CN1991354A

CN1991354A - Stationary electrolyte concentration cell for measuring sulfur content of molten iron

Info

Publication number: CN1991354A
Application number: CN 200510112078
Authority: CN
Inventors: 张立
Original assignee: Baoshan Iron and Steel Co Ltd
Current assignee: Baoshan Iron and Steel Co Ltd
Priority date: 2005-12-27
Filing date: 2005-12-27
Publication date: 2007-07-04

Abstract

The invention relates to fixed electrolyte concentration cell used to detect the content of sulfur in the molten iron that belongs to the electrochemistry field. The characteristics of fixed electrolyte concentration cell used to detect the content of sulfur in the molten iron are: the reference pole is Mo|Mo+MoS2, the solid electrolyte is MgS-TiS2, the content of TiS2 is 1-10%, the expression is Mo|Mo+MoS2|MgS-TiS2|[S]Fe|Mo, the [S]Fe|M is to be measured. The detecting sulfur probe can detect the sulfur content in the molten iron quickly and exactly, and the quick analysis can be realized, and the quick preprocess of molten iron can be done, and it improves the desulfurization efficiency, reduces the desulfurization cost and reduce the production cost in the steel-making course.

Description

Measure the stationary electrolyte concentration cell of sulfur content in the molten iron

(1) technical field

The present invention relates to a kind of stationary electrolyte concentration cell of measuring sulfur content in the molten iron, belong to electrochemical field.

(2) background technology

Some principal ingredients in the motlten metal as carbon and oxygen etc., can be implemented in the kinetic measurement and the control of smelting process basically at present.But,, also do not have more effective direct assay method at present for this a pair of smelting process of sulphur and the bigger element of product quality influence.In actual production process, the method for knowing the motlten metal sulfur content is very complicated, generally will pass through steps such as sampling, sample presentation, sample preparation, analysis, calculating.Although advanced wind-force sample presentation and data transmission system have been arranged at present, report and submit testing result to want 5-8 minute time at the soonest from being sampled to, such analytic process can not satisfy the needs of modernized smelting process.

At present, existing people begins to attempt replacing traditional combustion analysis method with additive method, directly measures the sulfur content in the motlten metal apace.Wherein general with the research that utilizes sulfur content in the solid electrolyte concentration cell mensuration motlten metal.Utilizing the solid electrolyte concentration cell to measure the research of motlten metal sulfur content, mainly is to be referred from ripe at present solid electrolyte concentration cell Direct Determination of Oxygen technology.Because the principle of utilizing the solid electrolyte concentration cell directly to decide sulphur and Direct Determination of Oxygen is identical, therefore successful Direct Determination of Oxygen technology has been created condition for research and development solid electrolyte sulphur concentration cell.

The oxygen solid electrolyte is the same with deciding, and when selecting sulfide to use as solid electrolyte, its primary condition is that it should have higher ionic conductivity, and to require conductive ion be S ^2-Or and S ^2-The kation that ion is directly related.In addition, as the high temperature solid electrolyte, except that having high melt point, also require it to have stable chemistry and physical property.

(3) summary of the invention

The object of the present invention is to provide a kind of stationary electrolyte concentration cell of measuring sulfur content in the molten iron, this stationary electrolyte concentration cell can be measured the sulfur content in the molten iron fast, realizes online express-analysis.

The present invention is achieved in that a kind of stationary electrolyte concentration cell of measuring sulfur content in the molten iron, it is characterized in that: the reference utmost point is Mo|Mo+MoS ₂, solid electrolyte is MgS-TiS ₂, its expression formula is:

Mo|Mo+MoS ₂|MgS-TiS ₂|[S] _Fe|Mo

Wherein: [S] _Fe| Mo is a measured side.

The stationary electrolyte concentration cell of sulfur content is characterized in that TiS in the above-mentioned mensuration molten iron ₂Content is between 1～10%.

The present invention utilizes the sulfide electrolyte to form concentration cell, its solid electrolyte is divided into tubulose and sheet by shape, the chemical composition of solid electrolyte and the concentration cell of assembling are made sulfur determination probe, can measure the sulfur content in the molten iron fast and accurately, realize online express-analysis, reach the purpose of quick Molten Iron Pretreatment, thereby improve desulfuration efficiency, reduce desulphurization cost, and then reduce the production cost in the steelmaking process.

(4) description of drawings

The invention will be further described below in conjunction with the drawings and specific embodiments.

Fig. 1 is MgS-TiS behind the sintering ₂The X-ray diffractogram of solid electrolyte;

Fig. 2 is MgS-TiS ₂The conductance of solid electrolyte and the graph of a relation of addition;

Fig. 3 is MgS-TiS ₂The volume density of solid electrolyte and the graph of a relation of addition;

Fig. 4 is TiS ₂Electromotive force when content is definite value and time chart, wherein curve 1 TiS ₂Content is 1%, curve 2 TiS ₂Content is 3%;

Fig. 5 is TiS ₂Electromotive force when content is definite value and time chart, wherein curve 3 TiS ₂Content is 5%, curve 4 TiS ₂Content is 7%;

Fig. 6 is TiS ₂Electromotive force when content is definite value and time chart, wherein curve 5 TiS ₂Content is 9%, curve 6 TiS ₂Content is 10%;

Fig. 7 is TiS ₂Electromotive force when content is definite value and time chart, wherein curve 7 TiS ₂Content is 12%, curve 8 TiS ₂Content is 15%;

Fig. 8 (a) is the chip solid electrolyte;

Fig. 8 (b) is the tube-type solid electrolyte;

Among Fig. 8: 10 molybdenum filaments lead-in wire, 11 high-temperature cements, 12 A1 ₂O ₃Powder, 13 Mo+MoS ₂, 14 quartz ampoules, 15 solid electrolytes;

Fig. 9 is the sulfur determination probe instrumentation plan.

Among Fig. 9: 1 loop electrode, 2 MoSi ₂Heater, 3 MgO crucibles, 4 decide the sulphur head, 5 molten iron, 6 thermopairs, 7 XMT-1 type temperature controllers, 8 YEW3056 type registering instruments.

(5) embodiment

The leading indicator that influences the solid electrolyte usability is the ionic conductivity of solid electrolyte.In addition, the densification degree of solid electrolyte itself also has material impact for the stability and the reappearance of test electromotive force signal.The present invention has selected MgS-TiS ₂As solid electrolyte.Its proportioning is as shown in table 1,

Table 1 solid electrolyte MgS-TiS ₂Form proportioning

Solid electrolyte	Component	Proportioning
Solid electrolyte	Component	Proportioning								MgS-TiS ₂	MgS	100	99.0	97.0	95.0	93.0	91	90	88	85
TiS ₂	0	1.0	3.0	5.0	7.0	9.0	10.0	12	15		MgS	100	99.0	97.0	95.0	93.0	91	90	88	85

Solid electrolyte MgS-TiS ₂Experimentation: synthetic sulfide is pressed the proportioning weighing shown in the table 1, and evenly mix.The sulfide powder that mixes is pressed into the sample of  5 * 10mm with the pressure of 200MPa.The solid electrolyte sample that suppresses is packed in the washing quartz ampoule good, end sealing, and the other end connects vacuum pump and vacuumizes.After reaching certain vacuum tightness, with coal-oxygen flame tube sealing.The quartz ampoule that envelope makes is put into the horizontal pipe stove, be heated to 1450 ℃, sintering time is 4 hours.For the solid electrolyte behind the sintering, utilize X-ray diffraction that its crystallization phase is analyzed and detected.Simultaneously, the ionic conductivity and the density of solid electrolyte are measured.When measuring ionic conductivity, the sulphur content pressure-controlled in the system is at p _S2＜10 ^-6Atm, temperature is 1200K.

Experimental result shows: referring to Fig. 1, and the MgS-TiS behind the sintering ₂Be solid electrolyte, its crystallization phase does not have too big variation, still is MgS and TiS ₂Referring to Fig. 2, Fig. 3, MgS-TiS ₂Be that solid electrolyte is at TiS ₂Addition is 5% o'clock, and ionic conductivity reaches maximal value, and its density value also reaches maximum.Work as TiS ₂When addition further increases, it is generally acknowledged the increase that can cause electronic conductivity, thereby, cause that ionic conductivity descends.

When sulfide used as solid electrolyte, its primary condition was that it should have higher ionic conductivity.When the sulphur activity on solid electrolyte both sides not simultaneously, by can Si Tedinglv, battery produces electromotive force.As sulfur determination probe, its electromotive force will be stablized.

TiS ₂Content is 1% o'clock, and referring to curve among Fig. 41, it had stable electromotive force signal after 0.6 minute.

TiS ₂Content is 3% o'clock, and referring to curve among Fig. 42, it had stable electromotive force signal after 0.5 minute.

TiS ₂Content is 5% o'clock, and referring to curve among Fig. 53, it had stable electromotive force signal after 0.8 minute.

TiS ₂Content is 7% o'clock, and referring to curve among Fig. 54, it had stable electromotive force signal after 0.8 minute.

TiS ₂Content is 9% o'clock, and referring to curve among Fig. 65, it had stable electromotive force signal after 0.8 minute.

TiS ₂Content is 10% o'clock, and referring to curve among Fig. 66, it had stable electromotive force signal after 0.8 minute.

TiS ₂Content is 12% o'clock, and referring to curve among Fig. 77, its electromotive force does not have stable signal.

TiS ₂Content is 15% o'clock, and referring to curve among Fig. 78, its electromotive force does not have stable signal.

Therefore, TiS ₂Content is chosen in 1～10%, and is suitable.

A kind of stationary electrolyte concentration cell of measuring sulfur content in the molten iron, its expression formula is:

Solid electrolyte is divided into sheet and tubulose by shape, referring to Fig. 8 (a), Fig. 8 (b).

By the sulfur determination probe that tubulose or chip solid electrolyte are assembled into, in the saturated carbon molten iron, to measure, its instrumentation plan is referring to Fig. 9.

Measurement result obtains stable electromotive force curve can be referring to Fig. 4, Fig. 5, Fig. 6; Unsettled electromotive force curve is referring to Fig. 7.

The present invention can measure the sulfur content in the molten iron fast and accurately by the enforcement of sulfur determination probe, realizes online express-analysis, reach the purpose of quick Molten Iron Pretreatment, thereby the raising desulfuration efficiency reduces desulphurization cost, and then reduces the production cost in the steelmaking process.

Claims

1. stationary electrolyte concentration cell of measuring sulfur content in the molten iron, it is characterized in that: the reference utmost point is Mo|Mo+MoS ₂, solid electrolyte is MgS-TiS ₂, its expression formula is:

Mo|Mo+MoS ₂|MgS-TiS ₂|[S] _Fe|Mo

Wherein: [S] _Fe| Mo is a measured side.

2. the stationary electrolyte concentration cell of sulfur content is characterized in that TiS in the mensuration molten iron according to claim 1 ₂Content is between 1～10%.