Claims
- 1. A method using optical spectrometry for monitoring and control of a smelt-metallugical process having individual process stages and carried out in a converter, in which light is emitted and absorbed by atomic or molecular species formed during the process, comprising:
- (a) identifying the atomic or molecular origin of at least one atomic or molecular species formed during the process, selecting at least two wavelengths at which said at least one species formed during the process has a measurable intensity, and measuring the intensity and spectral distribution of light emission, light absorption or both of said at least one species corresponding to said at least two wavelengths at least periodically throughout the process within the converter, wherein the emission, absorption, or both is characteristic of the process, and recording these values at least momentarily;
- (b) determining at least one ratio of the measured intensity of said at least one species at a minimum of two of said wavelengths;
- (c) comparing the ratio or ratios thus determined to known values of the same ratios at various individual stages in the process;
- (d) converting the results of this comparison to a signal for process control of the process; and
- (e) employing the signal as an input signal to means for varying process control parameters affecting the individual process stages.
- 2. A method according to claim 1, wherein the process controlled is copper conversion, the species formed during the process include PbO and PbS, and the emissions measured are those from PbO and PbS within the wavelength range 200 to 800 nm, the comparison with known values signaling the end of the slag production phase.
- 3. A method according to claim 2, wherein the wavelength range is 400 to 650 nm.
- 4. A method according to claim 1, wherein the process controlled is copper production, the species formed during the process include halogenides of precious metals, and the wavelengths selected are indicative of halogenides of precious metals present in the gas phase.
- 5. A method according to claim 1, wherein the process controlled is copper conversion, the species formed during the process include SO.sub.2, and the light absorptions measured are those from SO.sub.2 within the wavelength range 300 to 400 nm.
- 6. A method according to claim 1, wherein the process controlled is lead production, the species formed during the process include PbO and PbS, and the emissions measured are those from PbO and PbS.
- 7. A method according to claim 1, wherein the process controlled is iron and steel production, the species produced therein include carbon compounds and free atoms selected from the group consisting of Fe, Mn, K, and Na or a combination thereof, and the emissions measured are those from compounds or free atoms selected from the group consisting of Fe, Mn, K, and Na, or a combination thereof, within the wavelength range 200 to 800 nm.
- 8. A method according to claim 1, wherein the process controlled is iron and steel production, and measurements taken with respect to the alloying metals of an iron melt are converted to a process control signal and employed to monitor and control the addition of alloying metals and carbon to the process.
- 9. A method according to claim 7, wherein the process controlled is iron and steel production, and measurements taken with respect to the alloying metals of an iron melt are converted to a process control signal and employed to monitor and control the addition of alloying metals and carbon to the process.
- 10. A method according to claim 1, wherein the process produces species including K, Na, and Al, and is monitored by determining the light emission, light absorption, or both of one or more elements selected from the group consisting of K, Na, and Al.
- 11. A method according to claim 10, wherein the light emission, light absorption or both is measured for Na at 600 nm and for K at 400 nm.
- 12. A method according to claim 1, wherein measurements are spectrophotometrically made immediately above the melt.
- 13. A method according to claim 1, wherein measurements are spectrophotometrically made by means of a lance introduced into the melt, the lance comprising fiber optical measurement means.
Priority Claims (2)
Number |
Date |
Country |
Kind |
8703233 |
Aug 1987 |
SEX |
|
8800321 |
Feb 1988 |
SEX |
|
Parent Case Info
This application is a continuation of application Ser. No. 07/340,299, filed on Mar. 17, 1989.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/SE88/00420 |
8/17/1988 |
|
|
3/17/1989 |
3/17/1989 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO89/01530 |
2/23/1989 |
|
|
US Referenced Citations (5)
Foreign Referenced Citations (1)
Number |
Date |
Country |
255911 |
Dec 1985 |
JPX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
340299 |
Mar 1989 |
|