Skip to main content
European Commission logo print header

DEVELOPMENT OF HIGH TEMPERATURE SENSORS IN MOLTEN METALLURGICAL PHASES

Objetivo

The main objective is to develop, manufacture and test a range of sensors to measure low level concentrations of both metallic species like arsenic, antimony and sulphur in molten metallurgical phases such as refined molten metal, bullion, slag and matte. The project aims to develop solid state ionic conductors as sensors for a range of metallic and nonmetallic species in melts. Whilst zirconia based sensors for oxygen determination have had extensive application in the copper and steel industry, particularly in Japan, these have range limitations.
The past decade has seen increasing interest in the application of microelectronics to the monitoring, control, optimization and automation of industrial processes, especially where working conditions are either hazardous or environmentally unacceptable. However, for many high temperature processes the applications are frequently limited by the lack of reliable sensors to detect changes in the operations.

This problem was addressed by developing electrochemcial cells based upon solid electrolytes. These not only offer the possibility of an instantaneous measurement but also may meet the industrial requirements of reliability, ruggedness and compatibility with microelectronics.

The following sensors have been developed in the laboratory:
potentiometric copper sensor (the electrolyte is cusicon CuZr2(PO4)3, and the reference material is copper);
coulometric copper sensor (results demonstrate that it is possible to measure copper at high concentrations in molten metals and mattes);
antimony sensor (the electrolyte consisted of a 2 phase mixture of sodium beta-alumina and sodium antimonate and the reference was a mixture of alpha and beta alumina);
arsenic sensor (the sensor responded well in zinc arsenic melts but in copper melts, where the temperature was higher, the life of the sensors was relatively short);
sodium sensor (the electrolyte was sodium beta-alumina, the reference was a mixture of sodium ferrite and ferric oxide and the sensor responded to additions of sodium in zinc).

A number of probes have been tested in the copper refinery at Olen, Belgium. Structurally, probes can now withstand immersion in molten phosphorus deoxidized copper at 1160 C for 1 h or more. The voltage output signal has, in general, not yet correlated well with the oxygen content (as measured by conventional analysis). Subsequent examination has indicated that the problems are due to the complex crystallographic and microstructural nature of beta-alumina. However, the lates t generation of sensors are believed to incorporate material with an improved microstructure.

Considerable work has been undertaken on the preparation of the electrolyte and its specification. In addition a range of sheath materials and assembly methods have been investigated which should ensure that the project is able to have produced and tested commercial prototype sensors.
The sequential development, production and testing phases for each of the nominated elemental sensors will provide continuity of activity for all the participants, up to marketable devices at the completion of the programme.

The project is in 4 stages. In the development stage, basic research will identify electrochemical couples and potential reference electrodes. Prototype sensors will be produced and laboratory scale tests will be performed. The results from these, and field tests, will be assimilated to produce the design specifications necessary for the larger scale production.

The manufacturing aspect of the programme requires testing and evaluation of subassembly techniques of the electrodes and electrolyte in small thimbles which can be incorporated in robust sensors capable of withstanding immersion in molten metallic and other phases at temperatures of 1200 C and over. Special technology in ceramic lance material and sensor design will be used.

In the testing stage, the trials involve access to hot metal and slag hearth and launder systems in conjunction with plant personnel to carry out extended testing at metallurgical plants. The industrial associates will provide analytical and engineering information.

Finally, the joint final report and technical assessment will allow the industry to acquire the facility to obtain instantaneous analysis of these elements which, for both production control and process investigation, will mean higher metal specifications, lower losses and improved productivity.

Tema(s)

Data not available

Convocatoria de propuestas

Data not available

Régimen de financiación

CSC - Cost-sharing contracts

Coordinador

Mineral Industry Research Organisation
Aportación de la UE
Sin datos
Dirección
Expert House 6 Sandford Street
WS13 6QA Lichfield
Reino Unido

Ver en el mapa

Enlaces
Coste total
Sin datos

Participantes (1)