What Is The Process Flow Of Titanium Products?

The specific process is as follows:
(1) Crush the titanium ore into ore powder with Raymond mill, air sweep mill, ball mill, etc. to meet the fineness required by the process.
(2) Decompose the powdered ore with concentrated sulfuric acid to make soluble TiOSO4 solution. In the process of acid decomposition, most of the impurities in the ore powder are also decomposed, generating the corresponding soluble sulphate, and enter into the solution together with the soluble salt of titanium when leaching, forming black titanium solution. In order to effectively remove iron, with metal iron in the titanium solution of high-valent iron reduced to ferrous iron, at the same time, in order to avoid another oxidation of ferrous iron, but also must be used in excess of metal iron to quantitative tetravalent titanium reduced to trivalent titanium.
(3) The black titanium solution (TiOSO4 solution) contains soluble impurities and insoluble impurities. Most of the insoluble impurities, such as undecomposed titanium ore, sand, etc. by gravity can be removed by natural sedimentation. Insoluble impurities in the other part of the colloidal compounds of silicon and aluminium, as well as some early hydrolysis of titanium, although the number is not large, but has a high power stability, need to add another settling agent, to strengthen the settlement and clarification process. Iron, vanadium, chromium, manganese and other metal sulphates are soluble impurities, removed in the process of crystallisation or hydrolysis, water washing.
(4) After purification and settlement of the sludge also contains a large number of soluble and insoluble titanium, in order to ensure the yield, to use the plate and frame filter press to recover most of the titanium can be dissolved, insoluble titanium and other insoluble impurities as a waste slag discharge.
(5) black titanium liquid contains a large number of Fe2+, because iron has a greater impact on the colour of titanium dioxide, so it must be removed. FeSO4 solubility is greatly affected by the temperature of the solution. Therefore, in a certain composition of titanium liquid, the solubility of FeSO4 with the decrease in temperature and reduce. In this process, FeSO4- 7H2O crystals are usually generated by vacuum crystallisation and freeze crystallisation, and then FeSO4- 7H2O is solid-liquid separated by disc filter or centrifuge to remove a large amount of Fe2+ in the black titanium liquid.
(6) There are still some suspended impurities in the titanium liquid after settling, which will affect the colour of the finished product. Therefore, fine filtration is necessary. The use of plate and frame filter press, and charcoal powder (or diatomaceous earth, perlite) as a filter aid for the filter press, the use of charcoal powder's strong adsorption to further remove insoluble impurities in the titanium liquid, to achieve the purpose of purification.
(7) Concentration is to increase the concentration of titanium liquid to the index required for hydrolysis. The boiling point of titanium solution is high, which is already higher than the critical temperature of titanium solution hydrolysis, therefore, the concentration of titanium solution must be carried out at a lower temperature. The use of solution in a vacuum state boiling point reduction principle, the titanium liquid boiling at low temperatures, the titanium liquid water evaporation, so that the concentration of titanium liquid after fine filtration can be increased to meet the requirements of hydrolysis.
(8) The hydrolysis of titanium liquid is the process of titanium dioxide from liquid phase (titanium liquid) to solid phase. Titanium liquid has the nature of a common ionic solution, in the pH>0.5 when the hydrolysis occurs. More importantly, titanium liquids have the properties of colloidal solutions. In the case of high free acid, the hydrolysis reaction will also occur if it is maintained in the boiling state, which is the basis for us to produce hydrated titanium dioxide with certain application properties and product properties. By controlling the rate of heating, the titanium liquid will be hydrolysed according to the required hydrolysis rate to produce the hydrated titanium dioxide particles we need.
(9) The hydrated titanium dioxide after hydrolysis contains sulfuric acid and ions such as iron, aluminium, manganese, copper, nickel, vanadium, lead, etc. These ions will generate the corresponding oxides after calcination, displaying a variety of colours, thus contaminating the product to varying degrees, and so must be washed to remove them. Hydrated titanium dioxide is insoluble in water, while sulfuric acid and iron, aluminium, manganese, copper, nickel, vanadium, lead and other ions are soluble in water, which is a prerequisite for water washing, the use of washing water and hydrated titanium dioxide in the concentration of impurity ions in the difference between the impurity water to remove water. The washing process is mainly to prevent soluble impurity ions into insoluble impurity precipitation, therefore, the content of iron and other solid impurities in the washing water has certain requirements, so as not to let the impurities in the hydrated titanium dioxide on the accumulation and contamination of the product.
(10) calcined crystal seed preparation from the washing of qualified titanium dioxide slurry led to part of the titanium dioxide slurry, after measurement to join the alkali tank and after measurement to join the reaction of the lye, the reaction of the alkali soluble material after cooling with demineralised water washing, washing of qualified alkali soluble material after unloading slurry sent to the crystal seed preparation tank, dissolved in hydrochloric acid calcined crystal seed, and then pumped to the calcined crystal seed metering tank in the bleaching process to add. Then it is pumped to the calcined crystal seed metering tank and added in the bleaching process.
(11) after a wash of titanium dioxide, in a certain concentration, add a fixed amount of concentrated sulfuric acid, so that part of the titanium dioxide and concentrated sulfuric acid reaction to generate titanium sulfate, and then add aluminium powder, the titanium sulfate in the titanium sulfate of titanium tetravalent reduced to titanium trivalent, to maintain a certain concentration of trivalent titanium in the material after the bleaching process, to be oxidized in the process of water washing of iron ions and other metal elements into low-priced iron ions, and then a second water washing Then the second washing is carried out to make the washing of titanium dioxide more thorough.
(12) After two washing of titanium dioxide in the calcination before the need to add different types of additives to ensure that in the calcination process, the temperature is appropriate, the internal changes are smooth, so that the finished product of titanium dioxide to maintain a stable grain size and shape, in order to ensure that the titanium dioxide products have a good colour, gloss, good colouring power, covering power, low oil absorption and suitable, good dispersion in the use of media.
(13) Calcination is to remove the free water, combined water, sulfur trioxide, etc. from hydrated titanium dioxide through the process of dehydration, desulfurisation, crystal transformation, etc., and then carry out the finishing and transformation of the crystal type in the high temperature zone to get the granular material of anatase or rutile titanium dioxide primary products.
(14) Grinding is to crush the granular material of titanium dioxide primary products, usually using Raymond mill, roller mill and so on. Materials in the Raymond mill, through the high-speed rotation of the mill roll and the impact of the grinding ring, quickly be crushed, and then through the classification of the classifier, the coarse material returns to the crushing room, the fine material into the bag filter, through the star under the material into the spiral feeder, sent to the crushed material bin. Rutile products or uncoated rutile products are finished products after packaging, and coated rutile products have to be further processed.
(15) sand mill (wet grinding) will be evenly dispersed titanium dioxide slurry pumped into the sand mill grinding, grinding and dispersion of qualified slurry pumped to the surface treatment tank.

(16) in the surface treatment tank, according to different product grades, measurement to add a variety of different inorganic surface treatment agent, control the way of adding, slurry temperature and pH value, so that the inorganic surface treatment agent in a different form of coating on the surface of titanium dioxide particles, in order to achieve the purpose of improving the application of titanium dioxide.
(17) Wash the surface-treated material with demineralised water to remove the salt. After washing the qualified titanium dioxide filter cake is sent to the dryer, the filtrate is pumped to the calcining process as washing water and re-pulping process for pulping after recovering the filtered titanium dioxide.
(18) The washed and qualified slurry is sent to the dryer for drying after press filtration. Dry powder material with the hot airflow into the high temperature bag filter to recover TiO2, dry powder through the airflow conveying device sent to the steam powder before the silo, exhaust through the induced draft fan discharge.
(19) After drying, the material is sent to the steam mill through the metering screw machine, with superheated steam as the crushing medium, the material is crushed under the high-speed steam flow and intense collision, the crushed material enters the high-temperature bag filter with the spent steam, and most of the titanium dioxide products are separated into the finished product silo, and the finished product is sent to the finished product warehouse through the weighing and packing by the packaging machine. The spent vapour is cooled by the condenser with circulating cooling water, part of the vapour is condensed down and the condensate is recovered by the vapour-liquid separator, and the exhaust gas is exhausted by the high-temperature fan. The condensate enters the condensate tank, and the condensate pump sends it to the second or third washing process for heating the washing water.