Flocculating sedimentation method for improving sedimentation effect of sulfate process titanium dioxide titaniferous solution

Abstract

The invention provides application of high-molecular-weight cationic polyacrylamide in a titaniferous solution sedimentation process in a sulfuric acid method titanium dioxide process. The number-average molecular weight of the high-molecular-weight cationic polyacrylamide is greater than or equal to 10,000,000. The invention further provides a flocculating settling method for improving the titanium liquid settling effect in the sulfuric acid method titanium dioxide process. According to the method, cationic polyacrylamide is applied to the titanium dioxide titanium liquid sedimentation procedure through the sulfuric acid method, the preparation time of a flocculating agent can be shortened by more than half compared with that in the prior art, in the flocculation process, the concentration of dissociated ions is higher due to the high cationic degree, the adsorption effect on charges is higher, and the flocculation efficiency is improved. Particularly, the adsorbent has a relatively strong adsorption effect on a silicic acid component contained in the titanium liquid, so that the flocculating settling process is performed more quickly and thoroughly. By adopting the emulsion type high-ionic-degree high-molecular-weight cationic polyacrylamide, compared with the traditional flocculant product, the flocculating settling effect of the sulfate process titanium dioxide titanium liquid can be effectively improved, and the production cost is comprehensively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of precipitation of titanium dioxide liquid in a sulfuric acid process, and relates to the application of high molecular weight cationic polyacrylamide in the precipitation process of titanium dioxide liquid in a sulfuric acid process and a flocculation precipitation method for improving the precipitation effect of titanium dioxide liquid in a sulfuric acid process, and in particular to a flocculation precipitation method for improving the precipitation effect of titanium dioxide liquid in a sulfuric acid process. Background Art

[0002] The flocculants used in the sedimentation process of titanium dioxide liquid produced by the sulfuric acid process have gone through the development process of inorganic flocculants, mixed flocculants, and organic flocculants in the course of many years of development. Nowadays, most titanium dioxide manufacturers produced by the sulfuric acid process use polyacrylamide as the main flocculant, but the specific product selection is mostly low-molecular-weight polyacrylamide particles. The advantages of this product mainly lie in its low cost, easy procurement, and good sedimentation effect, but it also has the disadvantages of easy moisture absorption, poor sun resistance, slow dissolution, and short storage time after configuration. More importantly, when a large amount is added during the sedimentation of titanium dioxide liquid produced by the sulfuric acid process, it is easy to cause the viscosity of the titanium liquid to increase, reducing the sedimentation effect of the titanium liquid. When industrial technical problems such as the difficulty of flocculation and sedimentation of the titanium liquid occur, it is not easy to deal with.

[0003] Therefore, how to find a more suitable method for sedimentation of titanium dioxide liquid by sulfuric acid method, further refine and upgrade the selection of flocculants for titanium liquid sedimentation, and solve the above-mentioned technical problems existing in the existing process has become one of the urgent problems to be solved by many front-line researchers in the industry. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide an application of high molecular weight cationic polyacrylamide in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process and a flocculation sedimentation method for improving the titanium liquid sedimentation effect in the sulfuric acid titanium dioxide process, in particular, a flocculation sedimentation method for improving the sedimentation effect of the titanium liquid in the sulfuric acid titanium dioxide process. The present invention uses an emulsion type high ionicity high molecular weight cationic polyacrylamide for the titanium liquid sedimentation process in the acid titanium dioxide process. Compared with traditional flocculant products, it can effectively improve the flocculation and sedimentation effect of the titanium liquid in the sulfuric acid titanium dioxide process and comprehensively reduce the production cost; and the process is simple, controllable, and operable, which is more suitable for industrial promotion and application.

[0005] The present invention provides the application of high molecular weight cationic polyacrylamide in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process;

[0006] The number average molecular weight of the high molecular weight cationic polyacrylamide is greater than or equal to 10 million.

[0007] Preferably, the high molecular weight cationic polyacrylamide is specifically a high ionicity high molecular weight cationic polyacrylamide;

[0008] The cationic ionity of the high ionicity and high molecular weight cationic polyacrylamide is greater than or equal to 50%;

[0009] The polyacrylamide includes polyacrylamide emulsion.

[0010] Preferably, the application is specifically an application as a flocculant;

[0011] The mass concentration of the flocculant is 1‰ to 1.5‰;

[0012] The added volume of the flocculant is 3% to 8% of the volume of the titanium liquid.

[0013] Preferably, the molecular weight of the high molecular weight cationic polyacrylamide is 10 million to 15 million;

[0014] The cationic ion degree of the high molecular weight cationic polyacrylamide is 50% to 60%.

[0015] Preferably, the titanium liquid, in terms of element concentration, includes: TiO2: 110-130 g / L, Ti 3+ : 1~1.5g / L, Fe: 40~45g / L, Mg: 4~6g / L, Si: 0~1g / L, Al: 0~2g / L, Ca: 0~2g / L.

[0016] The present invention provides a flocculation sedimentation method for improving the sedimentation effect of titanium liquid in a sulfuric acid titanium dioxide process, comprising the following steps:

[0017] 1) mixing the cationic polyacrylamide emulsion and water to obtain a flocculant;

[0018] 2) Add the flocculant obtained in the above step to the titanium liquid produced by the sulfuric acid titanium dioxide process, and let it stand for sedimentation to obtain the settled titanium liquid.

[0019] Preferably, the molecular weight of the high molecular weight cationic polyacrylamide is greater than or equal to 10 million;

[0020] The cationic ionity of the high ionicity and high molecular weight cationic polyacrylamide is greater than or equal to 50%;

[0021] The mass concentration of the flocculant is 1‰ to 1.5‰.

[0022] Preferably, the mixing time is 10 to 30 minutes;

[0023] The total titanium concentration of the titanium liquid is 100-130 g / L;

[0024] The viscosity of the titanium liquid is 10-15 mPa·s.

[0025] Preferably, the specific gravity of the titanium liquid is 1.3 to 1.5;

[0026] The F value of the titanium liquid is 1.8 to 1.9;

[0027] The stability of the titanium liquid is 400-500 ml.

[0028] Preferably, the solid content of the titanium liquid is 14 to 16 g / L;

[0029] The static sedimentation time is 1 to 6 hours;

[0030] The step of separation is also included after the static sedimentation;

[0031] The solid content of the titanium liquid after sedimentation is 0-0.2 g / L.

[0032] The present invention provides the application of high molecular weight cationic polyacrylamide in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process; the number average molecular weight of the high molecular weight cationic polyacrylamide is greater than or equal to 10 million. Compared with the prior art, polyacrylamide is classified according to the difference in ionic properties, and can be divided into four categories: anionic polyacrylamide, cationic polyacrylamide, nonionic polyacrylamide and amphoteric polyacrylamide. It is generally believed that cationic polyacrylamide is often used for purification of organic sludge or strong alkaline sludge. Among them, the cationic degree of the finished cationic polyacrylamide is an important criterion for judging its decontamination ability. Cationic polyacrylamide is a high molecular polymer formed by copolymerization of acrylamide and cationic monomers. It has many cationic groups on the molecular chain. It reacts with negatively charged colloidal particles in sewage and sludge through electrical neutralization, adsorption bridging, net capture and sweeping, coagulation and flocculation to form precipitation, and remove pollutants from the water body. The present invention believes that the concentrated titanium liquid contains a large amount of unreacted acid hydrolysis residues and other impurities, which need to be removed by static sedimentation after adding a flocculant. Cationic polyacrylamide is used in the sedimentation process of sulfuric acid titanium dioxide liquid, and its effect is the best.

[0033] Based on this, the present invention creatively uses a specific high molecular weight cationic polyacrylamide as a flocculant in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process and provides a corresponding flocculation and sedimentation method for improving the titanium liquid sedimentation effect in the sulfuric acid titanium dioxide process. The present invention uses cationic polyacrylamide to apply to the sulfuric acid titanium dioxide titanium liquid sedimentation process, and the flocculant preparation time can be shortened by more than half compared with the previous one. During the flocculation process, the high cationic degree makes the dissociated ion concentration higher, and the adsorption effect on the charge is stronger, especially the silicate component contained in the titanium liquid has a strong adsorption effect, so that the flocculation and sedimentation process is carried out more quickly and thoroughly. The present invention uses an emulsion type high ionic degree and high molecular weight cationic polyacrylamide, which can effectively improve the flocculation and sedimentation effect of the sulfuric acid titanium dioxide titanium liquid compared with traditional flocculant products, and comprehensively reduce the production cost.

[0034] The present invention is applicable to the flocculation and sedimentation process of titanium dioxide liquid produced by the sulfuric acid process. A high-ionicity and high-molecular-weight cationic polyacrylamide flocculant product is used, which is added to the titanium liquid in a specific ratio, stirred evenly, and then allowed to settle. After sufficient sedimentation time, the titanium liquid is stratified, and the upper clear liquid is the desired titanium liquid product. Compared with traditional flocculants, for the same type of titanium liquid using the same amount of conventional flocculants, the present invention can increase the pumping speed of the titanium liquid by about 30%, and effectively reduce the process problem of unsatisfactory sedimentation effect. Moreover, this method greatly improves the quality of the titanium liquid, and will not have an adverse effect on the product quality. The on-site equipment modification is simple and easy to implement. It can be fully promoted in titanium dioxide enterprises produced by the sulfuric acid process that have demand, which is conducive to reducing costs and increasing efficiency. DETAILED DESCRIPTION

[0035] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention rather than limiting the patent claims of the present invention.

[0036] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0037] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably uses industrial pure materials or materials of conventional purity of flocculants used in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process.

[0038] The brands and abbreviations of all raw materials of the present invention are conventional brands and abbreviations in the art. Each brand and abbreviation is clear and definite in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods according to the brands, abbreviations and corresponding uses.

[0039] The present invention provides the application of high molecular weight cationic polyacrylamide in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process;

[0040] The number average molecular weight of the high molecular weight cationic polyacrylamide is greater than or equal to 10 million. Specifically, the high molecular weight cationic polyacrylamide emulsion has a cationic degree of more than 50% and a molecular weight of more than 12 million, and has the advantages of low apparent viscosity, fast dissolution rate, good flocculation effect, and long storage time. Its high effective ingredient content can reduce the amount added during use, thereby comprehensively improving economic benefits.

[0041] In the present invention, the high molecular weight cationic polyacrylamide is preferably a high ionicity high molecular weight cationic polyacrylamide.

[0042] In the present invention, the cationic ionity of the high-ionity and high-molecular-weight cationic polyacrylamide is preferably greater than or equal to 50%, more preferably greater than or equal to 52%, and more preferably greater than or equal to 53%.

[0043] In the present invention, the polyacrylamide preferably comprises polyacrylamide emulsion.

[0044] In the present invention, the application is preferably an application as a flocculant.

[0045] In the present invention, the mass concentration of the flocculant is preferably 1‰ to 1.5‰, more preferably 1.1‰ to 1.4‰, and more preferably 1.2‰ to 1.3‰.

[0046] In the present invention, the added volume of the flocculant is preferably 3% to 8% of the volume of the titanium liquid, more preferably 4% to 7%, and more preferably 5% to 6%.

[0047] In the present invention, the molecular weight of the high molecular weight cationic polyacrylamide is preferably 10 million to 15 million, more preferably 11 million to 14 million, and even more preferably 12 million to 13 million.

[0048] In the present invention, the cationic ion degree of the high molecular weight cationic polyacrylamide is preferably 50% to 60%, more preferably 52% to 58%, and more preferably 54% to 56%.

[0049] In the present invention, the titanium liquid preferably includes, in terms of element concentration, TiO2: 110-130 g / L, Ti 3+ : 1-1.5 g / L, Fe: 40-45 g / L, Mg: 4-6 g / L, Si: 0-1 g / L, Al: 0-2 g / L, Ca: 0-2 g / L, more preferably TiO2: 114-126 g / L, Ti 3+ : 1.1-1.4 g / L, Fe: 41-44 g / L, Mg: 4.4-5.6 g / L, Si: 0.2-0.8 g / L, Al: 0.4-1.6 g / L, Ca: 0.4-1.6 g / L, more preferably TiO2: 118-122 g / L, Ti 3+ : 1.2~1.3g / L, Fe: 42~43g / L, Mg: 4.8~5.2g / L, Si: 0.4~0.6g / L, Al: 0.8~1.2g / L, Ca: 0.8~1.2g / L.

[0050] The present invention provides a flocculation sedimentation method for improving the sedimentation effect of titanium liquid in a sulfuric acid titanium dioxide process, comprising the following steps:

[0051] 1) mixing the cationic polyacrylamide emulsion and water to obtain a flocculant;

[0052] 2) Add the flocculant obtained in the above step to the titanium liquid produced by the sulfuric acid titanium dioxide process, and let it stand for sedimentation to obtain the settled titanium liquid.

[0053] The present invention firstly mixes cationic polyacrylamide emulsion and water to obtain a flocculant.

[0054] In the present invention, the molecular weight of the high molecular weight cationic polyacrylamide is preferably greater than or equal to 10 million, more preferably greater than or equal to 11 million, and more preferably greater than or equal to 12 million.

[0055] In the present invention, the cationic ionity of the high-ionity and high-molecular-weight cationic polyacrylamide is preferably greater than or equal to 50%, more preferably greater than or equal to 52%, and more preferably greater than or equal to 54%.

[0056] In the present invention, the mass concentration of the flocculant is preferably 1‰ to 1.5‰, more preferably 1.1‰ to 1.4‰, and more preferably 1.2‰ to 1.3‰.

[0057] In the present invention, the mixing time is preferably 10 to 30 min, more preferably 14 to 26 min, and more preferably 18 to 22 min.

[0058] Finally, the present invention adds the flocculant obtained in the above steps to the titanium liquid produced by the sulfuric acid titanium dioxide process, and after static sedimentation, obtains the titanium liquid after sedimentation.

[0059] In the present invention, the total titanium concentration of the titanium solution is preferably 100 to 130 g / L, more preferably 105 to 125 g / L, and more preferably 110 to 120 g / L.

[0060] In the present invention, the viscosity of the titanium liquid is preferably 10 to 15 mPa·s, more preferably 11 to 14 mPa·s, more preferably 12 to 13 mPa·s, and may be 12.58 mPa·s.

[0061] In the present invention, the specific gravity of the titanium liquid is preferably 1.3 to 1.5, more preferably 1.34 to 1.46, more preferably 1.38 to 1.43, and specifically may be 1.43.

[0062] In the present invention, the F value of the titanium liquid is preferably 1.8 to 1.9, more preferably 1.81 to 1.86, more preferably 1.81 to 1.82, and specifically may be 1.81.

[0063] In the present invention, the stability of the titanium liquid is preferably 400-500 ml, more preferably 420-480 ml, more preferably 440-460 ml, and specifically 430 ml.

[0064] In the present invention, the solid content of the titanium liquid is preferably 14-16 g / L, more preferably 14.4-15.6 g / L, more preferably 14.8-15.2 g / L, and specifically may be 14.99 g / L.

[0065] In the present invention, the static sedimentation time is preferably 1 to 6 hours, more preferably 2 to 5 hours, and more preferably 3 to 4 hours.

[0066] In the present invention, the static sedimentation further preferably includes a separation step.

[0067] In the present invention, the solid content of the titanium liquid after sedimentation is preferably 0 to 0.2 g / L, more preferably 0.04 to 0.16 g / L, and more preferably 0.08 to 0.12 g / L.

[0068] The present invention is a complete and detailed overall technical solution to better improve the titanium liquid sedimentation effect. The flocculation sedimentation method for improving the titanium liquid sedimentation effect in the sulfuric acid titanium dioxide process may specifically include the following steps:

[0069] The design is as follows:

[0070] 1) Select emulsion polyacrylamide stock solution (molecular weight>10 million, cationic ion degree>50%) and add appropriate amount of water to prepare flocculant, the concentration is 1-1.5‰, and the stirring time is 10-30min.

[0071] 2) Add 3% to 8% of the prepared flocculant to the titanium liquid (total titanium concentration 100 to 130 g / L), mix thoroughly and let it stand to settle.

[0072] 3) After settling for a period of time, take the overflow supernatant to test the pumping speed and solid content. If it is qualified, it is the product titanium liquid that has completed the settling.

[0073] The concentrated titanium liquid contains a large amount of unreacted acid hydrolysis residues and other impurities, which need to be removed by static sedimentation after adding a flocculant. The present invention adopts a cationic polyacrylamide product for the sedimentation process of sulfuric acid titanium dioxide liquid. The flocculant preparation time can be shortened by more than half compared with the previous one. During the flocculation process, the high cationic degree makes the dissociated ion concentration higher, and the adsorption effect on the charge is stronger, especially the silicate component contained in the titanium liquid has a strong adsorption effect, so that the flocculation and sedimentation process is carried out more quickly and thoroughly.

[0074] The above content of the present invention provides the application of high molecular weight cationic polyacrylamide in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process and a flocculation sedimentation method for improving the titanium liquid sedimentation effect in the sulfuric acid titanium dioxide process. The present invention uses a specific high molecular weight cationic polyacrylamide as a flocculant in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process and provides a corresponding flocculation sedimentation method for improving the titanium liquid sedimentation effect in the sulfuric acid titanium dioxide process. The present invention uses cationic polyacrylamide to apply to the sulfuric acid titanium dioxide titanium liquid sedimentation process, and the flocculant configuration time can be shortened by more than half compared with the previous one. During the flocculation process, the high cationic degree makes the dissociated ion concentration higher, and the adsorption effect on the charge is stronger, especially the silicate component contained in the titanium liquid has a strong adsorption effect, so that the flocculation sedimentation process is carried out more quickly and thoroughly. The present invention uses an emulsion type high ionic degree high molecular weight cationic polyacrylamide, which can effectively improve the flocculation sedimentation effect of the sulfuric acid titanium dioxide titanium liquid compared with traditional flocculant products, and comprehensively reduce the production cost.

[0075] The present invention is applicable to the flocculation and sedimentation process of titanium dioxide liquid produced by the sulfuric acid process. A high-ionicity and high-molecular-weight cationic polyacrylamide flocculant product is used, which is added to the titanium liquid in a specific ratio, stirred evenly, and then allowed to settle. After sufficient sedimentation time, the titanium liquid is stratified, and the upper clear liquid is the desired titanium liquid product. Compared with traditional flocculants, for the same type of titanium liquid using the same amount of conventional flocculants, the present invention can increase the pumping speed of the titanium liquid by about 30%, and effectively reduce the process problem of unsatisfactory sedimentation effect. Moreover, this method greatly improves the quality of the titanium liquid, and will not have an adverse effect on the product quality. The on-site equipment modification is simple and easy to implement. It can be fully promoted in titanium dioxide enterprises produced by the sulfuric acid process that have demand, which is conducive to reducing costs and increasing efficiency.

[0076] In order to further illustrate the present invention, the application of the high molecular weight cationic polyacrylamide provided by the present invention in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process and a flocculation sedimentation method for improving the titanium liquid sedimentation effect in the sulfuric acid titanium dioxide process are described in detail in combination with the embodiments below. However, it should be understood that these embodiments are implemented on the premise of the technical scheme of the present invention, and detailed implementation methods and specific operating processes are given only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention, and the protection scope of the present invention is not limited to the following embodiments.

[0077] Example 1

[0078] See Table 1, which shows the physical property data of the titanium liquid used in the embodiments of the present invention.

[0079] Table 1

[0080] Physical properties Viscosity / mPa·s proportion F-number Stability / mL Solid content / g / L 12.58 1.43 1.81 430 14.99

[0081] See Table 2, which shows the chemical composition of the titanium liquid used in the embodiments of the present invention.

[0082] Table 2

[0083] element <![CDATA[TiO2]]> <![CDATA[Ti 3+ ]]> Fe Mg Si Al Ca Content g / L 128 1.24 43.3 5 0.09 0.58 0.29

[0084] Take 100 ml of the same titanium liquid, select different types and molecular weight flocculants to prepare a concentration of 1‰, add 5 ml of flocculant into the titanium liquid for flocculation and sedimentation, take 2 ml of the supernatant after 1 hour to test the solid content, filter 50 ml and record the filtration time. The results are shown in Table 3, which shows the sedimentation effect of different types of flocculants.

[0085] Table 3

[0086]

[0087] As shown in Table 3, cationic polyacrylamide (CPAM) has better flocculation and sedimentation effect than nonionic polyacrylamide (NPAM) and anionic polyacrylamide (APAM).

[0088] Example 2

[0089] Take 100 ml of the same titanium liquid, select different cationic flocculants to prepare a concentration of 1‰, add 5 ml of flocculant into the titanium liquid for flocculation and sedimentation, take 2 ml of the supernatant after 1 hour to test the solid content, filter 50 ml and record the filtration time. The results are shown in Table 4, which shows the sedimentation effect of CPAM with different cationic degrees.

[0090] Table 4

[0091] Flocculant Type Molecular weight Ionicity Filtration time Solid content g / L CPAM 1000 20 4′49″ 1.612 CPAM 1000 40 4′40″ 1.654 CPAM 1000 60 1′46″ 0.432

[0092] As shown in Table 4, the flocculation and sedimentation effect of CPAM with high cationicity is much higher than that of CPAM with low ionicity.

[0093] Example 3

[0094] The operation method is as shown above. The emulsion type CPAM and the solid CPAM are used to prepare the flocculant. The solid CPAM is stirred with a mechanical stirrer (speed 350r / min) after adding water. The preparation is completed after 1 hour. The emulsion type CPAM is stirred for 10 minutes after adding water. The results of the sedimentation experiment are shown in Table 5, which shows the sedimentation effect of CPAM with different cationic degrees.

[0095] Table 5

[0096] Types of flocculants Molecular weight Filtration time Solid content g / L Emulsion CPAM 1000 53″ 0.218 Solid CPAM 1000 2′00″ 0.416

[0097] As shown in Table 5, the emulsion type CPAM has a better flocculation effect, and the solid content of the titanium dioxide liquid obtained under the same conditions is about half as much.

[0098] Example 4

[0099] The operation method is as shown above, and different amounts of emulsion CPAM are added. The flocculation effect is shown in Table 6, which shows the sedimentation effect of different added amounts of CPAM.

[0100] Table 6

[0101] Types of flocculants Add Filtration time Solid content g / L CPAM 3％ 1′12″ 0.301 CPAM 5％ 53″ 0.218 CPAM 8％ 50″ 0.189

[0102] As shown in Table 6, as the amount of flocculant added increases, its effect also increases. In actual operation, the amount of flocculant added can be selected according to the difficulty of titanium liquid sedimentation. Reducing the amount added can reduce costs or increasing the amount added can improve the effect.

[0103] The above is a detailed introduction to the application of the high molecular weight cationic polyacrylamide provided by the present invention in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process and a flocculation sedimentation method for improving the sedimentation effect of the titanium dioxide liquid in the sulfuric acid process. The principle and implementation method of the present invention are described in detail using specific examples. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the textual expression of the claims, or if they include equivalent structural elements that are not substantially different from the textual expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. Application of high molecular weight cationic polyacrylamide in the titanium liquid sedimentation process in the sulfuric acid titanium dioxide process; The number average molecular weight of the high molecular weight cationic polyacrylamide is greater than or equal to 10 million.

2. The use according to claim 1, characterized in that: The high molecular weight cationic polyacrylamide is specifically a high ionicity high molecular weight cationic polyacrylamide; The cationic ionity of the high ionicity and high molecular weight cationic polyacrylamide is greater than or equal to 50%; The polyacrylamide includes polyacrylamide emulsion.

3. The use according to claim 1, characterized in that: The application is specifically an application as a flocculant; The mass concentration of the flocculant is 1‰ to 1.5‰; The added volume of the flocculant is 3% to 8% of the volume of the titanium liquid.

4. The use according to claim 1, characterized in that: The molecular weight of the high molecular weight cationic polyacrylamide is 10 million to 15 million; The cationic ion degree of the high molecular weight cationic polyacrylamide is 50% to 60%.

5. The use according to claim 1, characterized in that: The titanium liquid, measured by element concentration, includes: TiO2: 110-130 g / L, Ti 3+ : 1~1.5g / L, Fe: 40~45g / L, Mg: 4~6g / L, Si: 0~1g / L, Al: 0~2g / L, Ca: 0~2g / L.

6. A flocculation and sedimentation method for improving the sedimentation effect of titanium liquid in the sulfuric acid process titanium dioxide, characterized in that: The following steps are involved: 1) mixing the cationic polyacrylamide emulsion and water to obtain a flocculant; 2) Add the flocculant obtained in the above step to the titanium liquid produced by the sulfuric acid titanium dioxide process, and let it stand for sedimentation to obtain the settled titanium liquid.

7. The flocculation sedimentation method according to claim 6, characterized in that: The molecular weight of the high molecular weight cationic polyacrylamide is greater than or equal to 10 million; The cationic ionity of the high ionicity and high molecular weight cationic polyacrylamide is greater than or equal to 50%; The mass concentration of the flocculant is 1‰ to 1.5‰.

8. The flocculation sedimentation method according to claim 6, characterized in that: The mixing time is 10 to 30 minutes; The total titanium concentration of the titanium liquid is 100-130 g / L; The viscosity of the titanium liquid is 10-15 mPa·s.

9. The flocculation sedimentation method according to claim 6, characterized in that: The specific gravity of the titanium liquid is 1.3 to 1.5; The F value of the titanium liquid is 1.8 to 1.9; The stability of the titanium liquid is 400-500 ml.

10. The flocculation sedimentation method according to claim 5, characterized in that: The solid content of the titanium liquid is 14-16 g / L; The static sedimentation time is 1 to 6 hours; The step of separation is also included after the static sedimentation; The solid content of the titanium liquid after sedimentation is 0-0.2 g / L.

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