classification of calcium carbonate factory
US 1478347, Mitchell John L, Apparatus for calcining lithopone, published Dec 18, 1923, assigned to Mitchell John L
Honey buns are a popular snack enjoyed by people of all ages. These delicious pastries are typically made with a combination of flour, sugar, butter, eggs, and honey. However, the ingredients list for honey buns can vary depending on the manufacturer. One ingredient that is sometimes included in honey bun recipes is titanium dioxide.
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2025-08-14 14:01
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Titanium dioxide production begins with the extraction of raw materials, typically ilmenite or rutile, from mines. In a white titanium dioxide factory, these minerals undergo a rigorous refining process that includes steps like sulfuric acid digestion, chloride process, or sulfate process, depending on the factory's technology and resources. The resulting titanium dioxide pigment is then purified, dried, and ground to achieve the desired particle size and quality.
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2025-08-14 13:59
2044
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2025-08-14 13:49
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First, the ammonia leaching method is used as a technical means for the effective treatment of acid leaching slag, and the nano nitrite powder is prepared under a weak alkaline ( Ή 8 8.5 to 10) ammonia environment. In an alkaline environment, some metal impurities such as The solubility of Ca, Mg, Fe and Al hydroxides is low, and the impurities entering the final immersion liquid in the selective leaching of ammonia-ammonium sulfate are reduced, thereby ensuring the quality of the product; the traditional acid method for preparing lithopone is because of the zinc calcination. In the roasting and reduction process of the alkalized alkali, the elemental sulfur and sulfite are more or less produced, and the prepared white powder has a yellowish color, and the metathesis reaction of the patent is carried out in an ammonia solution (alkaline). The final product obtained is sulfate, which is quickly and thoroughly added by desulfurization through 3⁄40 2 , and the whiteness of the product can be ensured without high temperature calcination; the equipment requirement is lower than that of sulfuric acid leaching, and the ordinary steel leaching tank can complete the leaching; The environmental pollution problem of acid leaching residue, especially effectively solves the environmental pollution of heavy metals such as zinc, copper, lead, cadmium and arsenic in acid leaching residue and the influence of acid ions on the storage environment. Realize the recycling of high-value metal zinc in acid leaching slag, realize the acidity improvement of soil and have the comprehensive advantages of low cost, energy saving and environmental protection.
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2025-08-14 13:39
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2025-08-14 13:31
1938
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2025-08-14 13:24
1988
Titanium dioxide production begins with the extraction of raw materials, typically ilmenite or rutile, from mines. In a white titanium dioxide factory, these minerals undergo a rigorous refining process that includes steps like sulfuric acid digestion, chloride process, or sulfate process, depending on the factory's technology and resources. The resulting titanium dioxide pigment is then purified, dried, and ground to achieve the desired particle size and quality.
First, the ammonia leaching method is used as a technical means for the effective treatment of acid leaching slag, and the nano nitrite powder is prepared under a weak alkaline ( Ή 8 8.5 to 10) ammonia environment. In an alkaline environment, some metal impurities such as The solubility of Ca, Mg, Fe and Al hydroxides is low, and the impurities entering the final immersion liquid in the selective leaching of ammonia-ammonium sulfate are reduced, thereby ensuring the quality of the product; the traditional acid method for preparing lithopone is because of the zinc calcination. In the roasting and reduction process of the alkalized alkali, the elemental sulfur and sulfite are more or less produced, and the prepared white powder has a yellowish color, and the metathesis reaction of the patent is carried out in an ammonia solution (alkaline). The final product obtained is sulfate, which is quickly and thoroughly added by desulfurization through 3⁄40 2 , and the whiteness of the product can be ensured without high temperature calcination; the equipment requirement is lower than that of sulfuric acid leaching, and the ordinary steel leaching tank can complete the leaching; The environmental pollution problem of acid leaching residue, especially effectively solves the environmental pollution of heavy metals such as zinc, copper, lead, cadmium and arsenic in acid leaching residue and the influence of acid ions on the storage environment. Realize the recycling of high-value metal zinc in acid leaching slag, realize the acidity improvement of soil and have the comprehensive advantages of low cost, energy saving and environmental protection.
On November 23, 2022, the General Court of the European Union reversed the conclusion that titanium dioxide was carcinogenic and released a statement (1,2):
“First, the Commission made a manifest error in its assessment of the reliability and acceptability of the study on which the classification was based and, second, it infringed the criterion according to which that classification can relate only to a substance that has the intrinsic property to cause cancer.”
As part of our mission at CRIS we base our safety assessments on the currently available scientific evidence and consider many variables (e.g., study quality, journal of publication, etc.), even if it goes against previous conclusions. Evidence-informed decisions making is critical to ensure that the laws and regulations put into place are for the benefit of the population.
The EU General Court maintains that the scientific evidence presented wasn’t the complete picture for the ingredient, “in the present case, the requirement to base the classification of a carcinogenic substance on reliable and acceptable studies was not satisfied.”