china hp graphite electrode
China hp graphite electrode talk about graphite crucible alkali fusion method
Accurately take 0. sample, roughly weigh 3g sodium hydroxide and place it in a graphite crucible, put it in a high temperature furnace, heat up from low temperature to 650 degrees, keep it warm, take out the crucible and cool it slightly, put the graphite crucible in a beaker, and pour it 1:1 After immersing in 20mL hot hydrochloric acid for a few minutes, elute the crucible with 5% hydrochloric acid, melt the salt block until it is clear, heat the beaker on the electric furnace at low temperature (constantly stirring) to the wet salt state, remove it, add 10mL concentrated hydrochloric acid, Heat at low temperature (or leave it overnight).
Incubate at 70 degrees, add 6-8mL of newly configured 1% animal glue, stir well, continue to keep warm, remove and add 20mL of hot water, stir to dissolve the salt mass, after the precipitate settles, filter with medium-speed quantitative filter paper while it is hot ( The filtrate is received with a volumetric flask) Wash the precipitate with 2% hot hydrochloric acid, and transfer all the precipitate to the funnel on the wall of the beaker. Continue washing 10 times until the precipitate is no yellow, and then wash the precipitate 10 times with hot water.
The filtrate is cooled to a constant volume and can be used as an ion test.
The filter residue is put into a crucible (after weighing) and calcined at 950°C for 1 hour, and the mass is taken out and weighed until the weighing.