Method for preparing titanium slag with high acidolysis rate and high melting content

The invention provides a method for preparing high-acidolysis-rate and high-melt-content titanium slag. The method comprises the following steps that (1) liquid nitrogen is used for rapidly cooling the high-melt-content titanium slag; and (2) grinding the cooled high-melting-content titanium slag in the step (1) to obtain the high-acidolysis-rate high-melting-content titanium slag. The invention also relates to a method for producing titanium dioxide by a sulfuric acid method by taking the high-acidolysis-rate melt-separation high titanium slag prepared by the method as a raw material. The liquid nitrogen is used for rapidly cooling the melt-separated high-titanium slag, the acidolysis rate of the melt-separated high-titanium slag can be effectively increased, and the increased acidolysis rate is equivalent to the acidolysis rate of titanium concentrate. Therefore, the high-acidolysis-rate melt-separation high-titanium slag can be used for replacing titanium concentrate to serve as a production raw material o