Background technique
Fluorite, also known as fluorite, chemical formula CaF2, it is a kind of natural halogen compounds of calcium, is industrial the most useful
Fluorine mineral.Slag making in metallurgical industry, when fluorite is mainly used for converter or electric furnace steel making as flux.In chemical industry,
Fluorite is mainly used as the manufacture chemicals such as hydrofluoric acid and its derivative (sodium fluoride, ammonium fluoride etc.), is widely used in manufacture refrigeration
Agent, plating, glass corrosion, casting deoxidation, wood preservation, casting adhesive etc..In building materials industry, fluorite is also answered extensively
For industries such as glass, ceramics, cement.The main composition of fluorite is calcirm-fluoride, contains a certain amount of carbonate, sulfate, two
Silica, di-iron trioxide etc..The height of Calcium Fluoride Content determines the credit rating of fluorite, the survey of Calcium Fluoride Content in fluorite
Rule is the big event of fluorite constituent analysis.
The standard method that calcirm-fluoride measures in fluorite at present has chemical method and fluorescent spectrometry.Chemical analysis method is substantially
It is divided into two kinds, one kind is mixed-acid dissolution sample, total calcium in titration measuring fluorite, then subtracts calcium carbonate, calcium sulfate
Content acquires the content of calcirm-fluoride.Another kind removes calcium carbonate, after calcium sulfate to be leached with acetic acid, with mixed-acid dissolution residue,
The content of titration measuring calcirm-fluoride.Two kinds of chemical analysis methods are all cumbersome, the period is long, and acetic acid can also dissolve it is a small amount of
Calcirm-fluoride, so that the measurement result of calcirm-fluoride is relatively low, introducing error is big, precision is not high.It in addition is calcirm-fluoride for principal component
Fluorite, it is necessary to sample comminution is all passed through to 0.063mm sieve pore, the calcirm-fluoride in sample could be complete by acid dissolution, otherwise
Measurement result is relatively low.The granularity that 0.063mm can not be reached for the sample of our routine testing analysis preparations, needs again before analysis
The crushing of a sample is carried out, time-consuming for routine analysis, poor feasibility.It is used in X fluorescence spectrum method professional standard
Fuse piece method is measured the content of total calcium, is then converted into the content of total calcirm-fluoride, by calcium carbonate, the calcium sulfate in fluorite
It calculates, calcium carbonate, the higher sample of calcium sulfate is then not suitable for, test result is higher together as calcirm-fluoride.
Summary of the invention
The present invention provides a kind of short, accuracy easy to operate, time-consuming aiming at deficiencies of the prior art
The method of Calcium Fluoride Content in high, favorable reproducibility X-ray fluorescence spectra fusion method measurement fluorite.
Above-mentioned purpose to realize the present invention, a kind of X-ray fluorescence spectra fusion method of the present invention measure calcirm-fluoride in fluorite
The method of content, using following steps:
Step 1: accurately weighing 2.0000g fluorite sample, the dedicated mixed flux of 6.0000g fluorescence;The fluorescence is dedicated
Mixed flux is configured by lithium tetraborate, lithium metaborate, is matched by mass percentage are as follows: lithium tetraborate 67%, inclined boron
Sour lithium 33%;
Step 2: after mixing by weighed fluorite sample and the dedicated mixed flux of fluorescence, being placed in Huang-platinum crucible
In, release agent lithium-bromide solution 8 is added and drips, is melted in model machine automatically in high frequency, carries out fuse piece according to preset automatically molten sample program,
The fluorite sample sheet glass for analysis is made;Fuse piece condition are as follows: 170-190s of preheating time, 900-950 DEG C of melting temperature,
330-390s of melting time, from 220-260s of cool time, air-cooled 110-130s of time;Melting temperature is with 930-950 DEG C
It is good;Most suitable fuse piece condition are as follows: preheating time 180s, 950 DEG C of melting temperature, melting time 360s, from cool time 240s, wind
Cool time 120s;
The concentration of the release agent lithium-bromide solution are as follows: LiBr:30g/100mL.
Step 3: the fluorite sample sheet glass that melting prepares being put into Wavelength dispersion type x ray Fluorescence Spectrometer, is selected
Determine Xray fluorescence spectrometer running parameter to measure, calculates the content of calcirm-fluoride in fluorite sample automatically.
In step 3, the running parameter of Wavelength dispersion type x ray Fluorescence Spectrometer are as follows: select the K α line of fluorine as analysis
Spectral line, maximum peak position are actually detected peak position, and crystal is Rx25 crystal, and detector is PC detector, time of measuring 40s.
The beneficial effect of the method for Calcium Fluoride Content exists in a kind of X-ray fluorescence spectra fusion method measurement fluorite of the present invention
In: the present invention overcomes the granularity effect and mineral effect of sample better than the traditional chemical analysis method of calcirm-fluoride measurement in fluorite
It answers, while method is easy to operate, time-consuming is short, without chemical reagent waste liquid bring pollutes, analyst coverage is wide, accuracy is high, reappears
Property is good, suitable for calcirm-fluoride in the measurement of all kinds of fluorite ingredients, especially calcium carbonate, the higher fluorite raw ore of calcium sulphate content
Measurement.
Specific embodiment
To better describe the present invention, below with reference to embodiment, a kind of X-ray fluorescence spectra fusion method of the present invention is measured
The method of Calcium Fluoride Content is described in further details in fluorite.But the invention is not limited to embodiments.
(1) instrument and reagent
II type wavelength dispersion X-fluorescence instrument (Rigaku company, maximum power 4.0kW) of ZSX Primus;
Analymate V8C type high frequency fusion machine (the quiet remote century science and technology limited Company in Beijing);
Flux: the dedicated mixed flux of fluorescence (+33% lithium metaborate of 67% lithium tetraborate);
Release agent: lithium bromide (LiBr:30g/100mL) is analyzed pure.
(2) X fluorescence spectrometer running parameter
Gained calcirm-fluoride measuring condition is shown in Table 1 after optimized measuring condition.
Table 1: the selected X fluorescence spectrometer running parameter of calcirm-fluoride measurement
(3) test method
Accurately weigh 2.0000g fluorite sample, the dedicated mixed flux of 6.0000g fluorescence.
After mixing by weighed fluorite sample and the dedicated mixed flux of fluorescence, it is placed in Huang-platinum crucible, is added
Release agent lithium bromide (LiBr:30g/100mL) 8 drips, and melts in model machine automatically in high frequency, carries out according to preset automatically molten sample program
The fluorite sample sheet glass for analysis is made in fuse piece.It checks that the fluorite sample glass sheet surface for analysis should be free of not melt
Object should not also have crystallization and bubble, and defective fluorite sample sheet glass is discarded, again fuse piece.
The coupons that melting prepares are put into Wavelength dispersion type x ray Fluorescence Spectrometer, X-ray fluorescence spectra is selected
Instrument running parameter calculates the content of calcirm-fluoride in sample by apparatus measures automatically.Every time before measurement unknown sample, Yao Jinhang
The measurement of Quality Control sample.If Quality Control sample is overproof, need to carry out drift correction, until Quality Control sample can carry out not after meeting tolerance
Know the measurement of sample.
(4) test analysis
The selection of 1 sample pre-treatments condition
The selection of 1.1 beads
Glass flux sheet method is that sample and flux, release agent etc. are placed on together in crucible appropriate, melts at high temperature, is mixed
It is even, after rapid cooling, sheet glass is made.That is based on glass flux sheet method is the chemical breakdown reaction under high temperature,
And uniform solid glass body in order to obtain, then need the phase transition process in control fusant cooling procedure.X-ray fluorescence analysis is adopted
With the purpose of fuse piece method it is main there are two, first is that the compound in sample is made to react to form true solution completely with mixed flux,
Second is that melt is made to be cooled into completely amorphous matter solid glass, is evenly distributed with obtaining sample, the controllable sheet glass of size.
Due to the negligible amounts of fluorite national standard sample, and the content range of calcirm-fluoride is relatively narrow, is difficult to adopt fluorite mark
Substance is infused to establish analysis curve, it is therefore necessary to which standard curve is manually formulated using the method for melting.Bead has following
Advantage:
(1) granularity effect and mineral effect of sample are eliminated;
(2) diluting effect of flux, co-existing element interference effect reduce;
(3) human configuration standard curve sample is simpler;
Therefore, the sample-pretreating method for selecting glass flux sheet method to measure as Calcium Fluoride Content in fluorite.Bead
Method is also the most common method of Wavelength dispersion type X fluorescence spectrum quantitative analysis.
The selection of 1.2 flux
It is lithium tetraborate that X-ray fluorescence spectra, which analyzes common flux, and sample preparation is reproducible, but melting temperature generally exists
1100 DEG C, when temperature is higher than 1050 DEG C, F member is known as certain loss in melting process.Therefore the mixing of this experimental selection is molten
Agent (+33% lithium metaborate of 67% lithium tetraborate), melting temperature avoid the loss of F element in melting process at 950 DEG C.
1.3 flux are than selection
13.1 pairs of same fluorite samples and the dedicated mixed flux of fluorescence press 1:1,1:2,1:3,1:4,1:5 ratio system respectively
Make bead, every kind of ratio makes bead 11, measures intensity value to calcirm-fluoride in fluorite according to 1 condition of table, calculates
The relative standard deviation of each bead obtains: with the increase of flux ratio, the intensity value relative standard of calcirm-fluoride is inclined in fluorite
Difference reduces, and tends to be steady when ratio reaches 1:3.
1.3.2 by flux ratio test, it is 1:3 that this method, which selects flux ratio, and by experiment, molten mass weighs less than 5g
When, fuse piece is difficult to cover crucible bottom surface, and when melting body weight is greater than 9g, fuse piece is difficult to form.Therefore selection sample 2.0000g,
The dedicated mixed flux 6.0000g of fluorescence is added, to guarantee the stability of result.
The selection of 1.4 melting temperatures
With mixed flux (+33% lithium metaborate of 67% lithium tetraborate), melting temperature is lower than 900 DEG C, and sample melts endless
Entirely, bubble generation is had, melting temperature is higher than 950 DEG C, will cause the loss of F element.Therefore select melting temperature for 950 DEG C.
2 measuring conditions
2.1 instrument operating conditions: according to Rh target X-ray tube to the measuring condition of light element, as element numbers Z≤23, choosing
Select the tube voltage of 30~40kV and the tube current of 60~80mA.To guarantee that light element F obtains biggish analytical line intensity, Ying Xuanyong
Biggish excitation current, therefore select voltage 40kV, electric current 80mA as shooting condition.
2.2 calcirm-fluoride measuring conditions
According to instrumentation software, optimized rear gained calcirm-fluoride measuring condition is shown in Table 1.
The selection of 3 standard samples
Due to the negligible amounts of fluorite national standard substance, and the content range of calcirm-fluoride is relatively narrow, standard substance quantity and
The analyst coverage of calcirm-fluoride is all unable to satisfy the requirement that Calcium Fluoride Content detects in fluorite, it is therefore necessary to formulate standard using artificial
Curve point prepares bead according to the condition that sample pre-treatments select.This experiment utilizes existing standard sample and spectroscopic pure two
Silica is configured with the linear regression calculating that series of standards curve point participates in standard curve, is fluorinated calcium catalyst model in fluorite
It encloses, regression curve equation and linearly dependent coefficient are shown in Table 2.
Measurement range, regression curve equation and the linearly dependent coefficient of 2 calcirm-fluoride of table
4 precision and accuracy
4.1 precision
The same standard sample GBW07253 is repeated using fuse piece method to prepare 11 beads, according to the measurement of table 1
The standard curve that condition is set up respectively measures 11 beads, and measured result is counted, is shown in Table 3.
3 Precision Experiment table of table
4.2 accuracy
4.2.1 it takes the fluorite standard sample of different content to prepare glass and melts piece, the mark set up according to the measuring condition of table 1
Directrix curve respectively measures the bead of standard sample preparation, and measured result is counted, is shown in Table 4.
Table is tested in 4 accuracy of table
4.2.2 various sample is taken, is compared using chemical analysis method with this law, measured result is united
Meter, is shown in Table 5.
5 distinct methods of table measure Calcium Fluoride Content result table in fluorite
Sample number into spectrum |
Analysis project |
Chemical analysis method result/% |
This law result/% |
Deviation |
Fluorite 1# |
CaF2 |
56.23 |
56.03 |
-0.20 |
Fluorite 2# |
CaF2 |
66.58 |
66.65 |
0.07 |
Fluorite 3# |
CaF2 |
73.95 |
73.81 |
-0.14 |
Fluorite 4# |
CaF2 |
87.43 |
87.30 |
-0.13 |
Fluorite 5# |
CaF2 |
94.87 |
94.95 |
0.08 |
Above data shows the analysis of either laboratory monitoring different content standard substance, be also different analysis method into
Capable analysis, the testing result of this method in error range, and be better than national Specification range, this method have compared with
High accuracy and precision can satisfy the needs that calcirm-fluoride in fluorite quickly detects.