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Method for preparing magnesium hydroxide from calcium-magnesium-carbonate-containing ore

A technology of calcium magnesium carbonate and magnesium hydroxide, applied in the directions of magnesium hydroxide, calcium carbonate/strontium/barium, etc., can solve the problems of poor water solubility of organic amines, low utilization rate of magnesium ions, insufficient energy utilization, etc. Easy to wash, easy to handle, the effect of improved product quality

Inactive Publication Date: 2017-07-28
LONGYAN ZIYUN CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, most technologies still have technical problems such as high energy consumption, insufficient energy utilization, and low utilization of magnesium ions.
And organic amine has outstanding advantages as a kind of base in the production technology of precipitation magnesium ion synthesis magnesium hydroxide, but because the organic amine selected in previous research has poor water solubility, the yield of magnesium ion conversion into magnesium hydroxide is limited , Magnesium ions are easily entrained by gypsum in the process of recycling organic amines, resulting in waste of resources and increased costs

Method used

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  • Method for preparing magnesium hydroxide from calcium-magnesium-carbonate-containing ore

Examples

Experimental program
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Effect test

Embodiment 1

[0054] (1) Ammonium sulfate solution and dolomite ore powder are packed into the autoclave with a concentration of 15wt%, and the mol ratio NH of calcium and magnesium ions in the control ammonium ion and dolomite ore powder 4 + :(Ca 2+ +Mg 2+ )=2:1, control the reaction temperature to 220°C, and the reaction pressure to 2.5Mpa. After the reaction is complete, the gas phase obtains a high-pressure mixed steam of ammonia, carbon dioxide and water at a temperature of 220°C and a pressure of 2.5MPa, and the solute in the liquid phase Including magnesium sulfate solution, calcium sulfate is obtained in solid phase;

[0055] (2) The high-pressure mixed steam of ammonia, carbon dioxide and water obtained in step 1) first enters the primary evaporator as a heat source for evaporating and concentrating magnesium sulfate or the ammonium sulfate solution of recovery, and the secondary steam produced by evaporation is used for Subsequent calcium carbonate or magnesium hydroxide produc...

Embodiment 2

[0065] (1) Ammonium sulfate solution and magnesite powder with a concentration of 25wt% are packed into an autoclave to control the mol ratio NH of ammonium ion and magnesium ion in the magnesite powder 4+ :Mg 2+ =2.5:1, the control reaction temperature is 180 DEG C, and the reaction pressure is 1.5Mpa. After the reaction is complete, the gas phase obtains a temperature of 180 DEG C and a pressure of 1.5MPa ammonia, carbon dioxide and high-pressure mixed steam of water, and the liquid phase obtains magnesium sulfate Solution, solid phase obtains calcium sulfate;

[0066] (2) The high-pressure mixed steam of ammonia, carbon dioxide and water obtained in step 1) first enters the primary evaporator as a heat source, and is used for evaporating and concentrating magnesium sulfate or the ammonium sulfate solution of recovery, and the secondary steam produced by evaporation is used for Subsequent calcium carbonate or magnesium hydroxide products are dried, and at the same time, the...

Embodiment 3

[0076] (1) Ammonium sulfate solution and dolomite ore powder that concentration is 40wt% are packed in autoclave, control the mol ratio NH of calcium magnesium ion in ammonium root ion and dolomite ore powder 4+ : Mg 2+ =3:1, the control reaction temperature is 140 DEG C, and the reaction pressure is 0.4Mpa. After the reaction is complete, the gas phase obtains a high-pressure mixed steam of ammonia, carbon dioxide and water with a temperature of 140 DEG C and a pressure of 0.4 MPa, and the liquid phase obtains magnesium sulfate Solution, solid phase obtains calcium sulfate;

[0077] (2) The high-pressure mixed steam of ammonia, carbon dioxide and water obtained in step 1) first enters the primary evaporator as a heat source for evaporating and concentrating magnesium sulfate or the ammonium sulfate solution of recovery, and the secondary steam produced by evaporation is used for The subsequent calcium carbonate or magnesium hydroxide products are dried, and at the same time,...

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Abstract

The invention provides a method for preparing magnesium hydroxide from calcium-magnesium-carbonate-containing ore. The method includes the steps of (1), adding ammonium sulfate aqueous solution and carbonate ore into a reactor, separating reaction products to obtain a gas phase, a liquid phase and a solid phase; (2), subjecting the gas phase to fractional condensation to obtain ammonium carbonate solution; (3), adding the liquid phase to a water-soluble organic alkali solution while stirring, and then filtering to obtain a filter cake and filter liquor; (4), adding calcium hydroxide to the filter liquor obtained in the step (3) for reaction, filtering after finishing reaction to obtain a filter cake and filter liquor, and taking at least a part of the filter liquor as a raw material for the step (1); (5), subjecting the ammonium carbonate solution obtained in the step (2) and the filter cake obtained in the step (4) to reaction, filtering after finishing reaction to obtain filter liquor, and taking at least a part of the filter liquor as a raw material for the step (1). Compared with the conventional synthesis technique of magnesium hydroxide by ammonia-soda process, the method has the advantage of increasing utilization rate of magnesium ion greatly.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to a method for producing magnesium hydroxide from carbonate minerals containing calcium and magnesium. Background technique [0002] Magnesium hydroxide is an important inorganic magnesium salt series product, showing weak alkalinity. At the same time, magnesium hydroxide decomposes into magnesium oxide and water when the temperature reaches 300-350 ° C, and completely turns into magnesium oxide when the temperature is higher than 500 ° C. Two characteristics make magnesium hydroxide widely used, such as the industrial application of magnesium hydroxide as a flue gas desulfurization absorbent to replace the previously used sodium hydroxide and calcium hydroxide and to neutralize acidic wastewater. Magnesium hydroxide's high decomposition temperature, smokeless, non-toxic, and cheap characteristics make it also a good flame retardant, especially in the field ...

Claims

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Application Information

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IPC IPC(8): C01F5/16C01F5/14C01F11/18
CPCC01F5/14C01F5/16C01F11/18
Inventor 钟劲光吴明
Owner LONGYAN ZIYUN CHEM TECH
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