CN101825619A - Method for measuring rare earth content in rare earth alloy in combined way - Google Patents

Abstract

The invention relates to a method for measuring rare earth content in rare earth alloy in a combined way, comprising the following steps of: first step, using inductively coupled plasma emission spectrometry to measure the distribution component of mixed rare earth oxide in rare earth alloy sample, and calculating the molecular weight of the mixed rare earth oxide; and second steps, using the inductively coupled plasma emission spectrometry to calculate the average molecular weight of the mixed rare earth oxide in the rare earth alloy, and then using an EDTA method to titrate the rare earth content. The method for measuring the rare earth content in the rare earth alloy in the combined way has the characteristics of simple operation, rapid speed and high accuracy rate, can be used for rapidly and accurately measuring the content of the mixed rare earth oxide in the rare earth alloy, and meets the need of large-scale production and analysis in a factory.

Description

A kind of method of simultaneous determination rare earth alloy middle rare earth content

Technical field

The invention belongs to the detection method of field of metallurgy, especially a kind of method of simultaneous determination rare earth alloy middle rare earth content.

Technical background

At present, the common method of measuring rare earth alloy middle rare earth content is oxalates gravimetric method and chlorophosphonazo III photometry, but the oxalates gravimetric method exists operation steps complexity, long deficiency of analytic process time, and chlorophosphonazo III luminosity rule is deposited the shortcomings such as interference that measurement range is little, be subjected to thorium.Therefore these two kinds of methods are subjected to certain restriction in the practical application of rare earth alloy professional production producer, and are not suitable for the production analytical approach as rare earth alloy factory.

Summary of the invention

Purpose of the present invention just provides that a kind of speed is fast, accuracy rate is high, can satisfy the method that the simultaneous determination rare earth alloy middle rare earth content of needs is analyzed in plant layout production.

The method of simultaneous determination rare earth alloy middle rare earth content of the present invention may further comprise the steps:

The first step:, and calculate its molecular weight with the partition amount of mixed rare-earth oxide in the inductively coupled plasma emission spectrography measurement rare earth alloy sample; Second step: by the inductively coupled plasma emission spectrometry, calculate the mean molecular weight of mixed rare-earth oxide in the rare earth alloy, use its content of rare earth of EDTA method titration again.Concrete grammar is:

At first calculate the mean molecular weight of mixed rare-earth oxide in the rare earth alloy sample:

A, take by weighing 0.25 the gram～0.75 the gram sample in beaker, the nitric acid that adds 10ml～20ml density 1.42g/ml, after the question response calmness, the hydrofluorite that adds 5ml～10ml density 1.15g/ml, shake beaker sample is dissolved fully, Dropwise 5 drips the hydrogen peroxide hydrotropy, adds 50ml distilled water and 1 gram paper pulp, stir evenly, left standstill 10 minutes;

B, the solution in the beaker is filtered with the middling speed qualitative filter paper, to the distilled water washing precipitation of boiling 5～12 times, must treat when washing to wash again after the filtrate drip-dry at every turn with boiled;

C, will precipitate together with filter paper and put into the nitric acid that is added with 15ml～20ml density 1.42g/ml and the perchloric acid beaker of 5ml～10ml density 1.67g/ml, heating is also steamed to doing, take off cold slightly, with distilled water the test solution of inwall is washed, the hydrochloric acid that adds 5ml density 1.19g/ml, heating make the salt dissolving, after the cooling, filter in the 100ml volumetric flask constant volume;

D, absorption 40ml solution, the method for employing GB/T 18882.3-2002 is measured the partition amount of mixed rare-earth oxide in the rare earth alloy sample;

Mixed rare-earth oxide partition amount in e, the basis rare earth alloy of measuring is calculated its mean molecular weight with following formula

$M_{\mathrm{RexOy}}=\frac{100}{\begin{array}{c}(C_{Y2O3}/112.9)+(C_{\mathrm{la}2O3}/162.9)+(C_{\mathrm{CeO}2}/172.1)+(C_{\mathrm{Pr}6O11}/170.2)+(C_{\mathrm{Nd}2O3}/168.2)+(C_{\mathrm{Sm}2}\\ /174.4_{O3})+(C_{\mathrm{Eu}2O3}/176)+(C_{\mathrm{Gd}2O3}/181.2)+(C_{\mathrm{Tb}4O7}/187)+(C_{\mathrm{Dy}2O3}/186.5)+(C_{\mathrm{Ho}2O3}/189)\\ +\left(C_{\mathrm{Er}2O3}191.2\right)+(C_{\mathrm{Tm}2O3}/193)+(C_{\mathrm{Yb}2O3}/197)+(C_{\mathrm{Lu}2O3}/199)\end{array}}$

C in the formula _Y2O3, C _La2O3,, C _CeO2, C _Pr6O1l, C _Nd2O3, C _Sm2O3, C _Eu2O3, C _Gd2O3, C _Tb4O7, C _Dy2O3C _Ho2O3, C _Er2O3, C _Tm2O3, C _Yb2O3, C _Lu2O3Represent Y respectively ₂O ₃, La ₂O ₃, CeO ₂, Pr ₆O ₁L, Nd ₂O ₃, Sm ₂O ₃, Eu ₂O ₃, Gd ₂O ₃, Tb ₄O ₇, Dy ₂O ₃, Ho ₂O ₃, Er ₂O3, Tm ₂O ₃, Yb ₂O ₃, Lu ₂O ₃Relative content at rare earth alloy middle rare earth oxide;

Afterwards, calculate the mean molecular weight of mixed rare-earth oxide in the rare earth alloy according to the inductively coupled plasma emission spectrometry, content with mixed rare-earth oxide in the EDTA titrimetry titration rare earth alloy sample: draw the solution 40ml that produced in the above-mentioned c step in the 250ml Erlenmeyer flask, heating evaporation is concentrated into 20ml, after being cooled to room temperature, add Congored test paper, transfer to ammoniacal liquor (1+1) that to make Congored test paper be red, use hydrochloric acid (1+1) to transfer to Congored test paper again for blue, add ascorbic acid 0.5 gram, 20ml 20% hexamethylenetetramine, drip 3 0.2% xylenol orange indicator, get final product to becoming glassy yellow by aubergine with 0.001mol/L～0.01mol/L standard EDTA solution titration; The pure ammoniacal liquor of ammoniacal liquor (1+1) expression one volume adds a volume distilled water and is made into, and the pure hydrochloric acid of hydrochloric acid (1+1) expression one volume adds a volume distilled water and is made into.

Calculate at last: the content of mixed rare-earth oxide in the mean molecular weight calculating rare earth alloy sample of the mixed rare-earth oxide of calculating according to the EDTA volume that consumes and the first step by following formula

The method of simultaneous determination rare earth alloy middle rare earth content of the present invention has characteristics simple to operate, that speed is fast, accuracy rate is high, it can the rapid and accurate determination rare earth alloy in the content of mixed rare-earth oxide, satisfy plant layout production and analyze needs.

Embodiment

Embodiment 1: the modulizer product of choosing certain factory's production is as test specimens, and this product batching situation is as follows: the content that adds mishmetal oxygen thing is 2.0%, and its ree distribution pattern amount is: Y ₂O ₃/ RE ₂O ₃Be 50%, La ₂O ₃/ RE ₂O3 is 18%, CeO ₂/ RE ₂O ₃Be 28%, surplus≤4%.Take by weighing 0.75 this sample of gram in plastic beaker, add 20ml nitric acid (density 1.42g/ml) dissolving, add 10ml hydrofluorite (density 1.15g/ml) then, after the question response calmness, Dropwise 5 drips the hydrogen peroxide hydrotropy, add 50ml distilled water, 1 restrain paper pulp again, stir leave standstill ten minutes after, filter with the middling speed qualitative filter paper, with hot wash precipitation 12 times, then precipitation and filter paper being put into the beaker that is added with 10ml nitric acid and 5ml perchloric acid steams extremely dried on the 1000W electric furnace, adding the 5ml hcl acidifying, be settled in the 100ml volumetric flask. evaporation and concentration is to 20ml on the 1000W electric furnace to draw this solution of 40ml, and the method for employing GB/T 18882.3-2002 is measured its partition amount and is:

Element	??Y 2O??3	??La 2??O 3	??Ce??O 2	??Pr 6??O 1l	??Nd 2??O 3	??Sm 2??O 3	??Eu 2??O 3	??Gd 2??O 3	??Tb 4??O 7	??Dy 2??O 3	??Ho 2??O 3	??Er 2??O 3	??Tm 2??O 3	??Yb 2??O 3	??Lu 2??O 3
																The partition amount	??49.9??1	??18.7??7	??28.0??4	??0.11	??0.23	??0.82	??0.02	??1.35	??0.02	??0.02	??0.14	??0.59	??0.02	??0.02	??0.02

According to formula:

$M_{\mathrm{RexOy}}=\frac{100}{\begin{array}{c}(C_{Y2O3}/112.9)+(C_{\mathrm{la}2O3}/162.9)+(C_{\mathrm{CeO}2}/172.1)+(C_{\mathrm{Pr}6O11}/170.2)+(C_{\mathrm{Nd}2O3}/168.2)+(C_{\mathrm{Sm}2}\\ /174.4_{O3})+(C_{\mathrm{Eu}2O3}/176)+(C_{\mathrm{Gd}2O3}/181.2)+(C_{\mathrm{Tb}4O7}/187)+(C_{\mathrm{Dy}2O3}/186.5)+(C_{\mathrm{Ho}2O3}/189)\\ +\left(C_{\mathrm{Er}2O3}191.2\right)+(C_{\mathrm{Tm}2O3}/193)+(C_{\mathrm{Yb}2O3}/197)+(C_{\mathrm{Lu}2O3}/199)\end{array}}$

Calculating its mean molecular weight is 135.32; Drawing 40ml solution low temperature in conical flask again steams near dried, add the 20ml dissolved in distilled water, adding a slice Congored test paper after the cooling transfers to Congored test paper with hydrochloric acid (1+1) and ammoniacal liquor (1+1) and has just become blueness by redness, add 20ml 20% hexamethylenetetramine then, drip 3 xylenol orange (0.2%) indicator, EDTA solution titration with 0.003540mol/L is extremely yellow, consumes EDTA standard titration solution 13.00ml, according to formula

Result of calculation, wherein C _EDTABe the concentration of standard EDTA solution, V _EDTABe the volume of the standard EDTA solution that consumes, M _RexOyBe the mean molecular weight 135.32 that front inductively coupled plasma emission spectrometry is measured, m _SampleBe sample weighting amount, measuring the result is 2.08%, and within the error range 0.3% that national standard allows, also quite identical with the batching value, the result is satisfactory.

Embodiment 2: the rare earth ferrosilicon alloy of choosing certain factory's production is as test specimens, and this product batching situation is as follows: the content that adds mishmetal oxygen thing is 27%, and its ree distribution pattern amount is: Y ₂O ₃/ RE ₂O ₃Be 50%, La ₂O ₃/ RE ₂O3 is 24%, CeO ₂/ RE ₂O ₃Be 25%, surplus≤1%.Take by weighing 0.25 this sample of gram in plastic beaker, add the 20ml nitric acid dissolve, add 10ml hydrofluorite then, after the question response calmness, Dropwise 5 drips the hydrogen peroxide hydrotropy, adds 50ml distilled water, adds 1 gram paper pulp again, stir leave standstill ten minutes after, filter with the middling speed qualitative filter paper,, then precipitation and filter paper are put into the beaker that is added with 10ml nitric acid and 5ml perchloric acid with hot wash 12 times, on the 1000W electric furnace, steam to doing, add the 5ml hcl acidifying, be settled in the 100ml volumetric flask, draw this solution dilution of 40ml to 80ml, measuring its partition amount with the inductively coupled plasma emission spectrometry is

Element	??Y 2O??3	??La 2??O 3	??Ce??O 2	??Pr 6??O 1l	??Nd 2??O 3	??Sm 2??O 3	??Eu 2??O 3	??Gd 2??O 3	??Tb 4??O 7	??Dy 2??O 3	??Ho 2??O 3	??Er 2??O 3	??Tm 2??O 3	??Yb 2??O 3	??Lu 2??O 3
																The partition amount	??50.3??2	??23.9??5	??24.9??3	??0.29	??0.22	??0.13	??0.02	??0.22	??0.02	??0.02	??0.02	??0.02	??0.02	??0.02	??0.02

According to formula:

$M_{\mathrm{RexOy}}=\frac{100}{\begin{array}{c}(C_{Y2O3}/112.9)+(C_{\mathrm{la}2O3}/162.9)+(C_{\mathrm{CeO}2}/172.1)+(C_{\mathrm{Pr}6O11}/170.2)+(C_{\mathrm{Nd}2O3}/168.2)+(C\\ /174.4_{\mathrm{Sm}2O3})+(C_{\mathrm{Eu}2O3}/176)+(C_{\mathrm{Gd}2O3}/181.2)+(C_{\mathrm{Tb}4O7}/187)+(C_{\mathrm{Dy}2O3}/186.5)+(C_{\mathrm{Ho}2O}\\ /189)+\left(C_{\mathrm{Er}2O3}191.2\right)+(C_{\mathrm{Tm}2O3}/193)+(C_{\mathrm{Yb}2O3}/197)+(C_{\mathrm{Lu}2O3}/199)_3\end{array}}$

Calculating its mean molecular weight is 134.79; Drawing 40ml solution again steams on the 1000W electric furnace in conical flask to doing, add the 20ml dissolved in distilled water, add a slice Congored test paper after the cooling, transfer to Congored test paper with hydrochloric acid (1+1) and ammoniacal liquor (1+1) and just become blueness by redness, add 20ml 20% hexamethylenetetramine then, drip 3 xylenol orange (0.2%) indicator, the EDTA solution titration of using 0.007526mol/L is to glassy yellow, the standard EDTA volumetric soiutions that consumes is 26.70ml, according to formula

Result of calculation, wherein C _EDTABe the concentration of standard EDTA solution, V _EDTABe the volume of the standard EDTA solution that consumes, M _RexOyBe the mean molecular weight 134.79 that the front inductively coupled plasma emission spectrography is measured, m _SampleBe sample weighting amount, measuring the result is 27.12%, and within the error range 0.6% that national standard allows, also quite identical with the batching value, the result is satisfactory.

Embodiment 3: the rare earth tungalloy product of choosing certain factory's production is as test specimens, and this product batching situation is: the content that adds mishmetal oxygen thing is 2.0%, and its ree distribution pattern amount is: Y ₂O ₃/ RE ₂O ₃Be 60%, La ₂O ₃/ RE ₂O3 is 19%, CeO ₂/ RE ₂O ₃Be 19%, surplus≤2%.Take by weighing 0.75 this sample of gram in plastic beaker, add 6ml nitric acid (density 1.42g/ml) dissolving, add 18ml hydrofluorite (density 1.15g/ml) then, Dropwise 5 drips the hydrogen peroxide hydrotropy, add on the 1000W electric furnace close dissolving after, cooling adds 50ml distilled water, add 1 gram paper pulp again, stir leave standstill ten minutes after, filter with the middling speed qualitative filter paper,, then precipitation and filter paper are put into the beaker that is added with 10ml nitric acid and 5ml perchloric acid and on the 1000W electric furnace, steams extremely dried with hot wash precipitation 12 times, add the 5ml hcl acidifying, be settled in the 100ml volumetric flask.Evaporation and concentration is to 20ml on the 1000W electric furnace to draw this solution of 40ml, and the method for employing GB/T 18882.3-2002 determines its partition amount and is

Element	??Y 2O??3	??La 2??O 3	??Ce??O 2	??Pr 6??O 1l	??Nd 2??O 3	??Sm 2??O 3	??Eu 2??O 3	??Gd 2??O 3	??Tb 4??O 7	??Dy 2??O 3	??Ho 2??O 3	??Er 2??O 3	??Tm 2??O 3	??Yb 2??O 3	??Lu 2??O 3
																The partition amount	??59.9??2	??18.8??6	??19.1??2	??0.1	??0.14	??0.13	??0.02	??0.56	??0.02	??0.02	??0.25	??0.02	??0.02	??0.02	??0.02

According to formula:

$M_{\mathrm{RexOy}}=\frac{100}{\begin{array}{c}(C_{Y2O3}/112.9)+(C_{\mathrm{la}2O3}/162.9)+(C_{\mathrm{CeO}2}/172.1)+(C_{\mathrm{Pr}6O11}/170.2)+(C_{\mathrm{Nd}2O3}/168.2)+(C\\ /174.4_{\mathrm{Sm}2O3})+(C_{\mathrm{Eu}2O3}/176)+(C_{\mathrm{Gd}2O3}/181.2)+(C_{\mathrm{Tb}4O7}/187)+(C_{\mathrm{Dy}2O3}/186.5)+(C_{\mathrm{Ho}2O}\\ /189)+\left(C_{\mathrm{Er}2O3}191.2\right)+(C_{\mathrm{Tm}2O3}/193)+(C_{\mathrm{Yb}2O3}/197)+(C_{\mathrm{Lu}2O3}/199)_3\end{array}}$

Calculating its mean molecular weight is 130.73; Drawing 40ml solution again steams on the 1000W electric furnace in conical flask to doing, add the 20ml dissolved in distilled water, add a slice Congored test paper after the cooling, transfer to Congored test paper with hydrochloric acid (1+1) and ammoniacal liquor (1+1) and just become blueness by redness, add 20ml 20% hexamethylenetetramine then, drip 3 xylenol orange (0.2%) indicator, the EDTA solution titration of using 0.002550mol/L is to glassy yellow.Quota of expenditure EDTA volumetric soiutions 17.46ml is according to formula

Result of calculation, wherein C _EDTABe the concentration of standard EDTA solution, V _EDTABe the volume of the standard EDTA solution that consumes, M _RexOyBe the mean molecular weight 130.73 that front inductively coupled plasma emission spectrometry is measured, m _SampleBe sample weighting amount, measuring the result is 1.94%, and within the error range 0.3% that national standard allows, also quite identical with the batching value, the result is satisfactory.

Claims (1)

1. the method for a simultaneous determination rare earth alloy middle rare earth content is characterized in that: may further comprise the steps:

A, take by weighing 0.25 the gram～0.75 the gram sample in beaker, the nitric acid that adds 10ml～20ml density 1.42g/ml, after the question response calmness, the hydrofluorite that adds 5ml～10ml density 1.15g/ml, shake beaker sample is dissolved fully, Dropwise 5 drips the hydrogen peroxide hydrotropy, adds 50ml distilled water and 1 gram paper pulp, stir evenly, left standstill 10 minutes;

B, the solution in the beaker is filtered with the middling speed qualitative filter paper, to the distilled water washing precipitation of boiling 5～12 times, must treat when washing to wash again after the filtrate drip-dry at every turn with boiled;

C, will precipitate together with filter paper and put into the nitric acid that is added with 15ml～20ml density 1.42g/ml and the perchloric acid beaker of 5ml～10ml density 1.67g/ml, heating is also steamed to doing, take off cold slightly, with distilled water the test solution of inwall is washed, the hydrochloric acid that adds 5ml density 1.19g/ml, heating make the salt dissolving, after the cooling, filter in the 100ml volumetric flask constant volume;

D, absorption 40ml solution, the method for employing GB/T 18882.3-2002 is measured the partition amount of mixed rare-earth oxide in the rare earth alloy sample;

Mixed rare-earth oxide partition amount in e, the basis rare earth alloy of measuring is calculated its mean molecular weight with following formula

$M_{\mathrm{RexOy}}=\begin{array}{c}\frac{100}{(C_{Y2O3}/112.9)+(C_{\mathrm{la}2O3}/162.9)+(C_{\mathrm{CeO}2}/172.1)+(C_{\mathrm{Pr}6O11}/170.2)+(C_{\mathrm{Nd}2O3}/168.2)+(C_{\mathrm{Sm}2}}\\ /174.4_{O3})+(C_{\mathrm{Eu}2O3}/176)+(C_{\mathrm{Gd}2O3}/181.2)+(C_{\mathrm{Tb}4O7}/187)+(C_{\mathrm{Dy}2O3}/186.5)+(C_{\mathrm{Ho}2O3}/189)\\ +(C_{\mathrm{Er}2O3}/191.2)+(C_{\mathrm{Tm}2O3}/193)+(C_{\mathrm{Yb}2O3}/197)+(C_{\mathrm{Lu}2O3}/199)\end{array}$

C in the formula _Y2O3, C _La2O3,, C _CeO2, C _Pr6O11, C _Nd2O3, C _Sm2O3, C _Eu2O3, C _Gd2O3, C _Tb4O7, C _Dy2O3C _Ho2O3, C _Er2O3, C _Tm2O3, C _Yb2O3, C _Lu2O3Represent Y respectively ₂O ₃, La ₂O ₃, CeO ₂, Pr ₆O ₁1, Nd ₂O ₃, Sm ₂O ₃, Eu ₂O ₃, Gd ₂O ₃, Tb ₄O ₇, Dy ₂O ₃, Ho ₂O ₃, Er ₂O3, Tm ₂O ₃, Yb ₂O ₃, Lu ₂O ₃Relative content at rare earth alloy middle rare earth oxide;

Afterwards, calculate the mean molecular weight of mixed rare-earth oxide in the rare earth alloy according to the inductively coupled plasma emission spectrometry, content with mixed rare-earth oxide in the EDTA titrimetry titration rare earth alloy sample: draw the solution 40ml that produced in the above-mentioned c step in the 250ml Erlenmeyer flask, heating evaporation is concentrated into 20ml, after being cooled to room temperature, add Congored test paper, add ammoniacal liquor that a volume distilled water is made into the pure ammoniacal liquor of a volume and transfer to that to make Congored test paper be red, adding hydrochloric acid that a volume distilled water is made into the pure hydrochloric acid of a volume again, to transfer to Congored test paper be blue, add ascorbic acid 0.5 gram, 20ml 20% hexamethylenetetramine, drip 3 0.2% xylenol orange indicator, get final product to becoming glassy yellow by aubergine with 0.001mol/L～0.01mol/L standard EDTA solution titration;

The content of mixed rare-earth oxide in the mean molecular weight calculating rare earth alloy sample of the mixed rare-earth oxide of calculating according to the EDTA volume that consumes and the first step by following formula

。