1. Impurity removal process of soluble sulfate, barium carbonate and sulfideWeighing 0.5000g sample in 50mL High type beaker, add $number hydrochloric acid solution 10mL, after the low temperature furnace on the micro-boiling 30min, and then add 10% nitric acid solution 10mL to continue to micro-boiling after the 20min, slightly cold after the filter with slow quantitative filter, collect precipitation.
2.Sodium carbonate-zinc oxide semi-melting process to decompose specimenTransfer the above-mentioned precipitation and filter paper to 30mL porcelain crucible, and after the low temperature is fully ashing in muffle furnace, then increase the temperature to 700 ℃, add 5 grams of sodium carbonate-zinc oxide ($number) mixed solvents, stir evenly, and then cover 2 grams of mixed solvents, into muffle furnace, starting from the low-temperature temperature to 800 ℃, and keep burning 1hour.
3.leaching process of sulfate root in semi-molten matterTake the crucible out slightly cooler, place in 250mL beaker, add 100mL hot water immersion, wash out the crucible with hot 20% sodium carbonate solution, heat with slow filter paper in 500 ml beaker, then wash and precipitate 6-8 times with hot 20g/l sodium carbonate solution. The funnel is deposited together with the filter paper and transferred to the original beaker for standby
4.The precipitation and determination process of sulfate rootWith 50% hydrochloric acid solution and to red and excess 3mL, water to regulate the volume of filtrate to 300mL, boiling to remove carbon dioxide, add 100G/L barium chloride solution 25 ml, evenly stirring 1min after continuing to boil for several minutes, and heat preservation for half an hour, and then static overnight. Filter the precipitation with slow ration filter paper, move it into the 30mL porcelain crucible which is burnt to constant weight before low temperature ashing in 800 ℃ and then weigh after burning to constant weight. The total content of sulfur in barium sulfate, strontium sulfate, lead sulfate and silver sulfate
5.The removal process of sulphate interference of strontium, lead and silverA 50mL ($number) Hydrochloric acid solution was added to the precipitation collected during leaching of the semi-molten matter, in the low temperature electric furnace, the leachate is transferred to 250mL capacity bottle, and the content of SR, Pb and AG in the solution is detected by icp-oes and converted into each of strontium sulfate, the amount of sulphur in the presence of lead sulfate and silver sulfate, the total content of sulphur in the previous link is deducted from the sulphur content measured in this section, then the sulphur content of barium sulfate in barite and the amount of barium sulfate.