Background and overview[1]
As a new type of inorganic chemical product, titanium phosphate has the advantages of non-toxic, strong covering power, strong adhesion, strong UV reflection ability, heat resistance and flame retardancy. It can be used as a pigment and filler in color paste manufacturers. In industries such as coatings, plastics, rubber and papermaking, titanium phosphate can complex metal ions with a large radius and can also be used as a water treatment agent.
Preparation[1-3]
Report 1,
Weigh a certain amount of titanium dioxide waste acid and add it to the five-necked flask, then heat it to 80°C with a heating mantle, and pump it in with a peristaltic pump to a mass concentration of 5% (NH4) 2HPO4 solution, complete within 5 minutes. The mass ratio of titanium dioxide mass to diammonium hydrogen phosphate in the titanium dioxide waste acid is 1:2.5. Mix thoroughly and stir, keep warm for 5 minutes, slightly After cooling, filter and wash once with 200ml desalted water, then analyze the titanium content in the filtrate, and put the filter residue into a constant temperature oven at 105oC for 2 hours;
Finally, grind the dried filter residue into fine pieces and put it into a crucible for calcination. The calcination temperature is 800°C and the calcination time is 2 hours to obtain the titanium phosphate product.
The performance of this group of filtrate and filter residue reaches the following indicators:
After analysis, the titanium content in the filtrate was 0.5%, and the removal rate of titanium was about 80%. X-ray analysis of the calcined sample showed that a large amount was titanium phosphate with a small amount of impurities.
Report 2,
A method of producing titanium phosphate flame retardant by using titanium dioxide waste acid, which is characterized by adding phosphoric acid with a weight percentage concentration of 85% to waste sulfuric acid containing TiO2 to generate hydrated titanium phosphate. The mass ratio of phosphoric acid to TiO2 is 3:1; the generated hydrated titanium phosphate is washed with desalted water, precipitated and iron removed, dried at 105°C, and then roasted at 450°C for 2 hours. , after cooling, crush it to obtain white powder, which is the flame retardant titanium phosphate;
The reaction formula to generate hydrated titanium phosphate is as follows:
TiOSO4+2mH3PO4+nH2O→TiO2·mP2O5·nH2O↓+H2SO4.
Report 3,
Use a plate and frame filter press to press and separate the acid residue mixture containing wet phosphoric acid to obtain a solid sedimentation residue filter cake (wet process phosphoric acid sedimentation residue), and then press the solid (filter cake) to liquid mass volume ratio of 1:1 Add water and carry out cracking treatment. The cracked filter cake material is added to the reactor with pre-added water at a stirring speed of rpm and room temperature, and the total solid (filter cake) to liquid mass volume ratio is maintained at 1:5. , then add concentrated sulfuric acid to adjust the Ca:H2SO4 molar ratio in the material to 1:1.6. After reacting at room temperature for 6 hours, vacuum filtration separates to obtain the leachate; Add the supersaturated solution of titanium sulfate to the leachate at a stirring speed of 300 rpm and room temperature, so that Ti4+ and PO43- is 3:4. After 4 hours of reaction, titanium phosphate precipitate is generated. The mixed material is separated by vacuum filtration to separate the solid material. After filtration, the filter residue is washed 5 times with water twice the volume of the solid material, and then heated at 120°C. After drying for 6 hours, a titanium phosphate product was obtained; the sample was analyzed to be amorphous titanium phosphate, containing 7.31% Ti2 and 23.48% P2.
