Methods for chemical analysis of tantalite,columbite concentrate—Part 2:Determination of titanium dioxide content—Diantipyrinyl methane spectrophotometric method
Methods for chemical analysis of tantalite,columbite concentrate—Part 3:Determination of silicon dioxide content—Silicomolybdenum blue spectrophotometry and gravimetry
Methods for chemical analysis of tantalite,columbite concentrate—Part 4:Determination of tungsten trioxide content—Thiocyanate spectrophotometric method