CN106932385A - The assay method of total Boron contents in boron carbide-aluminum oxide pellet - Google Patents

Abstract

The invention belongs to Boron contents detection technique field, and in particular to the assay method of total Boron contents in a kind of boron carbide aluminum oxide pellet；The purpose of the present invention is, in view of the shortcomings of the prior art, provide being capable of a kind of assay method of total Boron contents based on the existing instrument and equipment in laboratory and in meeting scientific research, the boron carbide aluminum oxide pellet of the demand of production detection；The technical scheme is that：The assay method of total Boron contents, comprises the following steps in a kind of boron carbide aluminum oxide pellet：Step one, sample dissolving；Step 2, aluminium element interference is eliminated；Step 3, washing of precipitate；Step 4, sample determination；Step 5, result of calculation.

Description

The assay method of total Boron contents in boron carbide-aluminum oxide pellet

Technical field

The invention belongs to Boron contents detection technique field, and in particular to the assay method of total Boron contents in a kind of boron carbide-aluminum oxide pellet.

Background technology

Boron carbide aluminum oxide pellet is formed through high-temperature calcination after being mixed by a certain percentage with boron carbide powder and alumina powder, and the hardness of boron carbide is only second to diamond, insoluble in acid, alkali.And aluminum oxide is commonly called as corundum, matter is harder, water insoluble, is slightly soluble in alkali and acid.Therefore it is more stable through the boron carbide aluminum oxide chemical property after high-temperature calcination, it is less readily soluble in acid, alkali, the document that the measure of Boron contents is published in current boron carbide and alumina powder is more, and the measure of boron carbide aluminum oxide pellet dissolving method and Boron contents yet there are no open report.

The content of the invention

The purpose of the present invention is, in view of the shortcomings of the prior art, provide being capable of a kind of assay method of total Boron contents based on the existing instrument and equipment in laboratory and in meeting scientific research, the boron carbide-aluminum oxide pellet of the demand of production detection.

The technical scheme is that：

The assay method of total Boron contents, comprises the following steps in a kind of boron carbide-aluminum oxide pellet：

Step one, sample dissolving；

Step 2, aluminium element interference is eliminated；

Step 3, washing of precipitate；

Step 4, sample determination；

Step 5, result of calculation.

Comprised the following steps in the step one：

2~6g natrium carbonicum calcinatums and 0.5~1.5g potassium nitrate are added first in platinum crucible, 0.1~0.3g samples are accurately added, 0.1mg is accurate to, stirred；

Then 1~3g natrium carbonicum calcinatums are covered again on surface, add a cover, retain gap between lid and crucible, crucible is put into Muffle furnace, it is warming up to 600~650 DEG C of 1.5~2.5h of melting, 675~750 DEG C of meltings 0.5~1.5h, 775~850 DEG C of 0.5~1.5h of melting are risen to again, finally rise to 950~1100 DEG C of 1.5~2.5h of melt process；

Finally take out crucible and shake rapidly, sample is cooled down after being affixed on sidewall of crucible, be slowly added dropwise into crucible with 15% hydrochloric acid, fused mass is set to be transferred to completely in 250mL beakers, after fused mass is completely dispersed, excessive 15% hydrochloric acid is added, standing is completely dissolved precipitation.

The step 2 is comprised the following steps：

50.00mL test solutions are accurately pipetted first in beaker, add 10~40mL water,

0.1~0.2mL bromocresol green indicator is subsequently adding, to adding 1.5~2.5g Carbon Dioxides calcium to bubble-free to produce in solution, 5~20min of solution is boiled.

The step 3 is comprised the following steps：

First, the solution after boiling is filtered into conical flask, and with 15% salt acid elution beaker 4~8 times, washing precipitation 4~10 times is every time 2~10mL using 15% hydrochloric acid cleaning solution volume, and cleaning solution merges with filtered fluid；

Then heating is boiled volume concentration to 140~160mL.

The step 4 is comprised the following steps：

First, 15% hydrochloric acid is added dropwise makes solution just be changed into light yellow from blueness, continues to boil 5~10min, after cooling, solution is dropped to by xanthochromia indigo plant with standard solution of sodium hydroxide, and addition volume is not calculated.0.5~1mL phenolphthalein indicators and 2~3g mannitol are continuously added in the solution, and be titrated to solution with standard solution of sodium hydroxide is changed into purple from colourless；

Then, to 0.5~1.5g mannitol 1.2.7 are added in system, solution is titrated to again with standard solution of sodium hydroxide 1.2.16 and is changed into purple from colourless.Repeat the above steps when adding mannitol colour-fast as titration end-point.

In the step 5, measurement result is quoted by the average value analyzed twice, and the computing formula of boron percentage composition is：

In formula：

ω_(B)--- the percentage composition of boron, % in sample；

25500 --- constant volume and measured volume ratio；

0.01081 --- to the titer of boron, unit is gram every mM (g/mmol) to NaOH；

c_(NaOH)--- the substance withdrawl syndrome of standard solution of sodium hydroxide, unit is mole every liter (mol/L)；

V --- standard solution of sodium hydroxide consumes volume, and unit is milliliter (mL)；

V₀--- blank consumes standard solution of sodium hydroxide volume, and unit is milliliter (mL)；

The quality of m --- test portion, unit is gram (g).

The beneficial effects of the invention are as follows：

1. the present invention have selected the experiment conditions such as sample solution concentration, sample dissolution mechanism, the interference elimination method of aluminium element, washing of precipitate number of times, indicator, with the content of total boron in determination of acid-basetitration boron carbide-aluminum oxide pellet, the precision of method is better than 1%, and average recovery rate is between 90% 110%.Method accurately and reliably, meets the project analysis technical requirement；

2. the detection method of total Boron contents in titration measuring boron carbide-aluminum oxide pellet has been successfully established, the content of total boron can have accurately been determined using the experiment condition enumerated in the content of the invention, quoted accurate detection data, effectively coordinated the carrying out of special production.

Specific embodiment

The assay method of total Boron contents in a kind of boron carbide-aluminum oxide pellet proposed by the present invention is further introduced with reference to embodiment：

The assay method of total Boron contents, comprises the following steps in a kind of boron carbide-aluminum oxide pellet：

Step one, sample dissolving；

Step 2, aluminium element interference is eliminated；

Step 3, washing of precipitate；

Step 4, sample determination；

Step 5, result of calculation.

Comprised the following steps in the step one：

2~6g natrium carbonicum calcinatums and 0.5~1.5g potassium nitrate are added first in platinum crucible, 0.1~0.3g samples are accurately added, 0.1mg is accurate to, stirred；

Then 1~3g natrium carbonicum calcinatums are covered again on surface, add a cover, retain gap between lid and crucible, crucible is put into Muffle furnace, it is warming up to 600~650 DEG C of 1.5~2.5h of melting, 675~750 DEG C of meltings 0.5~1.5h, 775~850 DEG C of 0.5~1.5h of melting are risen to again, finally rise to 950~1100 DEG C of 1.5~2.5h of melt process；

Finally take out crucible and shake rapidly, sample is cooled down after being affixed on sidewall of crucible, be slowly added dropwise into crucible with 15% hydrochloric acid, fused mass is set to be transferred to completely in 250mL beakers, after fused mass is completely dispersed, excessive 15% hydrochloric acid is added, standing is completely dissolved precipitation.

The step 2 is comprised the following steps：

50.00mL test solutions are accurately pipetted first in beaker, add 10~40mL water,

0.1~0.2mL bromocresol green indicator is subsequently adding, to adding 1.5~2.5g Carbon Dioxides calcium to bubble-free to produce in solution, 5~20min of solution is boiled.

The step 3 is comprised the following steps：

First, the solution after boiling is filtered into conical flask, and with 15% salt acid elution beaker 4~8 times, washing precipitation 4~10 times is every time 2~10mL using 15% hydrochloric acid cleaning solution volume, and cleaning solution merges with filtered fluid；

Then heating is boiled volume concentration to 140~160mL.

The step 4 is comprised the following steps：

First, 15% hydrochloric acid is added dropwise makes solution just be changed into light yellow from blueness, continues to boil 5~10min, after cooling, solution is dropped to by xanthochromia indigo plant with standard solution of sodium hydroxide, and addition volume is not calculated.0.5~1mL phenolphthalein indicators and 2~3g mannitol are continuously added in the solution, and be titrated to solution with standard solution of sodium hydroxide is changed into purple from colourless；

Then, to 0.5~1.5g mannitol 1.2.7 are added in system, solution is titrated to again with standard solution of sodium hydroxide 1.2.16 and is changed into purple from colourless.Repeat the above steps when adding mannitol colour-fast as titration end-point.

In the step 5, measurement result is quoted by the average value analyzed twice, and the computing formula of boron percentage composition is：

In formula：

ω_(B)--- the percentage composition of boron, % in sample；

25500 --- constant volume and measured volume ratio；

0.01081 --- to the titer of boron, unit is gram every mM (g/mmol) to NaOH；

c_(NaOH)--- the substance withdrawl syndrome of standard solution of sodium hydroxide, unit is mole every liter (mol/L)；

V --- standard solution of sodium hydroxide consumes volume, and unit is milliliter (mL)；

V₀--- blank consumes standard solution of sodium hydroxide volume, and unit is milliliter (mL)；

The quality of m --- test portion, unit is gram (g).

Experiment shows that boron carbide powder can use Na₂CO₃、KNO₃High-temperature fusion is carried out, but can not be melted under this condition completely with the boron carbide-aluminum oxide pellet after alumina powder sintering.Therefore, this method, with the platinum crucible calcination at 650 DEG C, 1000 DEG C respectively, is then transferred in beaker, the solution that can be clarified by the way of gradient-heated with the HCl solution that concentration is 15%.

Total Boron nitrogen rings use acid-base titration, with the boron element in mannitol complex solution, are titrated with NaOH, then the aluminium element in solution can produce very strong interference to titration process.For the total Boron contents of Accurate Determining, it is necessary to which the interference of aluminium is eliminated.

Experiment found, a small amount of multiple to calcium carbonate powder is added in solution, and the hydrolysising balance of aluminium can be made to be moved to positive direction, is finally fully converted to aluminum hydroxide precipitation, can be removed by way of filtering.

Sample after same constant volume is carried out point to take titration, Boron nitrogen rings result is not parallel, because sample transfer is not net, cause boron element to lose.Experiment find, when beaker washing times more than 3 times, filter paper washing times more than 4 times when, the parallel determinations twice of boron are consistent.

Establish the detection method of total Boron contents in titration measuring boron carbide-aluminum oxide pellet.The present invention have selected the experiment conditions such as sample solution concentration, sample dissolution mechanism, the interference elimination method of aluminium element, washing of precipitate number of times, indicator, with the content of total boron in determination of acid-basetitration boron carbide-aluminum oxide pellet, the precision of method is better than 1%, and average recovery rate is between 90% 110%.Method accurately and reliably, meets the project analysis technical requirement.

Claims (6)

1. in a kind of boron carbide-aluminum oxide pellet total Boron contents assay method, its feature exists In：Comprise the following steps：

Step one, sample dissolving；

Step 2, aluminium element interference is eliminated；

Step 3, washing of precipitate；

Step 4, sample determination；

Step 5, result of calculation.

2. the always survey of Boron contents in a kind of boron carbide-aluminum oxide pellet as claimed in claim 1 Determine method, it is characterised in that：Comprised the following steps in the step one：

2~6g natrium carbonicum calcinatums and 0.5~1.5g potassium nitrate are added first in platinum crucible, it is accurate 0.1~0.3g samples are really added, 0.1mg is accurate to, stirred；

Then 1~3g natrium carbonicum calcinatums are covered again on surface, added a cover, protected between lid and crucible Gap is stayed, crucible is put into Muffle furnace, be warming up to 600~650 DEG C of 1.5~2.5h of melting, 675~750 DEG C of meltings 0.5~1.5h, 775~850 DEG C of 0.5~1.5h of melting are risen to again, finally Rise to 950~1100 DEG C of 1.5~2.5h of melt process；

Finally take out crucible and shake rapidly, sample is cooled down after being affixed on sidewall of crucible, with 15% Hydrochloric acid be slowly added dropwise into crucible, fused mass is transferred to completely in 250mL beakers, treat After fused mass is completely dispersed, excessive 15% hydrochloric acid is added, standing is completely dissolved precipitation.

3. the always survey of Boron contents in a kind of boron carbide-aluminum oxide pellet as claimed in claim 1 Determine method, it is characterised in that：The step 2 is comprised the following steps：

50.00mL test solutions are accurately pipetted first in beaker, add 10~40mL water,

0.1~0.2mL bromocresol green indicator is subsequently adding, to 1.5~2.5g of addition in solution Carbon Dioxide calcium to bubble-free is produced, and boils 5~20min of solution.

4. the always survey of Boron contents in a kind of boron carbide-aluminum oxide pellet as claimed in claim 1 Determine method, it is characterised in that：The step 3 is comprised the following steps：

First, the solution after boiling is filtered into conical flask, with 15% salt acid elution beaker 4~8 times, washing precipitation 4~10 times, every time using 15% hydrochloric acid cleaning solution volume for 2~ 10mL, cleaning solution merges with filtered fluid；

Then heating is boiled volume concentration to 140~160mL.

5. the always survey of Boron contents in a kind of boron carbide-aluminum oxide pellet as claimed in claim 1 Determine method, it is characterised in that：The step 4 is comprised the following steps：

First, 15% hydrochloric acid is added dropwise makes solution just be changed into light yellow from blueness, continue to boil 5~ 10min, after cooling, solution is dropped to by xanthochromia indigo plant with standard solution of sodium hydroxide, is not calculated and is added Enter volume.0.5~1mL phenolphthalein indicators and 2~3g mannitol are continuously added in the solution, Solution is titrated to standard solution of sodium hydroxide be changed into purple from colourless；

Then, to 0.5~1.5g mannitol is added in system, standard solution of sodium hydroxide weight is used Newly be titrated to solution is changed into purple from colourless, repeats the above steps when adding mannitol colour-fast As titration end-point.

6. the always survey of Boron contents in a kind of boron carbide-aluminum oxide pellet as claimed in claim 1 Determine method, it is characterised in that：In the step 5, measurement result is average by what is analyzed twice Value is quoted, and the computing formula of boron percentage composition is：

${\mathrm{\ω}}_{\left(B\right)}=\frac{250}{50}\×\frac{0.01081c_{\left(NaOH\right)}(V-V_0)}{m}\×100\%......\left(1\right)$

In formula：

ω_(B)--- the percentage composition of boron, % in sample；

--- constant volume and measured volume ratio；

0.01081 --- to the titer of boron, unit is gram every mM (g/mmol) to NaOH；

c_(NaOH)--- the substance withdrawl syndrome of standard solution of sodium hydroxide, unit is mole every liter (mol/L)；

V --- standard solution of sodium hydroxide consumes volume, and unit is milliliter (mL)；

V₀--- blank consumes standard solution of sodium hydroxide volume, and unit is milliliter (mL)；

The quality of m --- test portion, unit is gram (g).