Assertion: magnesium carbonate | /r/AtLocation | the mineral
Facets:
value: by calcining the mineral
type: MANNER
value: into oxide
type: OTHER
Source sentences:
text: A continuous cyclic process for the manufacture of pure magnesium carbonate and pure magnesium oxide from minerals containing the same which cornprises: transforming the magnesium carbonate contained in the mineral into oxide by calcining the mineral, adding water at room temperature to the calcined prod uct to form a suspension comprising magnesium hydroxide, said water being added in an amount sufficient to permit theoretically the complete dissolution of the magnesium calculated as magnesium bicarbonate, treating said suspension with carbon dioxide containing gas until all of the magnesium hydroxide has been dissolved in the form of magnesium bicarbonate, separating the magnesium bicarbonate solution from the insoluble residue, adding to the separated magnesium bicarbonate solution, Without subjecting said solution to heating, an amount of magnesium oxide substantially equal to the calculated amount of magnesium oxide contained in said magnesium bicarbonate solution to precipitate substantially immediately as hydrated magnesium carbonate both the magnesium added as magnesium oxide and the magnesium present as magnesium bicarbonate, said magnesium oxide being prepared by heating said precipitated hydrated magnesium carbonate to a temperature not exceeding 600 C., stirring until the motor liquor contains no more magnesiumbicarbonate than 0.15% by Weight calculated as magnesium oxide, separating the precipitated hydrated magnesium carbonate from its mother liquor and dividing the product into two equal parts, drying one of said parts to obtain anhydrous magnesium carbonate, calcining the other part at a temperature not exceeding 600 C. until magnesium oxide is formed and recycling said magnesium oxide to the magnesium bicarbonate solution.