With nearly 50 million housing units likely to be built if Africa is to meet its current housing deficit, demand for paint and coatings, ceramic surfaces, wallpapers, wood flooring, marble, stone, bathroom furnishings, brick, sanitary ware and tile is likely to grow and so will the utilization of titanium dioxide.
In Nigeria alone, an estimated $800,000 is spent every year on ceramic, kitchen, bathroom, sanitary, marble and stone products according to Elan Expo, which organized the Ceramica West Africa 2019.
Growth of the ceramic industry globally has been credited for driving the rising use of titanium dioxide despite emerging market and environmental issues around the production and continued use of the chemical, which is also a popular ingredient in the making of products such as plastic, paper and pharmaceuticals.
But with the cost of titanium dioxide having more than tripled in the last eight years, what options are available to ensure the manufacture of high-quality paint and coatings products to support the anticipated urban infrastructure and housing boom in Africa?
During this year’s Coatings Group-organized East African Coatings Congress (EACC) in Nairobi, it emerged the price of and demand for TiO2 is likely to remain high largely because the chemical is still a preferred ingredient in the manufacturing process of various products required by the building and construction industry.
“The market of cheap and plentiful titanium dioxide is clearly over and there is every indication that over the medium and long term TiO2 prices will climb further and production facilities will be put under continuing close scrutiny, which adds up to a revival of interest in white mineral extenders that can be used as partial replacement for TiO2,” said Andrew Pleeth, who spoke at the EACC on behalf of China Mineral Processing, which for more than three decades has been producing Snowhite and Snowpaque, high white fine particle-sized structured calcined kaolins used as extenders in the paints and coatings industry.
The use of TiO2, which some analysts separately predict will experience a compound annual growth rate of more than four percent by 2023, “is due primarily to its important physical characteristics which are high refractive index, high opacity, chemical inertness and high brightness,” he said.
In fact, Pleeth said paint and coating manufacturers have previously explored alternative fillers and extenders to mitigate TiO2 supply shortages, which in the past pushed up the price of the chemical. But they found out not all alternatives meant to match the standard TiO2 extension “are pure white, and even those that have good whiteness still cannot match TiO2 for opacity or hiding power,” he said.
“Two properties appear paramount when considering alternatives to standard TiO2; opacity and color,” he added.
He told EACC participants it is TiO2’s opacity and hiding power that attracts paint and coating manufacturers to it. Pleeth said the opacity has “the light-scattering ability of a pigment” which is characterized by refractive index, particle size and particle-
In decorative paint, Pleeth said, opacity is “the ability of the paint film to prevent light from interacting with the substrate and is achieved when all incident light is reflected back i.e. scattered or absorbed.”
“Light scattering occurs when light changes direction by refraction or diffraction.”
Two of the known ways that opacity can be achieved is through the high refractive index with the use of TiO2 and Dry hiding that comes from the air voids, he added.
High refractive index, Pleeth said, “Is an important mechanism in decorative paints and it provides good wet and dry opacity but is expensive” although some fillers/extenders can be utilized to improve the opacity and allow some reduction in the amount of TiO2 used, hence mitigate the high cost of the final product.
Dry hiding on the other hand “is also an important mechanism but for high PVC paints but which can also be achieved at a lesser cost with the use of certain fillers/extenders,” Pleeth said.
Since there is no known total substitute for TiO2, Pleeth said users have to resort to known ways to improve the performance of products such as paints and coatings.
Some of the options to consider include the use of Rutile, one of the three forms of TiO2 but with a high concentration of TiO2 content or utilizing “fine extenders for spacing and functional extenders for air entrapment together with carefully selected dispersants and functional binders.”
Pleeth said there is a strong case for the consumption of optimized calcined kaolins for high PVC paints to reduce the use of TiO2 because the former ingredients “are designed for this purpose, are readily available and can provide significant cost savings.”
“It is clear to us all that TiO2 is not 100 percent replaceable by filler, for example, to do so you may need a thicker layer by a factor of eight to 10 to maintain for example opacity, which is not a realistic option,” he said.
“Today more than ever, the paint sector buyers and technical departments have a responsibility to cut costs and with the relentless increasing prices in TiO2, there are real opportunities.”
In 2010 TiO2 was available at a cost of $500pmt, which in last eight years has spiked to more than $2200pmt, per Pleeth.
MarketWatch, which is published by Dow Jones & Co, said “the rising prices of TiO2 and its negative effects on human are pushing end-user industries to use substitute products.”
“This will hinder the growth of the titanium dioxide market during the forecast period,” per its ‘Titanium Dioxide (TiO2) Market Research Report to 2023’ report.
Nevertheless, paint makers across the globe can substantially reduce the cost of a can of paint and retain high product quality by use of functional fillers or extender pigments.
“For the paint maker the aim is to reduce costs but you need at the same time to maintain the necessary acceptable quality and this is the challenge that can be most successfully achieved with the use of so-called functional extenders rather than straight forward fillers,” Pleeth said.
Fillers make it possible to lower the cost of paint because they are “natural occurrence minerals such a clay, talc and carbonate and are often used and regarded as a cheap way of reducing the cost of a can of paint,” he added.
Pleeth said some of the fillers and extenders used by paint formulators to achieve desired product properties include Calcined kaolin, Hydrous kaolin, Synthetic Silicates, Calcium carbonates, Talc, Barium sulphate and Opaque polymer.
Some of the players in Africa’s TiO2 market include Tronox Limited, The Chemours Company, Cristal, Huntsman Corporation, Evonik Industries and Lanka Mineral Sands Limited.
Going forward, “Paint makers across the globe are expanding and modernizing their production facilities with increasing technical sophistication resulting in improved quality and decreased costs of production, this implemented together with careful selection of the latest raw materials is now a key focus of the industry,” Pleeth said.