The invention relates to a
calcium-
carbonate-containing
calcium oxide-based
manganese alloy dephosphorization
slag. The
calcium-
carbonate-containing
calcium oxide-based
manganese alloy dephosphorization
slag comprises the following components in parts, by weight: 15-30 parts of
calcium oxide,15-30 parts of
manganese oxide, 35-45 parts of
sodium carbonate, and 15-30 parts of
fluorite, wherein the particle size D50 of the
calcium oxide, the
manganese oxide, the
sodium carbonate and the
fluorite is less than or equal to 10 mm; the preparation method of the dephosphorization
slag comprises the following steps that pre-melting treatment on a mixed material is carried out, heating is carried out to 1000-1200 DEG C, and the temperature is kept for 30-50 minutes, the
molten slag is poured out, andnaturally cooling is carried out; crushing and screening are carried out on the slag which is cooled to the
room temperature, and finally the dephosphorization slag with the particle size smaller than or equal to 5 mm is obtained; and the application method of the dephosphorization slag is provided, when the manganese
alloy is smelted, the preheated dephosphorization slag is added in multiple times. The preparation and the application method have the beneficial effects that effects of dephosphorization in the slag is stabilized through the dephosphorization slag, the gas generated by
decomposition of the
sodium carbonate can play a role in stirring and removing
phosphorus slag at the same time, and a kinetic reaction condition is increased, the dephosphorization
melting point of the
manganese oxide and the
fluorite is reduced, the liquidity of the dephosphorization slag is improved, and the better dynamic condition is provided for the dephosphorization.