Acid hydrolysis process of acid soluble titanium slag

With the acid-soluble titanium slag as the raw material ratio of titanium to the iron ore as a starting material has the following advantages.

a. Due to the high content of TiO ₂ in the titanium slag, the total yield of the product can be increased by 2% to 3%, and the corresponding storage, transportation, drying, and ore crushing costs can be saved;

b. Due to the high titanium content and low iron content in the titanium slag, the acid consumption is also significantly reduced, and the acid (H ₂ SO ₄ ) consumption per ton of titanium dioxide can be saved by 25% to 30%, but the sulfuric acid concentration is higher during the reaction;

c. There is no by-product ferrous sulfate, and it is not necessary to use iron filings to reduce, so as to avoid the influence of impurities brought in by scrap iron on the quality of the finished product;

d. Low energy consumption, saving 0.6t steam/titanium dioxide, saving 8%, saving fuel or gas 4%, saving 5%, saving manufacturing cost by 12%;

e. The process is short, and the three process operations of reduction, ferrous crystallisation, separation and concentration can be omitted;

f. The titanium liquid formed by the reaction has good stability and the amount of seed crystal added is also small;

g. Waste acid, waste water, waste residue discharge is much less per ton of titanium dioxide than ordinary ilmenite acid hydrolysis process, and the cost of three waste treatment is relatively small.

Because the acid-soluble titanium slag smelting at high temperature for a reducing agent (anthracite), and therefore the product does not contain Fe ₂ O ₃ and FeO and the metal-containing divalent iron, so only acid hydrolysis process without the addition of iron Chips to reduce high-priced iron, sometimes because a small amount of oxidizing agent is added to the trivalent titanium content. In addition, since the acid-soluble titanium slag has a high content of titanium dioxide, a low total iron content, and no Fe ₂ O ₃ , the exothermic heat during the reaction is low, the steam heating time is required to be long, and the sulfuric acid concentration during the reaction is required to be high (91%). Mature and leaching takes longer.

Figure 1 shows the acid hydrolysis reaction process using Canadian QIT Solil acid-soluble titanium slag. It can be seen from the figure that 80 minutes before the reaction is the process of adding acid, casting and stirring, and the compressed air flow rate is 600 m ³ at this time. /h, then add dilution water for 7min, the exothermic temperature is raised from 50 °C to 80 °C due to the dilution of sulfuric acid, then the temperature is raised to 120 °C by steam heating for 25 min, the main reaction starts immediately, and the temperature increases from 120 °C to 200 in 5 min. °C or so. During the main reaction period, it is maintained for about 15 minutes. From 20 minutes before the dilution water is added to the main reaction period, the flow rate of compressed air is increased to 800~1000m ³ /h, and the air blowing is kept for 0.5h. At this time, the compressed air volume can be reduced to 500m ³ /h. The air blowing is stopped for about 4 hours, during which the temperature is slowly lowered from 190 ° C to 85 ° C, and then leached for about 7 hours without exceeding 90 ° C, and the compressed air flow for stirring during the leaching is about 800 m ³ /h. The relative density of the titanium liquid was 1.550 g/cm ³ . [next]

Figure 2 is a schematic diagram of a process flow and material balance using Canadian QIT Solil acid soluble titanium slag.