Basic magnesium carbonate, production method and use of the same
AssigneeNittetsu Mining Co., Ltd.
InventorsKohei Mitsuhashi, Katsuyuki Tanabe, Naoki Tagami
Life of this patent
Estimating the term…
Abstract
Basic magnesium carbonate comprising a tubular aggregated particle of flaky fine crystals.
Claims31
A basic magnesium carbonate comprising a tubular aggregated particle of flaky fine crystals, wherein the tubular aggregated particle has a hollow structure and said basic magnesium carbonate has hydroxyl group and water of crystallization and is represented by the formula mMgCO3·Mg(OH)2·nH2O, where m is 3 to 5 and n is 3 to 8.
A method for producing a basic magnesium carbonate comprising a tubular aggregated particle of flaky fine crystals, wherein the tubular aggregated particle has a hollow structure, which comprises a first step of mixing a water soluble magnesium salt and a water soluble carbonate salt in an aqueous solution to produce a columnar particle of a normal magnesium carbonate at a temperature of 20 to 60° C., and a second step of subjecting a suspension of the columnar particles of the normal magnesium carbonate to a heat treatment at a higher temperature than the temperature in the production of the normal magnesium carbonate in the first step, and at a temperature of 35 to 80° C.
A method for producing a basic magnesium carbonate comprising a tubular aggregated particle of flaky fine crystals, wherein the tubular aggregated particle has a hollow structure, which comprises a first step of introducing a gas containing carbon dioxide into a suspension of magnesium hydroxide to prepare a solution of magnesium hydrogen carbonate, a second step of adjusting the solution of magnesium hydrogen carbonate to have a pH of 7.5 to 11.0 to produce a columnar particle of a normal magnesium carbonate, and a third step of adjusting a suspension of the columnar particles of the normal magnesium carbonate to have a pH of 9.0 to 12.0 and a temperature in a range of 30 to 75° C., followed by keeping the temperature within the range to produce a basic magnesium carbonate.
Dependencies are inferred from the claim text.