# US 10,865,114 B2 · Process for preparing precipitated silica comprising a high compaction step

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- Number: US 10,865,114 B2
- Document ID: US10865114B2
- Status: Granted
- Kind: B2
- Application number: 14/386,015
- Filed: 2013-03-21
- Published: 2015-02-26
- Granted: 2020-12-15
- Earliest claimed: 2012-03-22
- Assignees: Rhodia Operations
- Applicants: Rhodia Operations
- Inventors: Sylvaine Neveu; Anne-Laure Pinault
- Web page: https://patentgrep.com/patent/US10865114B2

## CPC

- C01B 33/124: {Preparation of adsorbing porous silica not in gel form and not finely divided, i.e. silicon skeletons, by acidic treatment of siliceous materials}
- C01B 33/193: of aqueous solutions of silicates
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}

## Abstract

A process for preparing precipitated silica comprising a reaction of a silicate with an acidifying agent to obtain a suspension of precipitated silica, followed by a step of separation to obtain a cake and a step of drying said cake, wherein a step of compaction of said cake at a pressure greater than 10 bars is carried out between the step of separation and the step of drying.

## Claims

### Claim 1

A process for preparing precipitated silica, the process comprising;
reacting a silicate with an acidifying agent to obtain a precipitated silica suspension,
separating a precipitated silica from the suspension by a single separating step to obtain a cake, wherein the separating step consists of filtration, optional washing, and compacting on a filter press, and
drying the said cake,
wherein compacting said cake is carried out at a pressure between 10 and 45 bars and
wherein, after compacting and before drying, said cake has a dry matter level between 29 and 35 wt %.

### Claim 2 (depends on 1)

The process according to claim 1, wherein compacting said cake is carried out at a pressure between 15 and 45 bars.

### Claim 3 (depends on 1)

The process according to claim 1, wherein compacting said cake is carried out at a pressure of at least 20 bars.

### Claim 4 (depends on 1)

The process according to claim 1, not comprising a disintegrating step.

### Claim 5 (depends on 1)

The process according to claim 1, wherein the drying step is not carried out by atomization.

### Claim 6 (depends on 1)

The process according to claim 1, further comprising a lump breaking step which is carried out between the compacting step and the drying step.

### Claim 7 (depends on 1)

The process according to claim 1, wherein the dried cake is subjected to a grinding step.

### Claim 8 (depends on 1)

The process according to claim 1, wherein the dried cake is subjected to an agglomerating step.

### Claim 9 (depends on 1)

The process according to claim 1, wherein compacting said cake is carried out at a pressure between 20 and 35 bars.

### Claim 10 (depends on 1)

The process according to claim 1, wherein, after compacting and before drying, said cake has a dry matter level between 29 and 32 wt %.

### Claim 11 (depends on 7)

The process according to claim 7, wherein the dried cake that has been subject to the grinding step is subjected to an agglomerating step.