阅读说明：本技术 一种碳酸钙抑制剂及其制备方法和用途 (Calcium carbonate inhibitor and preparation method and application thereof ) 是由 廖义芳 祖兴龙 钟高胜 于 2021-08-13 设计创作，主要内容包括：本发明公开了一种碳酸钙抑制剂及其制备方法和用途,该碳酸钙抑制剂主要包括淀粉、醋酸、碳酸钠以及硫酸钠。其制备工艺简单,采用该碳酸钙抑制剂进行萤石矿浮选工艺,对碳酸钙及其他碳酸盐脉石矿物具有优异的抑制效果,使得萤石精矿产品既具有极低的碳酸钙含量,又能够极大的提高选矿的回收率,进而获得高品质的萤石精矿产品。同时该碳酸钙抑制剂还具有对设备无腐蚀损害,对环境无污染,无毒环保易降解等特点。(The invention discloses a calcium carbonate inhibitor, a preparation method and application thereof. The preparation process is simple, and the calcium carbonate inhibitor has excellent inhibition effect on calcium carbonate and other carbonate gangue minerals by adopting the fluorite ore flotation process, so that the fluorite concentrate product has extremely low calcium carbonate content, the recovery rate of ore dressing can be greatly improved, and the high-quality fluorite concentrate product is obtained. Meanwhile, the calcium carbonate inhibitor has the characteristics of no corrosion damage to equipment, no pollution to the environment, no toxicity, environmental protection, easy degradation and the like.)

1. a calcium carbonate inhibitor characterized by: the calcium carbonate inhibitor comprises:

68-84 parts of starch, preferably 70-80 parts of starch, and more preferably 72-78 parts of starch;

0.1 to 3 parts by weight of acetic acid, preferably 0.2 to 2.5 parts by weight, more preferably 0.3 to 2 parts by weight;

0.1 to 3 parts by weight of sodium carbonate, preferably 0.3 to 2.5 parts by weight, more preferably 0.5 to 2 parts by weight;

sodium sulfate 15-32 parts by weight, preferably 18-30 parts by weight, more preferably 20-28 parts by weight.

2. The calcium carbonate inhibitor according to claim 1, wherein: the acetic acid is an acetic acid solution, and the concentration of the acetic acid solution is 3-20 wt%, preferably 5-18 wt%, and more preferably 8-15 wt%; for example, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%.

3. The calcium carbonate inhibitor according to claim 1 or 2, characterized in that: the sodium carbonate is a sodium carbonate solution, and the concentration of the sodium carbonate solution is 3-18 wt%, preferably 5-15 wt%, and more preferably 8-12 wt%; for example, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%.

4. The calcium carbonate inhibitor according to any one of claims 1 to 3, characterized in that: the sodium sulfate is anhydrous sodium sulfate.

5. A method of preparing the calcium carbonate inhibitor of any one of claims 1 to 4, wherein: the method comprises the following steps:

1) uniformly mixing starch and acetic acid solution to obtain acidified starch;

2) pre-drying acidified starch, and then performing heat treatment to obtain a dry material;

3) and adding a sodium carbonate solution and sodium sulfate into the dry materials, and uniformly mixing to obtain the calcium carbonate inhibitor.

6. The method of claim 5, wherein: the step 1) is specifically as follows: adding starch into a mixer, and adjusting the stirring speed of the mixer to be 15-100r/min (preferably 30-80 r/min); then adding the acetic acid solution into the starch in a spraying or atomizing mode; after the addition is finished, stirring is continued for 1-15min (preferably 3-10min) to obtain the acidified starch.

7. The method according to claim 5 or 6, characterized in that: the step 2) is specifically as follows: putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 5-60min (preferably 10-40min) by using air flow, wherein the temperature of the air flow is 20-45 ℃ (preferably 25-35 ℃); then the pre-dried acidified starch is placed in a roaster to be thermally treated for 0.5-4h (preferably 1-3h) at the temperature of 100-.

8. The method according to any one of claims 5-7, wherein: the step 3) is specifically as follows: adding the dry materials into a mixer, adding a sodium carbonate solution into the dry materials in a spraying or misting mode, and adding sodium sulfate into the mixer; after the addition is finished, continuously stirring and uniformly mixing, and screening to obtain a powdery calcium carbonate inhibitor;

preferably, the particle size of the powdery calcium carbonate inhibitor is not more than 80 meshes, preferably not more than 100 meshes;

the water content of the powdery calcium carbonate inhibitor is 2 to 7% by weight, preferably 3 to 5% by weight, for example, any one of 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3.0%, 3.2%, 3.4%, 3.6%, 3.8%, 4.0%, 4.2%, 4.4%, 4.6%, 4.8%, 5.0%, 5.2%, 5.5%, 5.8%, 6.0%, 6.5%, 7.0% by weight.

9. Use of the calcium carbonate inhibitor according to any one of claims 1 to 4 or the calcium carbonate inhibitor prepared by the process according to any one of claims 5 to 8, wherein: the calcium carbonate depressant is used for ore flotation, preferably fluorite flotation.

10. Use according to claim 9, characterized in that: the calcium carbonate inhibitor is used for fluorite flotation, and specifically comprises the following steps: adding the powdery calcium carbonate inhibitor into water under stirring for dissolving, and obtaining 3-15 wt% (preferably 5-12 wt%) calcium carbonate inhibitor solution after complete dissolution; then, when the fluorite ore is roughly selected, raw ore is added into a primary selection groove according to the proportion of 300-800g/t (preferably 400-650g/t) of the raw ore by the weight of the dry powder of the calcium carbonate inhibitor;

preferably, when the content of calcium carbonate in the raw ore is more than 20 wt%, the calcium carbonate inhibitor solution is additionally added in the proportion of 150-300g/t (preferably 180-250g/t) of the raw ore based on the weight of the dry powder of the calcium carbonate inhibitor in the third concentration and/or the fifth concentration.

Technical Field

The invention relates to a calcium carbonate inhibitor, in particular to a calcium carbonate inhibitor, a preparation method and application thereof, and belongs to the technical field of ore dressing impurity inhibiting medicaments.

Background

Along with the continuous exploitation and use of fluorite, the high-grade fluorite and the easily selected fluorite are less and less, and the co-raw fluorite ore becomes the main stream of fluorite resource utilization. Many fluorite mineral reserves are (concomitant) generated with calcium carbonate ores (calcite and bluestone), and the ores belong to refractory ores in fluorite flotation purification production operation because the specific gravities of the fluorite, the calcite and the bluestone are not only similar, but also the activities of the fluorite, the calcite and the bluestone, which are acted by a flotation collector are also similar, and the impurities such as the calcite and the like are difficult to effectively inhibit and remove by adopting a conventional fluorite beneficiation reagent system. In order to inhibit calcium carbonate, mineral separation scientific research technicians develop various medicament systems, for example, inhibitors such as tannin, tannin extract, salinized water glass, acidified water glass, sodium hexametaphosphate, lignosulfonate, aluminum sulfate matched with water glass, citric acid, dextrin matched with a surfactant, sulfate and the like are adopted to inhibit calcium carbonate so as to realize the separation of calcium carbonate gangue impurities and fluorite, but the effects are not ideal, or calcium carbonate still cannot be reduced, so that the product cannot meet the industrial grade requirement, or the mineral separation recovery rate is low, and resources are wasted.

Chinese patent document CN101585016A discloses a flotation separation method for low-grade fluorite barite, which uses acidified water glass as an inhibitor for siliceous minerals and calcium carbonate minerals, uses oleic acid (in roughing and scavenging) as a collector for fluorite and barite, and uses starch, sodium sulfate, hydrochloric acid, and sodium hexametaphosphate as an inhibitor for barite minerals (in concentrating). Under the conditions that the grade of the feeding fluorite is 33.92-40.14 percent and the grade of the barite is 34.67-35.33 percent, the fluorite concentrate with the grade of more than 95 percent and the recovery rate of 75.5-78.55 percent is obtained; the barite grade is 92.3-93.27%, and the recovery rate is 75.2-79.73%.

Chinese patent document CN108246511A discloses a calcium carbonate inhibitor for fluorite ore dressing and a preparation method thereof, wherein the calcium carbonate inhibitor comprises dextrin, ABS and sulfate in a weight ratio of 1: 0.1-2: 0.5-3; preparing the calcium carbonate inhibitor. The calcium carbonate inhibitor is used for inhibiting the content of CaCO of 35.1 percent₃The 19.82% Henan Xinyang fluorite ore is subjected to mineral separation to obtain concentrate with calcium carbonate content of 0.87%, and the recovery rate of more than 80.2%, so that the grade of the concentrate reaches 97.59%.

Chinese patent document CN110052333A discloses an inhibitor for fluorite ore flotation process and a preparation method thereof, wherein oxalic acid and water are mixed to obtain a material A, water glass is mixed with water to obtain a material B, sodium p-aminotoluene sulfonate is dissolved in a tannic acid solution, heating to 90-100 deg.C, adding sodium carbonate, stirring, mixing, cooling in ice bath, adding sodium nitrite solution and aniline, adjusting pH to 9-10 with sodium hydroxide to obtain material C, mixing deionized water, starch, aluminum chloride and sodium sulfate with 80-90 deg.C under stirring to obtain material D, mixing material A, material B, material C and material D under stirring, and adding sodium hexametaphosphate, aluminum sulfate, tannin extract, zinc sulfate, polyaspartic acid, oleic acid and ethylene diamine tetraacetic acid, adding water, and dispersing by ultrasonic to obtain the inhibitor for the fluorite ore flotation process. The fluorite flotation process is carried out by adopting the inhibitor, and the recovery rate of concentrate is 75-79%.

In the prior art, either the content of calcium carbonate in ore concentrate is high, so that the product can not meet the requirement of industrial grade, or the ore dressing recovery rate is low, so that resources are wasted.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a calcium carbonate inhibitor and a preparation method and application thereof, the calcium carbonate inhibitor has simple component composition and convenient preparation process, and the calcium carbonate inhibitor has excellent inhibition effect on calcium carbonate and other carbonate gangue minerals by adopting a fluorite ore flotation process, so that the fluorite concentrate product has extremely low calcium carbonate content, and the mineral dressing recovery rate can be greatly improved, thereby obtaining the fluorite concentrate product with high quality. Meanwhile, the calcium carbonate inhibitor has the characteristics of no corrosion damage to equipment, no pollution to the environment, no toxicity, environmental protection, easy degradation and the like.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

according to a first embodiment of the present invention, there is provided a calcium carbonate inhibitor.

A calcium carbonate inhibitor, the calcium carbonate inhibitor comprising:

68-84 parts of starch, preferably 70-80 parts of starch, and more preferably 72-78 parts of starch.

Acetic acid is 0.1 to 3 parts by weight, preferably 0.2 to 2.5 parts by weight, and more preferably 0.3 to 2 parts by weight.

Sodium carbonate is 0.1 to 3 parts by weight, preferably 0.3 to 2.5 parts by weight, more preferably 0.5 to 2 parts by weight.

Sodium sulfate 15-32 parts by weight, preferably 18-30 parts by weight, more preferably 20-28 parts by weight.

Preferably, the acetic acid is an acetic acid solution, and the concentration of the acetic acid solution is 3-20 wt%, preferably 5-18 wt%, and more preferably 8-15 wt%; for example, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%.

In general, the acetic acid solution is prepared from commercially available 36 wt% concentrated acetic acid.

Preferably, the sodium carbonate is a sodium carbonate solution having a concentration of 3 to 18 wt%, preferably 5 to 15 wt%, more preferably 8 to 12 wt%. For example, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%.

It should be noted that, in general, a sodium carbonate solution is prepared by using commercially available 98 wt% industrial pure sodium carbonate.

Preferably, the sodium sulfate is anhydrous sodium sulfate.

According to a second embodiment of the present invention, a method of preparing a calcium carbonate inhibitor is provided.

A method of preparing a calcium carbonate inhibitor or a method of preparing a calcium carbonate inhibitor according to the first embodiment, the method comprising the steps of:

1) and uniformly mixing the starch and the acetic acid solution to obtain the acidified starch.

2) The acidified starch is pre-dried and then subjected to heat treatment to obtain a dry material.

3) And adding a sodium carbonate solution and sodium sulfate into the dry materials, and uniformly mixing to obtain the calcium carbonate inhibitor.

Preferably, step 1) is specifically: the starch is added to the mixer and the stirring rate of the mixer is adjusted to 15-100r/min (preferably 30-80 r/min). The acetic acid solution is then added to the starch by spraying or misting. After the addition is finished, stirring is continued for 1-15min (preferably 3-10min) to obtain the acidified starch.

Preferably, step 2) is specifically: the acidified starch is placed in a pre-dryer and pre-dried for 5-60min (preferably 10-40min) with an air stream at a temperature of 20-45 deg.C (preferably 25-35 deg.C). Then the pre-dried acidified starch is placed in a roaster to be thermally treated for 0.5-4h (preferably 1-3h) at the temperature of 100-.

Preferably, step 3) is specifically: the dry material is added to the mixer, then the sodium carbonate solution is added to the dry material by spraying or misting and the sodium sulfate is added to the mixer. After the addition is finished, the mixture is continuously stirred and uniformly mixed, and the powdery calcium carbonate inhibitor is obtained after screening.

Preferably, the particle size of the powdery calcium carbonate inhibitor is 80 mesh or less, preferably 100 mesh or less.

Preferably, the water content of the powdery calcium carbonate inhibitor is 2 to 7% by weight, preferably 3 to 5% by weight, for example, any one of 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3.0%, 3.2%, 3.4%, 3.6%, 3.8%, 4.0%, 4.2%, 4.4%, 4.6%, 4.8%, 5.0%, 5.2%, 5.5%, 5.8%, 6.0%, 6.5%, 7.0% by weight.

According to a third embodiment of the present invention, there is provided a use of a calcium carbonate inhibitor.

Use of a calcium carbonate inhibitor or a calcium carbonate inhibitor as described in the first embodiment or prepared by the process of the second embodiment for ore flotation, preferably fluorite flotation.

Preferably, the calcium carbonate inhibitor is used for fluorite flotation, and specifically comprises the following steps: the powdery calcium carbonate inhibitor is added into water to be dissolved under stirring, and after the dissolution is completed, a 3-15 wt% (preferably 5-12 wt%) calcium carbonate inhibitor solution is obtained. Then, in the rough concentration of the fluorite ore, the raw ore is added into a rough concentration tank at the ratio of 300-800g/t (preferably 400-650g/t) of raw ore based on the weight of the dry powder of the calcium carbonate inhibitor.

Preferably, when the content of calcium carbonate in the raw ore is more than 20 wt%, the calcium carbonate inhibitor solution is additionally added in the proportion of 150-300g/t (preferably 180-250g/t) of the raw ore based on the weight of the dry powder of the calcium carbonate inhibitor in the third concentration and/or the fifth concentration.

In the prior art, a calcium carbonate inhibitor is often needed for fluorite ores with high impurity content such as calcium carbonate and the like so as to improve the recovery rate of mineral separation products, in the prior art, the calcium carbonate is inhibited by adopting inhibitors such as tannin, tannin extract, saline water glass, acidified water glass, sodium hexametaphosphate, lignosulfonate, aluminum sulfate matched water glass, citric acid, dextrin matched surfactant, sulfate and the like so as to realize the separation of calcium carbonate gangue impurities and fluorite, but the effect is not ideal, or the calcium carbonate still can not be reduced, so that the product can not reach the industrial grade requirement, or the mineral separation recovery rate is very low, and resources are wasted.

In the invention, environment-friendly and renewable starch is used as a main raw material, and a series of cross-linking and cracking reactions are carried out on the starch under the conditions of heating at high temperature (for example, 100-200 ℃ and preferably 120-180 ℃) after the starch is subjected to acid leaching by using an acetic acid solution (the concentration is 3-20wt percent, for example, 10wt percent) to generate a plurality of low-molecular glucose polymers, wherein the low-molecular glucose polymers comprise a common glucose polymer only containing hydroxyl and aldehyde groups and a modified glucose polymer containing both hydroxyl aldehyde groups and carboxyl groups; hydroxyl, aldehyde group and carboxyl in the glucose polymers are active functional groups, so that the glucose polymers not only have flocculation performance, but also have good hydrophilicity, surface activity, complexing ability, adsorption and dispersion ability and the like. In neutral to weakly acidic environment, under the corrosive action of sulfate radicals and other ions released by sodium sulfate, calcium ions in crystal lattices of ore particles are easily exposed and then adsorbed on glucose polymer molecules with low molecules to form hydrophilic complex copolymer, so that the ore particles are inhibited from entering the ore pulp, and the aim of separating from foam minerals is fulfilled. Meanwhile, the carboxylic acid radical has stronger stability than the carbonate radical, so the carboxylic acid radical is introduced into the starch lysate through the acetic acid, the starch lysate (namely the low molecular glucose polymer) can be greatly increased in the pulp solution, and the starch lysate can be selectively adsorbed on the surface of carbonate minerals, thereby achieving the purpose of effectively inhibiting the carbonate minerals such as calcium carbonate and the like.

In the present invention, since the surface of calcium carbonate-containing minerals (calcite, bluestone, etc.) is often covered with metal impurities containing iron, aluminum, etc., on the one hand, the existing fluorite collector is generally opposite to Fe³⁺、Al²⁺Have certain collecting nature, the mistake is carried calcium carbonate and is carried on collecting too easily when collecting iron ion and aluminium ion, and on the other hand, because calcium carbonate is covered by iron, aluminium etc. on the surface, lead to calcium carbonate effectively to expose, and then be difficult for being inhibited by medicament adsorption complex hydrophilic copolymer. In order to solve the problems, sodium sulfate is added into the inhibitor, and the sodium sulfate releases a large amount of sulfate ions in a neutral to weakly acidic environment, and can form metal complexes with iron, aluminum and the like, namely the metal ions are eliminated by a complexing method, and simultaneously, because impurity layer metal such as iron, aluminum and the like is corroded by the sodium sulfate, calcium carbonate is exposed and then adsorbed by a low-molecular glucose polymer.

In the invention, the acidified starch wetted by the dilute acetic acid solution is subjected to high-temperature roasting treatment after being subjected to pre-drying, wherein the pre-drying generally adopts a mode of rapid air flow drying to accelerate moisture removal, and the pre-drying treatment of the acidified starch can prevent the problems of starch agglomeration, poor fluidity, uneven heating and the like during subsequent heat treatment roasting; typically, the moisture content of the acidified starch is between about 1% and about 5% after pre-drying. After the pre-drying is completed, the pre-dried acidified starch is placed in a roasting furnace for roasting heat treatment, the heat treatment temperature is generally 100-200 ℃ (preferably 120-180 ℃) for 0.5-4h (preferably 1-3h), and after the roasting is completed, the roasted acidified starch is cooled (preferably naturally cooled to room temperature, such as overnight cooling), so as to obtain the roasted dry material. In order to prevent foaming during water distribution, the present invention uses dilute soda ash solution (with a concentration of 3-18 wt%, for example, 10 wt%) to spray the dry material uniformly, and adds a certain amount of anhydrous sodium sulfate powder to mix uniformly, so that the water content of the final material (powdered calcium carbonate inhibitor) is between 2-7 wt% (preferably 3-5 wt%, for example, 3.8 wt%). The water content of the calcium carbonate inhibitor in a dry powder state is controlled, so that the problem of foaming in the subsequent use process, particularly in the water distribution use process, can be effectively prevented.

Compared with the prior art, the invention has the following beneficial technical effects:

1. according to the invention, acidulous acetic acid is adopted to carry out acidification treatment on starch, so that the acidified starch generates a plurality of glucose polymers containing hydroxyl, aldehyde and carboxyl low molecules through a series of crosslinking cracking reactions under the condition of heating at high temperature, and the polymers have good flocculation performance, hydrophilicity, surface activity, complexing capacity and adsorption and dispersion capacity, can be selectively adsorbed on the surface of carbonate minerals, and thus the purpose of effectively inhibiting carbonate minerals such as calcium carbonate and the like is achieved.

2. The calcium carbonate inhibitor prepared by the invention can be selectively adsorbed on the surface of carbonate minerals to form hydrophilic complex copolymers when the fluorite ore flotation process is carried out, the hydrophilic complex copolymers enter ore pulp to be inhibited, the aim of separating from foam minerals is achieved, the calcium carbonate inhibitor has good selectivity and inhibition performance, can effectively inhibit the carbonate minerals in fluorite, such as calcite, bluestone and the like, and improves the product grade of fluorite concentrate.

3. By using the calcium carbonate inhibitor, calcium carbonate minerals with the content of 5-30% or higher in fluorite raw ores and other carbonate gangue minerals can be inhibited in tailings, so that the calcium carbonate content of fluorite concentrate products is controlled within 1%, and the ore dressing recovery rate is over 90%; the grade of the concentrate is more than 97 percent; the product quality and the mineral separation recovery rate can be greatly improved, and the product quality and the mineral separation recovery rate reach the standard. The inhibitor is simple and convenient to use and prepare, has no corrosion to equipment, is degradable, has no pollution to water and environment, and meets the national requirements for building green mines.

Drawings

FIG. 1 is a flow chart of the preparation of calcium carbonate inhibition according to the present invention.

Detailed Description

The technical solution of the present invention is illustrated below, and the claimed scope of the present invention includes, but is not limited to, the following examples.

A method of preparing a calcium carbonate inhibitor, the method comprising the steps of:

1) and uniformly mixing the starch and the acetic acid solution to obtain the acidified starch.

2) The acidified starch is pre-dried and then subjected to heat treatment to obtain a dry material.

3) And adding a sodium carbonate solution and sodium sulfate into the dry materials, and uniformly mixing to obtain the calcium carbonate inhibitor.

Preferably, step 1) is specifically: the starch is added to the mixer and the stirring rate of the mixer is adjusted to 15-100r/min (preferably 30-80 r/min). The acetic acid solution is then added to the starch by spraying or misting. After the addition is finished, stirring is continued for 1-15min (preferably 3-10min) to obtain the acidified starch.

Preferably, step 2) is specifically: the acidified starch is placed in a pre-dryer and pre-dried for 5-60min (preferably 10-40min) with an air stream at a temperature of 20-45 deg.C (preferably 25-35 deg.C). Then the pre-dried acidified starch is placed in a roaster to be thermally treated for 0.5-4h (preferably 1-3h) at the temperature of 100-.

Preferably, step 3) is specifically: the dry material is added to the mixer, then the sodium carbonate solution is added to the dry material by spraying or misting and the sodium sulfate is added to the mixer. After the addition is finished, the mixture is continuously stirred and uniformly mixed, and the powdery calcium carbonate inhibitor is obtained after screening.

Preferably, the particle size of the powdery calcium carbonate inhibitor is 80 mesh or less, preferably 100 mesh or less.

Preferably, the water content of the powdery calcium carbonate inhibitor is 2 to 7% by weight, preferably 3 to 5% by weight, for example, any one of 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3.0%, 3.2%, 3.4%, 3.6%, 3.8%, 4.0%, 4.2%, 4.4%, 4.6%, 4.8%, 5.0%, 5.2%, 5.5%, 5.8%, 6.0%, 6.5%, 7.0% by weight.

Example 1

75 parts of starch were added to the mixer, and the stirring speed of the mixer was adjusted to 70 r/min. Then 0.72 parts of acetic acid (10% by weight acetic acid solution) is added to the starch by spraying or misting. After the addition is completed, stirring is continued for 10min to obtain acidified starch.

Putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified starch in a roaster to perform heat treatment at 160 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.47 parts of sodium carbonate (10 wt% sodium carbonate solution) into the dry materials in a spraying or sprinkling mode, adding 22.81 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor I.

Example 2

75 parts of starch were added to the mixer, and the stirring speed of the mixer was adjusted to 70 r/min. Then 0.72 parts of acetic acid (12 wt% acetic acid solution) is added to the starch by spraying or misting. After the addition is completed, stirring is continued for 10min to obtain acidified starch.

Putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified starch in a roaster to perform heat treatment at the temperature of 170 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.96 parts of sodium carbonate (10 wt% sodium carbonate solution) into the dry materials by adopting a spraying or atomizing mode, adding 22.32 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor II.

Example 3

74 parts of starch were added to the mixer, and the stirring rate of the mixer was adjusted to 80 r/min. Then 0.9 part of acetic acid (15 wt% acetic acid solution) is added to the starch by spraying or misting. After the addition is completed, stirring is continued for 10min to obtain acidified starch.

Putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified starch in a roaster to perform heat treatment at the temperature of 180 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.96 parts of sodium carbonate (12 wt% sodium carbonate solution) into the dry materials in a spraying or sprinkling mode, adding 23.14 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor III.

Example 4

74 parts of starch were added to the mixer, and the stirring rate of the mixer was adjusted to 80 r/min. Then 0.9 part of acetic acid (18 wt% acetic acid solution) is added to the starch by spraying or misting. After the addition is completed, stirring is continued for 10min to obtain acidified starch.

Putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified starch in a roaster to perform heat treatment at the temperature of 180 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.96 parts of sodium carbonate (12 wt% sodium carbonate solution) into the dry materials in a spraying or sprinkling mode, adding 23.14 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor IV.

Example 5

74 parts of starch were added to the mixer, and the stirring rate of the mixer was adjusted to 80 r/min. Then 0.9 part of acetic acid (30 wt% acetic acid solution) is added to the starch by spraying or misting. After the addition is completed, stirring is continued for 10min to obtain acidified starch.

Putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified starch in a roaster to perform heat treatment at the temperature of 180 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.96 parts of sodium carbonate (12 wt% sodium carbonate solution) into the dry materials in a spraying or atomizing mode, adding 23.14 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor V.

Example 6

74 parts of starch were added to the mixer, and the stirring rate of the mixer was adjusted to 80 r/min. Then 0.9 part of acetic acid (3 wt% acetic acid solution) is added to the starch by spraying or misting. After the addition is completed, stirring is continued for 10min to obtain acidified starch.

Putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified starch in a roaster to perform heat treatment at the temperature of 180 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.96 parts of sodium carbonate (12 wt% sodium carbonate solution) into the dry materials in a spraying or sprinkling mode, adding 23.14 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor VI.

Comparative example 1

75 parts of starch were added to the mixer, and the stirring speed of the mixer was adjusted to 70 r/min. 0.72 parts of hydrochloric acid (10% by weight hydrochloric acid solution) is then added to the starch by spraying or misting. After the addition is completed, stirring is continued for 10min to obtain acidified starch.

Putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified starch in a roaster to perform heat treatment at 160 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.47 parts of sodium carbonate (10 wt% sodium carbonate solution) into the dry materials by adopting a spraying or atomizing mode, adding 22.81 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor Ic.

Comparative example 2

75 parts of starch were added to the mixer, and the stirring speed of the mixer was adjusted to 70 r/min. 0.72 parts oxalic acid (12 wt% oxalic acid solution) is then added to the starch by spraying or misting. After the addition is completed, stirring is continued for 10min to obtain acidified starch.

Putting the acidified starch into a pre-dryer, and pre-drying the acidified starch for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified starch in a roaster to perform heat treatment at the temperature of 170 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.96 parts of sodium carbonate (10 wt% of sodium carbonate solution) into the dry materials in a spraying or sprinkling mode, adding 22.32 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor IIc.

Comparative example 3

75 parts of caustic starch was added to the mixer, and the stirring rate of the mixer was adjusted to 70 r/min. 0.72 parts of acetic acid (10% by weight acetic acid solution) is then added to the caustic starch by spraying or misting. After the addition was complete, stirring was continued for 10min to obtain acidified caustic starch.

The acidified starch was placed in a predryer and predried for 30min with 25 ℃ air flow. And then placing the pre-dried acidified caustic starch in a roaster to perform heat treatment at the temperature of 160 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, then adding 1.47 parts of sodium carbonate (10 wt% sodium carbonate solution) into the dry materials in a spraying or sprinkling mode, adding 22.81 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor IIIc.

Comparative example 4

74 parts of dextrin was added to the mixer, and the stirring rate of the mixer was adjusted to 80 r/min. Then 0.9 part of acetic acid (12 wt% acetic acid solution) is added to the dextrin by spraying or misting. After the addition was completed, stirring was continued for 10min to obtain acidified dextrin.

And (3) putting the acidified dextrin into a pre-dryer, and pre-drying the acidified dextrin for 30min by adopting 25 ℃ air flow. And then placing the pre-dried acidified dextrin in a roaster to perform heat treatment at the temperature of 180 ℃ for 2 hours, and after roasting is completed, cooling to room temperature and standing overnight to obtain a dry material.

Adding the dry materials into a mixer, adding 1.96 parts of sodium carbonate (12 wt% sodium carbonate solution) into the dry materials in a spraying or sprinkling mode, adding 23.14 parts of anhydrous sodium sulfate into the mixer, continuously stirring and uniformly mixing, and screening to obtain the powdery calcium carbonate inhibitor IVc.

Application example 1

The calcium carbonate inhibitors I to V obtained in examples 1 to 5 and the calcium carbonate inhibitors Ic to IVc obtained in comparative examples 1 to 4 were dissolved in water while stirring, and water was added during stirring to completely dissolve each of them, thereby obtaining dilute calcium carbonate inhibitor solutions each having a mass content of 8 wt%.

Selecting a certain fluorite ore with the calcium carbonate content of 28.12 wt% in the city of cupronickel, Guizhou province, carrying out flotation on the fluorite ore, adopting the calcium carbonate inhibitor dilute solution prepared in the above embodiment and comparative example as a beneficiation inhibitor, respectively adding the calcium carbonate inhibitor dilute solution into different ore selecting tanks at a raw ore ratio of 580g/t (by weight of calcium carbonate inhibitor dry powder) during mineral roughing, and simultaneously supplementing each calcium carbonate inhibitor at a raw ore ratio of 200g/t (by weight of calcium carbonate inhibitor dry powder) during third beneficiation. And after the flotation is finished, respectively measuring and calculating the calcium carbonate content, the recovery rate and the concentrate grade of the concentrate. The results are shown in table 1: