CN114956609B - Low-cost calcium hydroxide suspension and preparation method thereof - Google Patents
Low-cost calcium hydroxide suspension and preparation method thereof Download PDFInfo
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- CN114956609B CN114956609B CN202210709114.8A CN202210709114A CN114956609B CN 114956609 B CN114956609 B CN 114956609B CN 202210709114 A CN202210709114 A CN 202210709114A CN 114956609 B CN114956609 B CN 114956609B
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2/00—Lime, magnesia or dolomite
- C04B2/02—Lime
- C04B2/04—Slaking
- C04B2/08—Devices therefor
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2/00—Lime, magnesia or dolomite
- C04B2/02—Lime
- C04B2/04—Slaking
- C04B2/06—Slaking with addition of substances, e.g. hydrophobic agents ; Slaking in the presence of other compounds
Abstract
The invention discloses a low-cost calcium hydroxide suspension and a preparation method thereof, wherein high-activity quicklime and common active quicklime are uniformly mixed, crushed and sieved, slaking water is added into a reactor with a stirring device, an active accelerator and/or a stabilizer are added into the slaking water, quicklime is added into the reactor under the condition that the stirring device is continuously stirred, the reaction time of the slaking reaction temperature is not more than 70 minutes and not less than 20 minutes in the slaking reaction process, and the product mixed solution in the reactor is subjected to cyclone separation and/or sieving after the slaking reaction is finished, so that large particle impurities in the product mixed solution are removed, and a target calcium hydroxide suspension finished product is obtained. According to the invention, the calcium hydroxide suspension with low cost, low viscosity, high reactivity and high calcium hydroxide content can be obtained by adopting the mixture ratio of the high-activity quicklime and the common-activity quicklime to accurately control the raw materials, the process and the auxiliary agent, so that the application range of the product is increased.
Description
Technical Field
The invention belongs to the technical field of calcium hydroxide production, and relates to a low-cost calcium hydroxide suspension and a preparation method thereof.
Background
The calcium hydroxide is widely applied to the water treatment fields of acid wastewater neutralization, heavy metal ion removal, phosphate ion, sulfate ion, fluoride ion and the like. In water treatment practice, calcium hydroxide is generally used in suspension with water or after wet digestion of calcium oxide to give a calcium hydroxide suspension.
The calcium hydroxide has the advantages of good safety and cheaper price than inorganic alkaline treating agents such as sodium hydroxide, sodium carbonate and the like, but the defects mainly comprise two aspects: firstly, calcium hydroxide is slightly dissolved in water, and compared with water-soluble alkali such as sodium hydroxide, when chemical reaction occurs, calcium hydroxide is firstly dissolved in water, then calcium ions or hydroxyl ions react with harmful substances in wastewater, so that the treatment speed of the calcium hydroxide is slower than that of the water-soluble alkali such as sodium hydroxide when the wastewater is treated, and the water treatment efficiency is influenced; secondly, the solid content of the general calcium hydroxide suspension is 5-10% (the concentration of the sodium hydroxide solution which is commonly used in water treatment is more than 30%), and the concentration is higher, so that the viscosity of the suspension is too high, and the suspension is difficult to convey and meter, which obviously increases the production load and the production cost of the slurry preparation link. Besides the two main disadvantages, the calcium hydroxide has the problems of incomplete reaction, excessive addition, high impurity content, increased water treatment sludge amount and the like. Therefore, from the application point of view, calcium hydroxide suspensions with high reactivity, high solid content, low viscosity and low impurity content are ideal for the water treatment industry.
It was found that the dissolution rate of calcium hydroxide in water is related to the particle size, the smaller the particle size, the faster the dissolution rate, and the faster the dissolution rate, the faster the corresponding chemical reaction rate, and the better the reactivity of calcium hydroxide. At the same time, however, the smaller the particle size, the greater the viscosity of the suspension, which limits the increase in calcium hydroxide content of the suspension. Thus, it is technically difficult to obtain a suspension of calcium hydroxide having simultaneously high reactivity, high content and low viscosity.
To solve the above problems, a great deal of research has been conducted, mainly including:
1. the viscosity of the suspension is reduced by using an additive which forms a precipitate or a slightly soluble substance with calcium ions, for example, gypsum or the like is added to water when calcium oxide is subjected to a digestion reaction with water, so that the viscosity of lime milk is reduced. However, this type of process results in a decrease in the reactivity of calcium hydroxide.
2. The addition of an organic polymeric dispersant during the preparation of the calcium hydroxide suspension or during wet digestion of the calcium oxide reduces the viscosity, as in patent WO2018/048633A1 the addition of a polyacrylate dispersant reduces the viscosity of the calcium hydroxide suspension. Although the addition of the dispersing agent can reduce the viscosity of the suspension, the primary particle diameter of calcium hydroxide cannot be reduced, i.e., the effect of improving the reactivity of calcium hydroxide is not great.
3. The particle size of the calcium hydroxide is reduced by wet grinding (or grinding + dispersing agent) to thereby increase the reactivity of the calcium hydroxide, as disclosed in US 2019002301. The method increases the preparation steps of the suspension, is more complicated, and has smaller particle size, but the addition proportion of the corresponding additive is also increased, thus bringing about more obvious influence on the production cost.
4. High activity, low viscosity suspensions are prepared by varying the digestion process. For example, in CN106470960 and US2019092684, a suspension of calcium hydroxide is prepared by gradually adding water to lime, which contains a dispersing agent or an inorganic salt. This approach requires very high demands on the digestion equipment, because at low water to ash ratios the lime slaked product is pasty, with very high viscosity, and conventional equipment cannot meet the demands.
5. The high-activity quicklime is used as a raw material, and the characteristic of high reaction speed of the high-activity quicklime is utilized to reduce the particle size of calcium hydroxide and improve the reaction activity of the calcium hydroxide. However, the high activity quicklime has the disadvantages of high price and high cost of the obtained calcium hydroxide suspension, and also has the disadvantage of relatively high viscosity of the obtained calcium hydroxide suspension.
6. In order to solve the problems of slow digestion and low product activity of the common active lime, high-temperature water with the temperature of above 60 ℃ is usually used for digestion, and long-time aging is needed after the digestion to complete the digestion reaction. In the process, the source of high-temperature water and long-time aging both make the production of calcium hydroxide suspension by using common active lime low in efficiency and high in cost.
In summary, the method for preparing the calcium hydroxide suspension in the prior art has many defects, so that the calcium hydroxide suspension produced by the method cannot reach the indexes of high reactivity, high calcium hydroxide content, low viscosity and the like at the same time, and the cost is high by simply adopting the high-activity quicklime raw material, so that the industrial application of the calcium hydroxide suspension is further limited.
Disclosure of Invention
In order to fill the blank of the prior art, the invention provides a calcium hydroxide suspension with high reactivity, high calcium hydroxide content and low viscosity and a preparation method thereof, so as to overcome the defects in the prior art.
The technical scheme of the invention is as follows:
a method for preparing a low cost calcium hydroxide suspension comprising the steps of:
s1: respectively crushing and sieving high-activity quicklime with the activity degree not lower than 360 and common active quicklime with the activity degree of 240-320 to obtain quicklime with the particle size smaller than 8mm, weighing according to the mass ratio of 1:2-9:1, and uniformly mixing for later use;
s2: adding digestion water into a reactor with a stirring device, wherein the mass ratio of the digestion water to the spare quicklime is 2:1-4:1, the water temperature is controlled to be 20-45 ℃, an activity promoter and/or a stabilizer is/are added into the digestion water, the total mass ratio of the activity promoter and/or the stabilizer to the spare quicklime is 5:1000-35:1000, the activity promoter is a substance which can make water alkaline after being dissolved in water and is mixed with calcium hydroxide without generating precipitate, and the stabilizer is one or a mixture of a small molecular dispersing agent, sugar alcohol and sugar substances;
s3: adding spare quicklime into a reactor under the condition that a stirring device is continuously stirred, wherein the adding process ensures that the quicklime and water are uniformly mixed, the reactor does not produce accumulation of the quicklime, the time of the adding process is not longer than 15min, and the reaction time of the reactant at the temperature higher than 80 ℃ is not longer than 70min and not shorter than 20min in the digestion reaction process;
s4: and after the digestion reaction is finished, carrying out hydrocyclone separation and/or screening on the product mixed solution in the reactor, and removing large-particle impurities in the product mixed solution to obtain a target calcium hydroxide suspension finished product.
Further, the mass ratio of the high-activity quicklime to the common active quicklime is 7:3-8:2.
Further, in the step S1, the particle size of the spare quicklime particles is smaller than 5mm.
Further, in S1, the activity degree of the high-activity quicklime is not lower than 380.
Further, in the step S3, the duration of the feeding process does not exceed 10min.
Further, in the step S3, the duration of the feeding process is not more than 5min.
Further, the activity promoter is one or a mixture of more of sodium hydroxide, potassium hydroxide, sodium acetate, sodium formate, monoethanolamine, diethanolamine and triethanolamine.
Further, the stabilizer is one or a mixture of more of potassium pyrophosphate, sodium hexametaphosphate, xylitol, sorbitol, erythritol, sucrose, glucose and fructose.
Further, the ratio of the total mass of the active accelerator and/or the stabilizer to the mass of the ready-to-use quicklime is 10:1000-25:1000.
A low cost calcium hydroxide suspension prepared by any one of the above preparation methods, wherein the calcium hydroxide suspension has a calcium hydroxide mass content of about 25-45%, a particle size distribution of 4 μm or less D50 or less 6.5 μm, D97 or less 25 μm, D100 or less 45 μm, a viscosity of less than 350 centipoise (cP, 1 cP=1 mpa.s) at 25 ℃, and a reactivity t90 or less than 5 seconds.
The quicklime mentioned in the step S1 is tested according to the method specified in YB/T105-2005 Metallurgical lime physical examination method, and consists of high-activity quicklime with the activity degree not lower than 360 and preferably not lower than 380 and ordinary active lime with the activity degree of 240-320. Ordinary active quicklime activity below 240 slows down the reaction rate and reduces the product calcium hydroxide activity, while above 320 results in increased costs and uneconomical. The quick lime is crushed and then used, so that the digestion reaction process is more uniform and stable, the phenomena of bumping, local overheating and the like caused by porous block lime are reduced, and the stability of the product quality is facilitated. The quicklime particles after crushing and sieving are not more than 8mm, otherwise, phenomena such as detonation and boiling are easy to occur; the size of the crushed and sieved quicklime particles is preferably smaller than 5mm, and experiments show that the size has more remarkable effect on eliminating phenomena such as bumping. The mass ratio of the high-activity quicklime to the common active lime is 1:2-9:1, preferably 7:3-8:2. The ratio of the high-activity quicklime to the common active quicklime is lower than 1:2, so that the product activity is poor, and the effect of reducing the cost is not obvious when the product activity is higher than 9:1. When the ratio of the high-activity quicklime to the common active lime is 7:3-8:2, the product achieves the optimal effect in the balance of performance and cost.
In step S2, a digestion water temperature below 20 ℃ results in a decrease in the reactivity of the resulting calcium hydroxide suspension, while a temperature above 45 ℃ results in a significant increase in the viscosity of the calcium hydroxide suspension. The activity promoter mentioned means a substance which can make water alkaline after being dissolved in water, but does not include a substance which can react with calcium hydroxide to form a precipitate, preferably sodium hydroxide, potassium hydroxide, sodium acetate, sodium formate, monoethanolamine, diethanolamine, triethanolamine and the like. The mentioned stabilizers have the dual functions of improving the reactivity of calcium hydroxide and reducing the agglomeration of calcium hydroxide particles, and can be used alone or together with an activity promoter, and preferred stabilizers include small molecule dispersants such as potassium pyrophosphate, sodium hexametaphosphate, sugar alcohols such as xylitol, sorbitol, erythritol, and sugar substances such as sucrose, glucose, fructose, and the like. The total mass of the active accelerator and/or stabilizer is 0.5-3.5% of the mass of active quicklime, preferably 1-2.5%.
In step S3, the slow feeding speed of the quicklime affects the production efficiency on the one hand and causes a decrease in the reactivity of the product and an increase in the viscosity on the other hand, so that the feeding time of the quicklime is not more than 15 minutes, preferably not more than 10 minutes, and most preferably not more than 5 minutes. When calcium hydroxide is generated by slaking reaction of quicklime and water, heat is released to raise the temperature of the reaction system, and for preparing the calcium hydroxide suspension, the slaking reaction is more complete, but the reaction activity of the calcium hydroxide is reduced due to long-time high temperature, so that the time of the slaking reaction at 80 ℃ or more is not more than 70 minutes and not less than 20 minutes. The mass ratio of the water ash in the digestion reaction is 2:1-4:1, the viscosity is too high when the water ash ratio is too low, and the calcium hydroxide content in the suspension is lower when the water ash ratio is higher than 4:1, so that the economy is poor.
In the step S4, the suspension obtained after the digestion reaction is finished is subjected to large particle removal by a cyclone separator, a vibrating screen or the like, and unreacted impurities such as silicon oxide, aluminum oxide, unburnt limestone and the like carried in the lime raw material can be removed, so that the content of calcium hydroxide in the suspension is increased, and the sludge amount generated in sewage treatment is reduced.
In summary, the invention has the following beneficial effects:
(1) The invention uses the high-activity quicklime to compound with the common active lime, reduces the cost of raw materials, and is unexpected: in the reaction process, the high-activity quicklime preferentially reacts to release heat to improve the water temperature, so that the digestion speed of the ordinary active quicklime and the reaction activity of a digestion product are accelerated, the problems of low digestion speed of the ordinary active quicklime and low reaction activity of the product are overcome, the technical prejudice that the ordinary active quicklime cannot be selected to prepare the high-activity calcium hydroxide suspension in the industry is broken, the problem of high cost caused by simply using the high-activity quicklime is solved, the problems of higher digestion water temperature and long-time aging required by simply using the ordinary active quicklime are also solved, and the production cost is reduced on the premise of ensuring the product performance. The suspension prepared according to the scheme of the invention has lower viscosity and is suitable for application fields with higher requirements on viscosity and fluidity of the suspension, although the reactivity of the suspension is slightly reduced compared with the suspension prepared by simply using high-activity quicklime under the same conditions.
(2) According to the invention, through accurate design and control of raw materials, processes and auxiliaries, the calcium hydroxide suspension with high reactivity, high calcium hydroxide content, low viscosity, low cost and other indexes can be prepared, the situation that the suspension can only exist theoretically is broken through, various large-particle impurities existing in the suspension are screened out by adopting a cyclone separation or sieving mode, and the problems of low reaction speed, low production efficiency, excessive addition, more sludge and the like existing in the application of the existing calcium hydroxide suspension in water treatment and the like are solved.
(3) The invention does not use expensive polymer dispersing agent, the used additives are all common small molecule chemical reagents, and the optimal effect is realized by the combination of different reagents; meanwhile, the preparation method is directly carried out in a reaction kettle of the reactor, expensive and special equipment such as a high-torque digestion machine and the like are not needed in the preparation process, the equipment is simple to operate, the reaction flow is short, clear and easy to operate, the operation of a deep professional is not needed, the labor cost is reduced, and the design is beneficial to reducing the manufacturing cost of the suspension.
Detailed Description
The following describes specific embodiments of the present invention in detail.
Example 1
10kg of water at 45℃was charged into a stirred reactor, and 10g of sodium hydroxide and 10g of potassium pyrophosphate were dissolved in the water. 2.25kg of high-activity quicklime with the activity degree of 400 and the particle size of less than or equal to 5mm after crushing and sieving and 0.25kg of common quicklime with the activity degree of 240 and the particle size of less than or equal to 5mm after crushing and sieving are respectively weighed, and the high-activity quicklime and the common quicklime are uniformly mixed for standby (the mass ratio of the high-activity quicklime to the common quicklime is 9:1, and the total mass ratio of the high-activity quicklime to the common quicklime is 2.5 kg).
Adding 2.5kg of weighed spare quicklime into water under stirring, wherein the adding process ensures that the quicklime and the water are uniformly mixed, the reactor does not produce accumulation of the quicklime, and the adding is completed within 15 minutes. After quicklime is added, the reaction system is quickly heated, stirring is continued for 70 minutes after the temperature exceeds 80 ℃, stirring is stopped, suspension is discharged from the reaction kettle and is screened by a 200-mesh screen, and a finished product of the target calcium hydroxide suspension is obtained.
The calcium hydroxide suspension is obtained, wherein the content of the calcium hydroxide is tested according to the method specified in GB/T27815-2011, industrial milky calcium hydroxide; suspension viscosity was measured using an NDJ-9S rotational viscometer, the suspension temperature was stabilized at 25 ℃, and the suspension was measured using a No. 2 or No. 3 rotor at a rotational speed of 60 revolutions per minute; the particle size distribution of the solid particles in the suspension was tested using a laser particle sizer.
The reactivity of the calcium hydroxide in the suspension was determined by the conductivity method, i.e., based on the calcium hydroxide content in the suspension, 0.1g of the suspension containing calcium hydroxide was weighed and quickly poured into 700g of deionized water (water temperature 25 ℃) and the change in the conductivity of the deionized water over time was recorded, and the time spent from pouring the calcium hydroxide suspension until the conductivity reached 90% of the maximum was calculated and recorded as t 90. the smaller t90 means that the faster the calcium hydroxide dissolution rate, the higher the reactivity.
According to measurement, the calcium hydroxide suspension prepared in the embodiment has the following indexes: calcium hydroxide content 25%, t90=5 seconds, viscosity 163cp, d50=6.5 μm, d97=18.9 μm, d100=40.2 μm.
Example 2
Referring to example 1, 9kg of water having a temperature of 20℃was charged into a stirred reactor, 20g of sodium acetate and 90g of glucose were dissolved in the water, and a mixture of 1.5kg of quicklime powder having an activity of 360 and 3kg of quicklime powder having an activity of 320 (the particle size was all < 8mm, and the addition was completed within 5 minutes) was added to the water under stirring. After quicklime is added, the reaction system is rapidly warmed up, stirring is continued for 20 minutes after the temperature exceeds 80 ℃, then stirring is stopped, and the suspension is discharged from the reaction kettle and is sieved by a 200-mesh sieve, so that a calcium hydroxide suspension with the calcium hydroxide content of 45%, t90=4.1 seconds, the viscosity of 350cp, d50=5.5 μm, d97=17.5 μm and d100=37.5 μm is obtained.
Example 3
Referring to example 1, 9kg of water having a temperature of 25℃was charged into a stirred reactor, 60g of sorbitol and 30g of sodium hexametaphosphate were dissolved in the water, and a mixture of 2.55kg of quicklime powder having an activity of 380 and 0.45kg of quicklime powder having an activity of 260 (both particle sizes < 5mm, completed within 10 minutes) was added to the water under stirring. After quicklime is added, the reaction system is rapidly warmed up, stirring is continued for 40 minutes after the temperature exceeds 80 ℃, then stirring is stopped, and the suspension is discharged from the reaction kettle and passes through a 200-mesh sieve to obtain a calcium hydroxide suspension with the calcium hydroxide content of 35%, t90=4.5 seconds, the viscosity of 303cp, d50=5.8 μm, d97=20.5 μm and d100=40.5 μm.
Example 4
Referring to example 1, 10kg of water having a temperature of 30℃was charged into a stirred reactor, 25g of triethanolamine, 25g of xylitol and 12.5g of sucrose were dissolved in the water, and 1.25kg of quicklime powder having an activity of 390 and 1.25kg of quicklime powder having an activity of 280 (both particle sizes < 8mm, completed within 5 minutes) were added to the water under stirring. After quicklime is added, the reaction system is rapidly warmed up, stirring is continued for 30 minutes after the temperature exceeds 80 ℃, then stirring is stopped, the suspension is discharged from the reaction kettle and is sieved by a 200-mesh sieve, and the calcium hydroxide suspension with the calcium hydroxide content of 25%, t90=4.3 seconds, the viscosity of 125cp, d50=4.2 μm, d97=25 μm and d100=45 μm is obtained.
Example 5
Referring to example 1, 9kg of water having a temperature of 30℃was charged into a stirred reactor, 30g of erythritol and 35g of monoethanolamine were dissolved in the water, and a mixture of 2.1kg of quicklime powder having an activity of 380 and 0.9kg of quicklime powder having an activity of 320 (both particle sizes < 5mm, completed within 5 minutes) was added to the water under stirring. After quicklime is added, the reaction system is rapidly warmed up, stirring is continued for 30 minutes after the temperature exceeds 80 ℃, then stirring is stopped, and the suspension is discharged from the reaction kettle and passes through a 200-mesh sieve to obtain a calcium hydroxide suspension with the calcium hydroxide content of 35%, t90=3.5 seconds, the viscosity 223cp, d50=4 μm, d97=18.5 μm and d100=37.5 μm.
Example 6
Referring to example 1, 9kg of water having a temperature of 40℃was charged into a stirred reactor, 40g of diethanolamine and 12.5g of sucrose were dissolved in the water, and a mixture of 2.4kg of quicklime powder having an activity of 390 and 0.6kg of quicklime powder having an activity of 310 (both particle sizes < 5mm, completed within 5 minutes) was added to the water under stirring. After quicklime is added, the reaction system is rapidly warmed up, stirring is continued for 25 minutes after the temperature exceeds 80 ℃, then stirring is stopped, the suspension is discharged from the reaction kettle and is sieved by a 200-mesh sieve, and the calcium hydroxide suspension with the calcium hydroxide content of 35%, t90=3.3 seconds, the viscosity 255cp, d50=4.1 μm, d97=19 μm and d100=40 μm is obtained.
Through repeated experiments of continuous control variables, the content of calcium hydroxide in the prepared calcium hydroxide suspension is 25-45%, the particle size distribution is 4 μm-6.5 μm-D50, 25 μm-D97, 45 μm-D100, 350 centipoise (cP, 1 cP=1 Pa.s) at 25 ℃, and the reactivity t90 is less than or equal to 5 seconds.
Comparative example 1
Referring to example 1, the process conditions of additives, slaked water temperature, reaction time, etc. were the same as example 1 except that quicklime powder having an activity of 400 was used to obtain a calcium hydroxide suspension having a calcium hydroxide content of 25%, t90=4.8 seconds, a viscosity of 277cp, d50=5 μm, d97=17.5 μm, d100=40 μm.
In contrast, it was found that the suspension of calcium hydroxide obtained by mixing high-activity quicklime with ordinary quicklime in a certain ratio as a raw material had a lower viscosity although the reactivity was slightly lowered than the suspension obtained by simply using high-activity quicklime under the same conditions. Therefore, the invention is suitable for the application fields with higher requirements on viscosity and fluidity of the calcium hydroxide suspension, relatively lower requirements on reactivity and relatively sensitive cost.
The foregoing has shown and described the basic principles, principal features and advantages of the invention. The present invention is not limited to the above-described embodiments, and the above-described embodiments and descriptions merely illustrate the principles of the invention, and various changes and modifications may be made therein without departing from the spirit and scope of the invention, which is defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (10)
1. A method for preparing low-cost calcium hydroxide suspension, which is characterized by comprising the following steps: the method comprises the following steps:
s1: respectively crushing and sieving high-activity quicklime with the activity degree not lower than 360 and common active quicklime with the activity degree of 240-320, screening quicklime with the particle size smaller than 8mm, weighing according to the mass ratio of 1:2-9:1, and uniformly mixing for later use;
s2: adding digestion water into a reactor with a stirring device, wherein the mass ratio of the digestion water to the spare quicklime is 2:1-4:1, the water temperature is controlled to be 20-45 ℃, and an activity promoter and/or a stabilizer are added into the digestion water, wherein the total mass of the activity promoter and/or the stabilizer added to the spare quicklime is 5:1000-35:1000, wherein the activity promoter is a substance which can make water alkaline after being dissolved in water and does not generate precipitate after being mixed with calcium hydroxide, and the stabilizer is one or a mixture of a small molecular dispersing agent and a saccharide substance;
s3: adding spare quicklime into a reactor under the condition that a stirring device is continuously stirred, wherein the adding process ensures that the quicklime and water are uniformly mixed, the reactor does not produce accumulation of the quicklime, the time of the adding process is not longer than 15min, and the reaction time of the reactant at the temperature higher than 80 ℃ is not longer than 70min and not shorter than 20min in the digestion reaction process;
s4: and after the digestion reaction is finished, carrying out hydrocyclone separation and/or screening on the product mixed solution in the reactor, and removing large-particle impurities in the product mixed solution to obtain a target calcium hydroxide suspension finished product.
2. A method of preparing a low cost calcium hydroxide suspension according to claim 1 wherein: the mass ratio of the high-activity quicklime to the common active quicklime is 7:3-8:2.
3. A method of preparing a low cost calcium hydroxide suspension according to claim 1 wherein: in the step S1, the particle size of the spare quicklime particles is smaller than 5mm.
4. A method of preparing a low cost calcium hydroxide suspension according to claim 1 wherein: in the S1, the activity degree of the high-activity quicklime is not lower than 380.
5. A method of preparing a low cost calcium hydroxide suspension according to claim 1 wherein: in the step S3, the duration of the feeding process is not more than 10min.
6. A method of preparing a low cost calcium hydroxide suspension according to claim 1 or 5, wherein: in the step S3, the duration of the feeding process is not more than 5min.
7. A method of preparing a low cost calcium hydroxide suspension according to claim 1 wherein: the activity promoter is one or more of sodium hydroxide, potassium hydroxide, sodium acetate, sodium formate, monoethanolamine, diethanolamine and triethanolamine.
8. A method of preparing a low cost calcium hydroxide suspension according to claim 1 wherein: the stabilizer is one or more of potassium pyrophosphate, sodium hexametaphosphate, xylitol, sorbitol, erythritol, sucrose, glucose and fructose.
9. A method of preparing a low cost calcium hydroxide suspension according to claim 1 wherein: the ratio of the total mass of the added activity promoter and/or stabilizer to the mass of the ready-to-use quicklime is 10:1000-25:1000.
10. a low cost calcium hydroxide suspension characterized by: the calcium hydroxide suspension prepared by the preparation method according to any one of claims 1 to 9, wherein the calcium hydroxide suspension has a mass content of calcium hydroxide of 25 to 45%, a particle size distribution of 4 μm or less d50 or less 6.5 μm, d97 or less 25 μm, d100 or less 45 μm, a viscosity of 25 ℃ or less 350 centipoise (cP, 1 cp=1 mpa.s), and a reactivity t90 or less than 5 seconds.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112358205A (en) * | 2020-11-27 | 2021-02-12 | 广西合山市华纳新材料科技有限公司 | Preparation method of high-activity calcium hydroxide |
| CN113955955A (en) * | 2021-12-10 | 2022-01-21 | 安徽前江超细粉末科技有限公司 | Method for solving problem of easy caking in high-activity lime slaking process |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3995736B2 (en) * | 1996-03-29 | 2007-10-24 | 奥多摩工業株式会社 | High concentration calcium hydroxide aqueous suspension and method for producing the same |
| FR2998194B1 (en) * | 2012-11-19 | 2014-11-21 | Coatex Sas | AQUEOUS LIME SUSPENSION, PROCESS FOR PREPARATION AND USES |
| JP2014125423A (en) * | 2012-12-27 | 2014-07-07 | Tosoh Corp | Method of manufacturing calcium hydroxide aqueous suspension |
| WO2016041643A1 (en) * | 2014-09-08 | 2016-03-24 | S.A. Lhoist Recherche Et Developpement | Process for manufacturing a milk of slaked lime of great fineness and milk of lime of great fineness thereby obtained |
| WO2017152960A1 (en) * | 2016-03-08 | 2017-09-14 | S.A. Lhoist Recherche Et Developpement | Process for manufacturing a milk of slaked lime of great fineness and milk of lime of great fineness thereby obtained with process water |
| CN112125537B (en) * | 2020-09-28 | 2022-01-04 | 辽宁鑫钙环保科技有限公司 | Industrial preparation technology of calcium hydroxide |
| CN114522554A (en) * | 2022-02-20 | 2022-05-24 | 深圳市长隆科技有限公司 | Preparation and application of superfine suspended calcium hydroxide |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112358205A (en) * | 2020-11-27 | 2021-02-12 | 广西合山市华纳新材料科技有限公司 | Preparation method of high-activity calcium hydroxide |
| CN113955955A (en) * | 2021-12-10 | 2022-01-21 | 安徽前江超细粉末科技有限公司 | Method for solving problem of easy caking in high-activity lime slaking process |
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