阅读说明：本技术 一种免烘干粘合剂及其制备方法 (Drying-free adhesive and preparation method thereof ) 是由 田国庆 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种适用于型煤生产的免烘干粘合剂,通过氧化镁和碳酸盐的配合使用,使压球后的型煤堆垛放置干燥即可,无需摊开晾晒,合理使用生产场地,最大化地利用了空间；型煤干燥时间短,4～6个小时就可以装袋装车,相比于1～3天的晾晒干燥,节省了大量的生产时间；型煤硬度增长快,最快8个小时型煤的冷压硬度即可达到80kg以上,装袋装车后型煤硬度还会随着粘合剂反应的进行继续增加。此外,该粘合剂还可脱硫去味,型煤产生的灰分少,挥发比常规产品低40％左右,冬天防冻,夏天防雨,储存方便。(The invention discloses a drying-free adhesive suitable for briquette production, which is characterized in that through the matched use of magnesium oxide and carbonate, briquettes after being pressed into balls are stacked, placed and dried, the briquettes are not required to be spread out for airing, the production field is reasonably used, and the space is utilized to the maximum extent; the drying time of the molded coal is short, the molded coal can be bagged and loaded in a car within 4-6 hours, and compared with the drying in the sun for 1-3 days, the production time is greatly saved; the hardness of the molded coal is increased quickly, the cold pressing hardness of the molded coal can reach more than 80kg within 8 hours at the fastest speed, and the hardness of the molded coal after being bagged and loaded can be increased continuously along with the reaction of the adhesive. In addition, the adhesive can also be used for desulfurization and deodorization, the ash content generated by the molded coal is less, the volatilization rate is about 40 percent lower than that of the conventional product, and the molded coal is antifreezing in winter, rainproof in summer and convenient to store.)

1. The drying-free adhesive is characterized by comprising the following preparation raw materials in parts by weight:

40-90 parts of magnesium oxide;

10-60 parts of carbonate;

20-40 parts of an adhesion auxiliary agent;

the magnesium oxide is active magnesium oxide, and the active content is 50-80 wt%.

2. The oven-free adhesive of claim 1, wherein the adhesive aid is selected from the group consisting of cellulose adhesives, vegetable gum adhesives, animal gum adhesives, and polymeric adhesives.

3. The oven-free binder of claim 2 wherein the cellulosic binder is selected from the group consisting of starch, cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, and mixtures of one or more of hydroxyethyl cellulose.

4. The non-drying adhesive of claim 2, wherein the vegetable gum adhesive is selected from one or more of xanthan gum, guar gum, fenugreek gum, gum arabic, soybean gum, rosin, and sodium alginate.

5. The bakeless binder of claim 1 wherein the carbonate is selected from the group consisting of a mixture of one or more of normal carbonates, acidic carbonates, and basic carbonates.

6. The non-drying adhesive according to any one of claims 1 to 5, wherein the preparation raw materials further comprise one or more of magnesium chloride, calcium oxide, phosphate, gypsum powder, bentonite, fly ash, sodium silicate and sodium sulfate.

7. A non-drying adhesive as claimed in claim 6, wherein the magnesium chloride is used in an amount of 0 to 60 wt% based on the magnesium oxide, excluding 0.

8. The non-drying adhesive as claimed in claim 6, wherein the amount of the calcium oxide is 0-25 wt% of the magnesium oxide, excluding 0.

9. The non-drying adhesive as claimed in claim 6, wherein the phosphate is 0-15 wt% of the magnesium oxide, except 0.

10. A method for preparing a non-drying adhesive according to any one of claims 1 to 9, comprising the following steps: and physically blending the preparation raw materials to obtain the composite material.

Technical Field

The invention relates to the technical field of briquette processing, in particular to a drying-free adhesive and a preparation method thereof.

Background

Coal is one of the main energy sources used in the human world since the eighteenth century, and the coal resources in China are rich, the coal consumption is considerable, and the coal accounts for about 70% of the primary energy. Along with the increasing resource problem and environmental problem in the world, clean and efficient combustion of coal is beneficial to reducing environmental pollution and energy waste, and the most important thing is to prepare bulk coal into briquette with multiple purposes.

The molded coal is obtained by mixing, pressing and molding pulverized coal, an adhesive and water, the removal of water in the molded coal can be realized by drying or airing, the drying can increase a large amount of energy cost, and the molded coal needs to be spread and aired for 1-3 days after the adhesive of the existing oven-free molded coal on the market is used (refer to research and application of an oven-free waterproof molded coal adhesive, applicable to the technical market (No. 2 1999), Liqinghua, Jiangjian and Nagjun), so that the airing time is long, the production field is occupied, and the production efficiency is seriously influenced; chinese patent CN104774667 discloses a briquette binder in which a large amount of clay or bentonite is used, the use of such raw materials will increase ash content of coal after combustion, and increase the treatment cost of products after combustion; chinese patent CN1204685 discloses a waterproof baking-free coal binder, in which magnesia and halogen sheets (magnesium chloride) are used, and hydrogen chloride may be generated during the use of the binder, thus posing a threat to the health of workers and the production environment.

Disclosure of Invention

In order to solve the above problems, a first aspect of the present invention provides a non-drying adhesive, which is prepared from at least the following raw materials in parts by weight:

40-90 parts of magnesium oxide;

10-60 parts of carbonate;

20-40 parts of an adhesion auxiliary agent;

the magnesium oxide is active magnesium oxide, and the active content is 50-80 wt%.

In a preferred embodiment, the adhesive aid is one or more selected from the group consisting of cellulose adhesives, vegetable gum adhesives, animal gum adhesives, and polymer adhesives.

In a preferred embodiment, the cellulose-based binder is selected from one or more of starch, cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, and hydroxyethyl cellulose.

As a preferable technical scheme, the vegetable gum adhesive is selected from one or a mixture of xanthan gum, guar gum, fenugreek gum, arabic gum, soybean gum, rosin and sodium alginate.

As a preferred technical solution, the polymer binder is selected from one or more of polyvinyl alcohol, sodium polyacrylate, polyacrylamide, phenolic resin and urea resin.

As a preferred technical scheme, the carbonate is selected from one or more of carbonate, bicarbonate and alkali carbonate.

As a preferable technical scheme, the preparation raw material further comprises one or more of magnesium chloride, calcium oxide, phosphate, gypsum powder, bentonite, fly ash, sodium silicate and sodium sulfate.

As a preferable technical scheme, the dosage of the magnesium chloride is 0-60 wt% of the magnesium oxide, except 0.

As a preferable technical scheme, the dosage of the calcium oxide is 0-25 wt% of the magnesium oxide, except 0.

As a preferable technical scheme, the amount of the phosphate is 0-15 wt% of the magnesium oxide, except 0.

As a preferable technical scheme, the dosage of the gypsum powder is 0-25 wt% of magnesium oxide, except 0.

The second aspect of the present invention provides a preparation method of the above-mentioned non-drying adhesive, including the following steps: and physically blending the preparation raw materials to obtain the composite material.

Has the advantages that: the invention provides a drying-free adhesive suitable for briquette production, which is characterized in that through the matching use of magnesium oxide and carbonate, briquettes after being pressed into balls are stacked, placed and dried, the briquettes do not need to be spread out for airing, the production field is reasonably used, and the space is maximally utilized; the drying time of the molded coal is short, the molded coal can be bagged and loaded in a car within 4-6 hours, and compared with the drying in the sun for 1-3 days, the production time is greatly saved; the hardness of the molded coal is increased quickly, the cold pressing hardness of the molded coal can reach more than 80kg within 8 hours at the fastest speed, and the hardness of the molded coal after being bagged and loaded can be increased continuously along with the reaction of the adhesive. In addition, the adhesive can also be used for desulfurization and deodorization, the ash content generated by the molded coal is less, the volatilization rate is about 40 percent lower than that of the conventional product, and the molded coal is antifreezing in winter, rainproof in summer and convenient to store.

Detailed Description

The invention will be further understood by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. To the extent that a definition of a particular term disclosed in the prior art is inconsistent with any definitions provided herein, the definition of the term provided herein controls.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

As used herein, a feature that does not define a singular or plural form is also intended to include a plural form of the feature unless the context clearly indicates otherwise. It will be further understood that the term "prepared from …," as used herein, is synonymous with "comprising," including, "comprising," "having," "including," and/or "containing," when used in this specification means that the recited composition, step, method, article, or device is present, but does not preclude the presence or addition of one or more other compositions, steps, methods, articles, or devices. Furthermore, the use of "preferred," "preferably," "more preferred," etc., when describing embodiments of the present application, is meant to refer to embodiments of the invention that may provide certain benefits, under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. In addition, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

In order to solve the above problems, a first aspect of the present invention provides a non-drying adhesive, which is prepared from at least the following raw materials in parts by weight:

40-90 parts of magnesium oxide;

10-60 parts of carbonate;

20-40 parts of an adhesion aid.

Magnesium oxide, commonly known as magnesia, of the formula MgO, is a white solid at ambient temperature and has poor water solubility at 0.00062g/100mL (0 ℃) and 0.0086g/100mL (30 ℃) in water.

In some preferred embodiments, the magnesium oxide is activated magnesium oxide from the viewpoint of improving the reaction efficiency of the binder.

In some preferred embodiments, the active magnesium oxide has a magnesium oxide content of 50 to 90 wt%; more preferably, the content of magnesium oxide in the active magnesium oxide is 75-87 wt%.

In some preferred embodiments, the active content of the active magnesium oxide is 55 wt% to 85 wt%; more preferably, the active content of the active magnesium oxide is 60 wt% to 75 wt%.

In some preferred embodiments, the active magnesium oxide contains 3 wt% to 10 wt% of silica.

In some preferred embodiments, the active magnesium oxide contains 1 wt% to 6 wt% of calcium oxide; more preferably, the active magnesium oxide contains 1.1 wt% to 5 wt% of calcium oxide.

In some preferred embodiments, the particle size of the active magnesium oxide is 150 to 1000 mesh; more preferably, the particle size of the active magnesium oxide is 180-500 meshes.

The term "activated magnesium oxide" as used herein refers to magnesium oxide which has some water solubility and may be commercially available.

The term "magnesium oxide content" as used herein refers to the total content of magnesium element in terms of the content of magnesium oxide in the magnesium oxide product.

The term "active content" as used herein refers to the content of substances in the magnesium oxide which react with magnesium chloride and water to form magnesite cement. The method for determining the active content described herein may be any one known to those skilled in the art, such as hydration, citric acid titration, and the like.

The method for measuring the content of silica and calcium oxide in the active magnesium oxide described in the present application may be any one known to those skilled in the art, such as spectrophotometry, X-ray fluorescence spectroscopy, inductively coupled plasma spectroscopy, and the like.

The method for determining the particle size of the active magnesium oxide described herein may be any known to those skilled in the art, such as sieving. The particle size of the active magnesium oxide can be customized with the purchasing manufacturer.

Commercially available magnesium oxide generally contains impurities, and the content of magnesium oxide is calculated by converting the content of magnesium element into magnesium oxide, and due to the preparation process, the standing condition and the like, the magnesium oxide is converted into magnesium hydroxide, magnesium carbonate, calcined magnesium oxide and the like, and the magnesium-containing impurities cannot participate in the reaction for generating magnesite gel, so although the magnesium-containing impurities are converted into the content of magnesium oxide, the magnesium-containing impurities cannot be included in the active content, that is, the content of magnesium oxide and the active content are different concepts.

The term "carbonate" as used herein includes the carbonate plus salt (the anion being CO)₃ ^2-) Acid carbonate (anion is HCO)₃ ^-) Basic carbonate (anion is OH)^-And CO₃ ^2-)。

Examples of the carbonate salt include sodium carbonate, potassium carbonate, calcium carbonate, magnesium carbonate, barium carbonate, and zinc carbonate.

Examples of the acid carbonate include sodium hydrogencarbonate, potassium hydrogencarbonate, calcium hydrogencarbonate, magnesium hydrogencarbonate, and the like.

As the basic carbonate, basic copper carbonate can be exemplified.

In some preferred embodiments, the carbonate is selected from a mixture of one or more of normal carbonate, acid carbonate, and basic carbonate.

In some preferred embodiments, the carbonate is an acid carbonate and/or a base carbonate; further preferably, the carbonate is an acid carbonate.

The magnesium oxide is used in the production of the molded coal, on one hand, the magnesium oxide can provide a consolidation effect for the molded coal, and on the other hand, the magnesium oxide can carry out sulfur fixation in the combustion process of the coal. The solidification of magnesium oxide requires the addition of water, and because magnesium oxide has poor water solubility, it needs to be solidified after forming gel by other raw materials, as described in chinese patent CN1204685, magnesium oxide reacts with magnesium chloride and water to generate solid mg (oh) Cl precipitate. In actual production, heat is released in the process of magnesium oxide dissolution, and Mg (OH) Cl is decomposed under the heating condition to generate hydrogen chloride gas, so that the environment is polluted, and the health of workers is not facilitated.

The inventor researches and tests more than 100 magnesium oxide raw materials in various magnesium oxide manufacturers all over the country, and finally discovers that a specific active magnesium oxide can meet the use requirement, the specific active magnesium oxide and carbonate can form a very simple adhesive, the production cost is greatly reduced, the production process is simplified, and compared with the existing adhesive sold on the market, the product can be dried and hardened more quickly.

The active magnesium oxide has certain water solubility, a large amount of heat is released in the dissolving process, the moisture in the molded coal can be evaporated, and the drying-free effect is achieved. Carbonate generally plays a role in desulfurization and carbon fixation and improvement of combustion efficiency in briquette production, but the inventor unexpectedly discovers that the carbonate can greatly improve the reaction rate of magnesium oxide and water because the carbonate is decomposed under the influence of dissolution and heat release of magnesium oxide, particularly, bicarbonate can release water and carbon dioxide, magnesium hydroxide is difficult to attach to the outer layer of magnesium oxide in the process of releasing a large amount of gas outwards, the magnesium oxide is ensured to continuously react with water, and water generated by decomposition of bicarbonate can also participate in the hardening reaction of magnesium oxide, so that the hardness of the briquette is continuously improved in the standing process.

Generally, the higher the mesh number of the magnesium oxide and the less the impurities, the better the performance, however, the inventors have found unexpectedly in a large number of practices that, on the contrary, the too high mesh number of the magnesium oxide makes it difficult to increase the hardness of the briquette, presumably because the size of the magnesium oxide after consolidation is too small to form the supporting framework of the briquette; the inventor also finds that impurities of silicon dioxide and calcium oxide in the magnesium oxide have an effect of promoting the consolidation and hardening of the briquette, the reaction environment is changed into alkalinity due to the dissolution of the magnesium oxide and the hydrolysis of carbonate, the silicon dioxide and hydroxyl are gradually converted into sodium silicate due to the action of the sodium silicate, the bonding effect of the briquette is improved, and the calcium oxide is dissolved in water and then reacts with carbonate to form calcium carbonate, so that the hardening of the briquette is accelerated.

In some preferred embodiments, the carbonate is a normal carbonate and/or an bicarbonate.

In some preferred embodiments, the carbonate is a mixture of a normal carbonate and an acid carbonate in a weight ratio of 1: (10-70); further preferably, the weight ratio of the normal carbonate to the bicarbonate is 1: (15-60); further, the weight ratio of the normal carbonate to the bicarbonate is 1: (20 to 50).

The inventor finds that the combination of the carbonate and the bicarbonate can further shorten the consolidation time of the briquette and improve the hardness of the briquette because the bicarbonate is easier to decompose and release gas and increases the water solubility of magnesium oxide compared with the carbonate, while the carbonate is more alkaline and can supplement carbonate ions in a system to enable impurities in the magnesium oxide to play corresponding roles, and the two carbonates have different roles and generate synergy with the magnesium oxide.

In some preferred embodiments, the weight ratio of the magnesium oxide to the carbonate is (1-20): 3; more preferably, the weight ratio of the magnesium oxide to the carbonate is (3-15): 3; furthermore, the weight ratio of the magnesium oxide to the carbonate is (4-10): 3.

the binder aid in the present application is used to provide binding power to the molded coal, and its specific selection is not particularly limited and may be commercially available.

In some preferred embodiments, the bonding aid is selected from one or more of a cellulose-based adhesive, a vegetable gum-based adhesive, an animal gum-based adhesive, and a polymer-based adhesive.

Examples of the cellulose-based binder include one or a mixture of more of starch, cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, and hydroxyethyl cellulose.

Examples of the vegetable gum-based binder include xanthan gum, guar gum, fenugreek gum, gum arabic, soybean gum, rosin, and/or sodium alginate.

Examples of the animal glue-based adhesive include bone glue and skin glue.

The polymer binder may be one or a mixture of polyvinyl alcohol, sodium polyacrylate, polyacrylamide, phenol resin, and urea resin.

In some preferred embodiments, the preparation raw material further comprises a mixture of one or more of magnesium chloride, calcium oxide, phosphate, gypsum powder, bentonite, fly ash, sodium silicate and sodium sulfate.

From the viewpoint of further improving the water solubility of magnesium oxide in the binder and the sulfur fixing effect of the briquette, in some preferred embodiments, the preparation raw material further comprises magnesium chloride in an amount of 0-60 wt% of magnesium oxide, except for 0.

From the viewpoint of further improving the drying speed and hardness of the briquette, in some preferred embodiments, the preparation raw material further comprises calcium oxide in an amount of 0-25 wt% of magnesium oxide, except 0.

From the viewpoint of further improving the desulfurization and sulfur fixation effects of the molded coal, in some preferred embodiments, the preparation raw material further comprises 0-5 parts by weight of phosphate, the amount of phosphate is 0-15 wt% of magnesium oxide, except 0.

From the viewpoint of further improving the binding power of the binder and the hardness of the briquette, in some preferred embodiments, the preparation raw material further comprises gypsum powder in an amount of 0-25 wt% of magnesium oxide, except 0.

The second aspect of the present invention provides a preparation method of the above-mentioned non-drying adhesive, including the following steps: and physically blending the preparation raw materials to obtain the composite material.