The invention discloses a method for concentrating waste
sulfuric acid by utilizing
waste heat of a
titanium dioxide calcinator, comprising the following steps: at normal
temperature and pressure, proper amount of water absorbent is added to
titanium dioxide waste acid,
liquid water is dissolved out in the form of
solid crystal water through the water absorbent, filtrate after
solid-liquid separation is cooled, iron
vitriol in the solution is crystallized and dissolved out, and the acid liquid is further concentrated; the two steps are repeatedly carried out until the concentration of
sulfuric acid in the final filtrate reaches more than 60%, and then the final filtrate is utilized in the
acid hydrolysis procedure; and the water absorbent is dehydrated and dried to be regenerated by taking dustproof
tail gas of the calcinator, and the steam generated in the
drying and regeneration is cooled and flows back to technological process as washing water in
titanic acid rinsing or is drained. The method provided by the invention solves the problems of more equipment, long flow and easy blockage in the existing technology, and the equipment investment and
operating cost are reduced; and the water absorbent is recycled after being regenerated, so that the energy is saved, the consumption is reduced, and the efficiency is obvious; no
wastewater, waste gases and residues are generated in the whole technology, the
operability is strong, the productivity of equipment is high, the flow is simple, the investment is less, the cost is low, energy is saved, emission is reduced, and the benefit is obvious.