Alkali metal ion source with moderate rate of ion release and methods of forming

Patent metadata

Field	Value
Publication number	US-2016311727-A1
Application number	US-201615139456-A
Country	US
Kind code	A1
Filing date	Apr 27, 2016
Priority date	May 6, 2013
Publication date	Oct 27, 2016
Grant date	—

Abstract

An alkali metal ion source with a moderate rate of release of the ion (e.g. potassium) is formed by a method that includes: 1) combining an particulate ore that contains at least one of an alkali metal ion-bearing framework silicate (e.g. syenite ore) with at least one of an oxide and hydroxide of at least one of an alkali metal and alkaline earth metal such as calcium hydroxide; 2) milling the mixture of these two components optionally, with water, optionally, milling the dry components separately and blended thereafter, optionally, with water; 3) forming a mixture by adding water to the solid mixture after milling, if water was not added before milling; 4) exposing the mixture to an elevated temperature and pressure to form a gel that includes silica and the alkali metal of the framework silicate.

First claim

What is claimed is:

1 . A method of forming an alkali metal ion source with a moderate rate of ion release, comprising the step of reducing the size of a particulate alkaline-metal ion bearing silicate framework until at least about 50% by weight of the particles have a diameter of equal to or less than 5 μm as measured by laser-based particle-size distribution analysis.

2 . The method of claim 1 , wherein the alkali metal of the first component includes at least one member of the group consisting of lithium, sodium and potassium.

3 . The method of claim 2 , wherein the alkali metal of the alkali metal ion-bearing framework silicate includes potassium.

4 . The method of claim 3 , when the silicate of the particulate alkali metal ion-bearing framework silicate is an aluminosilicate.

5 . The method of claim 4 , wherein the particulate alkali metal bearing silicate framework includes at least one member selected from the group consisting of potassium feldspar (KAlSi 3 O 8 ), leucite (KAlSi 2 O 6 ), kalsilite (KAlSiO 4 ) and nepheline (Na 3 Kal 4 Si 4 O 16 ).

6 . The method of claim 5 , wherein the particulate alkali metalbearing silicate framework includes at least about 5% by weight of an equivalent amount of K 2 O. The method of claim 6 , wherein the particulate alkali metal ion-bearing silicate framework includes at least one member of the group consisting of syenite and granite.

8 . An alkali metal ion source with a moderate rate of release, formed by a method comprising the step of reducing the size of a particulate alkaline-metal ion bearing silicate framework until at least about 50% by weight of the particles have a diameter of equal to or less than 5 μm as measured by laser-based particle-size distribution analysis, an alkali metal ion, to thereby form the alkali metal ion source having Brunauer-Emmett-Teller (BET) specific surface area between about 3 m 2 /g and about 10 m 2 /g.

9 . The alkali metal ion source of claim 8 , wherein the alkali metal of the particulate alkali metal ion-bearing framework silicate includes at least one member of the group consisting of lithium, sodium and potassium.

10 . The alkali metal ion source of claim 9 , wherein the alkali metal of the particulate alkali metal ion-bearing framework silicate includes potassium.

11 . The alkali metal ion source of claim 10 , wherein the particulate alkali metal ion-bearing framework silicate is an aluminosilicate.

12 . The alkali metal ion source of claim 11 , wherein the particulate alkali metal bearing silicate framework includes at least one member selected from the group consisting of potassium feldspar (KAlSi 3 O 8 ), leucite (KAlSi 2 O 6 ), kalsilite (KAlSiO 4 ) and nepheline (Na 3 KAl 4 Si 4 O 16 ).

13 . The alkali metal ion source of claim 12 , wherein the particulate alkali metal ion-bearing framework silicate includes at least about 5% by weight of an equivalent amount of K 2 O.

14 . The alkali metal ion source of claim 8 , wherein the particulate alkali metal ion-bearing framework silicate includes at least one member of the group consisting of syenite, nepheline syenite, and granite.

Assignees

• Massachusetts Inst Technology

Inventors

• Skorina Taisiya
• Allanore Antoine

Classifications

• C05G1/00

  Mixtures of fertilisers belonging individually to different subclasses of C05 · CPC title

• C01B33/36

  having base-exchange properties but not having molecular sieve properties (regeneration thereof B01J49/00) · CPC title

• C05D9/00 Primary

  Other inorganic fertilisers · CPC title

• C05D9/02

  containing trace elements · CPC title

• C01F11/00

  Compounds of calcium, strontium, or barium (C01F7/00 takes precedence) · CPC title