china anatase rutile

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Having thus described the origin and uses of the pigment, we now come to the question, what is lithopone? It is, in short, a chemical compound usually consisting of 30.5 per cent zinc sulphide, 1.5 per cent zinc oxide and 68 per cent barium sulphate, but these proportions vary slightly in the different makes. Lithopone of this composition is sold as the highest grade, either as red seal or green seal, as it best suits the idea of the manufacturer. Many manufacturers, especially in Europe, sell and also export other brands under other seals, containing 24, 20, 18 and as little as 12 per cent of zinc sulphide with very small percentages of zinc oxide, the balance being usually barium sulphate, but sometimes certain portions of China clay or gypsum (calcium sulphate) or whiting (calcium carbonate). Such brands are not a chemical compound, but mechanical mixtures of the chemically compounded lithopone and the admixtures referred to.

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To address these challenges, researchers are exploring alternative production methods that are more energy-efficient and environmentally friendly. For example, the use of solar energy to power the oxidation of titanium ore has been proposed as a way to reduce the energy consumption of the sulfate process. Other approaches include the development of new catalysts that can replace sulfuric acid in the oxidation step, as well as the exploration of bio-based feedstocks for TiO2 production.

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