Summary of the invention
Object of the present invention is exactly the rapid assay methods that polycomponent content in a kind of continuous casting covering slag will be provided, to meet comprehensive utilization and the production scene real work requirement of continuous casting covering slag.
For achieving the above object, the technical solution used in the present invention is: the rapid assay methods of polycomponent content in a kind of continuous casting covering slag, comprises the steps:
1) the pre-carbon removal treatment of covering slag: covering slag is heated to 800 ℃~950 ℃, and calcination 20~40min carries out abundant aerobic ashing, to remove carbon, organism wherein, and the sulphur in sulfide;
2) Microwave samples digestion: add nitric acid, hydrochloric acid in the covering slag after pre-de-carbon, and hydrofluorite, and make it carry out in confined conditions micro-wave digestion, in digestion process, first with 20~25 ℃/min of programming rate, be warmed up to 80~100 ℃, then after continuing to be warming up to 120~150 ℃ with 10~15 ℃/min of programming rate, be incubated 5~15min, be incubated 5~15min after then continuing to be warming up to 200~220 ℃ with 10~15 ℃/min of programming rate; After micro-wave digestion gained solution is cooling, add yttrium standard solution water constant volume, make covering slag sample solution;
3) prepare the standard solution of component to be measured: each component standard model to be measured of getting different amounts according to the content range of different component, add therein and nitric acid, the hydrochloric acid of processing the same amount of covering slag, and hydrofluorite, and add therein the yttrium standard solution with covering slag sample solution moderate, water is settled to and covering slag sample solution equal-volume, makes series standard solution;
4) drawing standard curve: the wavelength of selecting object element in each standard solution, with ICP spectrometer, at respective wavelength place, measure respectively line strength of object element in each standard solution of variable concentrations, the concentration of each standard solution of take is horizontal ordinate, line strength of its object element is ordinate, draws out series standard curve;
5) measure each component concentration in covering slag: with step 4) under the same terms; with ICP spectrometer, measure respectively line strength of each object element in covering slag sample solution; then from respective standard curve, find component that each object element the is corresponding concentration in covering slag sample solution, conversion each component concentration in slag that can be protected.
Further, described step 2) in, the concentration of described yttrium standard solution is 0.5~2mg/mL, its consumption accounts for 3~6% of covering slag sample solution volume.
Further, described step 3) in, described component to be measured is kali, Lithia, manganese oxide, iron, silicon dioxide, calcium oxide, aluminium oxide, magnesium oxide, and sodium oxide molybdena, wherein, kali, Lithia, manganese oxide, the concentration range of the standard solution preparation of iron is 0.00%~6%, the concentration range of silicon dioxide standard solution preparation is 0.00%~50%, the concentration range of calcium oxide standard solution preparation is 0.00%~50%, the concentration range of aluminium oxide standard solution preparation is 0.00%~30%, the concentration range of magnesium oxide standard solution preparation is 0%~15%, the concentration range of sodium oxide molybdena standard solution preparation is 0.00%~15%.
Further, described step 2) in, the compound method of yttrium standard solution is: first take yttria and be cooled to room temperature after 745~755 ℃ of calcination 25~35min, then add hydrochloric acid, heating for dissolving yttria, gained solution is cooled to dilute with water constant volume after room temperature, makes the yttrium standard solution of desired concn.
Further, described step 2) in, the mass percent concentration of nitric acid used is 65%~68%, its consumption is 2~5ml/0.1g covering slag; The mass percent concentration of hydrochloric acid used is 36%~38%, and its consumption is 3~5ml/0.1g covering slag; The mass percent concentration of hydrofluorite used is 40%~47%, and its consumption is 1.8~2.2ml/0.1g covering slag, and hydrofluorite adds at twice.
Further, described step 2) in, the pressure of micro-wave digestion is: 1~3Mpa.
Compared with prior art, tool of the present invention has the following advantages:
One, the present invention is by Microwave samples digestion technology and inductively coupled plasma emission spectrography (ICP-AES) combination, ICP spectroscopic methodology can be measured various ingredients simultaneously, the scope of simultaneously measuring element has also expanded several times, thereby has realized the various ingredients content in single-time measurement continuous casting covering slag; Thereby micro-wave digestion is to utilize the sample in microwave heating closed container under high temperature pressurised condition, to make the rapidly-soluble Wet of sample, these two features of confined reaction and microwave heating have determined that it reacts completely, fast, and the advantage of low blank, with conventional molten sample technology, compare, reagent dosage has reduced more than 50%, and because Microwave Digestion is carried out in confined conditions, farthest prevented the loss of element to be measured and reduced laboratory pollution, in digestion process, strictly control temperature, guaranteed the accuracy of the measurement result of silicon; Measurement result of the present invention accurately and reliably, simple to operate, and reagent dosage greatly reduces, and analysis speed improves more than 50%, has significantly shortened determination period, met comprehensive utilization and the production scene real work requirement of continuous casting covering slag.
They are two years old, in continuous casting covering slag, contain a large amount of for regulating the carbon material of covering slag burn-off rate, as: graphite, carbon black, and coke blacking etc., general content is between 10%~30%, carbon is very obvious to the package action of sample, the conventional mineral acid for molten sample or alkali fusion method are difficult to sample to decompose completely, and the residual a large amount of carbon granule of meeting in test solution, after importing ICP spectrometer, can stop up sampling system, and if the sample of high-carbon content directly adopts Microwave samples digestion, a large amount of carbon and nitric acid react and can make rapid increasing of counteracting tank internal pressure and occur potential safety hazard under high-temperature and high-pressure conditions, the present invention carries out pre-carbon removal treatment to covering slag especially, remove the carbon of high-load in sample, organism and sulphur, completeness and security that sample decomposes have been guaranteed, improved the accuracy of measuring.
They are three years old, principal ingredient Si due to continuous casting covering slag, Ca, Mg etc. are according to the requirement of different casting blank and different, each constituent content to be measured changes greatly, the method of more difficult employing Matrix Match is proofreaied and correct, conventionally due to the spectral drift of ICP spectroscopic methodology, measure the accuracy of high-load composition poor, the present invention adds yttrium as internal standard element when measuring, made up due to instrument condition of work, nebulization efficiency, and the non-spectrum that matrix effect etc. causes disturbs and spectrum interference, effectively improved the preci-sion and accuracy that in covering slag, key component is measured, the recovery is between 96.5%~104.6%, the relative standard deviation (RSD)≤2% that each key component is measured, the relative standard deviation (RSD)≤5% that each microcomponent is measured.
Embodiment
Below in conjunction with drawings and Examples, the present invention is further illustrated, but the present invention is not limited to following embodiment.
The key instrument and the reagent that in following two embodiment, relate to are described below:
1) use instrument: microwave digestion system is MILESTONE Ethos TC type high-pressure microwave digestion system; ICP spectrometer is the whole direct-reading plasma emission spectrometers of TJA-IRIS Advantage.
2) use reagent: it is pure that agents useful for same is top grade, and experimental water is deionized water.
3) vessel used are all by drying for standby after high purity water immersion 24h.
4) each covering slag to be measured at 105 ℃, dry and be cooled to room temperature after standby.
5) the respective standard sample preparation that in covering slag to be measured, the standard inventory solution of 9 components all adopts purity to be greater than 99.99%, content is 1.00mg/mL.
6) compound method of the yttrium standard solution that concentration is 1.00mg/mL is: take 1.2699g calcination 30min be cooled to the yttria (> 99.95%) of room temperature at 745~755 ℃ of temperature in advance, put it in 250mL beaker, then add altogether at twice 30mL hydrochloric acid, after heating for dissolving, be cooled to room temperature and move in 1000mL volumetric flask, be diluted with water to scale, mix, make the yttrium standard solution of 1.00mg/mL.
Embodiment 1
1) take 0.1000g covering slag sample and be placed in the platinum crucible that is covered with one deck quantitative filter paper, crucible is put into 300 ℃ of following high temperature Muffle furnaces, be heated to 850 ℃ of aerobic calcination 30min, except the sulphur in carbon elimination, organism and sulfide;
2) the covering slag sample after pre-de-carbon is proceeded in tetrafluoroethene micro-wave diminishing pot, with deionized water, sample is moistening, adding successively 2mL mass percent concentration is 65%~68% nitric acid, 5mL mass percent concentration is 36%~38% hydrochloric acid, and the 1mL mass percent concentration hydrofluorite that is 40%~47%, after vigorous reaction finishes, add 1mL hydrofluorite, then the lid that installs counteracting tank carries out micro-wave digestion in confined conditions, the power of microwave digestion system is 1200W, clearing up pressure is 1~3Mpa, preferably 2MPa;
In micro-wave digestion heating process, first controlling programming rate is 20 ℃/min, makes the temperature in micro-wave diminishing pot reach 80 ℃; Continue heating, controlling programming rate is 10 ℃/min, is incubated 5min after making temperature in counteracting tank reach 125 ℃; Then controlling programming rate is 10 ℃/min, is incubated 5min after continuing to be warming up to 200 ℃; Finally carry out air draft, get rid of the waste gas in micro-wave diminishing pot, sample is cooled to room temperature;
Cooled sample is inserted in the quartzy volumetric flask of 100mL scale, add 5mL yttrium standard solution (1.00mg/mL), with deionized water, be diluted to scale, mix, make covering slag sample solution, wherein, nitric acid dosage in digestion process is no less than 2ml/0.1g, preferred 2~5ml/0.1g covering slag, hydrochloric acid consumption is 3~5ml/0.1g covering slag preferably, and the consumption of hydrofluorite is 1.8~2.2ml/0.1g covering slag preferably;
3) in the quartzy volumetric flask of 100mL scale, add and the nitric acid of processing the same amount of covering slag sample, hydrochloric acid, and hydrofluorite, according to the content range of different component, prepare series standard curve: wherein, the mass percent concentration of kali is distributed as 3.00%, iron 1.00%, Lithia 1.00%, manganese oxide 5% (that is: the kali that compound concentration scope is 0~3.00%, concentration range is 0~1.00% iron, concentration range is 0~1.00% Lithia, concentration range is 0~5% manganese oxide), the mass percent concentration of each key component is distributed as: silica 1 0%, calcium oxide 25.00%, aluminium oxide 20.00%, magnesium oxide 5.00%, sodium oxide molybdena 10.00%.Before constant volume, add respectively 5mL yttrium standard solution (1.00mg/mL), with deionized water, be diluted to scale, mix; make series standard solution; wherein, the concentration of yttrium standard solution is 0.5~2mg/mL preferably, and its volumetric usage preferably accounts for 3~6% of covering slag sample solution volume:
4) open ICP spectrometer, according to the icp analysis condition of work in table 1, at respective wavelength place, measure respectively line strength of object element in each standard solution:
Table 1
Wherein, the wavelength of each object element is selected (also can select other wavelength according to the actual conditions of the optimum analysis wavelength of instrument and sample) as shown in table 2:
Table 2
The concentration of each standard solution of take is horizontal ordinate, and line strength of its 9 corresponding object elements is ordinate, with computing machine, automatically draws out typical curve, and the typical curve of these 9 component sample to be measured as shown in Figures 1 to 9;
5) under the condition with identical in the typical curve step of above-mentioned drafting school; line strength with each object element in ICP spectrophotometer micro-wave digestion gained covering slag sample solution; computing machine is according to the typical curve of drawing before; with calibration procedure software, automatically calculate the content of each component in covering slag, the measurement result obtaining is as shown in table 3:
Table 3
By known 9 object elements of interference test (Si, Ca, Al, Mg, Na, K, Fe, Li, Mn), there is not each other interference, can measure simultaneously;
Precision test: randomly draw two covering slag sample solutions, according to above-mentioned test procedure replicate determination 11 times, the measurement relative standard deviation of each key component is all less than 2%, and the measurement relative standard deviation of each trace element is all less than 5%;
Accuracy test: adopt the mode (standard solution adds before sample decomposes) of mark-on recovery to check accuracy, the recovery is between 97.1~104.6%, and accuracy is good, meets and detects needs.
Embodiment 2
1) take 0.2000g covering slag sample and be placed in the platinum crucible that is covered with one deck quantitative filter paper, crucible is put into 300 ℃ of following high temperature Muffle furnaces, be heated to 900 ℃ of aerobic calcination 30min, except the sulphur in carbon elimination, organism and sulfide;
2) the covering slag sample after pre-de-carbon is proceeded in counteracting tank, micro-wave diminishing pot is placed in to the water of 10 ℃ of left and right, with deionized water, sample is moistening, add successively 5mL nitric acid, 5mL hydrochloric acid, and 1mL hydrofluorite, nitric acid, hydrochloric acid and hydrofluorite are commercially available pure, after vigorous reaction finishes, add 1mL hydrofluorite, the lid that then installs counteracting tank carries out micro-wave digestion in confined conditions, the power of microwave digestion system is 1200W, and clearing up pressure is 2.0MPa;
In micro-wave digestion heating process, first controlling programming rate is 25 ℃/min, makes the temperature in micro-wave diminishing pot reach 100 ℃; Continue heating, controlling programming rate is 15 ℃/min, is incubated 15min after making temperature in counteracting tank reach 150 ℃; Then controlling programming rate is 15 ℃/min, is incubated 15min after continuing to be warming up to 220 ℃; Finally carry out air draft, get rid of the waste gas in micro-wave diminishing pot, sample is cooled to room temperature;
Cooled sample is inserted in the quartzy volumetric flask of 100mL scale, add 5mL yttrium standard solution (1.00mg/mL), with deionized water, be diluted to scale, mix, make covering slag sample solution;
3) in the quartzy volumetric flask of 100mL scale, add and the nitric acid of processing the same amount of covering slag sample; hydrochloric acid; and hydrofluorite; according to the content range preparation series standard curve of different component: wherein, the mass percent concentration of kali is distributed as 5.00%, iron 2.00%, Lithia 0.50%, manganese oxide 0.5%, and the mass percent concentration of each key component is distributed as: silicon dioxide 30%; calcium oxide 40.00%; aluminium oxide 2.00%, magnesium oxide 5.00%, sodium oxide molybdena 10.00%.Before constant volume, add respectively 5mL yttrium standard solution (1.00mg/mL), with deionized water, be diluted to scale, mix, make series standard solution;
4) open ICP spectrometer, measure respectively line strength of object element in each standard solution according to the icp analysis condition of work in table 1 at respective wavelength place, wherein, the wavelength of each object element is selected as shown in table 2;
The concentration of each standard solution of take is horizontal ordinate, and line strength of its 9 corresponding object elements is ordinate, with computing machine, automatically draws out typical curve, and the typical curve of these 9 component sample to be measured as shown in Figures 1 to 9;
5) under the condition with identical in the typical curve step of above-mentioned drafting school; line strength with each object element in ICP spectrophotometer micro-wave digestion gained covering slag sample solution; computing machine is according to typical curve; with calibration procedure software, automatically calculate the content of each component in covering slag, the measurement result obtaining is as shown in table 3:
Table 4
By known 9 object elements of interference test (Si, Ca, Al, Mg, Na, K, Fe, Li, Mn), there is not each other interference, can measure simultaneously;
Precision test: randomly draw two covering slag sample solutions, according to above-mentioned test procedure replicate determination 11 times, the measurement relative standard deviation of each key component is all less than 2%, and the measurement relative standard deviation of each trace element is all less than 5%;
Accuracy test: adopt the mode (standard solution adds before sample decomposes) of mark-on recovery to check accuracy, the recovery is between 98.5~103.7%, and accuracy is good, meets and detects needs.