A method for separating solid and liquid of slurry and a method for recovering chlorinated waste residue

Abstract

The present application relates to waste recycling technical field, especially to a kind of slurry solid-liquid separation method and the recovery method of chlorinated waste residue.The present application of a kind of slurry solid-liquid separation method, including the following steps: after mixing and stirring slurry and flocculating agent, solid-liquid separation is carried out;Wherein the volume ratio of the flocculating agent and the slurry is (0.12-0.19):1;The linear velocity of the stirring is 6.28-9.3 m / s.The present application of a kind of chlorinated waste residue recovery method includes the slurry solid-liquid separation method described above.The present application of slurry solid-liquid separation method, by using flocculating agent and high-speed stirring combination mode, improve the slurry solid-liquid separation efficiency and separation effect, avoid the influence of slurry solid content fluctuation on solid-liquid separation effect;It is used in the recovery method of chlorinated waste residue, solve the problem that coke powder slurry and tailings slurry are difficult to solid-liquid separation, and the required equipment occupies small area.

Description

Technical Field

[0001] This invention relates to the field of waste recycling technology, and in particular to a method for solid-liquid separation of slurry and a method for recycling chlorinated waste residue. Background Technology

[0002] Currently, the slag discharged from the chlorination process mainly consists of extremely fine-grained titanium concentrate, petroleum coke fines, and some SiO2. Simply stockpiling or selling this slag would undoubtedly be a waste of resources. The separation of titanium concentrate and petroleum coke fines should employ flotation, gravity separation, and secondary gravity separation methods.

[0003] In the existing separation process of titanium concentrate and petroleum coke fine powder, the addition of flocculants is generally used for solid-liquid separation. However, due to the unstable composition of raw materials, the extremely fine particle size of products, and the generation of colloids in the slurry, the solid content of the slurry is unstable, which leads to the instability of the amount of flocculant added, thus adversely affecting the solid-liquid separation of the slurry.

[0004] The existing method of adding flocculants to slurries has the following drawbacks: the slurry produced in production requires a slurry tank, a flocculation tank for the reaction of flocculants and slurry, and a buffer tank (transition tank) after the supernatant overflows. Solid-liquid separation of a slurry requires three tanks, but coke powder slurry and tailings slurry are difficult to filter by pressure in production. Therefore, at least six tanks are needed to solve the problem of difficult filtration, which not only requires additional investment but also occupies a large area.

[0005] The dosage of flocculant is directly related to the solid content of the slurry and the amount of colloids in the solution. Changes in the solid content of the slurry have a significant impact on the separation effect of the flocculant. To achieve good flocculation and separation, a suitable dosage range needs to be selected. However, operators in each shift often fail to accurately control the dosage of flocculant, which can affect the flocculation and solid-liquid separation results.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The primary objective of this invention is to provide a method for solid-liquid separation of slurry, which improves the efficiency of solid-liquid separation by combining excessive flocculant with high-speed stirring, and avoids the impact of slurry solid content fluctuations on the solid-liquid separation effect.

[0008] The second objective of this invention is to provide a method for recycling chlorinated waste residue, including the solid-liquid separation method of the above-mentioned slurry, which solves the problem of difficulty in solid-liquid separation of coke powder slurry and tailings slurry; and the required equipment occupies a small area, requiring only one slurry tank, thus saving floor space.

[0009] To achieve the above-mentioned objectives of this invention, the following technical solution is adopted:

[0010] This invention provides a method for solid-liquid separation of a slurry, comprising the following steps:

[0011] After mixing and stirring the slurry and flocculant, solid-liquid separation is carried out;

[0012] The volume ratio of the flocculant to the slurry is (0.12–0.19):1.

[0013] The linear velocity of the stirring is 6.28–9.3 m / s.

[0014] Furthermore, the flocculant includes cationic polyacrylamide.

[0015] Furthermore, the mass concentration of the flocculant is 1.5‰ to 3‰.

[0016] Furthermore, the volume ratio of the flocculant to the slurry is (0.14–0.19):1;

[0017] And / or, the linear velocity of the stirring is 8.2 to 8.4 m / s.

[0018] Furthermore, the stirring time is 30–90 minutes.

[0019] The present invention also provides a method for recycling chlorinated waste residue, including the solid-liquid separation method of the slurry as described above.

[0020] Furthermore, the method for recovering the chlorinated waste residue includes the following steps:

[0021] S1. After pulping and flotation, chlorinated waste residue is used to obtain coke powder slurry and flotation tailings slurry.

[0022] S2. After solid-liquid separation of the coke powder slurry, coke powder is obtained; the solid-liquid separation method includes the solid-liquid separation method of the slurry as described above;

[0023] S3. The flotation tailings slurry is sequentially separated by a first spiral chute and a second spiral chute to obtain the first titanium concentrate slurry and the first tailings slurry.

[0024] S4. The first tailings slurry is separated by a first-stage shaking table, a second-stage shaking table and a third-stage shaking table to obtain the second titanium concentrate slurry and the second tailings slurry.

[0025] S5. After solid-liquid separation of the second tailings slurry, tailings are obtained; the solid-liquid separation method includes the solid-liquid separation method of the slurry as described above.

[0026] Furthermore, in step S1, the chlorinated waste residue includes iron oxide.

[0027] Furthermore, in step S1, the content of iron oxide in the chlorinated waste residue is ≤15wt%.

[0028] Furthermore, in step S1, the feed rate of the chlorinated waste residue from the flotation is ≤15t / h.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. The solid-liquid separation method for slurry provided by the present invention combines flocculant and high-speed stirring. By using an excess of flocculant and high-speed stirring at a certain linear velocity, the solid-liquid separation efficiency and separation effect of the slurry are improved. This method can avoid the impact of uncertain flocculant addition caused by fluctuations in the solid content of the slurry on the solid-liquid separation effect.

[0031] 2. The solid-liquid separation method of the slurry of the present invention is used in the recycling method of chlorinated waste residue, which solves the problem of difficult solid-liquid separation of coke powder slurry and tailings slurry, such as the difficulty of pressure filtration. It can realize continuous feeding during pressure filtration. Moreover, the required equipment occupies a small area, and only one slurry tank is needed to realize feeding, flocculation reaction and discharge operations. Unlike the traditional flocculation process, it saves space.

[0032] 3. The method for recycling chlorinated waste provided by the present invention increases the processing capacity by adding a spiral chute. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0034] The following describes in detail a solid-liquid separation method for slurry and a method for recovering chlorinated waste residue according to an embodiment of the present invention.

[0035] In some embodiments of the present invention, a method for solid-liquid separation of a slurry is provided, comprising the following steps:

[0036] After mixing and stirring the slurry and flocculant, solid-liquid separation is carried out;

[0037] The volume ratio of flocculant to slurry is (0.12–0.19):1;

[0038] The linear velocity of the stirring is 6.28–9.3 m / s.

[0039] The unstable composition of the slurry raw materials, the extremely fine particle size of the product, and the formation of colloids in the slurry lead to fluctuations in the solid content of the slurry, and the amount of flocculant added is uncertain, thus affecting the solid-liquid separation effect of the slurry. This invention uses a combination of excess flocculant and high-speed stirring to improve the efficiency and effect of solid-liquid separation, avoiding the problem of poor solid-liquid separation caused by fluctuations in the slurry's solid content, and meeting the flocculant dosage and solid-liquid separation effect required for production.

[0040] Adding excessive flocculant does not affect the flocculation effect of the slurry solid content, but it does affect the solid-liquid separation effect. Therefore, by using high-speed stirring, the flocculants (vanadium flocs) of the flocculant can be broken up, and the molecular structure of the flocculant can be destroyed, resulting in a faster solid-liquid separation speed.

[0041] In some embodiments of the present invention, typically but not limitingly, for example, the linear velocity of the stirring can be a range of 6.28 m / s, 7 m / s, 7.5 m / s, 8 m / s, 8.5 m / s, 9 m / s, 9.3 m / s, or any combination thereof. In some embodiments of the present invention, typically but not limitingly, for example, the volume ratio of flocculant to slurry can be a range of 0.12:1, 0.13:1, 0.14:1, 0.15:1, 0.16:1, 0.17:1, 0.18:1, 0.19:1, or any combination thereof.

[0042] In some embodiments of the present invention, the flocculant includes, but is not limited to, cationic polyacrylamide.

[0043] In some embodiments of the present invention, the mass concentration of the flocculant is 1.5‰ to 3‰; typically, but not limitingly, for example, the mass concentration of the flocculant can be a range of 1.5‰, 2‰, 2.5‰, 3‰ or any combination thereof.

[0044] In some embodiments of the present invention, the volume ratio of flocculant to slurry is (0.14 to 0.19):1.

[0045] In some embodiments of the present invention, the linear velocity of the stirring is 8.2 to 8.4 m / s; preferably 8.3 m / s.

[0046] In some embodiments of the invention, the stirring time is 30 to 90 minutes; typically, but not limitingly, for example, the stirring time can be a range of 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, or any combination thereof.

[0047] In some embodiments of the present invention, stirring includes mechanical stirring.

[0048] In some embodiments of the present invention, during the stirring process, the radius of the stirring rod is 2.5–8 cm, and the stirring speed is 990–3160 r / min. The present invention does not strictly limit the radius of the stirring rod and the stirring speed during the stirring process; as long as the calculated linear velocity range is met, it is acceptable.

[0049] In some embodiments of the present invention, a solid-liquid separation method for slurry is provided for improving the solid-liquid separation speed of slurry.

[0050] In some embodiments of the present invention, a method for recovering chlorinated waste residue is also provided, including the above-mentioned solid-liquid separation method of the slurry.

[0051] The solid-liquid separation method of the slurry of the present invention is used in the recycling method of chlorinated waste residue. It solves the problem of difficult solid-liquid separation of coke powder slurry and tailings slurry, and can realize continuous feeding during separation. It solves the problems of difficult pressure filtration and inability to continuously feed during pressure filtration. Moreover, the required equipment occupies a small area. Only one slurry tank is needed to realize the feeding, flocculation reaction and discharge operations. Unlike the traditional flocculation process, it saves space.

[0052] In some embodiments of the present invention, the method for recovering chlorinated waste residue includes the following steps:

[0053] S1. After pulping and flotation, chlorinated waste residue is used to obtain coke powder slurry and flotation tailings slurry.

[0054] S2. After solid-liquid separation of the coke powder slurry, coke powder is obtained; the solid-liquid separation method includes the solid-liquid separation method of the above slurry.

[0055] S3. After the flotation tailings slurry is separated by a first spiral chute and a second spiral chute, the first titanium concentrate slurry and the first tailings slurry are obtained.

[0056] S4. The first tailings slurry is separated by a first-stage shaking table, a second-stage shaking table, and a third-stage shaking table to obtain the second titanium concentrate slurry and the second tailings slurry.

[0057] S5. After solid-liquid separation of the second tailings slurry, tailings are obtained; the solid-liquid separation method includes the solid-liquid separation method of the above-mentioned slurry.

[0058] The method for recycling chlorinated waste provided by this invention increases the processing capacity of chlorinated waste by adding a spiral chute.

[0059] In some embodiments of the present invention, in step S1, the chlorination waste residue includes iron oxide; preferably, the content of iron oxide in the chlorination waste residue is ≤15wt%.

[0060] In some embodiments of the present invention, in step S1, the chlorinated waste residue includes chlorine; preferably, the chlorine content in the chlorinated waste residue is <20wt%.

[0061] Chlorinated waste contains iron and chlorine. When it is pulped with neutral water such as cooling water, primary water, or washing water, high-valence metal salt FeCl3 will be generated. The salt is easily hydrolyzed, thus generating Fe(OH)3 colloid.

[0062] In some embodiments of the present invention, in step S1, the chlorinated waste residue includes coke powder, mineral powder and silicon dioxide.

[0063] In some embodiments of the present invention, in step S1, the chlorinated waste residue comprises, by mass percentage, the following components:

[0064] TiO2 10%–25%, Fe3O4 5%–15%, SiO2 5%–20%, C 10%–45%, Cl 5%–15%, with the remainder being moisture and impurity elements; preferably, the impurity elements include at least one of magnesium, aluminum, calcium, manganese and sulfur.

[0065] In some embodiments of the present invention, step S1, pulping includes: mixing chlorinated waste residue and acid solution, and then pulping to obtain a slurry; preferably, the pH of the slurry is <0.5, and the solid content of the slurry is 15% to 25%. Pulping refers to the process of thoroughly stirring to form a uniform slurry.

[0066] In some embodiments of the present invention, in step S1, the pulping frequency is 33-35 Hz; preferably, flotation reagent is added during the pulping process; preferably, the reagent addition amount in the pulping tank is 3000-4000 g / h.

[0067] In some embodiments of the present invention, in step S1, the feed rate of the chlorinated waste residue from flotation is ≤15t / h. The feed rate of the chlorinated waste residue from flotation refers to the solid mass of the chlorinated waste residue before pulping.

[0068] In some embodiments of the present invention, in step S1, flotation includes a roughing and scavenging process (4 groups of foam are returned to 3 groups). The flotation reagent is a mixture of pine oil, diesel oil, and emulsifier (dodecyl dimethylamine or polyvinyl alcohol) (the mass ratio of pine oil, diesel oil, and emulsifier is 1-3:3-5:2-4). The reagent addition rate in the stirring tank before flotation is 2800-3800 g / h, the reagent addition rate in the second stage of scavenging is 2800-3800 g / h, the reagent addition rate in the third stage of scavenging is 2000-3000 g / h, and the reagent addition rate in the fourth stage of scavenging is 1000-2000 g / h.

[0069] In some embodiments of the present invention, in step S1, flotation includes using a flotation machine; preferably, the parameters of the flotation machine are: impeller speed of 200-220 r / min, scraper speed of 16 r / min, and blower air pressure ≥19.8 kPa.

[0070] In some embodiments of the present invention, in step S2, the solid content of the coke powder slurry is 15% to 30%.

[0071] In some embodiments of the present invention, in step S2, the coke powder slurry contains 20% to 40% +325 mesh solid particles, 10% to 30% 325 to 400 mesh solid particles, and 40% to 60% -400 mesh solid particles.

[0072] In some embodiments of the present invention, in step S2, a flocculant with a mass concentration of 2‰ is added to the coke powder slurry, and the volume ratio of the flocculant to the coke powder slurry is (0.12~0.19):1. Then, the mixture is stirred at a linear velocity of 8.3m / s for 30~90min, and after pressure filtration, coke powder is obtained; the C content in the coke powder is ≥55wt%.

[0073] In some embodiments of the present invention, in step S3, after the flotation tailings slurry enters a first-stage spiral chute for separation, titanium concentrate slurry A and middlings slurry B are obtained; after the middlings slurry B enters a second-stage spiral chute for separation, titanium concentrate slurry C and the first tailings slurry are obtained; titanium concentrate slurry A and titanium concentrate slurry C are mixed to obtain the first titanium concentrate slurry.

[0074] In some embodiments of the present invention, in step S4, the first tailings slurry is separated by a first-stage shaking table to obtain titanium concentrate slurry D, middlings slurry E, and tailings slurry F; the middlings slurry E is separated by a second-stage shaking table to obtain titanium concentrate slurry G and tailings slurry H; the tailings slurry H is separated by a third-stage shaking table to obtain titanium concentrate slurry I and tailings slurry J; titanium concentrate slurry D, titanium concentrate slurry G, and titanium concentrate slurry I are mixed to obtain a second titanium concentrate slurry, and tailings slurry F and tailings slurry J are mixed to obtain a second tailings slurry.

[0075] In some embodiments of the present invention, after the first titanium concentrate slurry and the second titanium concentrate slurry are filtered by pressure, titanium concentrate is obtained, and the TiO2 content in the titanium concentrate is ≥85wt%.

[0076] In some embodiments of the present invention, in step S4, the parameters of the first-stage, second-stage, and third-stage shaking tables are set the same; the stroke of the shaking table is 8-20 mm, and the sprint is 250-360 times / min.

[0077] In some embodiments of the present invention, in step S5, the solid content of the second tailings slurry is 4% to 12%; preferably, the solid content of tailings slurry F is 6% to 12%, and the solid content of tailings slurry J is 4% to 9%.

[0078] In some embodiments of the present invention, in step S5, the proportion of +325 mesh solid particles in the second tailings slurry is 10% to 20%, the proportion of 325 to 400 mesh solid particles is 2% to 15%, and the proportion of -400 mesh solid particles is 65% to 80%.

[0079] In some embodiments of the present invention, in step S5, a flocculant with a mass concentration of 2‰ is added to the second tailings slurry, and the volume ratio of the flocculant to the tailings slurry is (0.12~0.19):1. Then, the mixture is stirred at a linear velocity of 8.3m / s for 30~90min, and after filtration, the second tailings are obtained. Preferably, the pressing pressure of the filtration is <1.3MPa.

[0080] Example 1

[0081] The solid-liquid separation method for slurry provided in this embodiment includes the following steps:

[0082] Add a flocculant (aqueous solution of cationic polyacrylamide) with a mass concentration of 2‰ to the coke powder slurry (solid content of 27%) and mix well (stir for 30 s). Then stir at a linear velocity of 8.3 m / s (stirring rod radius of 3 cm and stirring speed of 2630 r / min) to obtain a mixed slurry. Filter 150 mL of the mixed slurry to obtain coke powder.

[0083] The coke powder, by mass percentage, includes the following components:

[0084] Carbon content: 55%–64.27%, ash content: 19.59%–21.33%, TiO2 content: 4.14%–5.27%, Fe2O3 content: 3.99%–6.33%, CaO content: 0.07%–0.11%, MgO content: 0.05%–0.2%, and SiO2 content: 3.86%–5.8%.

[0085] The amount of flocculant added, stirring time, and filtration time in the solid-liquid separation methods (1# to 6#) for each slurry are shown in Table 1.

[0086] Table 1

[0087]

[0088]

[0089] Example 2

[0090] The solid-liquid separation method for slurry provided in this embodiment includes the following steps:

[0091] Add a flocculant (aqueous solution of cationic polyacrylamide) with a mass concentration of 2‰ to a coke powder slurry (solid content of 15% to 25%) and mix well (stir for 30 s). Then stir at a linear velocity of 8.3 m / s (stirring rod radius of 3 cm and stirring speed of 2630 r / min) to obtain a mixed slurry. Filter 150 mL of the mixed slurry to obtain coke powder.

[0092] The coke powder, by mass percentage, includes the following components:

[0093] Carbon content: 55%–64.27%, ash content: 19.59%–21.33%, TiO2 content: 4.14%–5.27%, Fe2O3 content: 3.99%–6.33%, CaO content: 0.07%–0.11%, MgO content: 0.05%–0.2%, and SiO2 content: 3.86%–5.8%.

[0094] Table 2 shows the amount of flocculant added, stirring time, and filtration time in the solid-liquid separation methods for different batches of coke powder slurry (1# to 4#).

[0095] Table 2

[0096]

[0097]

[0098] Example 3

[0099] The solid-liquid separation method for slurry provided in this embodiment includes the following steps:

[0100] Add a flocculant (aqueous solution of cationic polyacrylamide) with a mass concentration of 2‰ to the coke powder slurry (solid content of 18%) and mix well (stir for 30s). The volume ratio of flocculant to slurry is 0.187:1. Then stir to obtain a mixed slurry. Filter 150mL of the mixed slurry to obtain coke powder.

[0101] The coke powder, by mass percentage, includes the following components:

[0102] Carbon content: 55%–64.27%, ash content: 19.59%–21.33%, TiO2 content: 4.14%–5.27%, Fe2O3 content: 3.99%–6.33%, CaO content: 0.07%–0.11%, MgO content: 0.05%–0.2%, and SiO2 content: 3.86%–5.8%.

[0103] The stirring parameters and filtration time for each slurry solid-liquid separation method (1# to 6#) are shown in Table 3.

[0104] Table 3

[0105] 1# 8 990 30 4′36″ 2# 8 990 50 5′12″ 3# 3 2630 30 5′31″ 4# 3 2630 50 5′35″ 5# 2.5 3160 30 4′35″ 6# 2.5 3160 50 5′07″

[0106] Example 4

[0107] The solid-liquid separation method for slurry provided in this embodiment includes the following steps:

[0108] Add a flocculant (aqueous solution of cationic polyacrylamide) with a mass concentration of 2‰ to the tailings slurry (solid content of 4-12%), stir for 30 seconds, and then stir at a linear velocity of 8.3 m / s (stirring rod radius of 3 cm and stirring speed of 2630 r / min) to obtain a mixed slurry; filter 150 mL of the mixed slurry.

[0109] Table 4 shows the amount of flocculant added, stirring time, and filtration time in the solid-liquid separation methods for different batches of tailings slurry (1# to 2#).

[0110] Table 4

[0111]

[0112] Example 5

[0113] The chlorination waste residue of this embodiment includes the following components by mass percentage:

[0114] TiO2 12.98%–22.69%, Fe3O4 7.08%–10.90%, CaO 0.18%–0.32%, MgO 0.53%–0.87%, SiO2 9.02%–15.62%, Al2O3 0.98%–15.62%, MnO 1.4%–2.29%, S 3.38%–5.72%, Cl 8.79%–14.35%, C 12.77%–42.66%, with the balance being water.

[0115] The method for recovering chlorinated waste residue provided in this embodiment includes the following steps:

[0116] S1. After mixing the chlorination waste residue and acid solution (waste acid or pickling wastewater with an acidity of 5% to 30%), the mixture is pulped at a frequency of 33 to 35 Hz. Flotation reagents are added during the pulping process at a rate of 3000 to 4000 g / h. After pulping, a slurry with a solid content of 15% to 25% and a pH of <0.5 is obtained.

[0117] The above slurry enters the flotation machine for flotation. The feed rate is 15t / h. The flotation includes one roughing and three scavenging stages (3 out of 4 groups of foam are returned). The reagent addition rate in the agitator before flotation is 2800-3800g / h, the reagent addition rate in the second stage of scavenging is 2800-3800g / h, the reagent addition rate in the third stage of scavenging is 2000-3000g / h, and the reagent addition rate in the fourth stage of scavenging is 1000-2000g / h.

[0118] S2. In the coke powder tank, add a flocculant (aqueous solution of cationic polyacrylamide) with a mass concentration of 2‰ to the coke powder slurry. The volume ratio of flocculant to flotation coke powder slurry is 0.17:1. Stir at a linear velocity of 8.3 m / s for 30-90 min, filter for 30 min, and feed at a rate of 60 m3 to obtain coke powder. The carbon content in the coke powder is ≥55 wt%.

[0119] S3. After the flotation tailings slurry in the flotation tailings pond enters the first spiral chute for separation, titanium concentrate slurry A and middlings slurry B are obtained. After the middlings slurry B enters the second spiral chute for separation, titanium concentrate slurry C and the first tailings slurry are obtained. Titanium concentrate slurry A and titanium concentrate slurry C are mixed to obtain the first titanium concentrate slurry.

[0120] S4. The first tailings slurry is separated by a first-stage shaking table to obtain titanium concentrate slurry D and middlings slurry E; middlings slurry E is separated by a second-stage shaking table to obtain titanium concentrate slurry F and tailings slurry G; tailings slurry G is separated by a third-stage shaking table to obtain titanium concentrate slurry H and tailings slurry I; titanium concentrate slurry D, titanium concentrate slurry F and titanium concentrate slurry H are mixed to obtain the second titanium concentrate slurry, and tailings slurry G and tailings slurry I are mixed to obtain the second tailings slurry; wherein, the stroke of the first-stage shaking table, the second-stage shaking table and the third-stage shaking table are all 8-20 mm, and the sprint is 250-360 times / min.

[0121] S5. Add a flocculant (aqueous solution of cationic polyacrylamide) with a mass concentration of 2‰ to the second tailings slurry. The volume ratio of flocculant to tailings slurry is 0.15:1. Then stir at a linear velocity of 8.3 m / s for 30–90 min. After filter pressing (pressing pressure < 1.3 MPa), the feeding time for filter pressing is 45 min, and the feed rate is 80 m³ / min. 3 The second tailings were obtained.

[0122] Comparative Example 1

[0123] The solid-liquid separation method for the slurry provided in this comparative example includes the following steps:

[0124] The coke powder slurry was stirred at a linear velocity of 8.3 m / s (stirring rod radius of 3 cm and stirring speed of 2630 r / min) for 50 min or 90 min to obtain a mixed slurry; 150 mL of the mixed slurry was then filtered.

[0125] The coke powder slurry is the same as in Example 1;

[0126] The filtration time for the mixture after stirring for 50 minutes is 15′31″.

[0127] The filtration time for the mixture slurry after stirring for 90 minutes is 16 minutes and 55 seconds.

[0128] Comparative Example 2

[0129] The solid-liquid separation method for the slurry provided in this comparative example includes the following steps:

[0130] Add a flocculant (aqueous solution of cationic polyacrylamide) with a mass concentration of 2‰ to the coke powder slurry. The volume ratio of flocculant to coke powder slurry is 0.1:1. After stirring for 30 seconds, stir at a linear velocity of 8.3 m / s (stirring rod radius of 3 cm and stirring speed of 2630 r / min) for 50 min or 90 min to obtain a mixed slurry. Filter 150 mL of the mixed slurry.

[0131] The coke powder slurry is the same as in Implementation 1;

[0132] The filtration time for the mixture slurry after stirring for 50 minutes is 15′82″.

[0133] The filtration time for the mixture after stirring for 90 minutes is 18′44″.

[0134] Comparative Example 3

[0135] The solid-liquid separation method for the slurry provided in this comparative example includes the following steps:

[0136] The tailings slurry was stirred at a linear velocity of 8.3 m / s (stirring rod radius of 3 cm and stirring speed of 2630 r / min) for 60 min to obtain a mixed slurry; 150 mL of the mixed slurry was then filtered.

[0137] The tailings slurry used was the same as that in Example 4 (1#); the filtration time was 15′29″.

[0138] Comparative Example 4

[0139] The solid-liquid separation method for the slurry provided in this comparative example includes the following steps:

[0140] Add a flocculant (aqueous solution of cationic polyacrylamide) with a mass concentration of 2‰ to the tailings slurry. The volume ratio of flocculant to coke powder slurry is 0.1:1. After stirring for 30 seconds, stir for 60 minutes at a linear velocity of 8.3 m / s (stirring rod radius of 3 cm and stirring speed of 2630 r / min) to obtain a mixed slurry. Filter 150 mL of the mixed slurry.

[0141] The tailings slurry is the same as that in Example 4 (1#); the filtration time is 11′41″.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solid-liquid separation method for a slurry used in the recovery of chlorinated waste residue, characterized in that, Includes the following steps: After mixing and stirring the slurry and flocculant, solid-liquid separation is carried out; The volume ratio of the flocculant to the slurry is (0.12~0.19):1; The linear velocity of the stirring is 6.28~9.3 m / s; The flocculant includes cationic polyacrylamide; The mass concentration of the flocculant is 1.5‰ to 3‰; The stirring time is 30-90 minutes.

2. The solid-liquid separation method for slurry used in the recovery of chlorinated waste residue according to claim 1, characterized in that, The volume ratio of the flocculant to the slurry is (0.14~0.19):1; And / or, the linear velocity of the stirring is 8.2~8.4 m / s.

3. A method for recovering chlorinated waste residue, characterized in that, The solid-liquid separation method for slurry used in the recovery of chlorinated waste residue as described in claim 1 or 2.

4. The method for recovering chlorinated waste residue according to claim 3, characterized in that, Includes the following steps: S1. After pulping and flotation, chlorinated waste residue is used to obtain coke powder slurry and flotation tailings slurry. S2. After solid-liquid separation, coke powder is obtained from the coke powder slurry; the solid-liquid separation method includes the solid-liquid separation method for slurry used for chlorination waste residue recovery as described in claim 1 or 2. S3. The flotation tailings slurry is sequentially separated by a first spiral chute and a second spiral chute to obtain the first titanium concentrate slurry and the first tailings slurry. S4. The first tailings slurry is separated by a first-stage shaking table, a second-stage shaking table and a third-stage shaking table to obtain the second titanium concentrate slurry and the second tailings slurry. S5. After solid-liquid separation of the second tailings slurry, tailings are obtained; the solid-liquid separation method includes the solid-liquid separation method for slurry used for chlorination waste residue recovery as described in claim 1 or 2.

5. The method for recovering chlorinated waste residue according to claim 4, characterized in that, In step S1, the chlorinated waste residue includes iron oxide.

6. The method for recovering chlorinated waste residue according to claim 4, characterized in that, In step S1, the content of iron oxide in the chlorinated waste residue is ≤15wt%.

7. The method for recovering chlorinated waste residue according to claim 4, characterized in that, In step S1, the feed rate of the chlorinated waste residue from the flotation is ≤15t / h.

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