Some standard content:
YC873.040
National Standard of the People's Republic of ChinaWww.bzxZ.net
GB/T 4633—1997
Determination of fluorine in coal
Promulgated on April 17, 1997
State Administration of Technical Supervision
Implementation on October 1, 1997
GE/T4633-1997
This standard is based on (/T4633—81), and the half-measure method with high blank and poor stability is eliminated. The determination of the actual slope of the front electrode is added in the determination steps. The rest is consistent with the original standard. This standard is in accordance with BT1.1-93 Standardization Work Guide Unit 1, Drafting and Table of Standards. The writing format of multiplication and calculation, the expressions of some diameter numbers and units are modified. This standard is in accordance with the requirements of the national standard for bacteria. This standard is based on the number of bacteria and replaces GB/T4633-81. This standard is proposed by the Ministry of Coal Industry of the People's Republic of China and is approved by the National Coal Standardization Technical Committee. The drafting unit of this standard is: Beijing Coal Chemistry Research Institute, General Coal Research Institute. The main drafter of this standard is Gao Xialiang. This standard is entrusted to Beijing Coal Chemistry Research Institute, General Coal Research Institute for the interpretation. 1 Scope National Standard of the People's Republic of China Determination of oxygen in coal GE/T4633-1997 Generation H/1 4533 -84
This standard specifies the method for determining the total oxygen content in coal by the high-pressure combustion hydrolysis-oxygen ionization selective forging method. It is applicable to the determination of oxygen in smelting coal, bituminous coal and smokeless coal. 2 Quality
Coal is burned and hydrolyzed in a mixture of oxygen and steam. The coal is converted into volatile organic compounds (SiF, and HF) and gradually falls into water. The oxygen ion mixing electrode is used as the indicator electrode, and the argon and argon electrodes are used as the ratio electrodes. The oxygen ion content in the sample is determined by the standard insertion method, and the total amount in the medium is calculated. 3 Reagents and materials
3.1 Water The water used in this method is deionized water with a charge density greater than 3 μm. 3.2 Quartz sand, single particle size (0.5~13mm. 3.3 Sodium hydroxide solution: 10g /L,
Add 1g of super-pure sodium hydroxide (GB/T629) to 100ml of water, 3.4 Nitric acid solution: 1+5 (V+V).
Add 20mL of super-pure nitric acid (GB626) to 100mL and mix. 3.5 Formic acid green indicator: 1B/Ethyl acetate solution. Add 0.1% formic acid green (HG3-1220) indicator to 100ml of alcohol. 3.6 Oxygen standard reserve solution: weigh super-pure sodium fluoride (GB/T126432.2101) that has been dried at 120K for about 2h in a flat beaker, add hydrolyzate, wash with water into a 1000mL volumetric flask and add to the scale, mix well, store in a plastic bottle for later use. This solution contains 1mL, and 1000 is used as a reserve solution.
3.7 Standard working solution: Use reserve pipette to prepare 1 ml of working solution containing 100g, 250g and 500g of fluorine respectively, and prepare them in plasticizer for use.
3.B Total height test solution: Weigh 294g of chemical sodium nitrate (Na2SO4, C2H2O) (HG3125S/4) and 20g of chemically pure potassium nitrate (GBT647) and dissolve them in 800mL of water, adjust the pH to 6.0 with nitric acid (3.4), and then dilute to 1L with water. Put it in a plastic bottle for later use.
3.9 Gas purity 99% or above,
4 Instruments and equipment
4.1 Instruments and containers. The instruments and containers used in this method should be plastic products in principle. 4.2 Combustion boat is made of porcelain - length 7mm. 8mm + upper width 12mm4.3 Analytical balance with a sensitivity of 0.1m.
National Thermal Technology Supervision Week 1997-04-17 Approved 1997-10-01 Yi Shi
4.4 High temperature combustion - water shadow cover,
GA/T4633--1997
4.4.1 Single-section high leakage furnace: the normal temperature is 1100℃, with a constant temperature zone of (80--1℃0)m long (1100±5)C and an automatic temperature controller. 4.4.2 Combustion element, transparent quartz tube, temperature resistant to 1300℃, specifications and dimensions see Figure 1. Exug
Quartz incense
4.4.3 Avoidance tube, spherical, specifications and dimensions see medical 2135
Figure 2 Cold kidney
4.4.4 Water consumption gas generator: composed of 500mL flat bottom furnace and adjustable pressure disc electric furnace. 4.4.5 Wide measuring range 1000mL/min. Small measurement 10ml./min. 4.5 Measuring potentiometer solution
4.5.1 Electromagnetic stirrer, continuous smoke
4.5.2 Oxygen path optional electric, auxiliary measuring line range 10-110-ma1/., 4.5.3 Embedded smelting electrode.
4.5.4 The input impedance of the digital meter is greater than 10\n, and the scale is 0.1msV. It can also be replaced by an integral voltmeter with the same performance. 5. Coal treatment
5.1 Preparation
As shown in Figure 3, assemble the gold-set instrument, connect the circuit, gas circuit and water circuit systems: Heat the single-section furnace to 1100℃. Add about 300ml of water to the flask and heat it until it is full. Add cold water, plug the sample injection knob, adjust the oxygen flow rate to 400mL/mia, and after the test, pass water vapor and air for 15min. Each operation must be performed once. 2
GB/r4633-1997
—capacity filling 12—cold energy tube: 3—quartz glycosides, 4—thermoelectric room 5—lazy burning storage: 6—single section from humidity protection: 7—water release [119—avoid sample push sample 19—say the amount of film 10—ancestral quality controller, 11.m each gas cylinder 112—western plate electric furnace, 13—normal burning benefit, 14—self-transformer volume 116 normal burning period: 16—self-transformer western device 3 high temperature combustion-hydrolysis device inductive diagram
5.2 operation steps
Weigh 0.5±0.0002)g of the gas T explosion coal sample and 0.5g of quartz sand (3.2) and put them in the combustion boat (4.2) and then spread an appropriate amount of quartz sand on it. Put the 100mL volume bottle under the cold avoidance to receive the condensation. Remove the sample pusher, put the combustion boat into the flask, insert the mixing rod, and discard the rubber stopper. Push the front end of the flask to the low temperature zone (about 300℃) prepared in advance to prevent the sample from burning. After that, push the combustion boat to the overflow zone in three sections within 15 minutes, and pull out the sample pusher to prevent melting. The combustion boat stays in the constant temperature zone for 15 minutes. During the whole operation, measure the condensation of water in the flask to control the condensation volume collected. In the first 15 minutes, about 3L is collected per minute, and in the last 15 minutes, about 2.5mL is collected per minute. The final total volume should be controlled within 85mL. After the combustion-hydrolysis is completed, adjust the voltage of the water gas generator to the "pregnant" position, remove the blood bottle, and stop the oxygen supply. Lower the injection rate and take out the combustion boat with a hook.
Place 3 ml of moist cresol green indicator (3.5) in the solution bottle filled with cold hard filter, neutralize it with sodium hydroxide or sodium chloride (3.3) until the indicator turns blue, add 1 ml of total concentration buffer (3.3), dilute to the scale with water, and measure the product potential after half an hour according to the provisions of Section 6.
6 Measure the potential
6.1 Connect the instrument as shown in Figure 4, start the stirrer, and change the water in the beaker several times until the potential displayed by the voltmeter reaches the empty potential of the mouse electrode.
1—Electromagnetic sample stirrer: 2—Micro stirrer; 3—Add ion selection and recovery; 4—Fear and ionization number 15—Digital high-voltage meter Figure 4 Schematic diagram of the potentiometer installation
6.2 Determination of the actual slope of the electrode:
GB/T46331997
Since the actual slope of the fluorine electrode is deviating from the theoretical value (59.2), the actual slope of the oxygen electrode should be tested regularly\6.2.1 After 5 hours, rinse 100mL of the selected In the container, add 1mL, 3mL, 5mL, 1mL of the standard liquid (F-100/m) respectively. For example, add 3 drops of indicator (3.4) and 1mL of the total high intensity adjustment (3.8) and rinse with water until the water is thick.
6.2.2 Pour the liquid into a 10ml beaker and measure the potential with an electrochemical tester. At each standard drop, the electrode finger depth, the degree of coverage, etc. shall be consistent.
6.2.3. Take the response potential (mV) of various concentrations of leaching as the ordinate and the corresponding logarithm of the concentration as the relative coordinate, and draw a graph on the single logarithmic coordinate. The actual slope of the electrode is obtained by comparing the response potentials corresponding to the two points lgc-0 and logc=1 on the typical line. 6.3 Potential measurement of sample solution
Filter the prepared sample and transfer it into 100ml flask. Put in no stirrer, insert oxygen electrode and oxygen electrode (insertion depth and stirring speed must be the same as the actual slope of the electrode). Start the stirrer, record the response potential after the position is verified, and immediately add 7.00mL of the standard solution (3.7). After the potential stabilizes, record the response potential of 5.7. Calculation of results
Where, F-
chlorine radical content in air dry explosion/g
S-actual material of oxygen electrode
AE-- E, - E, +mV;
…Standard filter concentration B/.
8 Specificity of the method
Reproducibility and reproducibility of oxygen determination in coal are as follows: Standard content figure
anti Ig
Repeatability limit
15Cmg/g）
%Push)
Re-observation critical plasticity
20tpg/g>
152（Push）
1) If the cumulative discharge is used continuously, it is not necessary to measure every day. If the discharge interval exceeds one period, it should be measured before use. When the actual solution is lower than 55, the electrode cell should be replaced or a new electrode should be replaced. 2) The standard oxygen amount added ((should be greater than the test amount (V times as much as possible in the actual data range, and the standard current should be selected as the root of the standard current, and controlled at 21~40mV,
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