ASTM D715-86 pdf free.Standard Test Methods for Analysis of Barium Sulfate Pigment.
These test methods cover the analysis of barium sulfatepigment.The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.This standard does not purport to address the safetyconcerns associated with its use. lt is the responsibility of theuser of this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.
Heavy Liquid (sp gr 2.9)—Dissolve 4 parts by weightof potassium iodide (Kl) in 6 parts of warm water, and add,while stirring constantly, 5 parts of mercuric iodide (Hgl z).Evaporate over a hot plate or gas flame, protected by screencloth,until a light crystalline scum forms. Cool，and filterthrough heavy paper. The solution will be a clear, deep, ambercolor of about 3.2 specific gravity.All filter washings showinga yellow color should be saved and evaporated. Determine the3.2 specific gravity accurately by means of a specific gravitybottle, and correct the solution to a specific gravity of 2.9 atroom temperature by adding water. Prepare approximately 200mL of the solution.
Carefully weigh 10 g of the finely ground dry bariumsulfate pigment and transfer to a carefully dried 125-mL clearglass separatory funnel of the long narrow type.Add 100 mLof the heavy liquid (sp gr 2.9),stopper，and shake well toliberate any air bubbles that might adhere to the particles, and also to break up all agglomerates. Set the separatory funnelaside and allow to stand in a perpendicular position for 2 h, orfor a sufficient time for the particles to rise or sink.Draw off the heavy particles through the stopcock intoa beaker along with 75 mL of the liquid. Add 50 mL of freshheavy liquid (sp gr 2.9) to the float particles and liquidremaining in the separatory funnel and repeat the procedure asdescribed in 17.1.
Draw off the heavy particles along with 75 mL of theliquid and add to those drawn off in accordance with 17.1,leaving the float particles in the funnel. Wash the particlesremaining in the funnel with fresh heavy liquid (sp gr 2.9),filter through a No. 2/0 paper (see Specification E 832),andwash free of solution with warm water.ASTM D715 pdf download.