Pigment TiO 2 TiO 2 End-Use Markets Quality-of-life product, no - PowerPoint PPT Presentation

Pigment – TiO 2

TiO 2 End-Use Markets Quality-of-life product, no effective substitutes Unsurpassed opacifying & whitening properties  Paints & coatings, plastics, paper, consumer products & specialties  Semi-specialty, differentiated & frequently customized TiO 2 Demand By End-Use Market Paper & Specialties 16% Paints & Plastics Coatings 25% 59% Total Market Size: 5.5 MM MT

Titanium Dioxide TiO 2 Technology 4

Why Use TiO2? • Achieve opacity • Obtain a given color • Provide UV protection

Titanium Dioxide Rutile Anatase Crystal Phase Tetragonal Tetragonal Refractive Index 2.71 2.55 Density (g/cm3) 4.2 4.0 Hardness ( Moh’s Scale) 6-7 5.5-6

Reflectivity Refractive Relative Index Reflectivity Rutile 2.71 100 Anatase 2.55 80 Zinc oxide 2.01 25 Kaolin 1.56 0.5 In organic binder with R.I. of 1.5

TiO 2 Production Process TiO 2 is produced using titanium containing ores such as Chloride Process Sulfate Process Ilmenite and rutile Natural Rutile , Synthetic Rutile, Ilmenite , Slag, Sulfuric Acid Slag, Ilmenite  Ilmenite: More plentiful than rutile but has a lower TiO 2 Digestion Coke Chlorine content (approximately 50% versus approximately 94% Scrap Iron for rutile). Ilmenite is usually upgraded to a higher TiO 2 Chlorination Reduction content Clarification Recycle TiCl 4 Crystallization  − Purification  Rutile: Natural occurring titanium ore found in ancient Byproduct TiOSO − 4 Solution mineral sand deposits containing high concentrations of Nuclei Byproduct Hydrolysis titanium Oxygen Filtration Oxidation Chlorine Calcination There are two major processes used to produce TiO 2 : TiO 2 TiO 2  Chloride process: A high-temperature process that Rutile or Rutile Anatase Finishing produces TiO 2 by reacting titanium ores with chlorine gas Milling  Sulfate process: A wet chemical process that produces Surface Treatment Finished TiO 2 by reacting titanium ores with concentrated sulfuric Drying and Grinding TiO 2 acid Pigment Packaging

TiO 2 Production Process Sulfate process advantages Chloride process advantages  Batch process: capacity additions can be made in  Produces a superior intermediate product, which is small increments purer and has a tighter range of particle size providing  Feedstocks with lower purity can be tolerated; an excellent base pigment suitable for a wide range of properties however, waste disposal concerns are an issue  Less labor and energy intensive  Preferred for producing pigment in specialty  Historically cash costs for the chloride process are applications such as food, catalysts, and inks  Easier process to operate approximately 15% lower than those for the sulfate process (1) 2013 production process mix (1)  The chloride process is believed to be more environmentally friendly compared to the sulfate 100% process due to higher purity feed stocks and lower 12% energy requirements 40% 80% 76% 60% 88% Tronox is well positioned as 100% 100% 88% 40% an industry leader with 100% 60% chloride technology in all 20% 24% three regions 12% 0% DuPont Cristal Huntsman Kronos Tronox Other Sulfate Chloride Source: (1) Internal estimates 10

Base Pigment • Sulfate Process –Originally developed in 1920’s – Produce anatase or rutile – Less expensive feedstocks • Chloride Process –Developed in the 1950’s – Produce rutile only – Lower contaminants – Higher brightness

Chloride Process • Chlorination of Raw or Synthetic Rutile • Purification of TiCl 4 • Oxidation of TiCl 4 • Wet Milling/Surface Treatment • Filtration/Washing/Drying • Micronization

Manufacturing Process of TiO2 TiO 2 TiO 2 Chloride Process Chloride Process T0 ATMOSPHERE RECYCLE CHLORINE DRYING SOLIDS GAS SEPARATION PURIFICATION PIGMENT & GAS CONDENSATION SEPARATION WASTE SOLIDS MILLING SURFACE TREATMENT WET MILLING PACKER CRUDE TiCl 4 STORAGE CHLORINATOR ORE STORAGE TiO 2 FILTRATION PURIFICATION STILL COKE RAW PIGMENT WAREHOUSE O 2 N 2 WATER SLURRY PRODUCTION PURE TiCl 4 STORAGE SLURRY TANK BURNER el1499 CHLORINE CAR RECYCLE CHLORINE OXYGEN TRONOX Confidential Information

Manufacturing Process of TiO2 TiO 2 Chloride Process TiO 2 Chloride Process T0 ATMOSPHERE Surface Finishing RECYCLE CHLORINE DRYING SOLIDS GAS SEPARATION PURIFICATION PIGMENT & GAS CONDENSATION SEPARATION WASTE SOLIDS MILLING SURFACE TREATMENT WET MILLING PACKER CRUDE TiCl 4 STORAGE CHLORINATOR ORE STORAGE TiO 2 FILTRATION PURIFICATION STILL COKE RAW PIGMENT WAREHOUSE O 2 N 2 WATER SLURRY PRODUCTION PURE TiCl 4 STORAGE SLURRY TANK BURNER el1499 CHLORINE CAR RECYCLE CHLORINE OXYGEN TRONOX Confidential Information

Wet Milling / Sandmilling • Raw TiO 2 dispersed in water • Sand milled to breakdown agglomerates • Classified to remove remaining oversized particles

Sandmilling • Objective: To narrow the Particle Size Distribution particle size distribution and 25 reduce the mean particle After milling diameter in order to optimize 20 both optical and physical Weight Percent 15 properties. 10 5 Before milling 0 0.1 1 10 Microns TRONOX Confidential Information

Sandmilling - A Key First Step Treatment, Micronization filtration & drying Sandmilling Agglomerated raw pigment Exposed TiO 2 surfaces Treatment, NO filtration & drying Sandmilling Micronization TRONOX Confidential Information

Finishing TREATMENT CHEMICALS RAW PIGMENT FILTRATION CLASSIFICATION TREATMENT MILLING FINISHED DRYER PIGMENT DISTRIBUTION MILLING PACKAGING

Surface Treatment • Consists of the Application of hydrous oxides of: – Silica – Titania – Zirconia – Alumina

Why is Surface Treatment Necessary? • TiO 2 particles are treated on the surface to obtain the maximum possible value from the pigment for the customer. • This value is expressed in terms of: – Dispersion – Hiding Power – Tinting Strength – Gloss – Durability

Surface Treatment • Basic Chemistry : 2NaAlO 2 + H 2 SO 4 + 2H 2 O 2Al(OH) 3 + Na 2 SO4 Na 2 SiO 3 + H 2 SO 4 + H 2 O Si(OH) 4 + Na 2 SO 4 Zr(SO4) 2 + 4NaOH Zr(OH) 4 + 2Na 2 SO 4 Precipitate onto the surface of the TiO 2 TRONOX Confidential Information

Silica Treatment • Most frequently used to promote: – Durability – Dry Hiding • Effect depends on deposition conditions – Slow addition at basic pH = durability – Quick addition at neutral or acid pH = dry hide • Reduces gloss

Silica Treatment

Dense Silica

Silica Treatment & Durability • When added slowly under alkaline conditions, the silica coating: – Forms dense impervious shell around the TiO 2 particles – Minimizes direct contact between TiO 2 surface and vehicle – Inhibits photocatalytic degradation of paint vehicle

Value of coating the pigment Durability UNTREATED TiO 2 TREATED TiO 2 uv light uv light Free radicals trapped beneath . OH + . O 2 H pigment coating Free radicals escape to react Coating of with resin or Dense SiO 2 & Al 2 O 3 polymer Or free radical re- absorbed by coating of ZrO 2 Resin TRONOX Confidential Information

Silica Treatment and Dry Hiding • When added rapidly under neutral or acidic conditions, the silica coating: – Forms silica gel which only loosely coats the pigment and maximizes air entrapment which in turn promotes high dry-hiding

Fluffy Silica

Zirconia Treatment • Although acknowledged for several decades for its unique properties, it is only in last few years that zirconia has attained the level of usage on TiO 2 • Applied principally for durability • Mechanism electron-hole trap

Alumina Treatment • Applied almost universally • Improves dispersibility and gloss • Helps to maximize hiding power by promoting inter-particle spacing • Can promote durability (co-burned) • External boehmite (AlOOH) coating provides large number of hydroxyl sites for rapid adsorption of organic milling aids and resins

Organic Treatment • Purpose – Improve compatibility & dispersion – Reduce water absorption – Reduce agglomeration during storage • Organic treatments used include – Polyhydroxy compounds – Amines , amine salts & amine soaps – Silicones & silanes • Not all pigments have organic treatment

Final Milling / Micronization • Typically fluid energy mill • Reduces agglomeration from treatment and drying resulting to optimizing dispersibility and optical properties of finished pigment • Intensity depends on – Treatment – End use • High for very good gloss • Low for dry hide grades – Previous milling

The Effect of Particle Size on Opacity 10 8 Relative Opacity 6 4 2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Particle Diameter (µm) TRONOX Confidential Information

Effect of Particle Size on Gloss Frequency 67 73 20° gloss in 78 solvent paint 81 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Particle diameter [µm] Schematic particle size distributions of 4 pigments and their gloss

Particle Size vs. Hiding Power, Gloss & Dispersion TRONOX Confidential Information

Titanium Dioxide Particle Inner Coating of Titania, Silica, Organic or Zirconia Moieties TiO 2 Core Outer Coating Hydroxyl of Alumina HO Groups