Method for settling and filtering artificial rutile leaching mother liquor

Abstract

The invention belongs to the field of chemical engineering, and particularly relates to a settling and filtering method of artificial rutile leaching mother liquor, which comprises the following steps: mixing the artificial rutile leaching mother liquor with anionic polyacrylamide, settling and filtering to respectively obtain titanium-rich material particles and clear mother liquor; the artificial rutile leaching mother liquor is solid-containing material liquid obtained after titanium ore particles are subjected to hydrochloric acid pressure leaching. According to the method, the anionic polyacrylamide (APAM) is added into the hydrochloric acid pressure leaching solid-containing mother liquor, so that particle aggregation is accelerated, the solid-liquid separation efficiency is improved, the filtering and settling time is shortened, and the titanium loss is reduced.

Description

Technical Field

[0001] The invention belongs to the field of chemical industry, and in particular relates to a sedimentation and filtration method for artificial rutile leaching mother liquor. Background Art

[0002] Artificial rutile refers to a titanium-rich raw material (TiO2 ≥ 90%) produced by using chemical processing methods to separate most of the impurities in titanium ore. Its composition and structural properties are the same as those of natural rutile. It is a high-quality substitute for natural rutile and is widely used in the production of chloride-process titanium dioxide.

[0003] Panzhihua is rich in titanium ore reserves, but the impurities are high in calcium and magnesium. Traditional electric furnace smelting and reduction corrosion methods are difficult to effectively remove impurities, resulting in insufficient quality of titanium-rich materials and restricting the development of chloride-based titanium dioxide. The hydrochloric acid pressure leaching method has the advantages of fast leaching speed, strong impurity removal ability, and recyclable hydrochloric acid, making it particularly suitable for the treatment of low-grade titanium ore in Panzhihua. This process uses high-temperature and high-pressure leaching to dissolve impurities such as calcium, magnesium, iron, and aluminum in the titanium ore. However, titanium dioxide is also dissolved into the solution and, under certain conditions, hydrolyzed to produce some fine particles and even positively charged colloidal substances. This results in slow sedimentation of the solid-containing mother liquor after leaching, low filtration efficiency, and the problem of fine TiO2 penetration, which ultimately affects the effect and efficiency of solid-liquid separation and titanium recovery rate.

[0004] How to achieve rapid sedimentation and filtration of artificial rutile leaching mother liquor is a problem that needs to be solved urgently in this field. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a sedimentation filtration method for artificial rutile leaching mother liquor, which can achieve rapid sedimentation filtration of artificial rutile leaching mother liquor.

[0006] The present invention provides a sedimentation and filtration method for artificial rutile leaching mother liquor, comprising the following steps:

[0007] The artificial rutile leaching mother liquor is mixed with anionic polyacrylamide, settled, and filtered to obtain titanium-rich material particles and clear mother liquor respectively;

[0008] The artificial rutile leaching mother liquor is a solid-containing liquid obtained by leaching titanium ore particles under pressure with hydrochloric acid.

[0009] Preferably, the number average molecular weight of the anionic polyacrylamide is 10 million to 15 million.

[0010] Preferably, the hydrolysis degree of the anionic polyacrylamide is 20-35%.

[0011] Preferably, the amount of the anionic polyacrylamide used is 0.05 to 0.2 g / L of mother liquor.

[0012] Preferably, the temperature of the artificial rutile leaching mother liquor is 60-80°C.

[0013] Preferably, the mixing speed is 100-200 rpm.

[0014] Preferably, the mixing time is 5 to 10 minutes.

[0015] Preferably, the sedimentation time is ≤4h.

[0016] Preferably, the TiO2 content of the titanium ore particles is 40-50wt%, and the total content of CaO and MgO is ≥5wt%.

[0017] Preferably, the hydrochloric acid pressure leaching is carried out at a temperature of 120 to 160° C. and for a time of 6 to 10 hours.

[0018] Compared with the prior art, the present invention provides a sedimentation and filtration method for artificial rutile leaching mother liquor, comprising the following steps: mixing the artificial rutile leaching mother liquor with anionic polyacrylamide, sedimenting, and filtering to obtain titanium-rich particles and a clear mother liquor, respectively; the artificial rutile leaching mother liquor is a solid-containing liquid obtained after titanium ore particles are leached under hydrochloric acid pressure. The present invention accelerates particle aggregation, improves solid-liquid separation efficiency, and reduces filtration sedimentation time and titanium loss by adding anionic polyacrylamide (APAM) to the solid-containing mother liquor leached under hydrochloric acid pressure. More specifically, the present invention has the following advantages:

[0019] (1) The anionic groups of APAM can neutralize the charge of the positively charged TiO2 colloidal particles in the mother liquor through electrostatic adsorption, thereby destroying the colloidal stability and increasing the sedimentation rate.

[0020] (2) APAM molecular chains can form “bridges” between particles in the mother liquor, thereby increasing the floc particle size and accelerating the sedimentation of the flocs.

[0021] (3) APAM can maintain a stable molecular structure in a strong acid environment, thus avoiding the hydrolysis failure problem of traditional flocculants. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0023] The present invention provides a sedimentation and filtration method for artificial rutile leaching mother liquor, comprising the following steps:

[0024] The artificial rutile leaching mother liquor is mixed with anionic polyacrylamide (APAM), settled, and filtered to obtain titanium-rich material particles and clear mother liquor respectively;

[0025] The artificial rutile leaching mother liquor is a solid-containing liquid obtained by leaching titanium ore particles under pressure with hydrochloric acid.

[0026] In the method provided by the present invention, the TiO2 content of the titanium ore particles is preferably 40-50wt%, specifically 47.5wt%; the total content of CaO and MgO in the titanium ore particles is preferably ≥5wt%, specifically ≥6.2wt%.

[0027] In the method provided by the present invention, the concentration of hydrochloric acid used for the hydrochloric acid pressure leaching is preferably 15-25wt%, specifically 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 19.3wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt% or 25wt%.

[0028] In the method provided by the present invention, the liquid-to-solid ratio (mL:g) of the hydrochloric acid pressure leaching is preferably (2-5):1, specifically 2:1, 2.3:1, 2.5:1, 2.7:1, 3:1, 3.4:1, 3.5:1, 3.7:1, 4:1, 4.2:1, 4.5:1, 4.7:1 or 5:1; the temperature of the hydrochloric acid pressure leaching is preferably 120-160°C, specifically 120°C, 125°C, 130°C, 135°C, 140°C, 145°C , 150℃, 155℃ or 160℃; the pressure of the hydrochloric acid pressure leaching is preferably 0.1-0.5MPa, specifically 0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, 0.4MPa, 0.45MPa or 0.5MPa; the time of the hydrochloric acid pressure leaching is preferably 6-10h, specifically 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h or 10h.

[0029] In the method provided by the present invention, the temperature of the artificial rutile leaching mother liquor is preferably 60-80°C, specifically 60°C, 62°C, 65°C, 67°C, 70°C, 72°C, 75°C, 78°C or 80°C.

[0030] In the method provided by the present invention, the number average molecular weight of the anionic polyacrylamide is preferably 10 million to 15 million, specifically 10 million, 10.5 million, 11 million, 11.5 million, 12 million, 12.5 million, 13 million, 13.5 million, 14 million, 14.5 million or 15 million; the degree of hydrolysis of the anionic polyacrylamide is preferably 20% to 35%, specifically 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34% or 35%.

[0031] In the method provided by the present invention, the dosage of the anionic polyacrylamide is preferably 0.05-0.2 g / L mother liquor, specifically 0.05 g / L, 0.06 g / L, 0.07 g / L, 0.08 g / L, 0.09 g / L, 0.1 g / L, 0.11 g / L, 0.12 g / L, 0.13 g / L, 0.14 g / L, 0.15 g / L, 0.16 g / L, 0.17 g / L, 0.18 g / L, 0.19 g / L or 0.2 g / L.

[0032] In the method provided by the present invention, the mixing speed is preferably 100-200 rpm, specifically 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm or 200 rpm; the mixing time is preferably 5-10 min, specifically 5 min, 5.5 min, 6 min, 6.5 min, 7 min, 7.5 min, 8 min, 8.5 min, 9 min, 9.5 min or 10 min.

[0033] In the method provided by the present invention, the sedimentation time is preferably ≤4 h, specifically 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h or 4 h.

[0034] The method provided by the present invention accelerates particle aggregation, improves solid-liquid separation efficiency, and reduces filtration sedimentation time and titanium loss by adding anionic polyacrylamide (APAM) to the hydrochloric acid pressure leaching solid-containing mother liquor.

[0035] For the purpose of greater clarity, the present invention is described in detail with reference to the following examples and comparative examples.

[0036] Example 1

[0037] Raw materials: Panzhihua titanium concentrate (TiO2 content 47.5wt%, CaO+MgO content ≥6.2wt%, particle size distribution see Table 1) was pressure leached with hydrochloric acid (hydrochloric acid concentration 19.3wt%, liquid-to-solid ratio (mL:g) 3.4:1, leaching temperature 140°C, leaching pressure 0.25MPa, leaching time 8 hours) to obtain a leaching mother liquor.

[0038] Table 1 Particle size distribution of titanium concentrate / %

[0039] Particle size / mm ＞0.45 0.45≥～＞0.125 0.125≥～＞0.090 0.090≥～＞0.074 ≤0.074 Percentage 0.48 53.55 25.99 11.79 8.18

[0040] APAM addition: The leaching mother liquor was cooled to 70° C., and then APAM (number average molecular weight 12 million, degree of hydrolysis 25%) was added to the leaching mother liquor at a concentration of 0.1 g / L, and stirred at 150 rpm for 5 minutes.

[0041] Sedimentation results: After stirring, the mixture was allowed to settle for 4 hours and filtered to obtain titanium-rich material and clear mother liquor, respectively. The titanium loss rate was 1.67%.

[0042] In the present invention, the titanium loss rate refers to the mass percentage of the sum of the amount of titanium remaining in the clear mother liquor and the amount of titanium lost by filtration to the total titanium content of the leaching mother liquor.

[0043] Example 2

[0044] Raw materials: same as in Example 1.

[0045] APAM addition: The leaching mother liquor was cooled to 80° C., and then APAM (number average molecular weight 15 million, degree of hydrolysis 30%) was added to the leaching mother liquor at a concentration of 0.2 g / L, and stirred at 200 rpm for 8 minutes.

[0046] Sedimentation results: After stirring, the mixture was allowed to settle for 2 hours and filtered to obtain titanium-rich material and clear mother liquor, respectively. The titanium loss rate was 0.73%.

[0047] Comparative Example 1

[0048] Raw materials: same as in Example 1.

[0049] Sedimentation results: The leaching mother liquor was naturally settled for 21 hours and filtered to obtain titanium-rich material and clear mother liquor, respectively. The titanium loss rate was 5.04%.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A sedimentation and filtration method for artificial rutile leaching mother liquor, characterized in that: The following steps are involved: The artificial rutile leaching mother liquor is mixed with anionic polyacrylamide, settled, and filtered to obtain titanium-rich material particles and clear mother liquor respectively; The artificial rutile leaching mother liquor is a solid-containing liquid obtained by leaching titanium ore particles under pressure with hydrochloric acid.

2. The sedimentation filtration method according to claim 1, wherein The number average molecular weight of the anionic polyacrylamide is 10 million to 15 million.

3. The sedimentation filtration method according to claim 1, characterized in that The hydrolysis degree of the anionic polyacrylamide is 20-35%.

4. The sedimentation filtration method according to claim 1, characterized in that The dosage of the anionic polyacrylamide is 0.05-0.2 g / L mother liquor.

5. The sedimentation filtration method according to claim 1, characterized in that: The temperature of the artificial rutile leaching mother liquor is 60-80°C.

6. The sedimentation filtration method according to claim 1, characterized in that: The mixing speed is 100-200 rpm.

7. The sedimentation filtration method according to claim 1, characterized in that: The mixing time is 5 to 10 minutes.

8. The sedimentation filtration method according to claim 1, characterized in that: The sedimentation time is ≤4h.

9. The sedimentation filtration method according to claim 1, characterized in that: The titanium ore particles have a TiO2 content of 40-50 wt%, and a total content of CaO and MgO of ≥5 wt%.

10. The sedimentation filtration method according to claim 1, characterized in that: The hydrochloric acid pressure leaching is carried out at a temperature of 120 to 160° C. and for a time of 6 to 10 hours.