CZ253091A3 - process for preparing dypingite - Google Patents

Abstract

The method consists in the effect of water vapor on the nesque chase at a temperature of 90-120 ° C for 2 to 3 hours.

Description

Technical field

The present invention relates to a process for producing dypingite by decomposing nesquehonite with water vapor.

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BACKGROUND OF THE INVENTION

Dypingite Mg ^ (CO ^ / ^ / OH / g · 5H ₂ O) belongs to the group of hydrated basic magnesium carbonates, similar to, for example, hydromagnesite Mg ^ / CO Č / ^ / OH ^ 4H ₂ Q, which under the titles of magnesia alba or magnesium carbonicum leve used in cosmetics and pharmaceutical industry, further in gymnastics to increase friction and reduce hand perspiration (FR 2 647 432), in the production of hydrotalkite and so-called lightweight and active forms of magnesium (magnesium mouth, magnesia ponderosa), usable in rubber and the plastics industry (JP 77-149 299), in the chemical and petrochemical industry as catalysts and catalyst supports, in mechanical engineering for surface treatment, transformer plates, in the preparation of vanadium corrosion inhibitors and others.

Among the hydrated basic magnesium carbonate is the most common hydromagnesite, normally pri-, prepares thermal decomposition nesquehonitu MgCO ^ · 3H ₂ O in TE. plate temperature range of 55 to about 200 ° C (depending on the partial pressure of carbon dioxide in the gas atmosphere). Hydromagitide and dypingite are formed as constituents of the basic magnesium carbonate prepared according to the invention. No. 196,905. Dypingite in pure form occurs as a relatively rare natural mineral and has also been found to be one of the intermediates produced by heating and aerating an aqueous solution of magnesium bicarbonate / Canterford,

JH - Tsambourakis, G .: Some observations on properties of dypingite, Mg ^ / co ^ / ^ / OH / ₂ . 5H ₂ O and related minerals.

Mineralogical Magazine 4S / 1984? 437-442 /. The method of its preparation in pure form is not mentioned in the literature.

SUMMARY OF THE INVENTION

Dypingite is formed by the decomposition of nesquehonite with water vapor in the temperature range of 90 to 120 ° C «

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Nesquehonite is subjected to water vapor for 2 h at 100 ° C. _{E The} resulting dypingite has a chemical composition and an X-ray diffraction pattern of polycrystalline samples according to the literature / cited data cited by Canterford and Tsambourakis / _O.

Example 2

Magnesium hydroxide suspension / 20 wt. in water) is converted into a suspension of nesquehonite by the action of carbon dioxide gas at 20 ° C, to which it is treated with bubbling hot air at 120 ° C for 3 hours. The resulting dypingite has the characteristics as in Example 1.

Example 3

After separation of the aqueous phase by decantation, the non-quehonite prepared as in Example 2 is treated with water vapor at 115 ° C for 2 hours. The dypingite produced in the quantitative yield has the characteristics as in Example 1.

Industrial applicability

The invention can be used in the manufacture of hydrotalcite, used as an antacid to control the pH of the stomach condition and as a polymer stabilizer, as well as in the cosmetics and pharmaceutical industries.

Claims (1)

PATENT CLAIMS Process for producing dypingite Mg 2 O 2 O 2 / OH / g. 5H ₂ ° / characterized in that it is impregnated with unsquehonite MgCO 3 · 3 → 0 with water vapor at a temperature of 90 to 120 ° C for 2 to 3 hours ·