agent is not sufficient and must be compensated for the raw materials are crushed and then briquetted to promote a reaction therebetween during the reaction between the raw materials the metal i e al or both al and si melts and permeates into the pores of the oxide or cao particles such permeation is promoted due to the presence of metallic si as compared with the case of the previous described method according to the present invention in which only the metallic reducing agent i e al is mixed with the oxides thus the metallic si enables improved reducing reaction efficiency of the cao like the previously described method the grain size of the raw materials is not very significant but is preferably approximately 1 mm or less the briquettes may also be compression formed by means of a briquetting machine or the like or may be formed by granulating the mixture of raw materials with starch cmc or another primary binder the briquettes can also be a granular aggregate or any other shape and the size of the briquettes is also not specifically limited but is preferably from 5 to 50 mm the amounts of oxides and metallic reducing agent are determined in accordance with the composition of the refining agent to be produced and reducing reaction formula 1 the resultant metallic ca is captured by the si which coexists with it in the raw materials and either ca si alloy or ca si al alloy is formed in the latter case the ca si al alloy is formed when excess al is incorporated into the ca alloy the resultant al 2 o 3 combines with an excess cao to form mcao.