The invention discloses a process for preparing
chrome green by using K3
raffinate and a
sulfur method. The process comprises two sections. The first section comprises the following steps: with neutral leaching yellow water or
sodium chromate alkaline solution as a
raw material in a workshop, adding liquid alkali in proportion to adjust
alkalinity, carrying out heating to a certain temperature onan electric furnace, adding levigated
sulfur paste, and carrying out curing for a period of time after completion of a pre-reaction; carrying out
filtration and washing successively, wherein the content of Na2S2O3 in the last washing is ensured; and
drying a
filter cake, then calcining the dried
filter cake in a
muffle furnace to obtain crude
chrome green, and subjecting the crude
chrome green towashing and
drying to obtain metallurgical-grade chrome green. The second section comprises the following steps: after complete reaction of
chromium hydroxide, mixing a filtrate with primary washing water; adding the
sodium chromate alkaline solution, carrying out heating and stirring, and then adding K3
raffinate at a certain temperature to adjust a pH value; carrying out curing for a certain period of time, carrying out filtering and measuring the content of Na2S2O3 in the obtained filtrate; then carrying out filtering, and leaching and
roasting the obtained
filter cake; and subjecting a semi-finished chrome green product to washing,
drying and levigation so as to obtain the
pigment-grade chrome green. The process provided by the invention solves problems in treatment of K3
raffinate, makes full use of the reducibility of Na2S2O3, and basically has no influence on the environment.