Laboratory equipment, coal ash, coal quality of the instruments of national measurement standards

 Determination of ash
This standard covers determination of coal ash in the two methods, namely slow and fast ashing ashing method. Slow ashing method for the Arbitration Law; rapid ashing method can be used as routine analysis.
3.1 slow ashing method
3.1.1 Summary
weigh a certain amount of air-dried coal sample, put muffle furnace heated to a certain speed to 815 + / -10 ℃, ash and a constant burning in quality. to the quality of the residue quality of coal ash yield as a percentage.
3.1.2 apparatus, equipment
3.1.2.1 muffle furnace: to maintain the temperature of 815 + / -10 ℃. sufficient temperature zone furnace. furnace wall of the upper diameter 25 ~ 30mm with a chimney, the lower end away from the furnace at 20 ~ 30mm,UGG boots, there is a thermocouple inserted in the hole, the door has a diameter of 20mm ventilation holes.
3.1.2.2 gray porcelain dish: rectangular, bottom length 45mm, width 22mm, high 14mm (see Figure 4).
3.1.2.3 dryers: built-in color gel or anhydrous calcium chloride.
3.1.2.4 analytical balance: a sense of the amount of 0.0001g. coal testing equipment, heat-resistant porcelain or asbestos
3.1.2.5: Dimensions and furnace fit.
3.1.3 analysis steps
3.1. 3.1 with the quality of pre-ignition to a constant ash pan, check the particle size of 0.2mm below the air-dried coal sample 1 + /-0.1g, accurate to 0.0002g, evenly spread levels in the ash pan in the quality of its per square centimeter no more than 0.15g.
3.1.3.2 into the ash pan temperature does not exceed 100 ℃, muffle furnace, close the door and make the gap of about 15mm left door. not less than 30min in the furnace within the time temperature slowly rose to about 500 ℃, and in this temperature for 30min. to continue to rise to 815 + / -10 ℃, and at this temperature burning 1h.
3.1.3.3 Remove the ash pan from the oven, on the resistance thermal porcelain or asbestos, in the cool air around 5min, cooled to room temperature into the dryer (about 20min), the weighing.
3.1.3.4 coal analysis equipment check of the ignition, every 20min until two consecutive changes in the quality of burning far less than 0.001g. by burning after the last calculated on the basis of quality. ash content of less than 15%, do not have to check of the ignition.
3.2 Rapid ashing
The standards include two rapid ashing method: Method A and Method B.
3.2.1 Method A
3.2.1.1 Method Summary
with coal ash will be placed in pre-heated pan 815 + / -10 ℃ Tester ash conveyor, automatic coal ash into the instrument completely and submit. to the quality of the residue quality of coal ash as a percentage of the yield.
3.2. 1.2 Special equipment: quick ash analysis (see Appendix A)
3.2.1.3 Analysis Step calorimeter
a. Ash Tester will be pre-heated to 815 + / -10 ℃.
b. start conveyor belt and send it around the speed controller to 17mm/min or other suitable speed.
c. constant with the quality of pre-burning to ash pan, check the particle size of 0.2mm below the air-dried coal sample of 0.5 + / - 0.01g, accurate to 0.0002g, spread evenly in the flat in the ash pan.
d. will be filled with coal ash in the ash pan on a conveyor belt Tester, ash pan that is automatically sent to the furnace.
e. sent from the furnace when the ash pan,UGG boots cheap, remove,cheap UGG boots, or asbestos on the heat-resistant porcelain on cooling in the air around 5min, cooled to room temperature into the dryer (about 20min), the weighing.
3.2. Method 2 Method B
3.2.2.1 Summary of coal analysis instruments
the pan with coal ash from the furnace gradually into the pre-heated to 815 + / -10 ℃ in a muffle furnace and burned to ash quality is constant. to the quality of the residue quality of coal ash yield as a percentage.
3.2.2.2 apparatus, equipment: the same section 3.1.2.
3.2.2.3 with pre-analysis steps
a. to the quality of constant burning ash pan, check the particle size of 0.2mm below the air-dried coal sample 1 + / - 0.1g, accurate to 0.0002g, evenly spread levels in the ash pan, the mass per square centimeter of it does not exceed 0.15 g. filled with coal ash pan pre-Sub or asbestos emissions in the heat-resistant porcelain on.
b. will muffle furnace heated to 850 ℃, open the door, put a dust pan to heat porcelain or asbestos slowly push the board in the muffle furnace, the first dish in the first row of the coal ash ash. to be 5 ~ 10min after the coal is no longer smoke, not more than 2mm per minute speed of the second and third four ash pan into the furnace hot part of the order (if the coal fire deflagration, test should be void). coal laboratory equipment
c. closed door, in the 815 + / -10 ℃ temperature burning 40min.
d. gray Remove pan from oven, cool on the air, 5min or so, into the desiccator to cool to room temperature (about 20min), the weighing.
e. inspection of the burn, each 20min, until two consecutive changes in the quality of burning far less than 0.001g. by burning after the last calculated on the basis of quality. Check the ignition results for the case of instability, the slow ashing method should be used instead to re-determination. ash content less than 15% do not have to check of the ignition.
3.3 The results of the calculation of air-dried coal sample
ash according to formula (4) Calculate:
where Aad mm air-dried ash yield of coal samples ,%;
m1mm the quality of residue, g;
mmm coal quality, g.
3.4 Determination of ash ash precision
repeatability and reproducibility of the determination of Table 2 provides:
4 Determination of volatile method
4.1 feed
weigh a certain amount of air-dried coal sample, on a covered porcelain crucible, in the 900 + / -10 ℃ temperature, cut off from the air heating 7min . to reduce the quality of the percentage of coal quality, minus the water content of the coal samples (Mad) as the volatile yield.
4.2 apparatus, equipment
4.2.1 volatile crucible: with a tight match porcelain crucible lid, shape and dimensions shown in Figure 5. crucible total mass of 15 ~ 20g.
4.2.2 muffle furnace: thermostat with pyrometers and devices, can maintain the temperature at 900 + / - 10 ℃, and with sufficient temperature zone (900 + / -5 ℃). stoves heat capacity,UGGs, when the initial temperature was 920 ℃, the crucible at room temperature into the frame and a number of crucible, close the door after 3min to restore to 900 + / -10 ℃. furnace wall has a vent hole and a thermocouple inserted. holes so positioned as to insert the thermocouple in the furnace after the thermal contacts between the crucible bottom and the bottom, Department 20 ~ 30mm from the bottom.
muffle furnace heated area should be measured under the closed door, and a determination of at least six months. pyrometer (including millivolt meter and thermocouple) calibrated at least once half a year.
Crucible 4.2.3 aircraft: The heat-resistant nickel-chromium wire or other metal wire made of. to make all of its specification size crucibles are heated in a muffle furnace area, and the crucible bottom of the thermocouple hot junction is located above and away from the furnace the end of 20 ~ 30mm (see Figure 6) shall prevail.