7 results about "Hydromagnesite" patented technology

The invention provides a method for preparing magnesium oxide by calcining magnesite, which comprises the following steps: introducing fuel into a decomposer or into the decomposer and an activity regulator, igniting, and discharging generated high-temperature flue gas after flowing through a multi-stage preheating unit, a drying unit and a tail gas separation unit, feeding a water-containing magnesite raw material into a dryer to be in contact with hot flue gas from a preheater so as to remove moisture; the dried material passes through a multi-stage preheater and is subjected to countercurrent flow heat exchange with high-temperature flue gas from a decomposer, so that the temperature of the material is increased; the preheated material is heated to the decomposition temperature in a decomposer, and magnesium carbonate is decomposed to generate magnesium oxide; separating the decomposed gas-solid mixture to obtain a high-temperature magnesium oxide solid; and performing countercurrent flow heat exchange on the high-temperature magnesium oxide solid and combustion-supporting air, and outputting cooled magnesium oxide. Through multi-stage countercurrent flow heat exchange and product sensible heat recovery, an efficient heat energy circulation system is constructed, and the fuel energy consumption in the calcination process is remarkably reduced; the method realizes flexible regulation and control of magnesium oxide product activity, and is suitable for continuous clean production of fine particle raw materials.

The present invention relates to a method of manufacturing a surface-modified material, wherein the method comprises the steps of applying a coating composition onto at least one surface of a substrate to form a porous coating layer thereon, wherein the coating composition comprises mineral particles selected from the group consisting of calcium carbonate, calcium phosphate, hydromagnesite, and mixtures thereof, and a binder, and infusing the porous coating layer with at least 150 wt.-%, based on the total weight of the porous coating layer, of an infusing liquid composition to form a contained liquid layer within and on the porous coating layer, wherein the infusing liquid composition is chemically inert to the substrate and the porous coating layer. Furthermore, the present invention relates to a corresponding surface-modified material, an article comprising the same, and the use of such materials.

The invention discloses hydromagnesite fractional precipitation and double-type compound silicon steel magnesium oxide and a preparation method thereof, and the preparation method comprises the following steps: mixing gradient-calcined light-boiled hydromagnesite with a hydrochloric acid solution to obtain a magnesium chloride solution; a-type magnesium oxide with the CAA activity of 20-50 s and B-type magnesium oxide with the CAA activity of 80-120 s are prepared by adding a precipitator ammonium bicarbonate or sodium hydroxide into a magnesium chloride solution through fractional precipitation, and the A-type magnesium oxide and the B-type magnesium oxide are regulated and controlled according to the physical compounding proportion to obtain the double-type compounded silicon steel magnesium oxide with the average particle size smaller than or equal to 3 microns, the purity larger than or equal to 99% and the CAA activity of 50-80 s. The method synergistically solves the contradiction between the silicon steel magnesium oxide hydration rate and the suspension stability, and is suitable for preparing the high-magnetic-induction oriented silicon steel annealing isolation coating.

This invention discloses a method for low-temperature roasting of magnesia from hydromagnesia, the resulting magnesium oxide, and its applications. The method includes: mixing a solution containing magnesia-chlorite with magnesia, drying and crushing the magnesia, followed by a one-step calcination to obtain magnesium oxide. The method provided by this invention ensures complete decomposition of magnesia while lowering the decomposition temperature, resulting in the production of magnesium oxide with higher activity and purity. It also effectively reduces energy consumption and CO2 emissions during the production process. Furthermore, the magnesium oxychloride cementitious material prepared using the aforementioned magnesium oxide exhibits superior mechanical properties.

The present invention relates to a method for directly capturing carbon dioxide from the air. The method for directly capturing carbon dioxide from the air according to the present invention is characterized by comprising the steps of: reacting seawater desalination concentrate with an alkali solution to form and separate magnesium hydroxide in a solid state; adding magnesium hydroxide to water to create a reaction solution and injecting carbon dioxide to precipitate hydromagnesite; heating the reaction solution to precipitate magnesium carbonate and basic magnesium carbonate and capturing carbon dioxide discharged from the reaction solution; injecting air containing carbon dioxide into the reaction solution to lower the pH; heating the reaction solution again to precipitate magnesium carbonate and basic magnesium carbonate and capturing carbon dioxide discharged from the reaction solution; and repeating the carbon dioxide injection step and the second capture step repeatedly and continuously after the second capture step.

The application discloses a kind of water magnesite-based fire extinguishing powder and its preparation method and application.The fire extinguishing powder of the application includes the fire extinguishing powder includes modified water magnesite and dry powder additive;The modified water magnesite powder is the water magnesite powder with modifier on surface;The modifier is selected from MHCO3, and M is monovalent metal ion.The modifier is loaded to the surface of water magnesite powder in the application, and water magnesite powder is given chemical inhibition effect, and the fire extinguishing efficiency thereof is further improved on the basis of physical inhibition;And by adding other inert ingredients, the hydrophobicity and oleophobicity, flowability and dispersion effect of water magnesite powder are improved, and the agglomeration phenomenon is reduced, so that the comprehensive performance reaches the design standard of dry powder fire extinguishing agent specified by the state.

The present invention refers to a dry composition for chemical and physical sun protection, the composition comprising at least one mineral material selected from the group consisting of surface reacted calcium carbonate and / or hydromagnesite, and from 0.1 wt.-% to 100 wt.-%, based on the dry weight of the at least one mineral material of at least one lignin. Furthermore, the present invention refers to an emulsion comprising the inventive dry composition as well as the use of the inventive emulsion for chemical and physical sun protection in a cosmetic formulation.