CN103055603A - Preparation method of ceramic film organic mineral substance filter aid - Google Patents

Abstract

The invention discloses a method for preparing a ceramic membrane organic mineral filter aid, which comprises the steps of: (1) adding water to the raw ore, mixing and stirring to acidify to obtain a slurry solution; (2) settling the slurry solution, filtering the filtered suspension Centrifugal separation and purification; (3) Dry the purified supernatant at 60-90 ⁰ C, grind, and pass through a 400-mesh sieve; (4) Add water to the sieved powder for alkalization; (5) Add sixteen Alkyltrimethylammonium bromide solution, stirred and reacted at 40-50 ^° C, suction filtered, washed with water, washed with ethanol, and centrifuged; (6) The filter cake after centrifugation was dried at 80 ^° C, ground, Pass through a 400 mesh sieve and pack. Adding the organic mineral filter aid of the present invention during the cross-flow microfiltration of emulsified oil wastewater can effectively improve the membrane flux of the ceramic membrane, and the stable flux can be increased from about 180L/(m ² h) of direct microfiltration to that of organic Mineral filter aid is about 235L/(m ² ·h), which can be increased by 30%.

Description

Preparation method of ceramic membrane organic mineral filter aid

technical field

The invention relates to a preparation method of a ceramic membrane organic mineral filter aid.

Background technique

Emulsified oil (oil-water emulsion) is widely used for the lubrication and cooling of tools and workpieces in the process of metal machining. It is easy to be mixed with metal debris and bacteria during use, so the service life is very short. This type of wastewater mainly includes metal cutting fluid, metal cleaning fluid, cold rolling fluid, etc. It is characterized by oil in an emulsified state, particle diameter is usually less than 3 μm , pH is alkaline, and oil concentration is high, requiring regular treatment. Especially for cutting oil, the general method is not easy to deal with. Although the ceramic microfiltration membrane has a good retention effect, it is still difficult to achieve the ideal treatment effect for high-concentration oil and water.

Clay minerals are important components of soil and widely exist in various soil environments, among which silicon, aluminum, oxygen, etc. are the most important elements. Common cations in mineral composition include sodium, potassium, calcium, magnesium, etc., which exist in the interlayer and have a great influence on the layered structure and surface properties of minerals. When mineral components are in a wet state, especially in aqueous solution, due to the strong hydration of cations, the mineral surface is covered with a layer of water film and has strong hydrophilicity, which cannot effectively adsorb organic pollutants. Through the cation exchange reaction, the original inorganic cations in the mineral components are exchanged for organic cations. Because the hydration of organic cations is very weak, the organic mineral components generated are hydrophobic, which can greatly enhance the removal of hydrophobic organic pollutants from water by clay minerals. Ability.

Clay raw ore mainly includes attapulgite clay, kaolin, bentonite, sepiolite clay, etc., which contain SiO ₂ , Fe ₂ O ₃ , MgO, Al ₂ O ₃ , TiO ₂ , MnO, K ₂ O, etc., which are a kind of Hydrous magnesium aluminum carbonate clay mineral, its ideal structural formula is: [(CH ₂ ) ₄ (Mg, Al,Fe) ₅ Si ₈ O ₂₀ (OH) ₂ ]·mH ₂ O, its crystal structure is silicic acid It is a transitional type of double-chain structure (hornblende) and layered structure (mica) of salt, and it is a 2:1 type clay mineral. Due to the existence of crystal channels in the crystal structure and the large internal surface area, it has strong adsorption performance.

In actual filtration applications, in order to improve the membrane flux and retention effect of the microfiltration process, it is sometimes necessary to add filter aids to the system, for example, when using ceramic membrane cross-flow microfiltration to treat oilfield produced water, by adding Adding bentonite in the water makes the small oil droplets and suspended solids in the water form large flocculated particles, and then forms a hydrophilic dynamic layer on the surface of the membrane, preventing fine oil droplets and suspended particles from entering the membrane pores to cause pollution, thereby improving the membrane flux. When Jeffrey Mueller et al. treated oily wastewater by cross-flow microfiltration, they also found that adding suspended solids to the feed would increase the stable flux value and enter the air with water vapor during the drying process, causing secondary pollution , the use is limited.

Contents of the invention

The purpose of the present invention is to provide a preparation method of a ceramic membrane organic mineral filter aid capable of improving the flux of the ceramic microfiltration membrane.

The preparation method of ceramic membrane organic mineral filter aid of the present invention comprises the following steps:

(1) Add water to the clay raw ore, mix and stir evenly, then add hydrochloric acid of 4%-8% raw ore quality to it, and continue stirring for 20-60 minutes to obtain a slurry solution; the mass concentration of the hydrochloric acid is 10%-20%;

(2) Settling the slurry solution obtained above, filtering, and centrifuging the filtered suspension;

(3) Dry the supernatant liquid after centrifugation at 60-90 ^℃ , grind the dried solid, and pass through a 400-mesh sieve;

(4) Add water to the sieved powder and stir evenly, then add a sodium carbonate solution of 4%-8% raw ore quality and stir evenly; the mass concentration of the sodium carbonate solution is 10%-30%;

(5) Add cetyltrimethylammonium bromide solution of 0.5-1.5 times the weight of the original ore to the solution obtained in step (4), stir and react at 40-50 ^° C for 1-3 hours, filter with suction, wash with water, and then Wash with ethanol and centrifuge; the mass concentration of the cetyltrimethylammonium bromide solution is 8%-12%;

(6) The filter cake after centrifugation is dried, ground, and passed through a 400-mesh sieve.

In the step (1), the mass of water added to the raw ore is preferably 5-8 times the mass of the raw ore.

In the step (1), the mass concentration of the added hydrochloric acid is preferably 15%, and the added amount is preferably 5% of the mass of the original ore.

In the step (2), it is better to settle the obtained slurry solution for at least 20 minutes.

In the step (3), it is better to dry the purified supernatant at 80 ^° C.

In the step (4), it is better to add water 4-6 times the mass of the raw ore to the sieved powder.

In the step (4), the mass concentration of the added sodium carbonate solution is preferably 20%, and the added amount is preferably 5% of the mass of the original ore.

Preferably, in the step (5), a cetyltrimethylammonium bromide solution having a mass concentration equal to that of the raw ore and having a mass concentration of 10% is added.

In the step (5), it is better to wash with water at least twice after suction filtration.

Adding the organic mineral filter aid of the present invention during the cross-flow microfiltration of emulsified oil wastewater can improve the flux of the ceramic membrane membrane, and the stable flux can be increased from about 180L/(m ² h) of direct microfiltration to the use of organic Mineral filter aid is about 235L/(m ² ·h), which can be increased by 30%. The reason why the organic mineral filter aid of the present invention increases the flux of the microfiltration membrane may be: 1) The adsorption of the organic mineral filter aid to the oil particles in the wastewater reduces the oil concentration in the main emulsion, making the membrane surface deposition layer , The particles in the gel layer are significantly reduced; 2) After the addition of organic mineral filter aids, the finely dispersed oil and emulsified oil in the water will coagulate rapidly and the particle size will increase, so that the specific cake resistance of the deposited layer on the membrane surface will decrease, and the particles will enter The probability of membrane pores is reduced, the clogging and pollution of membrane pores are reduced, and the permeation flux is increased; 3) The friction and erosion between the organic mineral filter aid particles and the sediment layer on the membrane surface will partially corrode the sediment layer, resulting in an increase in the porosity of the sediment layer. Filtration resistance is reduced, thus increasing permeate flux.

the

Description of drawings

Figure 1 is the flux attenuation curve of direct microfiltration of emulsified oil wastewater and microfiltration of emulsified oil wastewater after adding the organic mineral filter aid of the present invention.

Detailed ways

Example 1

(1) Weigh 100kg of bentonite with an average particle size of about 1 μm , add 600kg of water, stir in a stirrer (rotating speed 600r/min) for 5 minutes, then add 5kg of hydrochloric acid with a mass concentration of 15%, and continue stirring for 30 minutes.

(2) Settling the above slurry for 40 minutes, then filtering to remove massive impurities, and then separating and purifying the filtered suspension with a centrifuge (speed 2200r/min).

(3) The supernatant liquid purified by the centrifuge is dried at 80 ⁰ C, and the dried mineral solids are ground and passed through a 400-mesh sieve.

(4) Then add 500kg of water to the resulting powder, and then add 5kg of sodium carbonate solution with a mass concentration of 20% and continue stirring (speed 600r/min) for 1 hour.

(5) Then add 100kg of cetyltrimethylammonium bromide (CTMAB) solution with a mass concentration of 10%, stir at 40-50 ^° C (speed 600r/min) for 2 hours, filter with suction, and wash with water 3 times, and then washed with ethanol, and then centrifuged with a centrifuge (speed 2400r/min).

(6) The centrifuged filter cake is dried at 80 ^° C, ground, passed through a 400-mesh sieve, and then graded and packaged.

the

Example 2

(1) Weigh 100kg of kaolin with an average particle size of about 1 μm , add 800kg of water, stir in a stirrer (rotating speed 600r/min) for 10 minutes, then add 8kg of hydrochloric acid with a mass concentration of 20%, and continue stirring for 50 minutes.

(2) Settling the above slurry for 30 minutes, then filtering to remove massive impurities, and then purifying the filtered suspension with a centrifuge (rotating speed 2200r/min).

(3) The supernatant liquid purified by the centrifuge is dried at 70 ⁰ C, and the dried mineral solids are ground and passed through a 400-mesh sieve.

(4) Then add 500kg of water to the resulting powder, and then add 8kg of sodium carbonate solution with a mass concentration of 10% and continue stirring (speed 600r/min) for 1 hour.

(5) Then add 120kg of cetyltrimethylammonium bromide (CTMAB) solution with a mass concentration of 8%, stir at 40-50 ^° C (speed 600r/min) for 2 hours, filter with suction, and wash with water 2 times, and then washed with ethanol, and then centrifuged with a centrifuge (speed 2400r/min).

(6) The centrifuged filter cake is dried at 80 ^° C, ground, passed through a 400-mesh sieve, and then graded and packaged.

the

Example 3

(1) Weigh 100kg of attapulgite clay with an average particle size of about 1 μm , add 500kg of water, and stir in a stirrer (speed 600r/min) for 5 minutes, then add 4kg of hydrochloric acid with a mass concentration of 10%, and continue stirring 20 minutes.

(2) Settling the above slurry for 60 minutes, then filtering to remove massive impurities, and then purifying the filtered suspension with a centrifuge (rotating speed 2200r/min).

(3) The supernatant liquid purified by the centrifuge is dried at 80 ⁰ C, and the dried mineral solids are ground and passed through a 400-mesh sieve.

(4) Then add 500kg of water to the generated powder, and then add 4kg of sodium carbonate solution with a mass concentration of 30% and continue stirring (speed 600r/min) for 1 hour.

(5) Then add 80kg of cetyltrimethylammonium bromide (CTMAB) solution with a mass concentration of 12%, stir at 40-50 ^° C (speed 600r/min) for 2 hours, filter with suction, and wash with water 3 times, and then washed with ethanol, and then centrifuged with a centrifuge (speed 2400r/min).

(6) The centrifuged filter cake is dried at 80 ^° C, ground, passed through a 400-mesh sieve, and then graded and packaged.

The organic mineral filter aid of ceramic membrane obtained by the present invention is used for the treatment of emulsified oily wastewater. The experiment takes the emulsified oily wastewater in the process of rolling and stretching the aluminum-magnesium alloy with an oil content of 3720.9mg/L and a CODcr of about 2000mg/L. (Mechanical process waste water) 20L, take by weighing 20g organic mineral filter aid gained in the embodiment of the present invention 1 and drop into it, inject feed liquid tank after high-speed stirring 60min, wherein the average particle diameter of oil droplet in the emulsified oil waste water is 0.72 μ m, The average particle size of the organic mineral filter aid obtained in Example 1 of the present invention is 0.77 μm . Select zirconia microfiltration membrane with a pore size of 0.2 μm , cross-flow filtration for 120 minutes under the conditions of temperature 30°C, pressure 0.1MPa, and cross-flow velocity 2m/s, draw flux decay curve, and compare with that without filter aid The results are compared, and the experimental results are shown in Fig. 1. From Fig. 1, it can be known that adding the organic mineral filter aid of the present invention can improve the flux of the zirconia microfiltration membrane during the cross-flow microfiltration of emulsified oil wastewater, and the stable flux can be improved from direct About 180L/(m ² ·h) of microfiltration increased to about 235L/(m ² ·h) of organic mineral filter aid, an increase of 30%. Using the same method, take 20g of the organic mineral filter aid obtained in Example 2 and Example 3 of the present invention to treat the emulsified oil wastewater in the aluminum-magnesium alloy used in the above experiment, respectively, in the process of rolling and stretching, and stabilize the flux. It can be increased from about 180L/(m ² ·h) for direct microfiltration to about 220L/(m ² ·h) and 230L/(m ² ·h) for organic mineral filter aids, respectively.

Claims (9)

1. the preparation method of a ceramic membrane humatite matter filter aid is characterized in that: comprise the steps:

(1) in the clay raw ore, adds the water mixing and stirring again to the hydrochloric acid that wherein adds ore quality 4%-8%, continue to stir 20-60 minute to get slurry solution; Described hydrochloric acid mass concentration is 10%-20%;

(2) the above-mentioned gained slurry of sedimentation solution filters the suspension centrifugation after will filtering again;

(3) with the clear liquid after the centrifugation at 60-90 ⁰Dryout under the C, grind the solid after dryouting, cross 400 mesh sieves;

(4) add water in the powder after sieve and stir evenly, the sodium carbonate liquor that adds again ore quality 4%-8% stirs; Described sodium carbonate liquor mass concentration is 10%-30%;

(5) in step (4) gained solution, add ore quality 0.5-1.5 softex kw solution doubly, 40～50 ⁰C stirring reaction 1-3 hour, suction filtration, centrifugation is washed in washing again with ethanol; Described softex kw concentration of polymer solution is 8%-12%;

(6) the filter cake oven dry after centrifugal is ground, and crosses 400 mesh sieves.

2. the preparation method of ceramic membrane humatite matter filter aid as claimed in claim 1 is characterized in that: in the described step (1), the quality that adds water to raw ore be ore quality 5-8 doubly.

3. the preparation method of ceramic membrane humatite matter filter aid as claimed in claim 1, it is characterized in that: in the described step (1), the hydrochloric acid mass concentration of adding is 15%, and dosage is 5% of ore quality.

4. the preparation method of ceramic membrane humatite matter filter aid as claimed in claim 1 is characterized in that: in the described step (2), and sedimentation gained slurry solution at least 20 minutes.

5. the preparation method of ceramic membrane humatite matter filter aid as claimed in claim 1, it is characterized in that: in the described step (3), the clear liquid after the purification is 80 ⁰Dryout under the C.

6. the preparation method of ceramic membrane humatite matter filter aid as claimed in claim 1 is characterized in that: in the described step (4), add ore quality 4-6 water doubly in the powder after sieve.

7. the preparation method of ceramic membrane humatite matter filter aid as claimed in claim 1, it is characterized in that: in the described step (4), the sodium carbonate liquor mass concentration of adding is 20%, and dosage is 5% of ore quality.

8. the preparation method of ceramic membrane humatite matter filter aid as claimed in claim 1 is characterized in that: in the described step (5), add mass concentration with ore quality equivalent and be 10% softex kw solution.

9. the preparation method of ceramic membrane humatite matter filter aid as claimed in claim 1 is characterized in that: in the described step (5), and suction filtration after washing at least twice.