and Testing of Flaked Aluminum Powders and Pastes... 

Regeneration of process solutions used in titanium dioxide production, pickling plants, viscose fibre production, etc. 

Economic Commission For Europe. 1988. Use and Disposal of Wastes From Phosphoric Acid and Titanium Dioxide Production, ISBN 92-1-116433-1, ECE/CHEM/65, New York, NY, U.S.A. 

In the Huelva factoiy, the oldest and most common process for titanium dioxide production is used the sulphate process. This process uses concentrated sulphuric acid (H2SO4) to dissolve the titaniferous feedstocks which are milled and dried beforehand to aid the digestion process. 

Chloride process. The chloride process yields the rutile form of titanium dioxide. At temperatures between 800 and 1200 C, chlorine is reacted in a fluidized-bed reactor with a titanium-containing mineral under reducing conditions (in the presence of coke) to form anhydrous TiCh- Further purification requires separa-hon by fractional condensation. The conversion of TiCl, to Ti02 may be accomplished by either direct thermal oxidation, or by reaction with steam in the vapor phase at temperatures in the range of 900—1400 °C. A smaU amount of AICI3 is generaUy added to promote formation of the rutile form. The titanium dioxide product is then washed, calcined, and packaged (Kuznetsof, 2006). 

Granulation, dr5hng of yeast S5mgas to gasoline Titanium dioxide production Microorganism cultivation... 

Petrolerun Refineries Phosphoric Acid Production Silicon Carbide Production Soda Ash Production Titanium Dioxide Production... 

The chlorine used for titanium dioxide production is prepared by electrolysis of sodium chloride. Like titanium ore, sodium chloride is mined. 

The major use for chlorine is the chlorination of ethylene to make ethylene dichloride (this is always referred to as ethylene dichloride, but the more proper name is 1,2-dichlorethane) by addition of chlorine to the double bond. Ethylene dichloride, or EDC, is converted into vinyl chloride, which is then converted to polyvinyl chloride (PVC) polymer. There are many uses for PVC, but much of the demand is in the building and construction industry for items such as plumbing, vinyl siding, and window frames. Therefore the robustness of the construction business has a major effect on PVC demand and, in turn, chlorine demand. Other uses for chlorine include water purification, titanium dioxide production, phosgene production and orgamc... 

Within the last several years, a number of companies have investigated the application of Raman spectroscopy to process analysis. A review of the scholarly and patent literature reveals several examples PCI3 reactions, titanium dioxide production, diamondlike carbon (DLC) films production, polymeric fiber property detection, applications to gasoline, aromatic production, chlorosilane production, and gas-phase measurements. In Section in, some of these applications will be reviewed in order to illustrate the application of Raman spectroscopy to process chemistry and control. 

Figure 12 Schematic of the Raman probe installed for titanium dioxide production. 

In titanium dioxide production, there are two processes used the chloride process and the sulfate process. While the demand for titanium dioxide has historically been growing rapidly, the supply has sometimes exceeded demand and sometimes lagged. So in the past there was a history of shortages and allocations due to tight supply. Also there were periods of excess supply. 

A proven titanium dioxide product for the plastics industry widely used in polyolefin concentrates where its proprietary surface treatment provides excellent dispersion auid retention of rheological performance. Tiona RCL-4 resists the yellowing reaction that occurs in polyolefins with certain phenolic antioxidants. It is also recommended for use in non-durable rigid and flexible PVC applications. The consistent tint tone and high tint strength of Tiona RCL-4 makes it a preferred product for custom color applications. Tiona RCL-4 is NSF listed for plastic pipe applications. 

A durable titanium dioxide product that provides maximum color stability and chalking resistance in exterior applications. The pigment particles of Tiona RCL-6 are fully encapsulated with silica which minimizes chalking. Tiona RCL-6 is the product of choice for tinted vinyl siding and window profile systems where exterior durability is critical. Tiona RCL-6 is highly recommended in other applications where color stability is critical. 

Applications. Typical corrosion applications include titanium dioxide production (chloride route), perchlorethylene syntheses, vinyl chloride monomer (VCM), and... 

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