In a 0.05-0.1 N hydrochloric acid solution, a barium chloride solution was added to precipitate sulfate into barium sulfate. When the sulfate precipitation, along with the following materials is more or less co-precipitated barium sulfate: chloride, nitrate, and chlorate in the form of co-precipitated barium salt; an alkali metal, calcium and ferric sulphate or bisulphate Form co-precipitation. The degree of coprecipitation depends on the composition, concentration, acidity, temperature, precipitation method, and other factors of the solution. The adsorption of barium nitrate and barium chlorate by barium sulfate is much stronger than that of chloride. Therefore, when nitrate and chlorate are present, they must be evaporated twice with concentrated hydrochloric acid to completely remove the barium sulfate before it is precipitated. The burning temperature of the barium sulfate precipitate should not exceed 850° to avoid decomposition. When the carbon in the filter paper is burned out and burned at a high temperature, barium sulfate may be partially reduced to barium sulfide. In this case, the result of sulfur is low. The precipitate can be wetted by adding 1-2 drops of concentrated sulfuric acid, and the sulfuric acid is exhausted at a low temperature, and then re-burned to constant weight. Analysis procedure Sodium peroxide-sodium carbonate melting method: Weigh 0.2-0.5 g of the sample, place it in the iron crucible, add about 5 g of sodium hydride-sodium carbonate (7:1) mixed flux, stir well, and cover 1-2 g. In a high-temperature furnace, the temperature was raised to 700 ° and melted for 10-12 minutes, and taken out and cooled. Place the crucible in a 250 ml beaker, dip it with heated water (if there is purple or green high-priced manganese , add a few drops of ethanol to reduce), wash out the crucible, and boil for a few minutes. It was filtered through a dense filter paper, and the filtrate was taken up in a 400 ml beaker, and the beaker was washed 4-5 times with a 1% sodium carbonate solution and precipitated 7-8 times. A few drops of methyl orange indicator were added to the solution, neutralized with 1:1 hydrochloric acid and 3 ml in excess, and the volume was diluted to 300 ml with water. Heat and boil until the carbon dioxide is exhausted, add 10-15 ml of 10% cesium chloride hot solution (depending on the content), boil and keep for half an hour, and let it sit for more than 4 hours. The precipitate was filtered through a dense quantitative filter paper and washed with warm water until no chloride ions were reacted (checked with a silver nitrate solution). The precipitate and filter paper were transferred into a constant weight porcelain crucible, ashed, and burned at 800 ° for 1 hour, taken out, taken cold, and weighed. Repeat the burning for 30 minutes until constant weight. %S=[(W×0.1374)/G]×100 Where W-barium sulfate weight (g); G-sample weight (g); 0.1374-barium sulphate is converted to sulphur ground factor. Semi-melting method of sodium carbonate- zinc oxide (or potassium permanganate): Weigh 0.2-0.5 g of the sample and place it in a 30 ml porcelain crucible containing 3-5 g of mixed flux (sodium carbonate: zinc oxide: 3:2), stir well, and cover 1-2 g. Put it in a high-temperature furnace, gradually increase the temperature by 800 °, and keep it for 1 hour (slightly open the door). Remove and cool, place in a 250 ml beaker, dip with hot water (if there is green manganate, add a few drops of ethanol to reduce), heat to boil for a few minutes and mash the frit and filter. The filtrate was taken up in a 400 ml beaker, and the precipitate was washed 7-8 times with hot 2% sodium carbonate melt. The filtrate was acidified and the acidity was adjusted, and barium sulfate was precipitated according to the previous procedure. Filter, burn, and weigh. 0.09mm color pvc roll,pvc sheet roll color,pvc white SUZHOU OCAN POLYMER MATERIAL CO.,LTD , https://www.ocanplasticpolymer.com