# US 11,440,806 B2 · Stable solution of sodium and iron silicate, process for preparing said solution and uses thereof

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,440,806 B2
- Document ID: US11440806B2
- Status: Granted
- Kind: B2
- Application number: 16/993,661
- Filed: 2020-08-14
- Published: 2022-02-17
- Granted: 2022-09-13
- Earliest claimed: 2020-08-12
- Applicants: PQ Silica Brazil Ltda.
- Inventors: Joris Antonius van der Eerden; Flavio Ernesto Ribeiro; Ronaldo dos Santos Flor
- Web page: https://patentgrep.com/patent/US11440806B2

## CPC

- C01B 33/32: Alkali metal silicates ({C01B33/24} , C01B33/26 take precedence)
- C01B 33/325: {After-treatment, e.g. purification or stabilisation of solutions, granulation; Dissolution; Obtaining solid silicate, e.g. from a solution by spray-drying, flashing off water or adding a coagulant}
- B22C 1/188: {Alkali metal silicates}
- C01B 33/14: Colloidal silica, e.g. dispersions, gels, sols
- C01B 33/18: Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof (preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C)
- C04B 35/16: based on silicates other than clay {(zircon C04B35/48)}
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- B22C: FOUNDRY MOULDING (moulding refractory materials in general B28B)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

The present invention refers to a stable sodium and iron silicate solution that has a weight ratio of SiO2 to Na2O from 1.5 to 2.5 and a total percentage of solids, expressed by the sum of SiO2 and Na2O, from 20% to 55%. Said solution also has a soluble iron content, expressed by Fe, from 0.1% to 7%, and a water content from 38% to 79.9%. The present invention also refers to the process for preparing said stable solution of sodium and iron silicate, which comprises the steps of: (a) providing a siliceous material containing iron; (b) submitting said siliceous material containing iron to a hydrothermal treatment with caustic soda under high temperature and controlled pressure; and (c) filtering said reacted solution to separate the reacted portion of the hydrothermal treatment from the unreacted portion. Additionally, the present invention refers to the uses of said stable sodium and iron silicate solution.

## Claims

### Claim 1

A stable sodium and iron silicate solution having a weight ratio of SiO2 to Na2O from 1.5 to 2.5 and a total percentage of solids, expressed by the sum of SiO2 and Na2O, from 20% to 55%, said solution having a soluble iron content, expressed by Fe, from 0.1% to 1.0%, and a water content from 38% to 79.9%.

### Claim 2 (depends on 1)

The stable sodium and iron silicate solution of claim 1, wherein said solution is used as a binder agent for fines.

### Claim 3 (depends on 1)

The stable sodium and iron silicate solution of claim 1, wherein said solution is used in the manufacture of precipitated silica.

### Claim 4 (depends on 1)

The stable sodium and iron silicate solution of claim 1, wherein said solution is used as a binder for sand molds, as a deflocculant agent in the ceramic industry, or as binder for clays and adhesives.

### Claim 5 (depends on 1)

The stable sodium and iron silicate solution of claim 1, wherein said solution is used in the manufacture of silica gel.