Material Insights · Understanding the Material World

Chlorine and Titanium dioxide

The chloride route to titanium dioxide chlorinates titanium feed into titanium tetrachloride and then burns it back to pigment, recovering most of the chlorine for reuse, so only make-up chlorine is bought. About half of world pigment is made this way, but in China, the largest producer, the sulphate route, which uses sulphuric acid instead of chlorine, still dominates.

Chlorine (chemical) and Titanium dioxide (chemical): 4 relationships.

How they are linked

1. Chlorine in the chloride process

Physical flow · Strong · Chlorine used and recycled in pigment making

Titanium feed is mixed with coke and chlorinated to titanium tetrachloride, which is burned with oxygen to give pigment; the chlorine released is collected and sent back to the chlorinator.

  • about 90% share of chlorine that may be recycled in the chloride process (IARC, 1989)

Because most chlorine is recycled, a chloride plant buys only make-up chlorine, but it cannot run without it. Chemours, with about 1.1 Mt a year of chloride-route capacity, lists chlorine with ore, petroleum coke and energy as its key raw materials; in India, KMML chlorinates beneficiated ilmenite the same way.

Sources: International Agency for Research on Cancer (WHO); The Chemours Company (US SEC filing); The Kerala Minerals and Metals Ltd

2. Chloride versus sulphate route

Substitution · Medium · Sulphate route uses no chlorine

The sulphate route digests ilmenite in sulphuric acid instead of using chlorine, so the mix of routes decides how much chlorine the pigment industry needs.

  • about half share of world titanium dioxide made by the chloride route, 2023 estimate
  • about 13% chloride route share of China's output, 2023 estimate

The chloride route needs high-titanium feed such as rutile or titanium slag, while the sulphate route can use ilmenite; a tonne of pigment takes about 2.4 to 2.5 t of titanium concentrate. Because China's industry is still mostly on the sulphate route, pigment growth there adds little chlorine demand.

Sources: Anti-Dumping Commission, Australia (public record exhibit); International Agency for Research on Cancer (WHO)

3. Chlorine supply beside pigment plants

Joint production · Medium · Chlor-alkali units co-located with pigment

Chlorine is costly and hazardous to move, so chloride-route pigment plants secure supply from neighbouring chlor-alkali units or long-term contracts.

Chemours' New Johnsonville site in Tennessee has a third-party chlor-alkali plant on site, and the company has agreed a chlorine supply deal with the PCC Group. A chlorine outage at the supplier can therefore stop pigment output.

Sources: The Chemours Company (US SEC filing)

4. Price link: process input

Cost and price · Medium · Both ways

Pigment prices follow paint and plastics demand, and chlorine and power costs feed in over time, so the two move together over a year more than month to month.

  • 0.09 monthly change correlation
  • 0.68 12-month change correlation
  • 0.61 fitted elasticity

The site's chlorine proxy is an alkalies index, and the best fit comes with a lag of about three months. With most chlorine recycled, chlorine price is a minor cost for pigment; the shared drivers are energy and the construction and industrial cycle.

Sources: Material Insights (World Bank, FRED, IMF data)

For investors

Key learnings

  1. Chloride-route pigment makers need only make-up chlorine, so chlorine cost matters less than reliable supply.
  2. Half the world's pigment uses chlorine, but China's sulphate-heavy industry means pigment growth there adds little chlorine demand.
  3. A chlorine supplier outage is an operating risk for chloride-route plants that rely on a single neighbour.

What to track

  • Chloride route capacity additions in China: Would raise chlorine demand from pigment (Quarterly · company reports, industry consultants)
  • Titanium dioxide prices and Western closures: Show pressure on chloride-route plants (Monthly · industry price reports)
  • Chlorine supply incidents at co-located plants: Can stop pigment output (As reported · company announcements)

For policymakers

Key learnings

  1. India's only chloride-route pigment producer is KMML, so domestic chloride capacity depends on chlorine supply and upgraded ilmenite feed.
  2. Expanding chloride-route capacity creates a stable local chlorine outlet, which helps balance chlor-alkali production.
  3. The sulphate route avoids chlorine but uses large amounts of acid and ilmenite, so route choice is also a waste and feed policy choice.

What to track

  • KMML and other pigment capacity plans: Show future domestic chlorine demand from pigment (Annual · company reports)
  • India titanium dioxide imports: Show how much pigment demand is met abroad (Monthly · DGCI&S)

India

Kerala Minerals and Metals (KMML) is India's first and only maker of rutile-grade titanium dioxide by the chloride process, chlorinating beneficiated ilmenite from its own plant.

Sources

  1. Price correlation, Material Insights, Material Insights (World Bank, FRED, IMF data)
  2. IARC Monographs volume 47: titanium dioxide, section 2.1 production, International Agency for Research on Cancer (WHO) (1989)
  3. The Chemours Company Form 10-K for fiscal year 2025, The Chemours Company (US SEC filing) (2026)
  4. Basic chemical industry: titanium dioxide (Xueqiu article, exhibit B 3.45), Anti-Dumping Commission, Australia (public record exhibit) (2023)
  5. Process, The Kerala Minerals and Metals Ltd