lithopone is factories

From studies deemed relevant, the experts found that titanium dioxide as a food additive is poorly absorbed by the gastrointestinal tract of mice and rats, with no adverse effects observed in short-term studies in rodents receiving titanium dioxide in their diets. No observed adverse effect levels (NOAELs) of 15,000 milligrams per kilogram of bodyweight (mg/kg BW) per day and 5,000 mg/kg BW per day—the highest doses tested—were established for mice and rats, respectively.

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3) Metathesis reaction: Dissolve the sulfide in distilled water to obtain a clear decomposition liquid, and add nonionic surfactant to stir evenly, then slowly add it to the zinc sulfate ammonia complex solution to form a metathesis reaction, and obtain Lide powder opacity. The liquid is separated by filtration, and the separated ammonia liquid is returned to the leaching after ammonia adjustment, and the separated nZnS-BaS0 4 crystal filter cake is put into the next step;

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