CN114720445A - Method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry - Google Patents
Method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry Download PDFInfo
- Publication number
- CN114720445A CN114720445A CN202210389850.XA CN202210389850A CN114720445A CN 114720445 A CN114720445 A CN 114720445A CN 202210389850 A CN202210389850 A CN 202210389850A CN 114720445 A CN114720445 A CN 114720445A
- Authority
- CN
- China
- Prior art keywords
- arsenic
- digestion
- solution
- mercury
- briquette
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000029087 digestion Effects 0.000 title claims abstract description 79
- 239000004484 Briquette Substances 0.000 title claims abstract description 77
- 239000003245 coal Substances 0.000 title claims abstract description 71
- 229910052785 arsenic Inorganic materials 0.000 title claims abstract description 68
- 229910052753 mercury Inorganic materials 0.000 title claims abstract description 62
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 title claims abstract description 61
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 title claims abstract description 58
- 238000000034 method Methods 0.000 title claims abstract description 53
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 39
- 238000001027 hydrothermal synthesis Methods 0.000 title claims abstract description 29
- 238000001391 atomic fluorescence spectroscopy Methods 0.000 title claims abstract description 22
- 239000000243 solution Substances 0.000 claims abstract description 62
- 239000002253 acid Substances 0.000 claims abstract description 50
- -1 polytetrafluoroethylene Polymers 0.000 claims abstract description 31
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims abstract description 31
- 239000004810 polytetrafluoroethylene Substances 0.000 claims abstract description 31
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 12
- 239000010935 stainless steel Substances 0.000 claims abstract description 12
- 238000012360 testing method Methods 0.000 claims abstract description 12
- 238000007789 sealing Methods 0.000 claims abstract description 11
- 239000013582 standard series solution Substances 0.000 claims abstract description 7
- 238000007664 blowing Methods 0.000 claims abstract description 4
- 238000002791 soaking Methods 0.000 claims abstract description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 64
- 239000011550 stock solution Substances 0.000 claims description 46
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 39
- 239000000523 sample Substances 0.000 claims description 24
- 239000011230 binding agent Substances 0.000 claims description 19
- 238000005406 washing Methods 0.000 claims description 15
- 238000005485 electric heating Methods 0.000 claims description 14
- 238000001035 drying Methods 0.000 claims description 13
- 239000002028 Biomass Substances 0.000 claims description 12
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 12
- 238000005259 measurement Methods 0.000 claims description 12
- 229910017604 nitric acid Inorganic materials 0.000 claims description 12
- 239000012086 standard solution Substances 0.000 claims description 12
- 238000001514 detection method Methods 0.000 claims description 11
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 claims description 11
- 239000002131 composite material Substances 0.000 claims description 10
- 239000007788 liquid Substances 0.000 claims description 9
- 239000011259 mixed solution Substances 0.000 claims description 9
- 239000000843 powder Substances 0.000 claims description 9
- 238000005303 weighing Methods 0.000 claims description 9
- 238000011010 flushing procedure Methods 0.000 claims description 8
- 239000007789 gas Substances 0.000 claims description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 6
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 claims description 6
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 6
- 239000012496 blank sample Substances 0.000 claims description 6
- 239000003638 chemical reducing agent Substances 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 6
- 239000011591 potassium Substances 0.000 claims description 6
- 229910052700 potassium Inorganic materials 0.000 claims description 6
- 238000002360 preparation method Methods 0.000 claims description 6
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 claims description 6
- 239000010426 asphalt Substances 0.000 claims description 4
- 239000003153 chemical reaction reagent Substances 0.000 claims description 4
- 229920001903 high density polyethylene Polymers 0.000 claims description 4
- 239000004700 high-density polyethylene Substances 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 4
- 229920003023 plastic Polymers 0.000 claims description 4
- 239000011273 tar residue Substances 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 3
- 229910052786 argon Inorganic materials 0.000 claims description 3
- 229960005070 ascorbic acid Drugs 0.000 claims description 3
- 235000010323 ascorbic acid Nutrition 0.000 claims description 3
- 239000011668 ascorbic acid Substances 0.000 claims description 3
- 230000001680 brushing effect Effects 0.000 claims description 3
- 239000000084 colloidal system Substances 0.000 claims description 3
- 239000008367 deionised water Substances 0.000 claims description 3
- 229910021641 deionized water Inorganic materials 0.000 claims description 3
- 238000000227 grinding Methods 0.000 claims description 3
- 238000003825 pressing Methods 0.000 claims description 3
- 238000007873 sieving Methods 0.000 claims description 3
- 238000003756 stirring Methods 0.000 claims description 3
- 239000008399 tap water Substances 0.000 claims description 3
- 235000020679 tap water Nutrition 0.000 claims description 3
- 229910021642 ultra pure water Inorganic materials 0.000 claims description 3
- 239000012498 ultrapure water Substances 0.000 claims description 3
- 239000012159 carrier gas Substances 0.000 claims description 2
- 238000013329 compounding Methods 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- 238000007781 pre-processing Methods 0.000 claims description 2
- 235000013619 trace mineral Nutrition 0.000 abstract description 9
- 239000011573 trace mineral Substances 0.000 abstract description 9
- 239000007791 liquid phase Substances 0.000 abstract description 3
- 238000004140 cleaning Methods 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 10
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 239000007787 solid Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 6
- 235000020238 sunflower seed Nutrition 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 239000005416 organic matter Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 229920000742 Cotton Polymers 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229920002472 Starch Polymers 0.000 description 2
- 238000004380 ashing Methods 0.000 description 2
- 238000011088 calibration curve Methods 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 239000011280 coal tar Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000001095 inductively coupled plasma mass spectrometry Methods 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 238000000120 microwave digestion Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 238000002203 pretreatment Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000000197 pyrolysis Methods 0.000 description 2
- 239000008107 starch Substances 0.000 description 2
- 235000019698 starch Nutrition 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- QJZYHAIUNVAGQP-UHFFFAOYSA-N 3-nitrobicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid Chemical compound C1C2C=CC1C(C(=O)O)C2(C(O)=O)[N+]([O-])=O QJZYHAIUNVAGQP-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 206010011409 Cross infection Diseases 0.000 description 1
- 206010029803 Nosocomial infection Diseases 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 240000008042 Zea mays Species 0.000 description 1
- 235000005824 Zea mays ssp. parviglumis Nutrition 0.000 description 1
- 235000002017 Zea mays subsp mays Nutrition 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000012490 blank solution Substances 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001793 charged compounds Polymers 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011300 coal pitch Substances 0.000 description 1
- 235000005822 corn Nutrition 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 201000006549 dyspepsia Diseases 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 231100000171 higher toxicity Toxicity 0.000 description 1
- 239000004021 humic acid Substances 0.000 description 1
- 238000009616 inductively coupled plasma Methods 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 229920002521 macromolecule Polymers 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000012488 sample solution Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000010902 straw Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6402—Atomic fluorescence; Laser induced fluorescence
- G01N21/6404—Atomic fluorescence
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/44—Sample treatment involving radiation, e.g. heat
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Optics & Photonics (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
Abstract
The invention relates to the field of liquid phase chemistry, in particular to a method for determining mercury and arsenic in coal briquette based on hydrothermal synthesis reaction kettle digestion coal-atomic fluorescence spectrometry, which comprises the steps of adding a certain amount of coal briquette and a proper amount of mixed acid into a polytetrafluoroethylene sealed tank which is subjected to soaking, cleaning and preheating pretreatment for pre-digestion until gas is released, capping after the reaction tends to be mild, placing the sealed polytetrafluoroethylene sealed tank into a stainless steel sleeve, sealing, placing the stainless steel sleeve into an electrothermal blowing dry box for closed heating digestion, and then carrying out acid dispelling and volume fixing operations to obtain a solution to be measured; and preparing standard series solutions of mercury and arsenic elements, drawing a standard curve, testing the obtained digestion solution to be tested by using an atomic fluorescence spectrometer to obtain fluorescence intensity, and converting the standard curve to obtain the content of the corresponding element in the briquette. The invention can accurately measure the content of volatile trace elements represented by mercury and arsenic in the molded coal.
Description
Technical Field
The invention relates to the field of liquid phase chemistry, in particular to a method for measuring mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry.
Background
Coal is a complex geological product, consisting of a variety of organic and inorganic minerals. The briquette is compounded by taking coal As a base material and adding various binders (such As coal pitch, coal tar, starch, humic acid, biomass and the like), has more complex chemical components compared with the original coal, has dozens of harmful or potentially harmful trace elements such As Cr, Cl, Pb, Hg, Se, As and the like, has extremely low content of the trace elements compared with major harmful elements, has complex and various appearance and higher toxicity, can be gradually released and enriched in the thermal processing and utilization processes such As pyrolysis, combustion and the like, causes pollution to the ecological environment such As atmosphere, water body and soil, and further harms human health. Under the target requirement of 'double carbon', trace harmful elements in the molded coal are accurately measured, and the research on release and control technology is particularly important for the environmental protection problems of clean utilization, waste residue disposal and the like of the molded coal.
At present, the research on trace harmful elements in molded coal is deficient, and the previous research mainly focuses on raw coal, namely, raw coal is pretreated in a laboratory, particularly, a sample is digested into a solution or elements to be detected are transferred into the solution, and the raw coal can be determined by an inductively coupled plasma mass spectrometry (ICP-MS) method, an inductively coupled plasma emission spectroscopy (ICP-AES) method, an Atomic Absorption Spectroscopy (AAS) method and an atomic fluorescence spectroscopy method. Therefore, sample pretreatment-digestion is a critical step in performing instrumental analysis, and determines the accuracy and precision of the detection result. No unified method and standard for pretreating and digesting the briquette are provided for reference at present, and documents are not reported.
Compared with raw coal, the molded coal has certain particularity and complexity, and is mainly reflected in that the molded coal has complex chemical composition and contains a large amount of organic macromolecules, inorganic mineral substances and carbonaceous particles which are difficult to digest; the volatile component is high, and the excessive increase of pressure is easily caused by a large amount of gas generated by digestion; the binding interaction between various binders added into the briquette and the coal particles can weaken the action of acid, so that a set of pretreatment method suitable for the briquette is explored on the basis of analyzing and referring to the original coal digestion pretreatment and trace element content determination method and combining the characteristics of the briquette, so that the elements to be detected are transferred to the solution to the maximum extent, and the method is free from pollution and loss, and is extremely necessary.
At present, the pretreatment digestion method of raw coal includes an electric heating plate normal pressure open digestion method, a microwave digestion method, an ashing-digestion method and the like. The method is characterized in that an electric heating plate normal-pressure open digestion method directly digests a coal sample in an open container by using mixed acid, the method uses an electric heating plate for heating, the sample is heated unevenly, a large amount of acid is used in the process to form acid mist to influence the environment and easily cause cross infection, if the method is used for decomposing the briquette sample, due to the complexity and the particularity of briquette composition, the compatibility of the briquette and the mixed acid is poor, the temperature and the pressure cannot reach an ideal state, the sample is difficult to completely dissolve to cause serious distortion of a measurement result, the detection limit of the method is high, and the acid dosage is large. The microwave digestion method is advanced and reliable, but the equipment cost is high, and the popularization is difficult to achieve. If be used for the moulded coal sample to clear up, because binder and the coal grain interact weaken in the moulded coal with sour effect, it is big to reach limpid transparent effect of clearing up to exist with the acid volume, the later stage catches up with sour time long, can not guarantee that volatile element does not disappear and scatter, catch up with sour decomposition and easily produce a large amount of nitride gas, arouse and clear up jar deformation, secondly, organic binder joins in the moulded coal and makes the volatile content higher, when clearing up, fluid volume expansion in the airtight jar of clearing up, pressure sharply increases, have to arouse reaction out of control, cause and clear up jar and explode latent danger. The ashing-digestion method is used for digesting the ashed coal by using mixed acid, the ashing step is complicated, the decomposition temperature of most organic binders (starch, biomass and coal tar) in the molded coal is low, and volatile trace elements (such As Hg and As) escape along with organic volatile components in the ashing process, so that the determination result is low.
Disclosure of Invention
In order to solve the problems, the invention provides a method for determining mercury and arsenic in molded coal based on hydrothermal synthesis reaction kettle digestion molded coal-atomic fluorescence spectrometry, which adopts a closed, efficient, simple, convenient and safe hydrothermal synthesis reaction kettle to realize the digestion pretreatment of the molded coal, and adopts the atomic fluorescence spectrometry to accurately determine the trace element content represented by Hg and As in the molded coal. Specifically, the hydrothermal synthesis reaction kettle disclosed by the invention comprises a polytetrafluoroethylene sealed tank and a stainless steel outer sleeve, and the liquid mixed acid is used as a reaction system, so that the problems of difficult digestion caused by complex briquette composition, overlarge pressure caused by digestion and release of high volatile components of an organic binder in the briquette and heating and volatilization loss of volatile trace elements can be solved under the conditions of small acid amount and short consumed time, the thoroughness and safety of digestion of a briquette sample are ensured, the accuracy of trace element content detection is finally achieved, and the hydrothermal synthesis reaction kettle has important guiding significance for controlling pollution discharge of harmful trace elements and recycling of solid waste in the thermal processing and utilization processes such as briquette pyrolysis, combustion and the like.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for measuring mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry comprises the following steps:
s1, preprocessing:
repeatedly washing a polytetrafluoroethylene sealed tank of a hydro-thermal synthesis reaction kettle and a used container with tap water and deionized water, lightly brushing the inner wall with a soft cotton brush until the inner wall is cleaned, soaking the inner wall in a nitric acid solution with the mass concentration of 10% overnight, taking out the container, washing the container with ultrapure water for three times, washing away surface nitric acid, placing the sealed tank in a blast drying box at the temperature of 80 ℃, and drying and preheating the sealed tank for 30min for later use;
s2, pretreatment of the briquette:
weighing a proper amount of briquette, drying the briquette to constant weight at 105 ℃, grinding the briquette and sieving the briquette with a 200-mesh sieve;
s3, pre-digestion: weighing 50mg (accurate to 0.0002 g) of molded coal, placing the molded coal at the bottom of a preheated polytetrafluoroethylene sealed tank, adding mixed acid, standing for 30min, carrying out pre-digestion by utilizing the heat of the polytetrafluoroethylene sealed tank, and covering the polytetrafluoroethylene sealed tank when the gas is completely released and the reaction tends to be mild;
s4, closed digestion: putting the capped polytetrafluoroethylene sealed tank into a stainless steel sleeve, tightly pressing and sealing the polytetrafluoroethylene sealed tank by using a cover of the stainless steel sleeve, putting the whole reaction kettle into an electric heating blowing drying oven, heating for 4 hours at 180 ℃, and keeping the kettle body upright and stable;
s5, acid removal: taking out the hydro-thermal synthesis reaction kettle, cooling to room temperature, opening the stainless steel sleeve cover and the sealing tank cover one by one, pouring the digested molded coal into a polytetrafluoroethylene crucible, flushing the sealing tank and the cover with 5% hydrochloric acid, pouring the flushing liquid into the crucible, placing the crucible on an electric heating plate for acid removal treatment, removing the acid at the temperature of 140 ℃, and stopping acid removal when the solution is in a colloid shape;
s6, constant volume: washing the polytetrafluoroethylene crucible for at least 3 times by using 5% hydrochloric acid, transferring the washing liquid into a 50ml volumetric flask, fixing the volume to the scale by using 5% hydrochloric acid, standing for 10min, and transferring the solution serving as a digestion solution to be detected into an HDPE plastic small bottle for later use;
s7, preparation of standard stock solution: accurately measuring 0.10ml of mercury national standard solution and arsenic national standard solution, placing in a 100ml volumetric flask, fixing the volume to the scale with 5% hydrochloric acid solution, shaking up, placing for 10min to obtain mercury primary standard stock solution with the concentration of 1.0 mu g/ml and arsenic primary standard stock solution with the concentration of 1.0 mu g/ml for later use;
accurately measuring a certain volume of mercury primary standard stock solution and arsenic primary standard stock solution, respectively placing the mercury primary standard stock solution and the arsenic primary standard stock solution in 100ml volumetric flasks, and fixing the volume to a scale with 5% hydrochloric acid solution to obtain secondary standard stock solution;
s8, standard solution preparation: taking a certain amount of secondary standard stock solution, fixing the volume to a certain scale by using a standard medium to obtain a series of concentration standard solutions, and testing and drawing a standard curve by using an atomic fluorescence spectrometer;
s9, determining the element content of the digestion solution to be detected: and (4) testing the digestion solution to be tested obtained in the step S6 by using an atomic fluorescence spectrometer, repeatedly measuring for 3 times to obtain fluorescence intensity, and converting through the standard curve in the step S8 to obtain the content of the corresponding element in the molded coal.
S10, blank value measurement: and (3) specially setting a blank group, namely, not adding a digestion sample, simultaneously digesting the blank sample to be detected according to the steps, repeatedly measuring the obtained blank sample to be detected for 6 times, calculating the standard deviation of the detection result, and taking the average value of the 6 measurements as the blank value content of the corresponding element of the sample to be detected.
Further, in step S2, the briquette is prepared by the following method:
weighing 100m of 2.0% NaOH solution, placing the NaOH solution in a beaker, adding 5% of biomass powder which is naturally dried and crushed in three stages to be less than or equal to 0.2mm, stirring and heating the biomass powder at 80 ℃ for 2 hours, cooling the biomass powder, compounding the biomass powder with asphalt and tar residue according to the proportion of 1:6:3, and uniformly mixing to obtain a composite binder;
the pulverized coal and the composite binder are uniformly mixed according to the proportion of 7:3 and are placed in a forming machine for cold press forming, and the cylindrical coal briquette with the diameter of 30 mm multiplied by 30 mm is obtained.
Further, in step S3, HNO is sequentially added3 4ml、HF 2ml、HClO4 1ml、H2O21ml, and the total reagent amount is no more than 10 ml.
Further, in step S7, accurately measuring 5.00ml of the mercury primary standard stock solution, placing the mercury primary standard stock solution in a 100ml volumetric flask, and fixing the volume to a scale with 5% hydrochloric acid solution, wherein the concentration of the obtained mercury secondary standard stock solution is 50 ng/ml; 10.00ml of arsenic primary standard stock solution is accurately measured and placed in a 100ml volumetric flask, 5% hydrochloric acid solution is used for constant volume to reach the scale, and the concentration of the obtained arsenic secondary standard stock solution is 100 ng/ml.
Further, accurately measuring 0, 1.00, 2.00, 4.00, 8.00 and 10.00ml of mercury secondary standard stock solutions to 5 100ml volumetric flasks in step S8, and fixing the volume to the scale by using 5% hydrochloric acid to obtain mercury standard series solutions with the concentrations of 0, 0.50, 1.00, 2.00, 4.00 and 5.00 ng/ml;
accurately measuring 0, 1.00, 2.00, 4.00, 8.00 and 10.00ml arsenic secondary standard stock solutions to 5 100ml volumetric flasks, and metering to scale with an arsenic standard medium to obtain arsenic standard series solutions with concentrations of 0, 1.00, 2.00, 4.00, 8.00 and 10.00 ng/ml.
Further, the arsenic standard medium is a mixed solution of 5% hydrochloric acid +1% thiourea +1% ascorbic acid.
Further, in step S8, the atomic fluorescence spectrometer used carries 5% hydrochloric acid solution, the carrier gas is high purity argon gas, the pressure is 0.25MPa, and the flow rate is 400 ml/min. In addition, the lamp current is 60-30mA, the negative high voltage is 240V, the height of the atomizer is 10mm, the flow of the shielding device is 1000ml/min, the reading time is 15s, and the delay time is 1.0 s.
Further, in step S8, drawing a mercury standard curve by atomic fluorescence spectroscopy, wherein IF =2499.409c +48.011, where IF represents the fluorescence intensity of mercury and c represents the concentration of mercury in the solution; the arsenic standard curve is IF =122.398c +7.946, where IF represents the fluorescence intensity of arsenic and c represents the concentration of arsenic in solution.
Further, in step S9, when the atomic fluorescence spectrometer is used to measure the content of the mercury element, the reducing agent is a mixed solution of 1% potassium borohydride and 0.2% sodium hydroxide; when the content of the arsenic element is measured by an atomic fluorescence spectrometer, the reducing agent is a mixed solution of 2% of potassium borohydride and 0.5% of sodium hydroxide.
The invention has the following beneficial effects:
1) the method has the advantages that the hydro-thermal synthesis reaction kettle is adopted to digest the molded coal, the molded coal has the characteristics of high-pressure closed environment and thermodynamic angle, digestion solution steam circulates in the whole sealed tank at a certain pressure, pressurized steam rapidly guides heat into the molded coal sample with extremely strong penetrating power, a mode for enhancing heat transfer and promoting digestion is formed, and the problems that the surface of the sample is digested and the inside is difficult to digest due to the temperature gradient in the conventional open electric heating plate digestion are effectively avoided. In the dynamic angle and the heating process, the mixed acid solution can generate heat energy which is higher than that of a solid sample by several orders of magnitude, the strong vibration of chemical bonds of polar molecules in a liquid phase aggravates the friction and the collision with adjacent molecules, particularly molecules of the solid sample, the mass transfer and digestion reaction rate of the molecules is accelerated, the interaction force between coal particles and a binder is weakened, and the complex influence of the composition of the briquette can be basically eliminated. On the other hand, the mixed acid solution with higher heat energy forms convection to generate disturbance, and an inactive surface layer dissolved on the surface of the solid matter can be eliminated, so that a new solid interface is exposed and is better contacted with acid, the digestion solution fully reacts with the briquette sample under a reasonable mixed acid ratio, the complete digestion of the briquette is ensured, the acid consumption is greatly reduced, the digestion time is shortened, and some indissolvable substances are dissolved.
2) The key point is to grope out the mixed acid system and the reasonable proportion thereof according to the principle of minimum acid consumption, simple digestion procedure and optimal digestion effect. The organic matter content in the molded coal is high, and the complete digestion must be ensured by using a considerable amount of inorganic acid. Only the conventional concentrated nitric acid (the best pre-treatment reagent is recognized at present) and hydrofluoric acid (the only acid capable of decomposing silicon dioxide and silicate is used) are used for testing, the digestion is found to be incomplete, the bottom of a sample solution is precipitated, so that the organic tissue needs to be damaged, perchloric acid is added to promote the digestion of the organic matter, and the strong oxidizing property of hydrogen peroxide enables organic matter side chains and functional groups of the briquette to be oxidized and decomposed, so that the mercury in an organic binding state is decomposed thoroughly, some metals can be oxidized, and the digestion effect is greatly improved. The mixed acid system of the technical scheme does not contain hydrochloric acid which is adopted by most students, chlorine can form polyatomic ions which are the main interference of available isotopes of 75As, and the mixed acid system also has certain interference on Se, Cr, Ge and the like. The technical scheme avoids using sulfuric acid, because the sulfuric acid has a high boiling point, the sulfuric acid can not be completely removed in the acid removing process, the requirement on acidity in the measurement process of the atomic fluorescence spectrometry is strict, and the influence of residual sulfuric acid on the measurement result is large. In contrast, the total consumption of the mixed acid for digesting 50mg of the briquette coal is obtained by different mixed acid ratios, digestion time and digestion temperature comparison experimentsThe amount of the mixed acid is 8ml (less than 10 ml), and the mixed acid is HNO3:HF:HClO4:H2O2And (4) =4:2:1:1, heating the digestion tank at 180 ℃ for 4 hours, and obtaining a transparent and clear digestion solution without adopting a temperature and pressure programming mode.
3) The oxidizing effect of the mixed acid on the volatile organic binder in the molded coal is enhanced by utilizing the preheated energy of the polytetrafluoroethylene sealed tank, a large amount of gas is released, and the potential safety hazard of kettle body explosion caused by pressure surge during closed digestion is eliminated by means of pressure relief to a certain extent in the early stage. In addition, the polytetrafluoroethylene sealing tank has hydrophobicity, and pollution in the sample dissolving process is reduced to a great extent.
4) In a closed environment, the loss of mixed acid and volatile elements is less, the digestion is thorough, the Hg and As content is tested by using an atomic fluorescence spectrometry on a machine, the detection limit is low, and the accuracy of the measurement result is powerfully ensured. In addition, the method has the advantages of simple operation, mild and easily-controlled conditions, small pollution, low blank value, short time consumption, low instrument price and the like, and is an ideal scheme for the digestion pretreatment of the moulded coal.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a schematic flow diagram of the process of the present invention;
FIG. 2 is a schematic representation of a mercury calibration curve obtained in an example of the present invention; IF =2499.409c +48.011, R2=0.9999；
FIG. 3 is a schematic diagram of an arsenic calibration curve obtained in an embodiment of the present invention; IF =122.398c +7.946, R2=0.9997；
FIG. 4 is a comparative diagram of a coal briquette A hydrothermal synthesis reaction kettle digestion experiment in the embodiment of the invention;
FIG. 5 is a comparative graph of a coal briquette A open electric heating plate digestion experiment in a comparative example of the present invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
Example 1
As shown in figure 1, a method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry comprises the following steps:
(1) pretreatment: repeatedly washing a polytetrafluoroethylene sealed tank of a hydro-thermal synthesis reaction kettle and a used container with tap water and deionized water, lightly brushing the inner wall with a soft cotton brush until the inner wall is cleaned, soaking the inner wall in a nitric acid solution with the mass concentration of 10% overnight, taking out the container, washing the container with ultrapure water for three times, washing away surface nitric acid, placing the sealed tank in a blast drying box at the temperature of 80 ℃, and drying and preheating the sealed tank for 30min for later use;
(2) pretreating the briquette:
weighing a proper amount of briquette, drying the briquette to constant weight at 105 ℃, grinding the briquette and sieving the briquette with a 200-mesh sieve;
(3) pre-digestion: weighing 50mg (accurate to 0.0002 g) of molded coal, placing the molded coal at the bottom of a preheated polytetrafluoroethylene sealed tank, adding mixed acid, standing for 30min, performing pre-digestion by utilizing the heat of the polytetrafluoroethylene sealed tank, and covering the polytetrafluoroethylene sealed tank when the gas is completely released and the reaction tends to be mild;
(4) closed digestion: putting the capped polytetrafluoroethylene sealed tank into a stainless steel sleeve, tightly pressing and sealing the polytetrafluoroethylene sealed tank by using a cover of the stainless steel sleeve, putting the whole reaction kettle into an electric heating blowing drying oven, heating for 4 hours at 180 ℃, and keeping the kettle body upright and stable;
(5) acid removal: taking out the hydro-thermal synthesis reaction kettle, cooling to room temperature, opening the stainless steel sleeve cover and the sealing tank cover one by one, pouring the digested molded coal into a polytetrafluoroethylene crucible, flushing the sealing tank and the cover with 5% hydrochloric acid, pouring the flushing liquid into the crucible, placing the crucible on an electric heating plate for acid removal treatment, removing the acid at the temperature of 140 ℃, and stopping acid removal when the solution is in a colloid shape;
(6) and (3) volume fixing: washing the polytetrafluoroethylene crucible for at least 3 times by using 5% hydrochloric acid, transferring the washing liquid into a 50ml volumetric flask, fixing the volume to the scale by using 5% hydrochloric acid, standing for 10min, and transferring the solution serving as a digestion solution to be detected into an HDPE plastic small bottle for later use;
(7) preparation of standard stock solution: accurately measuring 0.10ml of mercury national standard solution and arsenic national standard solution, placing in a 100ml volumetric flask, fixing the volume to the scale with 5% hydrochloric acid solution, shaking up, placing for 10min to obtain mercury primary standard stock solution with the concentration of 1.0 mu g/ml and arsenic primary standard stock solution with the concentration of 1.0 mu g/ml for later use;
accurately measuring a certain volume of mercury primary standard stock solution and arsenic primary standard stock solution, respectively placing the mercury primary standard stock solution and the arsenic primary standard stock solution in 100ml volumetric flasks, and fixing the volume to a scale with 5% hydrochloric acid solution to obtain secondary standard stock solution;
(8) preparation of standard solution: taking a certain amount of secondary standard stock solution, fixing the volume to a certain scale by using a standard medium to obtain a series of concentration standard solutions, and testing and drawing a standard curve by using an atomic fluorescence spectrometer;
(9) and (3) determining the element content of the digestion solution to be detected: testing the digestion solution to be tested obtained in the step S6 by using an atomic fluorescence spectrometer, repeatedly measuring for 3 times to obtain fluorescence intensity, and converting through the standard curve in the step S8 to obtain the content of the corresponding element in the molded coal;
(10) blank value determination: and (3) specially setting a blank group, namely, not adding a digestion sample, simultaneously digesting the blank sample to be detected according to the steps, repeatedly measuring the obtained blank sample to be detected for 6 times, calculating the standard deviation of the detection result, and taking the average value of the 6 measurements as the blank value content of the corresponding element of the sample to be detected.
In the embodiment, in the step (2), the briquette is prepared by the following method: collecting sunflower seed hulls, naturally drying, carrying out three-stage crushing until the size of the sunflower seed hulls is less than or equal to 0.2mm, preparing 2.0% NaOH solution, weighing 100ml of 2.0% NaOH solution in a clean beaker, adding 5% sunflower seed hull powder, stirring and heating at 80 ℃ for 2 hours, and cooling to obtain the modified sunflower seed hull binder. The asphalt, the tar residue and the modified sunflower seed peel are compounded according to the ratio of 6:3:1 to prepare a composite binder A, and the pulverized coal and the composite binder A are uniformly mixed according to the ratio of 7:3 and are placed in a forming machine for cold press forming, so that the cylindrical briquette A with the diameter of 30 mm multiplied by 30 mm is obtained.
For example, in some embodiments, the NaOH solution mass concentration may be 1.5%, 2.5%. The ratio of the asphalt to the tar residue to the modified sunflower seed peel in the composite binder A can be 4:2:4, 4:3:3, 4:4:2, 5:3:2, 5:2:3, 5:4:1, 6:2:2 and 6:1: 3. The ratio of the pulverized coal to the composite binder A can be 8:2 and 9: 1.
In this embodiment, the step (3) specifically includes: sequentially adding concentrated HNO3 4ml、HF 2ml、HClO4 1ml、H2O21ml, and the total reagent amount is no more than 10 ml.
For example, in some embodiments, mixed acid HNO3:HF:HClO4:H2O2The ratio can be 5:2:0.5:0.5, 3:3:1:1, 3.5:2.5:1: 1.
In the embodiment, in the step (7), 5.00ml of mercury primary standard stock solution is accurately measured and placed in a 100ml volumetric flask, 5% hydrochloric acid solution is used for constant volume to reach a scale, and the concentration of the obtained mercury secondary standard stock solution is 50 ng/ml. 10.00ml of arsenic primary standard stock solution is accurately measured and placed in a 100ml volumetric flask, 5% hydrochloric acid solution is used for constant volume to reach the scale, and the concentration of the obtained arsenic secondary standard stock solution is 100 ng/ml.
In this embodiment, in the step (8), 0, 1.00, 2.00, 4.00, 8.00, 10.00ml of mercury secondary standard stock solution is accurately measured to 5 100ml volumetric flasks, and 5% hydrochloric acid is used to fix the volume to the scale, so as to obtain mercury standard series solutions with concentrations of 0, 0.50, 1.00, 2.00, 4.00, 5.00 ng/ml.
Accurately measuring 0, 1.00, 2.00, 4.00, 8.00 and 10.00ml arsenic secondary standard storage into 5 100ml volumetric flasks, and metering to scale by using an arsenic standard medium to obtain arsenic standard series solutions with the concentrations of 0, 1.00, 2.00, 4.00, 8.00 and 10.00ng/ml, wherein the arsenic standard medium is a mixed solution of 5% hydrochloric acid, 1% thiourea and 1% ascorbic acid.
In the embodiment, in the step (8), the current carrying of the atomic fluorescence spectrometer is 5% hydrochloric acid solution, the current carrying is high-purity argon, the pressure is 0.25MPa, and the flow is 400 ml/min. In addition, the lamp current is 60-30mA, the negative high voltage is 240V, the height of the atomizer is 10mm, the flow of the shielding device is 1000ml/min, the reading time is 15s, and the delay time is 1.0 s.
In this example, in step (8), the standard mercury curve was plotted by atomic fluorescence spectroscopy under the condition of IF =2499.409c+48.011, correlation coefficient: r2=0.9999, the linear relationship is good. Where IF represents the fluorescence intensity of mercury and c represents the concentration of mercury in the solution. Standard curve of arsenic IF =122.398c +7.946, correlation coefficient: r2=0.9997, the linear relationship is good. Wherein IF represents the fluorescence intensity of arsenic, and c represents the concentration of arsenic in the solution.
In this embodiment, in the step (9), when the atomic fluorescence spectrometer is used to measure the content of the mercury element, the reducing agent is a mixed solution of 1% potassium borohydride and 0.2% sodium hydroxide. When the atomic fluorescence spectrometer is used for measuring the content of the arsenic element, the reducing agent is a mixed solution of 2% of potassium borohydride and 0.5% of sodium hydroxide.
Example 2
The other steps are the same as those in the embodiment 1, the biomass in the composite binder is different, the embodiment selects the biomass as corn straw, and the obtained composite binder B and pulverized coal are molded to prepare the briquette B as a digestion sample.
Comparative example 1
And (3) digesting the briquette A by using an open electric heating plate.
Comparative example 2
And (3) digesting the briquette B by using an open electric heating plate.
The specific procedure of comparative examples 1 and 2 was as follows:
50mg of briquette A and briquette B are weighed to two clean polytetrafluoroethylene crucibles, and HNO is added in sequence respectively3 5ml、HF 2ml、HClO4 1ml、H2O21ml, covering the cover, placing the mixture on an electric hot plate, heating and digesting the mixture, and keeping the temperature of the electric hot plate at 180 ℃.
Observing the color of the digestion solution and the color of the residual solid in the crucible, wherein the color of the liquid is almost clear and transparent, and when the solid is offwhite, the digestion of the sample is considered to be finished. If the solution is turbid and darker in color and the solid sample is dark brown, adding the mixed acid, and placing the solution on an electric hot plate for continuous digestion. In the comparative examples 1 and 2, when completely digesting, the mixed acid amount HNO is added for the first time every 50mg of the briquette3 5ml、HF 2ml、HClO4 1ml、H2O21ml, the amount of the mixed acid added for the second time is half of that of the mixed acid added for the first time, namely HNO3 2.5ml、HF 1ml、HClO4 0.5ml、H2O20.5ml, total consumption of final mixed acidThe amount was 22.5ml, i.e. 12.5ml HNO3 +5ml HF+2.5ml HClO4+2.5ml H2O2Digestion time is 10 h.
Heating the digestion solution in the crucible at 140 ℃ by an electric heating plate to remove acid, flushing the polytetrafluoroethylene crucible for at least 3 times by using 5% hydrochloric acid when the solution is colloidal, transferring the flushing liquid into a 50ml volumetric flask together, fixing the volume to the scale, standing for 10min, and transferring the solution into a HDPE plastic vial to be tested. The post-treatment work is the same as the digestion treatment method of the hydrothermal synthesis reaction kettle.
The digestion result alignment is shown in table 1, and the measurement results are shown in tables 2 and 3.
TABLE 1 comparison of digestion results
TABLE 2 blank test results for samples
The blank solution 6 times of Hg and As content detection mean values are respectively 0.0009 mu g/L and 0.6471 mu g/L, and the blank values are used As blank values of Hg and As content detection in a sample to be detected. The standard deviation SD of the repeated detection values is 0.0082 mu g/L and 0.0108 mu g/L respectively.
TABLE 3 test results of examples and comparative examples
In conclusion, the Hg and As detection values of the example 1 and the example 2 are higher than those of the comparative example 1 and the comparative example 2, and the hydrothermal synthesis reaction kettle has better digestion effect and less element loss compared with an open electric hot plate. The repeated measurement standard deviation is small, the uncertainty is lower than 1, the measurement result of the method is accurate and reliable, and the test efficiency is high.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.
Claims (9)
1. A method for measuring mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry is characterized by comprising the following steps: the method comprises the following steps:
s1, preprocessing:
repeatedly washing a polytetrafluoroethylene sealed tank and a container of a hydro-thermal synthesis reaction kettle by using tap water and deionized water, brushing the inner wall until the inner wall is cleaned, soaking the sealed tank and the container in a nitric acid solution with the mass concentration of 10% overnight, taking out the sealed tank, washing the sealed tank and the container for three times by using ultrapure water, washing away surface nitric acid, placing the sealed tank in a blast drying box with the temperature of 80 ℃, and drying and preheating the sealed tank for 30min for later use;
s2, pretreatment of the briquette:
weighing a proper amount of briquette, drying the briquette to constant weight at 105 ℃, grinding the briquette and sieving the briquette with a 200-mesh sieve;
s3, pre-digestion: weighing 50mg of molded coal, placing the molded coal at the bottom of a preheated polytetrafluoroethylene sealed tank, adding mixed acid, standing for 30min, performing pre-digestion by utilizing the self-heat of the polytetrafluoroethylene sealed tank, and covering the polytetrafluoroethylene sealed tank when the gas is completely released and the reaction tends to be mild;
s4, closed digestion: putting the capped polytetrafluoroethylene sealed tank into a stainless steel sleeve, tightly pressing and sealing the polytetrafluoroethylene sealed tank by using a cover of the stainless steel sleeve, putting the whole reaction kettle into an electric heating blowing drying oven, heating for 4 hours at 180 ℃, and keeping the kettle body upright and stable;
s5, acid removal: taking out the hydro-thermal synthesis reaction kettle, cooling to room temperature, opening the stainless steel sleeve cover and the sealing tank cover one by one, pouring the digested molded coal into a polytetrafluoroethylene crucible, flushing the sealing tank and the cover with 5% hydrochloric acid, pouring the flushing liquid into the crucible, placing the crucible on an electric heating plate for acid removal treatment, removing the acid at the temperature of 140 ℃, and stopping acid removal when the solution is in a colloid shape;
s6, constant volume: washing the polytetrafluoroethylene crucible for at least 3 times by using 5% hydrochloric acid, transferring the washing liquid into a 50ml volumetric flask, fixing the volume to the scale by using 5% hydrochloric acid, standing for 10min, and transferring the solution serving as a digestion solution to be detected into an HDPE plastic small bottle for later use;
s7, preparation of standard stock solution: accurately measuring 0.10ml of mercury national standard solution and arsenic national standard solution, placing in a 100ml volumetric flask, fixing the volume to the scale with 5% hydrochloric acid solution, shaking up, placing for 10min to obtain mercury primary standard stock solution with the concentration of 1.0 mu g/ml and arsenic primary standard stock solution with the concentration of 1.0 mu g/ml for later use;
accurately measuring a certain volume of mercury primary standard stock solution and arsenic primary standard stock solution, respectively placing the mercury primary standard stock solution and the arsenic primary standard stock solution in 100ml volumetric flasks, and fixing the volume to a scale with 5% hydrochloric acid solution to obtain secondary standard stock solution;
s8, standard solution preparation: taking a certain amount of secondary standard stock solution, fixing the volume to a certain scale by using a standard medium to obtain a series of concentration standard solutions, and testing and drawing a standard curve by using an atomic fluorescence spectrometer;
s9, determining the element content of the digestion solution to be detected: testing the digestion solution to be tested obtained in the step S6 by using an atomic fluorescence spectrometer, repeatedly measuring for 3 times to obtain fluorescence intensity, and converting the standard curve in the step S8 to obtain the content of the corresponding element in the molded coal;
s10, blank value measurement: and (3) specially setting a blank group, namely, not adding a digestion sample, simultaneously digesting the blank sample to be detected according to the steps, repeatedly measuring the obtained blank sample to be detected for 6 times, calculating the standard deviation of the detection result, and taking the average value of the 6 measurements as the blank value content of the corresponding element of the sample to be detected.
2. The method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry as claimed in claim 1, wherein the method comprises the following steps: in step S2, the briquette is prepared by the following method:
weighing 100m of 2.0% NaOH solution, placing the NaOH solution in a beaker, adding 5% of biomass powder which is naturally dried and crushed in three stages to be less than or equal to 0.2mm, stirring and heating the biomass powder at 80 ℃ for 2 hours, cooling the biomass powder, compounding the biomass powder with asphalt and tar residue according to the proportion of 1:6:3, and uniformly mixing to obtain a composite binder;
the pulverized coal and the composite binder are uniformly mixed according to the proportion of 7:3 and are placed in a forming machine for cold press forming, and the cylindrical coal briquette with the diameter of 30 mm multiplied by 30 mm is obtained.
3. The method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry as claimed in claim 1, is characterized in that: in step S3, HNO is added in sequence3 4ml、HF 2ml、HClO4 1ml、H2O21ml, and the total reagent amount is no more than 10 ml.
4. The method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry as claimed in claim 1, is characterized in that: in the step S7, accurately measuring 5.00ml of mercury primary standard stock solution, placing the mercury primary standard stock solution in a 100ml volumetric flask, and fixing the volume to a scale by using a 5% hydrochloric acid solution to obtain a mercury secondary standard stock solution with the concentration of 50 ng/ml; 10.00ml of arsenic primary standard stock solution is accurately measured and placed in a 100ml volumetric flask, 5% hydrochloric acid solution is used for constant volume to reach the scale, and the concentration of the obtained arsenic secondary standard stock solution is 100 ng/ml.
5. The method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry as claimed in claim 1, is characterized in that: accurately measuring 0, 1.00, 2.00, 4.00, 8.00 and 10.00ml of mercury secondary standard stock solution to 5 100ml volumetric flasks in step S8, and fixing the volume to the scale by using 5% hydrochloric acid to obtain mercury standard series solutions with the concentrations of 0, 0.50, 1.00, 2.00, 4.00 and 5.00 ng/ml;
accurately measuring 0, 1.00, 2.00, 4.00, 8.00 and 10.00ml arsenic secondary standard stock solutions to 5 100ml volumetric flasks, and metering to scale with an arsenic standard medium to obtain arsenic standard series solutions with concentrations of 0, 1.00, 2.00, 4.00, 8.00 and 10.00 ng/ml.
6. The method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry as claimed in claim 5, is characterized in that: the arsenic standard medium is a mixed solution of 5% hydrochloric acid, 1% thiourea and 1% ascorbic acid.
7. The method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry as claimed in claim 1, is characterized in that: in step S8, the atomic fluorescence spectrometer is used to carry 5% hydrochloric acid solution, the carrier gas is high purity argon, the pressure is 0.25MPa, and the flow rate is 400 ml/min. And the lamp current is 60-30mA, the negative high voltage is 240V, the height of the atomizer is 10mm, the flow of the shielding device is 1000ml/min, the reading time is 15s, and the delay time is 1.0 s.
8. The method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry as claimed in claim 1, is characterized in that: in step S8, an atomic fluorescence spectrometer is used to test and draw a mercury standard curve as IF =2499.409c +48.011, where IF represents the fluorescence intensity of mercury and c represents the concentration of mercury in the solution; the arsenic standard curve is IF =122.398c +7.946, where IF represents the fluorescence intensity of arsenic and c represents the concentration of arsenic in solution.
9. The method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry as claimed in claim 1, is characterized in that: in step S9, when the atomic fluorescence spectrometer is used to measure the mercury content, the reducing agent is a mixed solution of 1% potassium borohydride and 0.2% sodium hydroxide; when the content of the arsenic element is measured by an atomic fluorescence spectrometer, the reducing agent is a mixed solution of 2% of potassium borohydride and 0.5% of sodium hydroxide.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210389850.XA CN114720445A (en) | 2022-04-14 | 2022-04-14 | Method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry |
| PCT/CN2023/071498 WO2023197712A1 (en) | 2022-04-14 | 2023-01-10 | Method for determining mercury and arsenic in briquettes based on atomic fluorescence spectrometry and digestion of briquettes using hydrothermal synthesis reactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210389850.XA CN114720445A (en) | 2022-04-14 | 2022-04-14 | Method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114720445A true CN114720445A (en) | 2022-07-08 |
Family
ID=82243787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210389850.XA Pending CN114720445A (en) | 2022-04-14 | 2022-04-14 | Method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN114720445A (en) |
| WO (1) | WO2023197712A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023197712A1 (en) * | 2022-04-14 | 2023-10-19 | 中国矿业大学 | Method for determining mercury and arsenic in briquettes based on atomic fluorescence spectrometry and digestion of briquettes using hydrothermal synthesis reactor |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117214283B (en) * | 2023-11-07 | 2024-02-23 | 西安中钛华测检测技术有限公司 | Method for measuring cadmium element in hafnium and hafnium alloy |
| CN117470618A (en) * | 2023-12-28 | 2024-01-30 | 中国科学院烟台海岸带研究所 | Ultrafiltration separation detection method for colloidal iron in seawater |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103543055A (en) * | 2013-10-25 | 2014-01-29 | 环境保护部华南环境科学研究所 | Pretreatment method for heavy metal element detection in solid sample and application of pretreatment method |
| CN110487758B (en) * | 2019-08-15 | 2021-05-14 | 华北电力大学 | Method for measuring arsenic, selenium and lead in coal-fired power plant coal and combustion byproducts thereof |
| CN114720445A (en) * | 2022-04-14 | 2022-07-08 | 中国矿业大学 | Method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry |
-
2022
- 2022-04-14 CN CN202210389850.XA patent/CN114720445A/en active Pending
-
2023
- 2023-01-10 WO PCT/CN2023/071498 patent/WO2023197712A1/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023197712A1 (en) * | 2022-04-14 | 2023-10-19 | 中国矿业大学 | Method for determining mercury and arsenic in briquettes based on atomic fluorescence spectrometry and digestion of briquettes using hydrothermal synthesis reactor |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023197712A1 (en) | 2023-10-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114720445A (en) | Method for determining mercury and arsenic in briquette coal based on hydrothermal synthesis reaction kettle digestion briquette coal-atomic fluorescence spectrometry | |
| Ma et al. | Hydrothermal treatment of antibiotic mycelial dreg: More understanding from fuel characteristics | |
| Trubetskaya et al. | Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity | |
| Peng et al. | Co-pyrolysis of industrial sludge and rice straw: Synergistic effects of biomass on reaction characteristics, biochar properties and heavy metals solidification | |
| CN103543055A (en) | Pretreatment method for heavy metal element detection in solid sample and application of pretreatment method | |
| CN115326914B (en) | Method for simultaneously and rapidly measuring chlorine, bromine and iodine by high-temperature hydrolysis combined ICP-MS | |
| Chen et al. | Pyrolysis characteristics and stage division of red mud waste from the alumina refining process for cyclic utilization | |
| CN110487758B (en) | Method for measuring arsenic, selenium and lead in coal-fired power plant coal and combustion byproducts thereof | |
| Raček et al. | Heavy metal fixation in biochar after microwave pyrolysis of sewage sludge | |
| Papp et al. | Application of microwave digestion to the analysis of peat | |
| CN110161015B (en) | Method for determining content of phosphorus-magnesium-iron-aluminum-calcium-manganese-titanium oxide in black shale | |
| Enders et al. | Total elemental analysis of metals and nutrients in biochar | |
| Stolarek et al. | Influence of liming on kinetics of sewage sludge pyrolysis | |
| Graber et al. | Determining acidic groups at biochar surfaces via the Boehm titration | |
| Tanner et al. | Microwave vacuum drying of marine sediment: determination of moisture content, metals and total carbon | |
| CN111443056B (en) | Method for measuring mercury content in copper concentrate | |
| CN109867421A (en) | A kind of chromium-bearing sludge processing method and system based on supercritical water oxidation | |
| Asta et al. | Dissolution kinetics of marcasite at acidic pH | |
| ZHOU et al. | Volatility of cadmium during pyrolysis of typical low rank coals | |
| CN113029981A (en) | Method for detecting sludge total phosphorus of urban sewage plant | |
| Yaru et al. | Determination of Cd, Cu, Pb, and Zn in biological tissues using Zeeman graphite furnace AAS after microwave digestion in non-pressurized, semi-closed vessel | |
| CN111982651A (en) | Rapid microwave digestion treatment method for solid-containing residual oil | |
| Mong et al. | Pyrolysis Behaviour and Kinetic Analysis of Food Waste Sludge Cake. | |
| CN106540651B (en) | A method of dephosphorization material is prepared using microwave heating technique modified sediment | |
| CN112255077A (en) | Method for digesting low-quality coal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |