A modified colloidal type adhesive and its preparation and use

Abstract

The application belongs to the technical field of colloidal adhesive and specifically relates to a method for modifying colloidal adhesive, wherein a modifier is added to the colloidal adhesive, and the modified colloidal adhesive is prepared by mixing; the modifier comprises three or more than three of anionic polyacrylamide, polyvinyl alcohol, alginic acid derivative, fatty acid derivative, cellulose derivative, sulfonic acid derivative, phosphoric acid derivative and amine derivative. The application innovatively finds that the addition of the modifier to the colloidal adhesive can increase the content of polar functional groups in the colloidal adhesive, optimize the fluid characteristics of the colloidal adhesive, solve the problems of instability, sedimentation and gelation of the colloidal adhesive in a short time, delay the change range of the apparent viscosity of the colloidal adhesive, and improve the long-term storage stability of the colloidal adhesive.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pellet binders, and particularly relates to the technical field of colloidal binders. BACKGROUND

[0002] Binders are one of the essential raw materials for pellet production. The use of inorganic binders in pellet production has the disadvantages of large dosage, large residual amount, and reduced iron grade of pellets. Although the use of organic binders has the advantages of small dosage, small residual amount, and no reduction of the iron grade of pellets, the organic binders have poor thermal stability and low strength of preheated pellets. The composite binder has the advantages of both organic and inorganic binders, and can simultaneously solve the problems of large residual amount of inorganic binders and poor thermal performance of organic binders. Therefore, many pellet plants or binder plants are currently modifying organic to process bentonite into organic composite bentonite to improve the binding performance and reduce the dosage of binders. Good application effects have been achieved in production practice. However, objectively, the preparation of organic composite bentonite is still mainly based on bentonite, and only bentonite and high molecular organic matter are mixed to form the organic-inorganic composite, and the ratio is still high (about 1.5%), and the inherent problems caused by the residual inorganic binders and the pyrolysis of organic binders have not been fundamentally solved.

[0003] In view of the problems in the prior art, the present application team discloses a colloidal type pellet binder, its preparation and application in Chinese patent publication CN 117305581 A. The raw materials are widely sourced, the price is low, the preparation process is simple, the prepared binder product has the advantages of small dosage, good binding performance, good raw material adaptability, and low use cost, and the iron grade of the pellets is not affected. The iron concentrate is added in the form of a concentrated solution, and then balling is performed after mixing. However, in the subsequent research and actual production application, it is found that the colloidal type binder prepared from part of the raw materials will quickly cross-link and overlap under the self-assembly effect with the extension of the storage time, the apparent viscosity continuously increases, and the colloidal type binder becomes gel state in a short time, resulting in poor aggregation stability of the colloidal type binder, shortened shelf life, and adverse effects on the uniform dispersion of the binder in the iron concentrate. SUMMARY

[0004] In view of the problems of instability and sedimentation and gelation of the colloidal type binder in a short time, the first object of the present application is to provide a modification method of the colloidal type binder, which aims to alleviate the problems of instability and sedimentation, or transformation to gel state of the colloidal type binder, and improve the stability, uniformity, dispersion in the iron concentrate, and binding performance of the colloidal type binder.

[0005] The second object of the present application is to provide the modified colloidal type binder prepared by the method and the application of the binder in the preparation of pellets / briquettes.

[0006] The third object of the present application is to provide green pellets or green briquettes prepared by using the modified colloidal binder and the oxidized / reduced pellets / briquettes obtained by further calcination.

[0007] The present application aims to provide a colloidal binder, but early research and development found that inappropriate colloidal binder is not only a simple replacement of the substance form, but also needs to face many unknown technical problems, such as solving the system instability caused by the aggregation of colloidal binder, the unsatisfactory rheological property, the obvious decay of the bonding and calcination performance with the system instability (system sedimentation), and the gradual gelation problem faced by the pseudoplastic fluid characteristics of the colloidal binder. In view of the technical problems, the present application proposes the following solutions after in-depth research:

[0008] A method for modifying a colloidal binder, wherein a modifier is added to the colloidal binder, and the modified colloidal binder is prepared by mixing.

[0009] The modifier includes three or more of anionic polyacrylamide, polyvinyl alcohol, alginate derivative, fatty acid derivative, cellulose derivative, sulfonic acid derivative, phosphoric acid derivative, and amine derivative.

[0010] The alginate derivative is at least one of alginic acid and ester and salt thereof.

[0011] The fatty acid derivative is at least one of fatty acid and ester and salt thereof.

[0012] The cellulose derivative is at least one of cellulose and graft and salt thereof.

[0013] The sulfonic acid derivative is at least one of sulfonic acid and ester and salt thereof.

[0014] The phosphoric acid derivative is at least one of phosphoric acid, phosphonic acid and ester and salt thereof.

[0015] The amine derivative is at least one of amine and derived amide, polymer and salt thereof.

[0016] The present application innovatively finds that adding the compatible modifier to the colloidal binder can increase the content of polar functional groups in the colloidal binder, change the fluid characteristics of the colloidal binder, solve the problems of instability and sedimentation of the colloidal binder in a short time and gelation, improve the apparent viscosity of the binder, reduce the instability and excessive aggregation of the colloidal binder, delay the growth rate of the apparent viscosity, and improve the stability of long-term storage.

[0017] The modifier is a monomer, a polymer or a precursor for preparing each component comprising the above raw materials.

[0018] Preferably, the salt in the modifier is at least one of the ammonium, sodium, potassium salt of the anion of each component.

[0019] Preferably, the alginate derivative is at least one of alginic acid, sodium alginate, ammonium alginate, propylene glycol alginate.

[0020] Preferably, the fatty acid derivative is at least one of C4-C 20 unit or polybasic water-soluble carboxylic acid, ester and water-soluble salt thereof, further preferably at least one of citric acid and water-soluble salt thereof, and further preferably at least one of sodium citrate and potassium citrate.

[0021] Preferably, the cellulose derivative is at least one of sodium carboxymethyl cellulose and hydroxyethyl cellulose.

[0022] Preferably, the sulfonic acid derivative is at least one of C6-C 20 unit or polybasic water-soluble sulfonic acid derivative. For example, the structure can be wherein at least one of R1, R2 is C6-C 20 alkyl, and the remaining substituent is C6-C 20 alkyl or H, M, M is sodium / potassium, and further preferably at least one of sodium lignosulfonate and sodium dodecylbenzenesulfonate.

[0023] Preferably, the phosphoric acid derivative is at least one of inorganic phosphate, organic phosphonic acid, and organic phosphate ester salt, the inorganic phosphate is at least one of sodium hexametaphosphate and sodium tripolyphosphate; the organic phosphate ester salt includes at least one of C1-C 20 unit or polybasic phosphate / ester salt, and the structure is wherein at least one of R1, R2 is C1-C 20 alkyl, and the remaining substituent is C1-C 20 alkyl or H, M, M is sodium / potassium, and further preferably at least one of sodium glycerophosphate and xylose 1-phosphate ester.

[0024] Preferably, the amine derivative includes at least one of C3-C 20 unit or polybasic fatty amine, amide and polymeric amine-containing polymer, salt thereof, and further can be at least one of polyaspartic acid and polyurethane.

[0025] The present application shows that the combination of the components of the modifier can effectively improve the stability and effect of the colloidal adhesive.

[0026] The modifier contains at least anionic polyacrylamide.

[0027] Preferably, the content of anionic polyacrylamide in the modifier is above 40wt%.

[0028] Preferably, the modifier further comprises polyvinyl alcohol.

[0029] Preferably, the content of polyvinyl alcohol in the modifier is above 20wt%.

[0030] Preferably, the modifier comprises anionic polyacrylamide, polyvinyl alcohol and cellulose derivative, wherein the weight ratio of polyacrylamide, polyvinyl alcohol and cellulose derivative is 45-65:20-30:10-25; further preferably, the weight ratio of polyacrylamide, polyvinyl alcohol and cellulose derivative is 55-65:24-26:14-16. Studies show that under the preferred ratio, the stability and modification effect of the colloidal adhesive can be effectively improved.

[0031] Preferably, the modifier comprises more than 5 of the above ingredients. In the present application, under the preferred combination, the stability and modification effect of the colloidal adhesive can be further improved.

[0032] Preferably, the modifier comprises anionic polyacrylamide, polyvinyl alcohol, cellulose derivative, phosphate derivative and sulfonic acid derivative. Further preferably, the weight ratio of anionic polyacrylamide, polyvinyl alcohol, cellulose derivative, phosphate derivative and sulfonic acid derivative is 40-50:25-35:5-15:5-15:1-10; further preferably, 43-47:28-32:8-12:8-12:4-6. Studies show that under the preferred ingredients and ratio, synergy can be further achieved, which helps to further improve the modification effect of the colloidal adhesive.

[0033] The modifier comprises anionic polyacrylamide, polyvinyl alcohol, fatty acid derivative, sulfonic acid derivative and phosphate derivative. Further preferably, the weight ratio of anionic polyacrylamide, polyvinyl alcohol, fatty acid derivative, sulfonic acid derivative and phosphate derivative is 40-50:25-35:5-15:5-15:1-10; further preferably, 45-49:26-30:6-10:10-14:4-6. Studies show that under the preferred ingredients and ratio, synergy can be further achieved, which helps to further improve the modification effect of the colloidal adhesive.

[0034] The present application researches and finds that the preferred combination modifier of the present application helps to further reduce the zeta potential of the colloidal binder, build a steric hindrance effect, thus delaying the sedimentation and gelation of the colloidal solution and improving the stability thereof. Meanwhile, the content of the polar functional groups in the colloidal binder is improved, the adsorption on the mineral surface is improved, and thus the performance of the pellet is improved.

[0035] In the present application, the amount of the modifier is comprehensively considered in terms of processing cost and use effect, and the addition amount of the modifier relative to the colloidal binder is preferably 1-5 g / L (further preferably 1.5-3 g / L). That is, 1-5 g of the modifier is added per liter of colloidal binder before modification.

[0036] The present application researches and finds that, under the modification of the modifier, further combined control of the components of the colloidal binder and the preparation can further realize synergy, further improve the modification effect of the modifier, and help to further improve the performance of the modified colloidal binder.

[0037] In the present application, the modifier can be uniformly mixed with the raw materials for preparing the colloidal binder in advance, and the modifier is added synchronously in the preparation process of the colloidal binder to make the two react together; and / or the modifier is directly added to the colloidal binder product and uniformly mixed to prepare the modified colloidal binder.

[0038] As preferred, in the present application, the colloidal binder is prepared by mechanically activating the raw materials containing humic acid substances and clay components in water with alkaline substances.

[0039] The colloidal binder of the present application can be prepared according to CN 117305581 A.

[0040] In the present application, the colloidal binder has a pseudoplastic fluid property, and the apparent viscosity at 25℃ is 2000-30000 mPa·s. -1

[0041] The present application researches and finds that the raw materials containing humic acid substances and clay components and alkaline substances are physically and chemically activated under mechanical action, and the combined control of the humic acid substances, total acid group content, clay components in the raw materials, and the amounts of water and alkaline substances and the temperature in the mechanical activation stage can prepare a colloidal binder with good rheological property and good system stability, and the colloidal binder can obtain better green ball performance and roasting performance at a lower dosage. The colloidal binder obtained by the preparation process and the modifier of the present application are combined, which helps to synergize and further improve the modification effect.

[0042] ​In the present application, the raw material can be a coal-based raw material containing the humic acid substance and having a required content of clay component, and preferably at least one of peat, lignite or weathered coal containing the humic acid substance and having a required content of clay component. Research shows that using the coal-based raw material meeting the requirements of the humic acid substance, total acid group and content of clay component as the raw material can help to further improve the synergy between the raw material and the mechanical activity, further cooperate with the modification of the modifier of the present application, and help to further improve the system stability, bonding property and pellet roasting performance of the obtained colloidal binder.

[0043] The present application also includes a modified colloidal binder prepared by the method for modifying the colloidal binder.

[0044] In the present application, the fluid property of the modified colloidal binder is pseudoplastic fluid, and the apparent viscosity thereof at 25℃ is 2000-30000 mPa·s. -1

[0045] Preferably, the soluble content of the modified colloidal binder is 50-140 g / L, the insoluble content is 40-80 g / L, and the modifier content is 1-5 g / L, calculated based on the dry mass.

[0046] The present application also provides an application of the modified colloidal binder as a binder for pelletizing or briquetting of ore fines to prepare green pellets or green briquettes, and further oxidizing roasting or reducing roasting to obtain oxidized pellets or reducing pellets.

[0047] Further preferably, the modified colloidal binder is mixed with ore fines uniformly by atomization spraying, and the mixture is pelletized or briquetted after high-pressure roller milling to prepare green pellets or green briquettes; and further oxidizing roasting or reducing roasting to produce oxidized pellets / briquettes or reducing pellets / briquettes.

[0048] Preferably, the addition amount of the modified colloidal binder is 0.5%-3.0% (further can be 1-1.5%) of the mass of ore fines, and the dry mass of the binder is 0.1%-0.6% of the mass of ore fines.

[0049] Advantages

[0050] (1) In view of the problems of aggregation and gelation of colloidal binders, the present application innovatively finds that modifying the colloidal binder with the modifier can effectively improve the stability of the colloidal binder and improve its bonding performance and performance stability.

[0051] (2) Using the preferred combination of modifiers can achieve synergy, which helps to further improve the stability and performance stability of the colloidal binder.

[0052] ​(3) The adding method is simple, and no additional colloid binder production equipment is needed.

[0053] (4) The adding amount is small, and the cost is low. The raw material adding amount is only 1-5 g / L, and the production cost of each ton of binder is only increased by 6-30 yuan. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 The apparent viscosity changes of the colloid binders in various examples and comparative examples after being placed for different time. DETAILED DESCRIPTION

[0055] The following examples are intended to further illustrate the present application, but not limit the protection scope of the present application.

[0056] The anionic polyacrylamide (APAM) used in the examples is a Macklin AR pure reagent, Mw = 5 million, CAS number 9003-05-8; the polyvinyl alcohol (PVA) is a Macklin 98% hydrolysis reagent, Mw = 13,000-23,000, CAS number 9002-89-5; and the sodium hexametaphosphate is a Macklin 65% reagent, CAS number 10124-56-8.

[0057] Comparative Example 1

[0058] The colloid binder is prepared using the method and raw materials of Example 1 in the publication CN 117305581 A, wherein the soluble content is 92.6 g / L, and the insoluble content is 67.1 g / L. The total acid group content of the dry base of the colloid binder is 4.688 mmol / g, the pH is 11.64, the zeta potential is -47.0 mV, the apparent viscosity is 5855 mPa·s at a shear rate of 1 s -1 after being placed for 2 days at 25°C, and the apparent viscosity is 20670 mPa·s at a shear rate of 1 s -1 after being placed for 14 days at 25°C.

[0059] The prepared colloid binder is used to prepare oxidized pellets. The colloid binder is added in an amount of 1%, and after being fully mixed and crushed by a high-pressure roller, the green pellets are formed with a pelletizing time of 12 min and a green pellet size of 14-16 mm. The green pellet drop strength is 15.2 times / (0.5 m), the compressive strength is 31.6 N / p, and the burst temperature is 570°C; under the conditions of preheating at 880°C for 16 min and roasting at 1280°C for 16 min, the preheated pellet strength is 572 N / p, and the roasted pellet strength is 3352 N / p.

[0060] Example 1

[0061] The colloid type binder was prepared by using the method and raw materials of Comparative Example 1, and a modifier composed of 60wt% anionic polyacrylamide, 25wt% polyvinyl alcohol and 15wt% sodium carboxymethyl cellulose was synchronously added into the raw material system for preparing the colloid type binder during the preparation of the binder, and the addition amount of the modifier was 2.7g / L. The total acid group content of the dry base of the colloid type binder was 4.715mmol / g, the pH was 11.76, the zeta potential was -51.2mV, the apparent viscosity was 5352mPa-s measured at 1s -1 of the shearing rate at 25°C after standing for 2d, and the apparent viscosity was 12598mPa-s measured at 1s -1 of the shearing rate at 25°C after standing for 14d.

[0062] The prepared colloid type binder was used for preparing oxidized pellets, the colloid type binder was added in an amount of 1%, and after being mixed uniformly, the mixture was subjected to high-pressure roller milling to form balls, the balling time was 12min, and the green ball size was 14-16mm. The green ball drop strength was 17.8times / (0.5m), the compressive strength was 31.0N / p, and the burst temperature was 550°C; under the conditions of preheating at 880°C for 16min and roasting at 1280°C for 16min, the preheated pellet strength was 556N / p, and the roasted pellet strength was 3436N / p.

[0063] The prepared colloid type binder was used for preparing reduced briquettes, the colloid type binder was added in an amount of 2.5%, and after being mixed uniformly, the mixture was subjected to high-pressure roller milling to form briquettes, the briquettes were dried after being formed by a pair of rollers, the pressure was 2200N / cm 2 , and the briquette size was 20cm. The wet briquette drop strength was 25.6times / (0.5m), the compressive strength was 115.8N / p, the dry briquette drop strength was >50times / (0.5m), and the compressive strength was 3213N / p. After being reduced at 1050°C for 1h, the reduction degree was 86.9%, and the metallization rate was 81.3%.

[0064] It can be known from Comparative Example 1 and Example 1 that the performance of the colloid binder can be improved by using the modifier of the application, and then the performance of the subsequent pellets can be improved, and in particular, the performance of the green balls can be effectively improved.

[0065] Example 2

[0066] Compared with Example 1, the main difference lies in that the addition mode of the modifier is different, and specifically:

[0067] A colloidal binder was prepared using the method and raw materials of Comparative Example 1, and a modifier composed of 60 wt% anionic polyacrylamide, 25 wt% polyvinyl alcohol, and 15 wt% sodium carboxymethyl cellulose was added to the colloidal binder (colloidal binder a) that was left standing for 2 d and mixed uniformly, and the amount of the modifier added was 2.7 g / L. The total acid group content of the colloidal binder dry base was 4.632 mmol / g, the pH was 11.72, the zeta potential was -49.6 mV, the apparent viscosity was 4625 mPa-s at a shear rate of 1 s -1 at 25°C after standing for 2 d, and the apparent viscosity was 14293 mPa-s at a shear rate of 1 s -1 at 25°C after standing for 14 d.

[0068] The colloidal binder prepared was used to prepare oxidized pellets, and the colloidal binder was added in an amount of 1%, mixed uniformly, and then subjected to high-pressure roll milling to form balls, and the balling time was 12 min, the green ball size was 14-16 mm. The green ball drop strength was 19.4 times / (0.5 m), the compressive strength was 30.6 N / p, and the burst temperature was 550°C; under the conditions of preheating at 880°C for 16 min and roasting at 1280°C for 16 min, the preheated pellet strength was 532 N / p, and the roasted pellet strength was 3488 N / p.

[0069] From Examples 1 and 2, it can be seen that no matter at which stage, the modifier described in the present application can improve the performance of the colloidal binder, and especially when the modifier is involved in the in-situ co-reaction synthesis process of the colloidal binder, the colloidal network can be further optimized, which helps to further improve the stability of the colloidal binder and the performance of the pellets prepared subsequently, and especially can effectively improve the performance of the green pellets.

[0070] Example 3

[0071] Compared with Example 1, the main difference is that the type of the modifier is changed, and specifically:

[0072] A colloidal binder was prepared using the method and raw materials of Comparative Example 1, and a modifier composed of 60 wt% anionic polyacrylamide, 25 wt% polyvinyl alcohol, and 15 wt% sodium carboxymethyl cellulose was added to the colloidal binder (colloidal binder a) that was left standing for 2 d and mixed uniformly, and the amount of the modifier added was 2.7 g / L. The total acid group content of the colloidal binder dry base was 4.632 mmol / g, the pH was 11.72, the zeta potential was -49.6 mV, the apparent viscosity was 4625 mPa-s at a shear rate of 1 s -1 at 25°C after standing for 2 d, and the apparent viscosity was 14293 mPa-s at a shear rate of 1 s -1 at 25°C after standing for 14 d.

[0073] The prepared colloidal binder is used to prepare oxidized pellets, and the colloidal binder is added in an amount of 1%. After being mixed uniformly, the pellets are prepared by high-pressure roller milling, and the pelletizing time is 12 min, and the green pellet size is 14-16 mm. The green pellet drop strength is 20.5 times / (0.5 m), the compressive strength is 31.5 N / p, and the explosion temperature is 560°C. Under the conditions of preheating at 880°C for 16 min and roasting at 1280°C for 16 min, the preheated pellet strength is 544 N / p, and the roasted pellet strength is 3431 N / p.

[0074] Example 4

[0075] Compared with Example 1, the main difference is that the type of modifier is changed, and specifically:

[0076] The colloidal binder is prepared by using the method and raw materials of Comparative Example 1, and a modifier composed of 47 wt% anionic polyacrylamide, 28 wt% polyvinyl alcohol, 8 wt% sodium citrate, 12 wt% sodium hexametaphosphate, and 5 wt% sodium dodecylbenzenesulfonate is synchronously added in the starting raw material system of the colloidal binder synthesis. The modifier is added in an amount of 2.4 g / L. The total acid group content of the colloidal binder is 4.736 mmol / g, the pH is 11.78, the zeta potential is -52.3 mV, the apparent viscosity is 3892 mPa·s at a shear rate of 1 s -1 -1 measured at 25°C after standing for 2 d, and the apparent viscosity is 6250 mPa·s at a shear rate of 1 s -1 -1 measured at 25°C after standing for 14 d.

[0077] The prepared colloidal binder is used to prepare oxidized pellets, and the colloidal binder is added in an amount of 1%. After being mixed uniformly, the pellets are prepared by high-pressure roller milling, and the pelletizing time is 12 min, and the green pellet size is 14-16 mm. The green pellet drop strength is 20.1 times / (0.5 m), the compressive strength is 30.6 N / p, and the explosion temperature is 560°C. Under the conditions of preheating at 880°C for 16 min and roasting at 1280°C for 16 min, the preheated pellet strength is 530 N / p, and the roasted pellet strength is 3377 N / p.

[0078] It can be known from Example 1, Example 3, and Example 4 that the five-component modifier can obtain excellent colloidal binder modification effect at a lower modifier amount, and can effectively improve the green pellet performance.

[0079] Comparative Example 2

[0080] Compared with Example 4, the main difference is that only a single type of modifier is added, and the experimental groups are as follows:

[0081] A: Only anionic polyacrylamide is added, and the modifier is added in an amount of 2.4 g / L.

[0082] The total acid group content of the dry base of the colloidal binder was 4.714 mmol / g, the pH was 11.70, the zeta potential was -51.7 mV, the apparent viscosity was 5756 mPa-s at a shear rate of 1 s -1 The apparent viscosity was 18650 mPa-s at a shear rate of 1 s -1 The apparent viscosity was 18650 mPa-s at a shear rate of 1 s

[0083] B: only polyvinyl alcohol was added, and the amount of the modifier was 2.4 g / L.

[0084] The total acid group content of the dry base of the colloidal binder was 4.714 mmol / g, the pH was 11.70, the zeta potential was -51.7 mV, the apparent viscosity was 5756 mPa-s at a shear rate of 1 s -1 The apparent viscosity was 18650 mPa-s at a shear rate of 1 s -1 The apparent viscosity was 18650 mPa-s at a shear rate of 1 s

[0085] C: only sodium hexametaphosphate was added, and the amount of the modifier was 2.4 g / L.

[0086] The total acid group content of the dry base of the colloidal binder was 4.714 mmol / g, the pH was 11.70, the zeta potential was -51.7 mV, the apparent viscosity was 5756 mPa-s at a shear rate of 1 s -1 The apparent viscosity was 18650 mPa-s at a shear rate of 1 s -1 The apparent viscosity was 18650 mPa-s at a shear rate of 1 s The colloidal binder prepared was used to prepare oxidized pellets, the colloidal binder was added in an amount of 1%, and after being mixed thoroughly, the mixture was subjected to high-pressure roller milling to form balls, the balling time was 12 min, and the green ball size was 14-16 mm. The green ball drop strength was 15.0 times / (0.5 m), the compressive strength was 29.7 N / p, and the burst temperature was 560°C; under the conditions of preheating at 880°C for 16 min and roasting at 1280°C for 16 min, the preheated pellet strength was 525 N / p, and the roasted pellet strength was 3286 N / p.

[0087] Comparative Example 3

[0088] Compared with Example 4, the main difference was that the combination of the modifier was not within the preferred range, and the experimental groups were as follows:

[0089] A: 60% anionic polyacrylamide + 40% sodium carboxymethyl cellulose, and the amount of the modifier was 2.4 g / L.

[0090] The colloidal binder has a total acid group content of 4.828 mmol / g, a pH of 11.85, a zeta potential of -51.5 mV, an apparent viscosity of 5520 mPa·s at a shear rate of 1 s -1 after standing for 2 days at 25°C, and an apparent viscosity of 17365 mPa·s at a shear rate of 1 s -1 after standing for 14 days at 25°C. The viscosity change effect is not obvious.

[0091] B: 50% sodium dodecyl benzene sulfonate + 50% sodium tripolyphosphate, modifier addition amount is 2.4 g / L.

[0092] The colloidal binder has a total acid group content of 4.656 mmol / g, a pH of 11.66, a zeta potential of -48.0 mV, an apparent viscosity of 6020 mPa·s at a shear rate of 1 s -1 after standing for 2 days at 25°C, and an apparent viscosity of 23845 mPa·s at a shear rate of 1 s -1 after standing for 14 days at 25°C. The viscosity change effect is not obvious.

[0093] Comparative Example 4

[0094] Compared with Comparative Example 1, the main difference is that the raw materials of the colloidal binder are changed, specifically:

[0095] The colloidal binder is prepared using the method and raw materials of Example 5 in CN 117305581 A, wherein the soluble content is 81.0 g / L, and the insoluble content is 107.3 g / L. The colloidal binder has a total acid group content of 3.664 mmol / g, a pH of 11.86, a zeta potential of -46.2 mV, an apparent viscosity of 3205 mPa·s at a shear rate of 1 s -1 after standing for 2 days at 25°C, and an apparent viscosity of 29878 mPa·s at a shear rate of 1 s -1 after standing for 14 days at 25°C. The viscosity change effect is not obvious.

[0096] The prepared colloidal binder is used to prepare oxidized pellets. The colloidal binder is added in an amount of 1%, and after being mixed uniformly, the mixture is subjected to high-pressure roller milling to form balls, with a balling time of 12 min and a green ball size of 14-16 mm. The green ball drop strength is 31.7 times / (0.5 m), the compressive strength is 35.9 N / p, and the burst temperature is 570°C; under the conditions of preheating at 880°C for 16 min and roasting at 1280°C for 16 min, the preheated pellet strength is 613 N / p, and the roasted pellet strength is 3545 N / p.

[0097] Example 5

[0098] A colloidal binder was prepared using the method and raw materials of Comparative Example 4, and a modifier composed of 60 wt% anionic polyacrylamide, 25 wt% polyvinyl alcohol, and 15 wt% sodium carboxymethyl cellulose was added to the colloidal binder simultaneously, the modifier being added at a content of 2.7 g / L. The total acid group content of the dry colloidal binder was 3.824 mmol / g, the pH was 11.89, the zeta potential was -48.4 mV, the apparent viscosity was 2303 mPa-s at a shear rate of 1 s -1 at 25°C after standing for 2 days, and the apparent viscosity was 8592 mPa-s at a shear rate of 1 s -1 at 25°C after standing for 14 days.

[0099] The colloidal binder prepared was used to prepare oxidized pellets, the colloidal binder being added at a dosage of 1%, and after being mixed thoroughly, the mixture was subjected to high-pressure roll milling and then pelletizing, the pelletizing time being 12 min and the green pellet size being 14-16 mm. The green pellet drop strength was 33.6 times / (0.5 m), the compressive strength was 35.2 N / p, and the burst temperature was 550°C; under the conditions of preheating at 880°C for 16 min and roasting at 1280°C for 16 min, the preheated pellet strength was 580 N / p, and the roasted pellet strength was 3502 N / p.

Claims

1. A method for modifying a colloidal type adhesive, characterized by, The modified colloid type adhesive is prepared by adding a modifier into the colloid type adhesive and mixing uniformly. The modifier comprises three or more of anionic polyacrylamide, polyvinyl alcohol, alginate derivative, fatty acid derivative, cellulose derivative, sulfonic acid derivative, phosphoric acid derivative and amine derivative. The alginate derivative is at least one of alginic acid, sodium alginate, ammonium alginate and propylene glycol alginate. The fatty acid derivative is at least one of citric acid, sodium citrate and potassium citrate. The cellulose derivative is at least one of sodium carboxymethyl cellulose and hydroxyethyl cellulose. The sulfonic acid derivative is at least one of sodium lignosulfonate and sodium dodecyl benzene sulfonate. The phosphoric acid derivative is at least one of inorganic phosphate salt and organic phosphate ester salt, wherein the inorganic phosphate salt is at least one of sodium hexametaphosphate and sodium tripolyphosphate, and the organic phosphate ester salt is at least one of glycerophosphate sodium and xylose 1-phosphate. The amine derivative is at least one of polyaspartic acid and polyurethane. The modifier comprises at least anionic polyacrylamide and polyvinyl alcohol. The content of the anionic polyacrylamide is more than 40 wt%, and the content of the polyvinyl alcohol is more than 20 wt%. The addition amount of the modifier relative to the colloid type adhesive is 1-5 g / L.

2. The method of modifying a colloidal type adhesive as claimed in claim 1, wherein, The modifier comprises anionic polyacrylamide, polyvinyl alcohol and cellulose derivative, and the weight ratio of the polyacrylamide, polyvinyl alcohol and cellulose derivative is 45-65:20-30:10-25.

3. The method of modifying a colloidal type adhesive according to claim 2, wherein The weight ratio of the polyacrylamide, polyvinyl alcohol and cellulose derivative is 55-65:24-26:14-16.

4. The method of modifying a colloidal type adhesive as claimed in claim 1, wherein, The modifier comprises anionic polyacrylamide, polyvinyl alcohol, cellulose derivative, phosphoric acid derivative and sulfonic acid derivative.

5. The method of modifying a colloidal type adhesive according to claim 4, wherein The weight ratio of the anionic polyacrylamide, polyvinyl alcohol, cellulose derivative, phosphoric acid derivative and sulfonic acid derivative is 40-50:25-35:5-15:5-15:1-10.

6. The method of modifying a colloidal type adhesive according to claim 5, wherein The weight ratio of the anionic polyacrylamide, polyvinyl alcohol, cellulose derivative, phosphoric acid derivative and sulfonic acid derivative is 43-47:28-32:8-12:8-12:4-6.

7. The method of modifying a colloidal type adhesive as claimed in claim 1, wherein, The modifier comprises anionic polyacrylamide, polyvinyl alcohol, fatty acid derivative, sulfonic acid derivative and phosphoric acid derivative.

8. The method of modifying a colloidal type adhesive according to claim 7, wherein The weight ratio of the anionic polyacrylamide, polyvinyl alcohol, fatty acid derivative, sulfonic acid derivative, phosphoric acid derivative is 40-50:25-35:5-15:5-15:1-10.

9. The method of modifying a colloidal type adhesive according to claim 8, wherein The weight ratio of the anionic polyacrylamide, polyvinyl alcohol, fatty acid derivative, sulfonic acid derivative, phosphoric acid derivative is 45-49:26-30:6-10:10-14:4-6.

10. The method of modifying a colloidal type adhesive as claimed in claim 1, wherein, The addition amount of the modifier relative to the colloid type adhesive is 1.5-3 g / L.

11. The method of modifying a colloidal type adhesive as claimed in claim 1, wherein, The modifier is mixed with the raw material for preparing the colloidal binder in advance, and the modifier is added synchronously during the preparation of the colloidal binder to make the two react together, so as to prepare the modified colloidal binder; and / or the modifier is directly added into the colloidal binder product and mixed thoroughly, so as to prepare the modified colloidal binder.

12. The modified colloidal binder prepared by the method of any one of claims 1-11. The fluid property of the modified colloidal adhesive is pseudoplastic fluid, the apparent viscosity of the adhesive colloid at 1 s -1 under 25℃ is 2000-30000 mPa·s; The soluble content of the modified colloidal binder is 50-140 g / L, the insoluble content is 40-80 g / L, and the modifier content is 1-5 g / L, in terms of dry mass.

13. Use of a modified colloidal adhesive prepared according to the method of any one of claims 1 to 11, characterized in that The modified colloidal binder is used as a binder for pelletizing or briquetting of ore fines, to prepare green pellets or green briquettes, which are further oxidized to obtain oxidized pellets or reduced to obtain reduced pellets.

14. Use according to claim 13, wherein the compound is ###00010### or a pharmaceutically acceptable salt thereof. The addition amount of the modified colloidal binder is 0.5%-3.0% of the mass of the ore fines, and the dry mass of the binder is 0.1%-0.6% of the mass of the ore fines.

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