The invention provides a hot
metal pretreatment desulfurization technology with
calcite and
passivation particle
magnesium injected in a composite mode and belongs to the field of the steel industry. The
calcite is used for replacing
lime in existing hot
metal pretreatment desulfurizing agents, and the composite-injection
calcite and the
passivation particle
magnesium of desulfurizing agents are prepared anew. The proportion that the
granularity of the calcite is lower than 1mm by
cracking the calcite is larger than 100%, during injection, the material ratio of the calcite to the particle
magnesium is controlled between 6:1 and 9:1, the feeding speed of the particle magnesium is controlled to be 6-8kg / min, the feeding amount of the calcite is controlled to be 41.5-54kg / min, overall feeding speed is controlled to be 60kg / min, a straight-drum spraying gun is used, the distance between the head of the spraying gun and the bottom of a
ladle tank is set to be 300mm, and the
powder-gas ratio during a desulfurization injection process can reach 120kg / m<3>. According to the hot
metal pretreatment desulfurization technology, the using rate of
passivation magnesium is improved, desulfurization efficiency is improved, loss of the particle magnesium is lowered, and desulfurization cost is lowered. The calcite is natural minerals, after the qualified
granularity of the calcite is achieved by
cracking the calcite, the calcite can be directly used, extra
machining cost is of no need, and the price is one-fourth of the
lime.