CN106404997A - Method for determining content of calcium in calcium-silicon alloy by potentiometric titration - Google Patents
Method for determining content of calcium in calcium-silicon alloy by potentiometric titration Download PDFInfo
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- G01N31/16—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using titration
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- G01N31/164—Determining the equivalent point by means of a discontinuity by electrical or electrochemical means
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Abstract
The invention discloses a method for determining a content of calcium in calcium-silicon alloy by potentiometric titration. An automatic potentiometric titration instrument and a copper ion selective electrode are adopted to realize accurate determination of the content of calcium in the calcium-silicon alloy. A sample is dissolved in nitric acid (concentrated)-hydrofluoric acid, and ammonium hydroxide separation is realized once each time perchloric acid smokes. Compared with the Chinese standard GB/T 4700.2-1988, the method has advantages that a sample dissolving and separation process is simplified while uniform sample dissolving effects are achieved. Automatic end point determination is realized through potential jump by the aid of the automatic potentiometric titration instrument, errors caused by manual end point determination are reduced, and precision and accuracy of analysis results are improved. By replacement of a calcium ion selective electrode with the copper ion selective electrode, the service life of the electrode is prolonged, and analysis cost is saved.
Description
Technical field
The present invention relates to a kind of method that constant-current titration measures calcium content in calcium-silicon, belong to chemical analysis technology neck
Domain.
Background technology
Calcium-silicon is the composite alloy elementary composition by silicon, calcium and ferrum etc., be a kind of ideal double deoxidizer,
Desulfurizing agent.It is widely used in the specific alloy such as the steel grades such as high-quality steel, mild steel, rustless steel and nickel-base alloy, titanium-base alloy
In production, and it is suitable as the additive in the inovulant and spheroidal graphite cast-iron production of cast iron.The inspection of calcium content in existing calcium-silicon
Test, mainly adopt the EDTA complexometric titration (GB/T 4700.2-88) of visual titration, the method process is loaded down with trivial details, Mao Gao
Twice, ammonia separates twice chloric acid cigarette, spends the time long, and using valuable platinum ware during molten sample, testing cost is relatively
High.In addition, visual titration leans on eye-observation terminal, error is relatively large.
Content of the invention
The present invention is intended to provide a kind of method that constant-current titration measures calcium content in calcium-silicon, simplify molten sample and separated
Journey, and the calcium content in calcium-silicon is determined using automatic potential titrator tests, method is easy, quick, result is accurate.
The present invention solve key issue be：1. molten sample separation process, not impact analysis result how are simplified；2. traditional
Calcium ion-selective electrode is expensive, and use condition is harsh, and service life is short, is typically only capable to about half a year, causing to detect into
This height.Therefore, the electrode that will select a kind of long service life replaces calcium ion-selective electrode, and optimizes Titration Conditions realization to silicon
The Accurate Determining of calcium content in calcium alloy.
The invention provides a kind of method that constant-current titration measures calcium content in calcium-silicon, using automatic potentiometric titration
Instrument, using copper ion selective electrode, realizes the Accurate Determining of calcium content in calcium-silicon；Comprise the following steps：
（1）Sample is placed in polytetrafluoroethylene beaker, adds nitric acid, the molten sample of Fluohydric acid., perchloric acid smoked；
（2）It is subsequently adding ammonium hydroxide and forms precipitation filtration interfering ion, measure filtrate；
（3）Because copper ion selective electrode has the advantages that long service life, using copper ion selective electrode to the response of copper Lai
Indirect determination calcium.
The method that above-mentioned constant-current titration measures calcium content in calcium-silicon, specifically includes following steps：
1st, sample treatment：First demarcate the concentration of EDTA with calcium standard solution, then take the CuSO of 0.025 mol/L4Solution 10 mL
In beaker, add 10 mL ammonia ammonium chloride buffer solution, EDTA titrates CuSO4To terminal, record volume V mL, then take
The CuSO of 0.025 mol/L4In beaker, the EDTA being quantitatively adding V mL forms 1 to solution 10mL:1 CuEDTA solution；Described
Ammonia ammonium chloride buffer solution is：Weigh that 67.5 g ammonium chloride are soluble in water, add the hydroxide that 570 mL density are 0.9g/mL
Ammonium, is diluted to 1000 mL with water, mixes；This pH value of solution is 10；
Sample is placed in polytetrafluoroethylene beaker, adds nitric acid, Deca Fluohydric acid.；Decompose when being water-cooled, treat acutely anti-
After should stopping, adding 10 mL perchloric acid, be evaporated to emit perchloric acid white cigarette, by its volume concentration to 1 mL；
Take off polytetrafluoroethylene beaker cooling, add hydrochloric acid, so that solubility salt is dissolved；Transferring in beaker, adding water, while stirring
Mixing side and being slowly added to ammonium hydroxide to solution is in yellow, is filtered with quantitative filter paper, filtrate is contained in beaker after heated and boiled 5 min
In；Precipitation on filter paper is washed for several times with ammonium nitrate, then with 50-70 DEG C of warm water cleaning；Contain in the beaker of filtrate, add three ethanol
Amine, adds ammonia ammonium chloride buffer solution and the CuEDTA preparing, sample is put on potentiometric titrimeter titration platform, start
The analysis program editting, determines the parameter setting of equivalent point, inserts sample number into spectrum and sample size, with the titration of EDTA standard solution
To terminal；Do blank assay in company with test portion；
On the basis of every gram of sample, the consumption of above-mentioned nitric acid is：Every gram of sample dissolution is in 100mL nitric acid（Density is 1.42 g/
mL）In, the amount of Deca Fluohydric acid. is：Every gram of sample uses 50mL Fluohydric acid.（Density is 1.15 g/mL）；The consumption of perchloric acid
For：Every gram of sample uses 50mL perchloric acid（Density is 1.67 g/mL）；The consumption of hydrochloric acid is：Every gram of sample uses 100mL hydrochloric acid
（Density is 1.19 g/mL）；The consumption of triethanolamine is：50mL（The mass ratio of triethanolamine and water is 1:3）；Ammonia chlorination
The consumption of ammonium buffer solution is：100mL；The consumption of CuEDTA：10mL；
2nd, the selection of titration mode
The titration mode of 855 potentiometric titrimeters mainly has two kinds：MET- equivalent titration mode：Volumetric solutionIncrementIt is manually set, drip
Determine process by setIncrementTo equivalent point propulsion, until findingEquivalent point.This pattern is particularly suitable for weak anti-of chemomotive force
Should, non-aqueous system andWeak electrolyteThe titration of system.The dynamic titration mode of DET-：TitrationLiquidIncrementWithTitration curveChange and
Change,TitrationVery fast when speed starts, but with closeEquivalent pointAnd automatically slow down, until find equivalent point.This pattern can be looked for
To minimum hop, automatically determine pK value, be suitable for most of aqueous phase system titration.Titrate silico-calcium from two kinds of titration mode respectively
Alloy standard sample GSB03-2197-2008, calcium content is 25.07%, two kinds of titration mode respectively titration 5 times, and analysis result shows
Show：More accurate using MET pattern measurement result, so selecting MET titration mode.
3rd, the judgement of titration end-point
" equivalent point criterion of identification value " i.e. △ E/ △ V is titration end-point higher than preset value.In order to prevent various pseudo-ending points from being missed
It is considered titration end-point, investigated the many factors of impact endpoint.Under this titration system, " equivalent point criterion of identification " is
Main affecting parameters, the too low easy situation occurring stopping less than terminal titrating；Too high, easily occur to terminal not stopping
The only situation of titration.Through multiple test it is determined that endpoint parameter setting is as follows：
Signal drift value：50 mv/min；
Pre-add volume：10mL；
The volume adding after reaching equivalent point：2mL；
Rate of liquid aspiration：Maximum
Band volume window evaluation lower limit：11 mL
The band volume window evaluation upper limit：100mL.
The setting of above-mentioned endpoint parameter, from the angle of protection instrument, stops volume and is generally 100.00mL；Mean as
Fruit potentiometric titrimeter does not find hop, is titrated to 100.00mL and stops, and will not no stop most titration and go down to make solution to overflow.
The principle of the present invention：Because Cu EDTA has higher complexation constant（logK=18.8）, therefore in solution only
Minimal amount of free Cu2+Exist.
Cu EDTA=Cu2++ EDTA2-
The Cu EDTA that 1 mL is prepared is added in the sample of ammonia ammonium chloride buffer solution, high concentration Ca2+Presence,
So that reaction is carried out to the right,
Ca2++ CuEDTA=Cu2++ CaEDTA
Free Cu2+Concentration increases, and response in copper ion selective electrode.With the addition of EDTA, Ca2+React with EDTA and reach
Balance, Cu2+Start and EDTA complexation, close to terminal, current potential bust, produce hop.Due to the prior Cu EDTA adding release
EDTA and last Cu2+The EDTA equivalent being consumed with EDTA complexation, is cancelled out each other, so the volume consuming EDTA is titration Ca2 +Volume, Cu EDTA only serve indicating electrode response effect.
Beneficial effects of the present invention：
（1）Simplify molten sample separation process, it is to avoid using valuable platinum ware：Sample adopts nitric acid (dense)-hydrofluoric acid dissolution, high chlorine
Acid is smoldered once, and ammonia separates once, compared with GB GB/T 4700.2-1988, simplifies molten sample separation process, but molten sample
Effect is consistent；
（2）Shorten analytical cycle, reduce analysis cost：Amount of reagent halves, and analytical cycle shorten to 3 hours by 1 day；
（3）Terminal is automatically judged using potential break according to automatical potentiometric titrimeter, reduces the artificial error judging that terminal brings,
Improve the preci-sion and accuracy of analysis result.
（4）According to the characteristic not containing magnesium elements in calcium-silicon, calcium ion is replaced to select electricity using copper ion selective electrode
Pole, extends the service life of electrode, has saved analysis cost.
Specific embodiment
To further illustrate the present invention below by embodiment, but to be not limited to following examples.
Embodiment：
Calcium-silicon standard sample GSB03-2197-2008, GSBH12002-90 is taken to be tested.
Specifically include following steps：
1st, sample treatment：First demarcate the concentration of EDTA with calcium standard solution, then take the CuSO of 0.025 mol/L4Solution 10 mL
In beaker, add 10 mL ammonia ammonium chloride buffer solution, EDTA titrates CuSO4To terminal, record volume V mL, then take
The CuSO of 0.025 mol/L4In beaker, the EDTA being quantitatively adding V mL forms 1 to solution 10mL:1 CuEDTA solution.
Weigh 0.1000 g sample respectively to be placed in polytetrafluoroethylene beaker, add 10 mL nitric acid, Deca about 5 mL hydrogen fluorine
Acid.Decompose when being water-cooled, after vigorous reaction stops, adding 10 mL perchloric acid, be evaporated to emit perchloric acid white cigarette, will
Its volume concentration is to about 1 mL.
Take off polytetrafluoroethylene beaker cooling, add 10 mL hydrochloric acid, so that solubility salt is dissolved.Transfer to 400 mL to burn
In cup, add 200 mL water, being slowly added to ammonium hydroxide while stirring to solution is in yellow, with quantitation after heated and boiled 5 min
Filter paper filtering, filtrate is contained in 300 mL beakers.On filter paper, precipitation is washed for several times with ammonium nitrate, then uses warm water cleaning.Contain filtrate
Beaker in, add 5 mL（1+3）Triethanolamine, add 10 mL ammonia ammonium chloride buffer solution, 1 mL prepare
CuEDTA, sample is put on potentiometric titrimeter titration platform, starts the analysis program having editted, inserts sample number into spectrum and examination
Sample amount, is titrated to terminal with EDTA standard solution.Do blank assay in company with test portion.
2nd, result compares
Two methods measure calcium content in calcium-silicon standard sample GSB03-2197-2008 and GSBH12002-90 respectively, knot
Fruit is shown in Table 1.
Table 1 distinct methods measurement result（%）
Table 1 result shows, the molten sample of GB：With platinum ware, nitric acid (1+1)-hydrofluoric acid dissolution, perchloric acid is smoldered twice, and ammonia divides
From twice although standard, but process is loaded down with trivial details, spends the time long.Molten sample after improvement：With polytetrafluoroethylene beaker, nitric acid (dense)-
Hydrofluoric acid dissolution, perchloric acid smoked to volume concentration to 1 mL about, ammonia separates once, and process is relatively simple, and result is accurate
Degree is high.Can be seen that after contrast that after improving, effect reaches the molten sample effect being equal to GB, but avoid using valuable platinum
Ware, simplifies molten sample separation process, selects more simple, convenient, timesaving document molten sample prescription case.
3rd, the selection of titration mode
The titration mode of 855 potentiometric titrimeters mainly has two kinds：MET- equivalent titration mode：Volumetric solutionIncrementIt is manually set, drip
Determine process by setIncrementTo equivalent point propulsion, until findingEquivalent point.This pattern is particularly suitable for weak anti-of chemomotive force
Should, non-aqueous system andWeak electrolyteThe titration of system.The dynamic titration mode of DET-：TitrationLiquidIncrementWithTitration curveChange and
Change,TitrationVery fast when speed starts, but with closeEquivalent pointAnd automatically slow down, until find equivalent point.This pattern can be looked for
To minimum hop, automatically determine pK value, be suitable for most of aqueous phase system titration.Titrate silico-calcium from two kinds of titration mode respectively
Alloy standard sample GSB03-2197-2008, calcium content is 25.07%, two kinds of titration mode respectively titration 5 times, analysis result such as table
Shown in 2.
2 two kinds of titration mode results of table were contrasted with the time
As can be seen from Table 2, MET pattern measurement result is more accurate, so selecting MET titration mode.
4th, the judgement of titration end-point
" equivalent point criterion of identification value " i.e. △ E/ △ V is titration end-point higher than preset value.In order to prevent various pseudo-ending points from being missed
It is considered titration end-point, investigated the many factors of impact endpoint.Under this titration system, " equivalent point criterion of identification " is
Main affecting parameters, the too low easy situation occurring stopping less than terminal titrating；Too high, easily occur to terminal not stopping
The only situation of titration.Through multiple test it is determined that endpoint parameter sets as shown in table 3.
Table 3 equivalent point identification parameter
5th, preci-sion and accuracy checking
By test method, each 9 times of mensure calcium-silicon standard sample GSB03-2197-2008, GSBH12002-90, result is such as
Under.
Table 4 preci-sion and accuracy result (n=11)
Can be seen that from the test of above preci-sion and accuracy：This method is suitable for the mensure of calcium element content in calcium-silicon,
Preci-sion and accuracy preferably, using standard sample checking, can meet the requirement of production testing.
6th, sample analysis
Select 3 samples（Calcium-silicon standard sample GSB03-2197-2008, GSBH12002-90 and a production sample 1#
Sample）, it is measured with automatic potentiometric titration, compare with manual titrimetry result, the results are shown in Table 5.
Table 5 analysis result comparesw/%
As can be seen from Table 5, the test result of potentiometric titration is close with manual titrimetry.
Claims (5)
1. a kind of constant-current titration measure calcium content in calcium-silicon method it is characterised in that：Using automatical potentiometric titrimeter, adopt
With copper ion selective electrode, realize the Accurate Determining of calcium content in calcium-silicon；Comprise the following steps：
（1）Sample is placed in polytetrafluoroethylene beaker, adds nitric acid, the molten sample of Fluohydric acid., perchloric acid smoked；
（2）It is subsequently adding ammonium hydroxide and forms precipitation filtration interfering ion, measure filtrate；
（3）Using copper ion selective electrode to the response of copper come indirect determination calcium.
2. constant-current titration according to claim 1 measure calcium content in calcium-silicon method it is characterised in that：Including with
Lower step：
（1）Sample treatment：
First demarcate the concentration of EDTA with calcium standard solution, then take the CuSO of 0.025 mol/L4Solution 10 mL in beaker, plus
Enter 10 mL ammonia ammonium chloride buffer solution, EDTA titrates CuSO4To terminal, record volume V mL, then take 0.025 mol/L's
CuSO4In beaker, the EDTA being quantitatively adding V mL forms 1 to solution 10mL:1 CuEDTA solution；Described ammonia ammonium chloride delays
Rushing solution is：Weigh that 67.5 g ammonium chloride are soluble in water, add the ammonium hydroxide that 570 mL density are 0.9g/mL, with water dilution
To 1000 mL, mix；This pH value of solution is 10；
Sample is placed in polytetrafluoroethylene beaker, adds nitric acid, Deca Fluohydric acid.；Decompose when being water-cooled, treat acutely anti-
After should stopping, adding perchloric acid, be evaporated to emit perchloric acid white cigarette, by its volume concentration to 1 mL；
Take off polytetrafluoroethylene beaker cooling, add hydrochloric acid, so that solubility salt is dissolved；Transferring in beaker, adding water, while stirring
Mixing side and being slowly added to ammonium hydroxide to solution is in yellow, is filtered with quantitative filter paper, filtrate is contained in beaker after heated and boiled 5 min
In；Precipitation on filter paper is washed for several times with ammonium nitrate, then with 50-70 DEG C of warm water cleaning；Contain in the beaker of filtrate, add three ethanol
Amine, adds ammonia ammonium chloride buffer solution and the CuEDTA preparing, sample is put on potentiometric titrimeter titration platform, start
Compiled good analysis program, determines the parameter setting of equivalent point, inserts sample number into spectrum and sample size, is dripped with EDTA standard solution
Determine to terminal；Do blank assay in company with test portion；
（2）The selection of titration mode：
Select MET- equivalent titration mode：Volumetric solution increment is manually set, and titration process is pushed away to equivalent point by set increment
Enter, until finding equivalent point；
（3）The judgement of titration end-point
" equivalent point criterion of identification value " i.e. △ E/ △ V is titration end-point higher than preset value.
3. constant-current titration according to claim 2 measure calcium content in calcium-silicon method it is characterised in that：With every gram
On the basis of sample, the consumption of nitric acid is：In 100mL nitric acid, the amount of Deca Fluohydric acid. is every gram of sample dissolution：Every gram of sample makes
Use 50mL Fluohydric acid.；The consumption of perchloric acid is：Every gram of sample uses 50mL perchloric acid；The consumption of hydrochloric acid is：Every gram of sample uses
100mL hydrochloric acid；The consumption of triethanolamine solution is：50mL；The consumption of ammonia ammonium chloride buffer solution is：100mL；CuEDTA's
Consumption：10mL.
4. constant-current titration according to claim 3 measure calcium content in calcium-silicon method it is characterised in that：Described nitre
Acid：Density is 1.42 g/mL；Fluohydric acid.：Density is 1.15 g/mL；Perchloric acid：Density is 1.67 g/mL；Hydrochloric acid：Density is
1.19 g/mL；In triethanolamine solution, the mass ratio of triethanolamine and water is 1:3.
5. constant-current titration according to claim 2 measure calcium content in calcium-silicon method it is characterised in that：Described etc.
When the parameter setting of point is as follows：
Signal drift value：50 mv/min；
Pre-add volume：10mL；
The volume adding after reaching equivalent point：2mL；
Rate of liquid aspiration：Maximum
Band volume window evaluation lower limit：11 mL
The band volume window evaluation upper limit：100mL.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107202831A (en) * | 2017-06-05 | 2017-09-26 | 深圳市华星光电技术有限公司 | The assay method of copper ion concentration in a kind of copper acid etch liquid |
| CN113281458A (en) * | 2021-06-17 | 2021-08-20 | 山西太钢不锈钢股份有限公司 | Analysis method for free total calcium content of steel slag |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3121613A (en) * | 1961-04-26 | 1964-02-18 | Donald L Bittner | Calcium determination method |
| JP3898940B2 (en) * | 2001-11-26 | 2007-03-28 | 九州電力株式会社 | The measuring method of the Ca component amount in ash in a pressurized fluidized bed combustion apparatus, and the control method of a pressurized fluidized bed combustion apparatus. |
| CN101344489A (en) * | 2008-09-02 | 2009-01-14 | 武汉钢铁(集团)公司 | Method for measuring calcium constituent in silicon aluminum calcium barium alloy |
| CN105911049A (en) * | 2016-04-13 | 2016-08-31 | 内蒙古包钢钢联股份有限公司 | Method for determining calcium oxide in rare earth concentrate |
-
2016
- 2016-10-14 CN CN201610898932.1A patent/CN106404997A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3121613A (en) * | 1961-04-26 | 1964-02-18 | Donald L Bittner | Calcium determination method |
| JP3898940B2 (en) * | 2001-11-26 | 2007-03-28 | 九州電力株式会社 | The measuring method of the Ca component amount in ash in a pressurized fluidized bed combustion apparatus, and the control method of a pressurized fluidized bed combustion apparatus. |
| CN101344489A (en) * | 2008-09-02 | 2009-01-14 | 武汉钢铁(集团)公司 | Method for measuring calcium constituent in silicon aluminum calcium barium alloy |
| CN105911049A (en) * | 2016-04-13 | 2016-08-31 | 内蒙古包钢钢联股份有限公司 | Method for determining calcium oxide in rare earth concentrate |
Non-Patent Citations (4)
| Title |
|---|
| 中华人民共和国冶金工业部: "硅钙合金化学分析方法 EDTA滴定法测定钙量", 《中华人民共和国国家标准 硅钙合金化学分析方法 EDTA滴定法测定钙量》 * |
| 乐薇等: "铜离子选择电极络合滴定法分步滴定锌和镁", 《中华民族大学学报（自然科学版）》 * |
| 刘兴沂等: "EGTA滴定法直接快速测定硅钙合金中钙", 《理论检验学术交流论文集-湿法分析》 * |
| 杨懂艳: "电位滴定法测定水中总硬度的不确定度评定", 《分析试验室》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107202831A (en) * | 2017-06-05 | 2017-09-26 | 深圳市华星光电技术有限公司 | The assay method of copper ion concentration in a kind of copper acid etch liquid |
| CN113281458A (en) * | 2021-06-17 | 2021-08-20 | 山西太钢不锈钢股份有限公司 | Analysis method for free total calcium content of steel slag |
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