Title:
TREATMENT OF TALC
Document Type and Number:
Japanese Patent JPH01111711
Kind Code:
A
Abstract:
PURPOSE: To remove impurities such as asbestos from talc powder by treating the talc powder at a specified temp. with phosphoric acid or a compd. thereof.
CONSTITUTION: Talc powder contg. asbestos is treated at 70W250°C with phosphoric acid or compd. Thereof, e.g., phosphoric acid, condensed phosphoric acid such as pyrophosphoric acid, an orthophosphate such as sodium phosphate or a condensed phosphate such as sodium tripolyphosphate to remove the asbestos by the solubility difference between talc and asbestos. The asbestos is made soluble by the treatment but talc has a lower solution velocity than asbestos and other impurities because of the multilayered structure, so the asbestos, etc., can be removed from the talc powder.
Inventors:
YAMADA OSAMU
SHINOHARA KOZO
SHINOHARA KOZO
Application Number:
JP26995687A
Publication Date:
April 28, 1989
Filing Date:
October 26, 1987
Export Citation:
Assignee:
ASADA SEIFUN KK
International Classes:
C08K3/00; A61K8/19; A61K8/25; A61K8/30; A61K47/02; A61Q1/02; C01B33/22; C01B39/06; C08K3/34; C09C1/28; C09D7/12; (IPC1-7): A61K7/02; A61K47/00; C01B33/22; C08K3/00; C08K3/34; C09D7/12
Attorney, Agent or Firm:
Kyozo Yuasa (3 outside)