YB/T 4007-1991 Chemical analysis method of high quality magnesia Determination of alumina content by chrome azure S photometric method (English Version)
1991YB/T 4007-1991 Chemical analysis method of high quality magnesia Determination of alumina content by chrome azure S photometric method
YB/T 4007-1991 Chemical analysis method of high quality magnesia Determination of alumina content by chrome azure S photometric method was changed to GB/T 5069-2007 Chemical analysis of magnesia-alumina refractories.