Compositions and methods for producing high purity filter aids

Patent metadata

Field	Value
Publication number	US-10913049-B2
Application number	US-201615541587-A
Country	US
Kind code	B2
Filing date	Jan 13, 2016
Priority date	Jan 13, 2015
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A filter aid may include acid-washed diatomaceous earth having high purity, and perlite. A method of making a high purity filter aid may include acid washing diatomaceous earth to reduce the h in the diatomaceous earth, and combining the acid-washed diatomaceous earth with high purity perlite to obtain to obtain a high purity filter aid. A method of reducing extractable metals from diatomaceous earth may include washing the diatomaceous earth in a first acid, rinsing the diatomaceous earth, and washing the diatomaceous earth in a second acid. The first acid may include an inorganic acid having a first strength, and the second acid may include an organic acid having a second strength different than the first strength. A method of filtering a beverage may include passing the beverage through a filter including a filter aid including acid-washed diatomaceous earth having high purity, and perlite.

First claim

What is claimed is:

1. A method of making a filter aid, the method comprising:
acid washing diatomaceous earth to reduce the trace amounts of extractable metal in the diatomaceous earth;
rinsing the acid-washed diatomaceous earth with water in order to remove the acid; and
combining the acid-washed diatomaceous earth with perlite to obtain a filter aid;
wherein acid washing the diatomaceous earth comprises:
in a first washing step, washing the diatomaceous earth in a first acid comprising an inorganic acid; and
in a second washing step that follows the first washing step, washing the diatomaceous earth in a second acid comprising an organic acid.

2. The method of claim 1 , wherein the first acid has a first acid strength and the second acid has a second acid strength different than the first acid strength.

3. The method of claim 2 , wherein the first acid strength is greater than the second acid strength.

4. The method of claim 2 , wherein the first acid strength is 0.5 Normal or less.

5. The method of claim 2 , wherein the second acid strength is 0.3 Normal or less.

6. The method of claim 1 , wherein the acid washing occurs at a temperature of 60 degrees C. or less.

Assignees

• Imerys Usa Inc

Inventors

• Fleming Robert
• Jose Nicholas
• Taniguchi Jeffrey D
• Wang Bo

Classifications

• C04B2111/00793

  as filters or diaphragms · CPC title

• B01J20/14

  Diatomaceous earth · CPC title

• B01D2239/1258

  Permeability · CPC title

• Y02W30/91

  Use of waste materials as fillers for mortars or concrete · CPC title

• B01J20/28076

  being more than 1.0 ml/g · CPC title