
Scrap zinc or concentrated zinc ores are dissolved in sulfuric acid, the solution is purified, and the two solutions are reacted. A heavy mixed precipitate results that is 28 to 30% zinc sulfide and 72 to 70% barium sulfate.

In the meantime, some big manufacturers boosted their product pricing to better their margins, such as Venator, which increased its titanium dioxide prices by roughly 160 USD /MT for the third quarter of 2021 in the North America region. Overall, prices for Anatase grade in the United States hovered about 3485 USD /MT through the end of June.
In a 2021, Chinese researchers examined the impact of E171 on lipid digestion and vitamin D3 bioaccessibility in a simulated human gastrointestinal tract model. They examined Vitamin D’s bioaccessibility, or the amount it was released in the gastrointestinal tract, becoming available for absorption, and found it “significantly decreased from 80% to 74%” with the addition of E171. In the experiment, E171 decreased lipid digestion dose-dependently. Researchers wrote: “The findings of this study enhance our understanding toward the potential impact of E171 on the nutritional attributes of foods for human digestion health.” The study was published in the Journal of Agricultural and Food Chemistry,
Particle size: optimum particle size to produce maximum opacity is 200–300 nm.