Method for producing synthetic hectorite at low temperature and atmospheric pressure

Patent metadata

Field	Value
Publication number	US-10843928-B2
Application number	US-201716074385-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Nov 14, 2016
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

The present invention relates to a method for producing synthetic hectorite at a low temperature and atmospheric pressure and synthetic hectorite produced by the same, and more particularly, to a method for producing synthetic hectorite and synthetic hectorite produced by the same in which: a step of forming Li—Mg precipitates is introduced and thereby ensures an improved crystallization reaction condition and synthetic hectorite having excellent properties; and composition ratios of reactants are controlled, and thus, property control is easy.

First claim

The invention claimed is:

1. A method for producing synthetic hectorite, the method comprising the steps of:
1) preparing a source solution mixture comprising a lithium (Li) source, a fluorine (F) source, and a magnesium (Mg) source;
2) adding a basic catalyst that is one or more selected from the group consisting of sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH) 2 ), and ammonium hydroxide (NH 4 OH), into the source solution mixture in an amount to adjust a pH of the source solution to 7 to 10 to form Li—Mg precipitates; and
3) adding a silica (Si) source into the Li—Mg precipitates and performing a crystallization reaction at a temperature of 70° C. to 85° C. under a pressure of 1 bar to 1.21 bar for 10 hours to 40 hours to yield the synthetic hectorite,
wherein a molar ratio of the lithium source and the fluorine source is 1:1 to 1:10.

2. The method for producing synthetic hectorite of claim 1 , wherein the silica source and the magnesium source are added in a molar ratio of 2:1 to 1:1.

3. The method for producing synthetic hectorite of claim 1 , wherein a washing or filtering step is not performed prior to the crystallization of step 3).

4. The method for producing synthetic hectorite of claim 1 , wherein the lithium source is one or more selected from the group consisting of lithium fluoride (LiF), lithium hydroxide (LiOH), lithium chloride (LiCl), lithium carbonate (Li 2 CO 3 ), and lithium sulfate (Li 2 SO 4 ).

5. The method for producing synthetic hectorite of claim 1 , wherein the fluorine source is one or more selected from the group consisting of hydrofluoric acid (HF), sodium fluoride (NaF), fluosilicic acid ((H 3 O) 2 (SiF 6 )), and sodium silico fluoride (Na 2 (SiF 6 )).

6. The method for producing synthetic hectorite of claim 1 , wherein the magnesium source is one or more selected from the group consisting of magnesium carbonate (MgCO 3 ), magnesium sulfate (MgSO 4 ), magnesium chloride (MgCl 2 ), and magnesium hydroxide (Mg(OH) 2 ).

7. The method for producing synthetic hectorite of claim 1 , wherein the crystallization reaction is performed at a temperature of 85° C. under a pressure of 1 bar for 40 hours.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Jong Hun
• Lee Je Kyun

Classifications

• C01P2006/60

  Optical properties, e.g. expressed in CIELAB-values · CPC title

• C01P2006/22

  Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability · CPC title

• C01B33/32 Primary

  Alkali metal silicates ({C01B33/24} , C01B33/26 take precedence) · CPC title

• C01B33/405 Primary

  not containing aluminium · CPC title