Coal dust for use in the. When tested in accordance with IS: 1350 1969? and IS: 1350 (part III) – 1969: must comply with the requirements listed in table 1. General requirements for the supply of coal should be also provided to CT: 1387-1967 *.
The material should consist of high quality finely crushed bituminous coal and will be free from any foreign matter, such as the iron pyrite and slate, which may prove detrimental to the castings. 3 GRADES are of three categories, namely, grades 1, 2 and 3, depending on the chemical composition. In addition, they must be classified into three categories, namely, F, M, and C qualifications against the fineness of the grain. For example, coal dust covered Grade 2 function of chemical composition and grade M versus the fineness of the grain must be designated as year 2 M.