CN1959382A - Method for measuring content of phosphor in metal silicon - Google Patents

Abstract

A method for analyzing P content in metal silicon includes placing metal silicon sample containing 0.0025-0.125 wt% of P into acidic proof bottle, adding distilled water of 4-5mL and nitric acid of 15-20mL as well as perchloric acid of 4-6mI into bottle per each gram of said sample, then adding 1-2mL hydrochloric acid per each gram of said sample slowly then adding 10-15mL of hydrochloric acid, heating it on electric heating plate till solution is dried to be 0.5-1ml, adding 12-14ml of nitric acid and 250ml of distilled water, plotting standard curve then using computer to determine P content as per said curve.

Description

Measure the method for phosphorus in silicon metal content

Technical field

The present invention relates to the analysis test method of impurity element phosphorus content in impurity content assay method, the especially metallic silicon in the chemical field.

Technical background

Metallic silicon extensively applies to industries such as communication, light transmitting fiber, computing machine, semiconductor material, solar cell, and quality requirements is higher.State Standard of the People's Republic of China GB/T2881-91 " industrial silicon technical conditions ", GB/T14849-93 " industrial silicon chemical analysis ", inspection and quarantine industry standard SN/T0550.1-96 " iron in the outlet metallic silicon, aluminium, the mensuration of calcium (spectrophotometric method) ", SN/T0550.2-96 " iron in the outlet metallic silicon, aluminium, the mensuration of calcium (volumetric method) " and SN/T1650-2005 " iron in the metallic silicon, aluminium, calcium, magnesium, manganese, zinc, copper, titanium, chromium, nickel, the mensuration ICP-AES of vanadium " etc. standard, method, stipulated iron, aluminium, the assay method of major impurity elements such as calcium, but do not have the detection method of phosphorus.

Phosphorus be in the metallic silicon non-metallic impurities element it, detection difficult.The metallic silicon of low phosphorus content, price is higher in the international market, has stronger competitive power of export.The method of checked for impurities element phosphor is not appeared in the newspapers as yet from metallic silicon but up to the present.

Summary of the invention

Purpose of the present invention is intended to overcome the defective of prior art, provides a kind of employing inductively coupled plasma atomic emission spectrometer (ICP-AES) to measure the method for phosphorus in silicon metal content.

The method of mensuration phosphorus in silicon metal content of the present invention is made up of following steps:

One, choosing the phosphorus weight percentage is 0.0025～0.25% metallic silicon sample, places acid-resistant container;

Two, add 4～5mL distilled water, 15～20mL nitric acid, 4～6mL perchloric acid, mixing successively according to every gram metallic silicon sample;

Three, slowly add 1～2mL hydrofluorite according to every gram metallic silicon sample, treat to add 10～15mL hydrofluorite again, jog, placement after brown gas reduces;

During four, to the dissolving of most of metallic silicon, no obvious black solid particle, move to temperature and be heating evaporation on 150～200 ℃ the electric hot plate, perchloric acid emits white cigarette;

Five, above-mentioned solution evaporation is done near, surplus 0.5～1mL;

Six, above-mentioned solution is taken off cooling, adding 12～14mL volumetric concentration by every gram metallic silicon sample is 10% nitric acid, adds distilled water again to 250mL, mixing;

Seven, draw calibration curve: getting weight concentration is 0.0,0.1,0.2,0.5,1.0,10.0 μ g/mL phosphorus standard solution, under the instrument condition of work, measure, and with the phosphorus concentration horizontal ordinate, line strength is an ordinate, the computer automatic drafting calibration curve;

Eight, the same step 7 of step 6 gained measured in solution records phosphorus line strength, and computing machine checks in phosphorus content the sample solution automatically from calibration curve, calculates the percentage composition of phosphorus in the metallic silicon sample.

Above-mentioned nitric acid, perchloric acid, that hydrofluorite is top grade is pure.

The method of the invention be with the metallic silicon sample through hydrofluorite, nitric acid dissolve, perchloric acid is smoldered, evaporation process, major component silicon is decomposed, discharges, it is less to influence each other between surplus element, does not have matrix to disturb.Phosphorus enters atomizer in the sample solution, form gasoloid, be written into the high temperature high-frequency plasma by argon gas, ionization takes place, produce characteristic spectral line, (ICP-AES) measures line strength with inductively coupled plasma atomic emission spectrometer, and its intensity is directly proportional with phosphorus content, adopt calibration curve to carry out quantitative measurement, computing machine calculates the percentage composition of phosphorus in silicon metal automatically.Test liquid be must guard against evaporate to dryness or burnt the paste in the step 5, otherwise, produce pyrophosphoric acid, cause the result on the low side.

The result calculates:

The content of phosphorus is calculated as follows in the sample:

$X=\frac{C\×V}{M}\×{10}^{-4}$

In the formula:

X---the percentage composition of phosphorus in the sample, unit are %;

C---the concentration of phosphorus in the sample solution, unit is every milliliter of microgram (μ g/mL);

V---sample solution cumulative volume, unit are milliliter (mL);

M---sample mass, unit is gram (g).

Result of calculation keeps two position effective digitals.

Principal feature of the present invention:

1, use inductively coupled plasma atomic emission spectrometer (ICP-AES) to measure the percentage composition of phosphorus in silicon metal.Can measure simultaneously with other element, applied widely, can be used for metallic silicon manufacturing enterprise and testing agency.

2, detection limit is low, surveys phosphorus detection limit 0.0025%;

3, sensing range: 0.0025～0.25%;

4, recovery experiment: recovery of standard addition is between 88.0～133.2%;

5, accurate experiment: relative standard deviation＜4.0%, error is less, and the result is accurate.

Description of drawings

Fig. 1 is the phosphorus calibration curve.

Among the figure: p is the weight concentration of phosphorus standard solution; I is phosphorus line strength.

Embodiment

Embodiment:

1 uses instrument:

Inductively coupled plasma atomic emission spectrometer (being called for short ICP-AES), model: LEEMAN Prodigy.

2 use reagent:

Distilled water is redistilled water, and chemical reagent is that top grade is pure;

Nitric acid (ρ 1.42g/mL); Hydrofluorite (ρ 1.14g/mL); Perchloric acid (ρ 1.67g/mL);

Phosphorus standard inventory solution (100 μ g/mL): take by weighing 0.4394 gram benchmark potassium dihydrogen phosphate (105 ℃ were dried by the fire 1 hour, and exsiccator is cooled to room temperature), be dissolved in 100mL surely with 2% nitric acid.To become weight concentration be the phosphorus standard solution of 0.0,0.1,0.2,0.5,1.0,10.0 μ g/mL to 2% nitric acid stepwise dilution during use.

3 phosphorus calibration curves are drawn

Use the phosphorus standard solution of 0.0,0.1,0.2,0.5,1.0,10.0 μ g/mL, under table 1 instrument condition of work, measure, computer automatic drafting phosphorus calibration curve, the phosphorus calibration curve is seen Fig. 1.

Table 1 ICP-AES instrument condition of work

4 sample determinations:

Become to be numbered LA2006-59, LA2006-61, PY2006-B phosphorus content percentage by weight is that 0.0025～0.25% metallic silicon sample, 0.2 gram (being accurate to 0.0001 gram) is in polytetrafluoroethylene beaker, add 2～3mL distilled water successively, 5mL nitric acid, 2mL perchloric acid, jog, drip 0.5～1mL hydrofluorite, treat to add 3mL hydrofluorite again after brown gas reduces, to most of sample dissolution, when not having obvious black solid particle, move on about 150～200 ℃ of electric hot plates and heat, perchloric acid emits white cigarette, (sample liquid remains 0.5～1mL), must guard against evaporate to dryness or burnt the paste to be evaporated near doing.Take off cooling, add 4mL nitric acid (1+1), move to the 50mL volumetric flask, distilled water washing beaker, washing lotion is incorporated volumetric flask into, constant volume, shakes up (with doing blank).Measure, the percentage composition of phosphorus the results are shown in Table 2 in the calculation sample.

Table 2 sample LA2006-59, LA2006-61, PY2006-B measurement result (%)

Numbering	Measured value			Mean value
					LA2006-59	0.0027	0.0033	0.0029	0.0030
LA2006-61	0.0073	0.0069	0.0072	0.0071
					PY2006-B	0.0082	0.0080	0.0082	0.0081

The embodiment technical identification:

The detection limit experiment:

Blank assay:

Use blank solution, METHOD FOR CONTINUOUS DETERMINATION phosphorus 10 times the results are shown in Table 3.

Table 3 phosphorus detection limit experiment (n=10, μ g/mL)

Numbering	Concentration	Measured value					Standard deviation	3 times of standard deviations
									Blank solution	0.00	-0.0031 -0.0041	0.0053 -0.0007	-0.0045 0.0034	0.0039 0.0000	-0.0031 -0.0055	0.00387	0.01

Blank solution experimental results show that the theory of phosphorus detects and is limited to 0.01 μ g/mL, is similar to 0.1 μ g/mL.

Survey phosphorus detection limit confirmatory experiment:

With the metallic silicon sample of numbering LA2006-59, before sample preparation, quantitatively add phosphorus standard solution 0.10 μ g/mL and carry out recovery experiment, see Table 4.

Table 4 detection limit mark-on reclaims experiment (n=9, μ g/mL)

Numbering	Background values	The phosphorus addition	Measured value			Yield			The recovery, %
												LA2006 -59	0.1223	0.10	0.2555 0.2320 0.2537	0.2167 0.2117 0.2103	0.2312 0.2347 0.2483	0.1332 0.1097 0.1314	0.0944 0.0894 0.0880	0.1089 0.1124 0.1260	133.2 109.7 131.4	94.4 89.4 88.0	108.9 1l2.4 126.0

The recovery of standard addition of detection limit phosphorus concentration satisfies and measures needs between 88.0～133.2%.

Calculate the sensing range of phosphorus by this densimeter: detect and be limited to 0.1 * 50 ÷ 0.2=25mg/kg, promptly detect and be limited to 0.0025%.So upper limit of detection 10.0 * 50 ÷ 0.2=2500mg/kg are sensing range 0.0025～0.25%.

The recovery of standard addition experiment:

With numbering LA2006-59, LA2006-61, the different metallic silicon sample of three phosphorus contents of YB2006-B, quantitatively add phosphorus standard solution 0.10,0.20,0.50,1.00 μ g/mL respectively and carry out recovery experiment, see Table 5.

Table 5 metallic silicon sample mark-on reclaims experiment (n=9, μ g/mL)

Numbering	Background values	The phosphorus addition	Measured value			Yield			The recovery, %
												LA2006 -59	0.1223	0.10	0.2555 0.2320 0.2537	0.2167 0.2117 0.2103	0.2312 0.2347 0.2483	0.1332 0.1097 0.1314	0.0944 0.0894 0.0880	0.1089 0.1124 0.1260	133.2 109.7 131.4	94.4 89.4 88.0	108.9 112.4 126.0
LA2006 -61	0.2830	0.20	0.4974 0.4643 0.4893	0.4870 0.4521 0.4738	0.4694 0.4595 0.4846	0.2144 0.1813 0.2063	0.2040 0.1691 0.1908	0.1864 0.1765 0.2016	107.2 90.6 103.2	102.0 84.6 95.4	93.2 88.2 100.8
												PY2006 -B	0.3251	0.50	0.7755 0.8810 0.7893	0.7770 0.8515 0.8143	0.8245 0.8412 0.8310	0.4504 0.5559 0.4642	0.4519 0.5264 0.4892	0.4994 0.5161 0.5059	90.1 111.2 92.8	90.4 105.3 97.8	99.9 103.2 101.2
PY2006 -B	0.3251	1.00	1.3216 1.2931 1.3676	1.2953 1.2734 1.2909	1.2829 1.3106 1.3836	0.9965 0.9680 1.0425	0.9702 0.9483 0.9658	0.9578 0.9855 1.0585	99.6 96.8 104.2	97.0 94.8 96.6	95.8 98.6 105.8

Experimental results show that:

Recovery of standard addition is between 88.0～133.2%, and this recovery is the recovery when detecting lower bound, and the recovery of other concentration is 88.2～111.2%, is better than this point, satisfies the check needs.

Detect accurate experiment

Replicate determination contains the phosphorus concentration different solutions 10 times, and the result compares, and standard deviation, relative standard deviation (RSD) see Table 6.

Table 6 is surveyed phosphorus precision experiment (n=10, μ g/mL)

Phosphorus concentration	Measured value					Mean value	Standard deviation	RSD，％
									0.10	0.1133 0.0906	0.0936 0.1154	0.1023 0.0906	0.0961 0.1003	0.0989 0.1140	0.1015	0.0096	9.60
0.20	0.1904 0.2019	0.2143 0.1792	0.2040 0.1992	0.1875 0.2095	0.1930 0.1862	0.1965	0.0111	5.55
									0.50	0.4952 0.5068	0.5137 0.5158	0.5171 0.5061	0.5013 0.5075	0.4945 0.5068	0.5065	0.0078	1.56
1.00	1.0267 1.0144	1.0624 1.0686	0.9704 1.0446	1.0817 1.0288	1.0205 1.0459	1.0364	0.0319	3.19

Experimental result: 4 groups of each replicate determinations of solution 10 times, relative standard deviation 1.56～9.60%,＜10%.

Relative standard deviation RSD=9.60% is the relative standard deviation of detection limit, and phosphorus content in the common metal silicon sample＜0.0025% less measured the in the majority of relative error＜5%.

Claims (2)

1, a kind of method of measuring phosphorus in silicon metal content is characterized in that being made up of following steps:

One, choosing the phosphorus weight percentage is 0.0025～0.25% metallic silicon sample, places acid-resistant container;

Two, add 4～5mL distilled water, 15～20mL nitric acid, 4～6mL perchloric acid, mixing successively according to every gram metallic silicon sample;

Three, slowly add 1～2mL hydrofluorite according to every gram metallic silicon sample, treat to add 10～15mL hydrofluorite again, jog, placement after brown gas reduces;

During four, to the dissolving of most of metallic silicon, no obvious black solid particle, move to temperature and be heating evaporation on 150～200 ℃ the electric hot plate, perchloric acid emits white cigarette;

Five, above-mentioned solution evaporation is done near, surplus 0.5～1mL;

Six, above-mentioned solution is taken off cooling, adding 12～14mL volumetric concentration by every gram metallic silicon sample is 10% nitric acid, adds distilled water again to 250mL, mixing;

Seven, draw calibration curve: getting weight concentration is 0.0,0.1,0.2,0.5,1.0,10.0 μ g/mL phosphorus standard solution, under the instrument condition of work, measure, and with the phosphorus concentration horizontal ordinate, line strength is an ordinate, the computer automatic drafting calibration curve;

Eight, the same step 7 of step 6 gained measured in solution records phosphorus line strength, and computing machine checks in phosphorus content the sample solution automatically from calibration curve, calculates the percentage composition of phosphorus in the metallic silicon sample.

2, the method for mensuration phosphorus in silicon metal content as claimed in claim 1 is characterized in that described nitric acid, perchloric acid and hydrofluorite are that top grade is pure.

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