Method for removing phosphorus from phosphorus-containing substance

Patent metadata

Field	Value
Publication number	US-2021071274-A1
Application number	US-201816957444-A
Country	US
Kind code	A1
Filing date	Dec 12, 2018
Priority date	Dec 26, 2017
Publication date	Mar 11, 2021
Grant date	—

Abstract

Proposed is a method for removing phosphorus from a phosphorus-containing substance which is applicable in an industrial scale so as to effectively reduce phosphorus contained in the phosphorus-containing substance. In this method, the phosphorus-containing substance used as a raw material for metal smelting or metal refining is reacted with a nitrogen-containing gas at a treatment temperature T (° C.) which is lower than a melting temperature (T m ) of the substance, so that phosphorus is removed preferably in the form of phosphorus nitride (PN). In this regard, a nitrogen partial pressure and an oxygen partial pressure in the nitrogen-containing gas are preferably controlled, thereby reducing a load of dephosphorization process, for example.

First claim

1 . A method for removing phosphorus from a phosphorus-containing substance,
characterized in that the phosphorus-containing substance used as a raw material for metal smelting or metal refining is reacted with a nitrogen-containing gas at a treatment temperature T (° C.) which is lower than a melting temperature (T m ) of the substance.

2 . The method for removing phosphorus from a phosphorus-containing substance according to claim 1 ,
wherein phosphorus nitride (PN) is formed by a reaction of the phosphorus-containing substance with the nitrogen-containing gas and removed.

3 . The method for removing phosphorus from a phosphorus-containing substance according to claim 1 ,
wherein the reaction of the phosphorus-containing substance with the nitrogen-containing gas is performed under control of a nitrogen partial pressure P N2 and an oxygen partial pressure P O2 in the nitrogen-containing gas.

4 . The method for removing phosphorus from a phosphorus-containing substance according to claim 1 ,
wherein the nitrogen partial pressure P N2 (atm) in the nitrogen-containing gas is controlled to satisfy a condition represented by the following formula (1);
[Formula 1]
0.2≤ P N2 ≤0.9  (1)

5 . The method of removing phosphorus from a phosphorus-containing substance according to claim 1 ,
wherein the treatment temperature T (° C.) is controlled to satisfy a condition of the following formula (2) and the oxygen partial pressure P O2 (atm) in the nitrogen-containing gas is controlled to satisfy a condition of the following formula (3);
750≤ T≤ 0.95× T m   (2)

[Formula 2],
wherein T m is a melting point (° C.) of the phosphorus-containing substance;
[Formula 3]
log P O2 ≤−0.000025× T 2 +0.0723× T− 60.9  (3)

6 . The method for removing phosphorus from a phosphorus-containing substance according to claim 1 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO).

7 . The method for removing phosphorus from a phosphorus-containing substance according to claim 1 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO) and carbon dioxide (CO 2 ) and the oxygen partial pressure P O2 is controlled by a partial pressure ratio P CO /P CO2 .

8 . The method for removing phosphorus from a phosphorus-containing substance according to claim 3 ,
wherein the nitrogen partial pressure P N2 (atm) in the nitrogen-containing gas is controlled to satisfy a condition represented by the following formula (1);
[Formula 1]
0.2≤ P N2 ≤0.9  (1)

9 . The method of removing phosphorus from a phosphorus-containing substance according to claim 3 ,
wherein the treatment temperature T (° C.) is controlled to satisfy a condition of the following formula (2) and the oxygen partial pressure P O2 (atm) in the nitrogen-containing gas is controlled to satisfy a condition of the following formula (3);
750≤ T≤ 0.95× T m   (2)

[Formula 2],
wherein T m is a melting point (° C.) of the phosphorus-containing substance;
[Formula 3]
log P O2 ≤−0.000025× T 2 +0.0723× T− 60.9  (3)

10 . The method of removing phosphorus from a phosphorus-containing substance according to claim 4 ,
wherein the treatment temperature T (° C.) is controlled to satisfy a condition of the following formula (2) and the oxygen partial pressure P O2 (atm) in the nitrogen-containing gas is controlled to satisfy a condition of the following formula (3);
750≤ T≤ 0.95 ×T m   (2)

[Formula 2],
wherein T m is a melting point (° C.) of the phosphorus-containing substance;
[Formula 3]
log P O2 ≤−0.000025× T 2 +0.0723× T− 60.9  (3)

11 . The method for removing phosphorus from a phosphorus-containing substance according to claim 3 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO).

12 . The method for removing phosphorus from a phosphorus-containing substance according to claim 4 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO).

13 . The method for removing phosphorus from a phosphorus-containing substance according to claim 5 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO).

14 . The method for removing phosphorus from a phosphorus-containing substance according to claim 10 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO).

15 . The method for removing phosphorus from a phosphorus-containing substance according to claim 13 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO).

16 . The method for removing phosphorus from a phosphorus-containing substance according to claim 14 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO).

17 . The method for removing phosphorus from a phosphorus-containing substance according to claim 3 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO) and carbon dioxide (CO 2 ) and the oxygen partial pressure P O2 is controlled by a partial pressure ratio P CO /P CO2 .

18 . The method for removing phosphorus from a phosphorus-containing substance according to claim 4 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO) and carbon dioxide (CO 2 ) and the oxygen partial pressure P O2 is controlled by a partial pressure ratio P CO /P CO2 .

19 . The method for removing phosphorus from a phosphorus-containing substance according to claim 5 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO) and carbon dioxide (CO 2 ) and the oxygen partial pressure P O2 is controlled by a partial pressure ratio P CO /P CO2 .

20 . The method for removing phosphorus from a phosphorus-containing substance according to claim 14 ,
wherein the nitrogen-containing gas includes carbon monoxide (CO) and carbon dioxide (CO 2 ) and the oxygen partial pressure P O2 is controlled by a partial pressure ratio P CO /P CO2 .

Assignees

• Jfe Steel Corp

Inventors

• Nakase Kenji
• Nakai Yoshie
• Kikuchi Naoki

Classifications

• C21C1/025 Primary

  Agents used for dephosphorising or desulfurising · CPC title

• C22B1/02

  Roasting processes (C22B1/16 takes precedence) · CPC title

• C22B1/11

  Removing sulfur, phosphorus or arsenic other than by roasting · CPC title

• Y02W30/50

  Reuse, recycling or recovery technologies · CPC title

• C22B1/216

  in rotary furnaces · CPC title