Sodium tungstate white powder  

Weigh 0.5 g of the sample into a 250 ml beaker, dissolve it with a little water, add 100 ml of 60-80 ℃ hot water, 2 drops of 0.1% methyl orange indicator (add it if the indicator is brown), and add hydrochloric acid (1+1) Neutralize to red, add 10ml of 10% cinchonine under constant stirring, continue to stir to make the precipitation coagulate, the upper liquid is clear and let it stand, after the precipitation settles, filter with fast quantitative filter paper, and the filtrate is carried in a 250ml volumetric flask, The precipitate was washed with 0.2% cinchonine lotion for more than five times. After washing, the precipitate was transferred to a porcelain crucible together with filter paper, dried and carbonized on an electric furnace, and then carbonized and burned in a muffle furnace at 750 to 800 ° C for 30 to 45 minutes, and cooled. Weigh. Filtrate according to tannin, methyl violet colorimetry. Company Profile Jiangsu Leiji Metal Materials Co., Ltd. is a manufact…