... 98Hydrochloric acid insoluble matter% ≤ 0.20Free alkali content of qualifiedHeavy Metals ≤ 20ppmBarium content% ≤ 0.03Magnesium and alkali ... carbonateEnglish Name: Calcium CarbonateChinese Synonyms: light calcium; activity of calcium carbonate; light calcium carbonate; calcite; precipitated ... 93Melting point: 825 °CBoiling point: for the production of cement, ceramics, lime, calcium, toothpaste, dyes, ...