How to deal with dust when calcium hydroxide powder is selected?

Calcium hydroxide powder selection is to make the extracted calcium hydroxide mesh more pure. There are many kinds of powder separators, such as centrifugal, three-separation, fly ash and other different types. Qualified powder is selected.

In the process of calcium hydroxide production, even if it is produced by professional calcium hydroxide production line equipment, it is almost inevitable to mix impurities. In order to improve the quality and purity of calcium hydroxide powder, it is necessary to select qualified powders. For this qualification, in addition to requiring purity, the fineness of the powder should also be distinguished.

Small calcium hydroxide powder also has many parameters. It is based on these parameters that people keep thinking about the method of powder selection and design a powder separator. For example, according to the quality and density of the powder, under a certain wind speed, the powder can be divided into two piles with a cyclone separator. Obviously, the pile is needed, and the pile is the so-called impurity.

For the powder separator, the simpler the structure, the better, and the overly complicated powder selection channel is not conducive to the discharge of the selected powder from the powder selection device.

Due to the centrifugal force of the calcium hydroxide powder separator during the powder selection process, it is inevitable that dust will occur. When it comes to dust removal, the first thing that comes to mind is the pulse bag filter.

calcium hydroxide

Pulse dust removal adopts pulse bag type dust removal technology, which overcomes the shortcomings of conventional pulse dust collectors and sub-chamber back-flushing dust collectors. The land area is small, the operation is stable and reliable, and the economy is good. And the falling powder can be recycled and reused, which is a link to reduce the cost of producing calcium hydroxide powder, which overcomes the problem of re-pollution of water dust removal. Any conveying device falls directly into the digester and enters the powder selection system.

Moreover, the clean hot air after dust removal enters the vertical heat conversion device to heat and digest water. In this way, the equipment is protected, the later maintenance is simple, and the impact of dust emission pollution on the surrounding environment can be greatly improved in terms of environmental protection, and the working environment of workers is also greatly improved.

In addition to pulse bag dust removal, there is also a water dust removal method. The water precipitator is a device that makes the dust-containing gas in close contact with water, and uses the inertial collision of water droplets and particles and other effects to capture or increase the particles. The manufacturing cost of the water precipitator is relatively low. However, it is an ideal dust removal method for dust with moisture, stickiness and irritating odor generated in the chemical industry, painting, glaze, pigment and other industries.

In comparison, water dust removal is an ideal dust removal method in the calcium hydroxide powder selection process. How to deal with calcium hydroxide after dust removal?

1. Powdered products are used in bleaching, hydrometallurgy, sewage treatment, sugar refining, papermaking, paint, glass production, food industry, etc. In organic chemistry, calcium hydroxide is widely used as a strong base.

2. Paste calcium hydroxide is used for building materials, protecting tree trunks and painting walls.

3. Liquid calcium hydroxide reacts with carbon dioxide to produce calcium carbonate, and liquid lime milk (calcium hydroxide particles suspended in water) can also be used for water treatment, dry flue gas purification, etc.

The energy saving way in calcium hydroxide production is mainly reflected in the selection of digestion equipment. The trough type drying machine and the wet drying machine are ideal equipment, which can be digested with cold water to keep it in a boiling state, so that the product quality is excellent and the energy consumption is low.

The environmental treatment in the production of calcium hydroxide is mainly alkaline dust treatment. First, a closed production line should be selected. Material conveying, feeding, dividing, and packaging equipment should be closed for operation to prevent the overflow of alkaline dust. The digestion steam should be dry. , Wet dust removal to recover steam and dust; crushing and grinding should be carried out under airtight or slightly negative pressure to prevent dust leakage.

Summary of structure and characteristics of lime digester in calcium hydroxide equipment

Lime digester, also called ash digester, lime digester, is a special equipment for digesting quicklime (calcium oxide) into lime milk or slaked lime powder. The lime digester has the function of vigorously stirring and digesting quicklime. It has the characteristics of simple operation and maintenance, thorough digestion, high production efficiency, large specific surface area of the digested slaked lime powder, environmental protection and hygiene, etc. It is especially suitable for the digestion of poor quality quicklime.

Structure of lime digester for calcium hydroxide equipment

Stirring tank lime digester (ash mixer) is mainly a device that digests quicklime into slaked lime powder, and can also digest quicklime into lime milk. It is divided into two types: single-shaft stirring and double-shaft stirring. Combination of two forms. Each is composed of a power unit, a stirring tank body, a stirring shaft, a wear-resistant stirring blade, a spray device, and a dust removal device.

GFEX Case

The characteristics of calcium hydroxide equipment lime digester

1. The equipment has its own independent and reasonable dust removal system, so there is no pollution, and the equipment has the characteristics of compact structure:

2. A set of screw feeders are designed at the feed port of the digester to prevent the backflow of steam and dust generated during the digestion process, so that the formed steam and dust can be concentrated to the dust outlet and enter the dust removal equipment to reduce corrosion and damage to surrounding equipment. damage, provide an excellent working environment. At the same time, the utilization rate of quicklime is also improved. This equipment adopts the cover type water adding device, the water adding amount is more uniform, and the quicklime is digested more thoroughly.

3. The equipment adopts double-helix digestion, so it has good digestion effect, uniform feeding, no spraying, and no blocking. It adopts the form of double-shaft stirring, which has multiple functions and effects such as stirring, crushing agglomeration and self-cleaning. Its unique blade and stirring method make the quicklime and water mix evenly and react fully; it can break the agglomeration produced in the reaction process.

4. The equipment has a special outlet for steam and dust discharge, which can be discharged to a special dust removal pipe through a connecting pipe, which can well handle the dust steam and harmful gas generated during the digestion process of quicklime. After use, the waste dust quicklime can be reused , There is no dust pollution in the on-site environment, so that the quicklime digester can reasonably add the required water to achieve the effect of fully digesting the quicklime.

GFEX Case

5. The biaxial blades are made of high-manganese wear-resistant materials, and the heat-treated high-strength wear-resistant alloy materials have the function of self-cleaning bonding materials; effectively avoiding poor discharge and blade wear caused by bonding lime Even the occurrence of problems such as broken shafts prolongs the service life of the equipment.

6. This type of biaxial quicklime digester can be improved in relevant dimensions according to the requirements of the enterprise, and can also be automatically equipped according to the requirements of the enterprise.

7. The blade of the screw shaft is inlaid with cemented carbide, so it has the characteristics of long service life, and the service life is one year with the advantage of equipment.

The above is the summary of the structure and characteristics of the lime digester for calcium hydroxide equipment. Through the above introduction, it is not difficult to know that the main feature of the lime digester (ash machine) is that when the spray device feeds a certain amount of water to the mixing tank After the quicklime is sprayed with water, through the rotation of the specially designed wear-resistant stirring blade, the quicklime is vigorously stirred in the stirring tank and gradually dissolved, digested, slaked and homogenized. The stirring blade also pushes the digested slaked lime powder forward. sports. The components of the damping plate and the limit plate in the stirring tank ensure the digestion time of the quicklime, so that the quicklime is completely digested.

Installation requirements and precautions for calcium hydroxide production line

In order to ensure the stable operation of the calcium hydroxide production line and ensure normal production, it is inseparable from the correct installation. For the installation requirements and precautions of the calcium hydroxide production line, the calcium hydroxide production line manufacturer gave us a detailed introduction. One Get up and find out!

Calcium hydroxide production line installation requirements

GFX Stepped Case

1. Device positioning

According to the layout of the entire production line and the axis or edge line and elevation line of the building, the installation reference line is delineated. Equipment that is connected, connected or arranged with each other should release a common installation reference line; according to needs, the target board or reference point can be embedded, and the specific basic position line and elevation line can be set.

2. Overall inspection

After installation, check the overall equipment, check the coordinate position of the foundation, the elevations of different planes, the dimensions of the plane, the dimensions of the plane on the boss, the dimensions of the cavity, the level of the plane, the vertical degree of the foundation, and the pre-buried ground. The elevation and center distance of the anchor bolts, the center position, depth and vertical degree of the hole wall of the embedded anchor bolt hole, the elevation and center position of the anchor plate of the embedded movable anchor bolt, the grooved anchor plate and the threaded anchor plate. level, etc.

3. Preload test

The preload test is a preventive measure taken to prevent the installation of heavy equipment from unqualified installation due to uneven subsidence of the foundation after installation. The preload of the test is not less than the sum of the forces acting on the foundation of the equipment under full load operation. The points shall not be affected by the settlement of the foundation, and the observation points shall be no less than four points evenly distributed around the foundation. Observations should be timed and should be until the foundation is substantially stable.

GFX Stepped Calcium Hydroxide Production Line

4. Fixed equipment

In addition to movable equipment, other heavy, high-speed, high-vibration mechanical equipment needs to be firmly fixed on the basis of the equipment. If it is not fixed, accidents may occur. Assemble again.

Precautions for the use of calcium hydroxide production line

1. Regular inspection: The calcium hydroxide production line should maintain the equipment during use, and regularly inspect all parts of the production line. If the parts are found to be worn, they should be replaced to avoid affecting the normal operation.

2. Handle abnormal situations in a timely manner: If an abnormal situation is found in the operation of the calcium hydroxide production line, it must be stopped immediately, and the abnormal situation should be checked. After the fault is solved, the production can be continued to avoid unnecessary losses.

After the above introduction, it can be seen that the installation requirements of the calcium hydroxide production line include equipment positioning, overall inspection, pre-loading test, fixed equipment, etc. Handle abnormal situations, so as to effectively reduce the failure rate of equipment and improve the service life of the production line.

How to check whether calcium hydroxide has deteriorated? Inspection methods and reasons for deterioration

Calcium hydroxide is widely used in industrial production and life, but we often find that the effect of calcium hydroxide in use is not in line with the routine, so the deterioration of calcium hydroxide has become a problem that needs urgent attention. How to test calcium hydroxide Whether it has deteriorated, and the reasons for the deterioration of calcium hydroxide, we have introduced the following details, let’s find out together!

Identification method of calcium hydroxide deterioration

1. Hydrochloric acid identification method

Take out some calcium hydroxide and add enough hydrochloric acid. If there is gas, it means that the calcium hydroxide has deteriorated.

2. Water identification method

Another method introduced by calcium hydroxide manufacturers is that after adding sufficient water, there are still insolubles, which also means that calcium hydroxide has deteriorated, because calcium carbonate is insoluble in water.

3. Carbon dioxide identification method

Calcium hydroxide is easily hardened with carbon dioxide in the air to form calcium carbonate. Therefore, we only need to determine whether there is calcium carbonate in the calcium hydroxide powder to know whether it has deteriorated.

Reasons for the deterioration of calcium hydroxide

calcium hydroxide
​​1. The temperature is too high

The reason for the deterioration is temperature, and increasing the temperature can cause thermal cracking or thermal cross-linking of calcium hydroxide. But the basic effect of heat is activation. Improve the oxygen diffusion rate and activate the oxidation reaction, thereby accelerating the oxidation reaction rate of calcium hydroxide, which is a common aging phenomenon – thermal oxygen aging

2. Air contact

In the storage and transportation of calcium hydroxide, if it is exposed to the air for a long time, oxygen will react with the rubber molecules in the calcium hydroxide free radical chain reaction, and the molecular chain will be broken or excessively cross-linked, which will cause the change of rubber properties. Oxidation is one of the important reasons for rubber aging. There is also ozone in the air, the chemically active oxygen of ozone is much higher and more destructive, it also breaks the molecular chain, but the effect of ozone on calcium hydroxide varies with whether the rubber is deformed or not. When used as a deformed rubber reinforcing agent, cracks that are straight in the direction of stress action, the so-called “ozone cracks”, appear.

3. Ultraviolet rays are too high

Stored in the open air, the shorter the light wave, the greater the energy. What destroys calcium hydroxide is ultraviolet rays with higher energy. In addition to the direct rupture and cross-linking of the rubber molecular chain caused by ultraviolet light, calcium hydroxide generates free radicals by absorbing light energy, which initiates and accelerates the oxidation chain reaction process. The external light plays a role in heating. Another feature of the light effect is that it mainly grows on the surface of the oak. For samples with high glue content, there will be network cracks on both sides, that is, the so-called “optical outer layer cracks”. Factors that cause calcium hydroxide aging include chemical media, variable valence metal ions, high-energy radiation, electricity, and biology.

The above is the answer to the question of how to check whether calcium hydroxide has deteriorated. Knowing the reason for the deterioration can effectively prevent the deterioration of calcium hydroxide and ensure the quality of calcium hydroxide. Calcium hydroxide is transported separately during the transportation process to avoid mixing with acids, inflammables, organics, etc., to ensure the quality of calcium hydroxide.

The use of calcium hydroxide in the chemical industry

Calcium hydroxide, commonly known as hydrated lime, is a material based on limestone and is the “first filler” in the industry. It is a binary medium and strong alkali (calcium hydroxide is considered a strong alkali in the middle school stage, but in fact it cannot be completely ionized in water, so it is considered a medium and strong alkali), with alkali properties, good for skin, fabrics Corrosive.​​

Calcium hydroxide is processed through strict calcination of calcium hydroxide production line, processed into high-quality ash as raw material, and then processed through careful selection. The application fields of calcium hydroxide are becoming more and more extensive. It is a commonly used building material, and is also used as a fungicide and chemical raw materials. The development of the industry is also very rapid. Calcium hydroxide has the following uses in the chemical industry:

1. The application of calcium hydroxide in the coating industry is also very extensive. In addition to being used as a filler in coatings, it also replaces titanium dioxide and pigments, and is also used to replace light calcium and precipitated barium sulfate;

2. Calcium hydroxide is used as a filler for rubber products in the rubber industry, which can improve the processing properties of rubber and improve the mechanical properties of products, such as improving tearing or tearing strength, flex resistance, and achieving initial strength or semi-reinforcing. Effect;

3. The important inorganic filler in the paper industry is still calcium hydroxide! It can improve the penetration and diffusion ability of paper products.


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The above three points are the contributions of calcium hydroxide to the industry. In fact, it also contributes a lot to industries such as water treatment, sewage purification treatment, construction, rubber, plastic filling aids, roadbed reconstruction, incineration, thermal power plant desulfurization, and deacidification.
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In addition, calcium hydroxide has also been widely used in agriculture. It is used in agriculture to reduce soil acidity and improve soil structure. The pesticide Bordeaux mixture is prepared with lime milk and copper sulfate aqueous solution in a certain proportion.
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This sky-blue, viscous suspension pesticide for fruit trees and vegetables uses copper to destroy pests and diseases. It not only utilizes the property that calcium hydroxide can react with copper sulfate, but also utilizes the feature that calcium hydroxide is slightly soluble in water to make the liquid medicine viscous, which is beneficial to the adhesion of the liquid medicine on plant branches and leaves.

In addition, calcium hydroxide reacts with carbon dioxide in the air to form calcium carbonate that is slightly soluble in water, which is also beneficial for the liquid to adhere to the surface of plants for a period of time and not be washed away by rainwater.

What is the process flow of the hydrated lime production line?

The hydrated lime production line is to crush the qualified hydrated lime blocks to a particle size of about 40mm by the jaw crusher, and send them to the hydrated lime storage tank silo through the bucket elevator. The digester performs preliminary digestion. When the hydrated lime completes the primary digestion, it enters into the Ⅱ-level digestion or the Ⅲ-level digester, so that the hydrated lime is completely digested and decomposed, and the qualified hydrated lime primary product is generated, and the digestibility reaches 98%. The design is divided into single-axis, double-axis and multi-axis models).

The digested and decomposed hydrated lime is then sent to the classifier by the semi-finished product screw conveyor, and the product impurities separation and fineness classification are completed by the powder classifier, and the final qualified product after the classification is completed. Warehouses are packaged separately. All polluted nodes of this production line are completed by pulse dust collectors, and the dust collection rate reaches 99.5%.

Hydrated lime production line equipment composition

15T installation site of Weinan Yaobai Cement Plant

Crushing System: Hammer Crusher

Conveying system: bucket elevator, conveyor

Digestion system: Qualified hydrated lime enters the digester for preliminary digestion. When the hydrated lime completes primary digestion, it enters into the secondary or tertiary digester to complete the digestion and decomposition of hydrated lime to generate qualified primary product of hydrated lime with a digestibility of 98%.

Slag discharge system: primary and secondary slag discharge, the slag discharge first discharges the impurities larger than 0.5cm in the semi-finished product, and then the secondary slag discharge discharges the components less than 0.5cm and sand and coal ash.

Dust removal system: Collect the dust generated by the equipment itself, without secondary pollution

Powder selection system: adopt closed circulating air to collect powder

Electric control system: The electric control system of the equipment adopts PLC centralized control, which is mainly used to complete data processing, parameter setting, and directly display the equipment operation status, product quality process control and equipment failure alarm through the computer screen.

Packaging system: including unmetered packaging

Process flow of hydrated lime production line

(1) Raw material storage and transportation

Limestone with a particle size of 10-50mm is transported to the factory area and stacked in the material yard, and the loader is used for the operation of the material yard. The materials with qualified particle size are loaded into the receiving chute set in the material yard by the loader, and the feeder is quantitatively fed under the receiving chute. The qualified particle size is weighed and sent to the top silo of the preheater by the large inclination conveyor. The powder under the sieve is sent to the yard by the 3# conveyor and is regularly transported by forklifts.

(2) Limestone calcination

Limestone calcination is composed of vertical preheater + rotary kiln + vertical cooler, the output is 100~800t/d. The incoming high-temperature flue gas preheats the material to above 1000 °C, so that the limestone is partially decomposed, and then pushed into the tail of the rotary kiln by the hydraulic push rod, and then unloaded into the cooler after being calcined at a high temperature in the rotary kiln, and blown into it by a fan. The cold air is used for cooling, and the material is cooled to below the ambient temperature +60 °C and discharged from the cooler. The air blown in by the cooler enters the rotary kiln as secondary air and participates in the combustion.

(3) Finished product transportation

After the finished lime is discharged from the cooler, it is transported to each finished lime storage by chain conveyor, bucket elevator and belt conveyor. The discharge valve under the lime silo is used to load the lime in the silo into a car or a tanker and then transport it out. Storage bins of different sizes are set up according to customer storage requirements.
The finished product silo adopts circular silo, 2 5~50mm finished product silo, 1 <5mm finished product silo, the capacity of each silo is about 800t;

(4) Flue gas treatment

The high temperature flue gas generated by the combustion of the rotary kiln, after the heat exchange with the limestone in the preheater, the temperature drops below 250 ℃, and then enters the cyclone dust collector for dust collection, and the large particles of dust are collected, and then enter the bag After dust removal, it is discharged into the atmosphere through a high temperature fan, and the dust concentration of the exhaust gas is less than 30mg/m3. A cold air control system is installed at the inlet of the dust collector to protect the dust collector.

The above is all about the production process of the hydrated lime production line. I hope it can be helpful to everyone. When operating the hydrated lime equipment, you must follow the correct technological process.

Compared with the traditional calcium hydroxide production process, what are the advantages of the calcium hydroxide production line?

The traditional production process of calcium hydroxide is mainly based on manual production, but there are many disadvantages. With the development of society, the scale of mechanized production has gradually expanded, replacing manual production, and it has been widely used. Today, the editor of Zhongcai is here. Let me introduce to you the advantages of calcium hydroxide production line compared with traditional calcium hydroxide production process!

Disadvantages of traditional calcium hydroxide production process

15T installation site of Weinan Yaobai Cement Plant

1. Pollution of the environment

Because it is produced by hand, a large amount of high-temperature steam and dust generated during the digestion process will permeate everywhere, and the pollution radius can reach more than 1,000 meters, causing serious damage to the forests and crops within the polluted area.

2. Affect health

Manual production is labor-intensive, the production environment is poor, and the pollution of dust and steam will affect the physical and mental health of production workers.

3. Low production efficiency

The efficiency of manual production is very low. On average, each person does not exceed 1 ton of finished calcium hydroxide during the day. The production scale is small, the average annual output is only a few hundred tons, and the larger scale is only about 5,000 tons. The demand of pharmaceutical food, petroleum, papermaking and other industries.

4. Unstable quality

Manual production is all judged by the experience of the staff. Everyone’s experience is different, so the quality of the finished products is uneven, sometimes good and sometimes bad, which cannot meet the requirements of the petrochemical industry and the fine chemical industry.

Advantages of calcium hydroxide production line

1. Easy to operate

The calcium hydroxide production line has a high degree of mechanization and can be operated only through simple training, with simple operation and low labor intensity.

2. Protect the environment

The mechanical operation reduces the amount of flue gas emissions, and the production line is equipped with dust removal equipment, which reduces environmental pollution and prevents workers’ health from being affected.

3. High production efficiency

The production line has various specifications. The output of small-sized equipment in one hour can exceed the output of labor in one day, and different specifications can be selected according to different output requirements, and the production efficiency is very high.

4. Good quality

The whole production line is controlled by computer, the discharge temperature is controlled at about 45 degrees Celsius, and the water content of the discharge is controlled at about 1%. In this way, the agglomeration of finished products is prevented, and all products are standardized, which meet the needs of users in various industries.

The above is the answer to the question of what are the advantages of the calcium hydroxide production line. After the above introduction, it can be seen that the traditional calcium hydroxide production process will pollute the environment, affect health, low production efficiency and unstable quality. In contrast, calcium hydroxide The production line has the advantages of convenient operation, environmental protection, high production efficiency and good quality.

What is the relationship between the solubility of calcium hydroxide and temperature?

Calcium hydroxide is a substance that can be dissolved in water, but its solubility decreases as the temperature increases. Due to the particularity of the decrease in the solubility of calcium hydroxide with temperature changes, many people can’t help asking questions, causing calcium hydroxide The relationship between solubility and temperature What are the influencing factors of this state? With this question in mind, the calcium hydroxide production line manufacturer will introduce the relationship between the solubility of calcium hydroxide and temperature.

The relationship between calcium hydroxide solubility and temperature:

1. After a series of tests, we found that during the reaction process, a lot of heat was released, which made the temperature of the solution rise. During the whole reaction process, the mass of water in the solution decreases due to the consumption of part of the water.

2. Due to the decrease of the solvent in the solution and the increase of the solution temperature, part of the solute Ca(OH)2 is precipitated, which makes the quality of the solute in the solution decrease. After a while, as the temperature of the solution decreases, when the temperature of the solution returns to the original temperature, it still cannot reach the original quality.

3. The subtle changes in the quality of the solvent and the solute in the solution cause similar fluctuations in the quality of the solution. The quality of the solution first decreases and then increases a little bit. Compared with the beginning, the quality of the obtained solution is less than that before adding quicklime. the quality of the solution.

4. The temperature of the solution increases first and then decreases, and slowly returns to the original temperature. The obtained solution is still a saturated solution at the original temperature, so during the whole process, the solute mass fraction first decreases and then increases to the original value.

5. This is because there are two processes when calcium hydroxide dissolves in water. First, the chemical bonds or intermolecular forces inside the substance are pulled apart. In this step, heat is absorbed, and then the pulled apart substance ions or molecules are separated from water or The water ions recombine, and heat is released in this step, most of which are soluble in water.

7. The energy released when calcium hydroxide combines with water is greater than the energy absorbed by dismantling the original structure of the substance in the previous step, so the result is that the total chemical energy of the system becomes lower, so the melting process can occur spontaneously.

8. The exothermic temperature of calcium hydroxide increased during the experiment, but there are a small number of substances like calcium hydroxide, the energy released by their combination with water is less than the energy absorbed by dismantling the original structure, but their melting process It can happen spontaneously, even when the temperature drops.

The above is the editor’s analysis of the relationship between the solubility and temperature of calcium hydroxide. The liquid state of calcium hydroxide is much more messy than the state of solid calcium hydroxide plus pure water. In other words, the solubility of calcium hydroxide solution is much higher, so although calcium hydroxide dissolves in water, the total chemical energy is increased, but it slows down during the dissolution process. High-purity calcium hydroxide is inseparable from the production of the entire production line

What are the uses of calcium hydroxide

When it comes to calcium hydroxide, many people may not know what it is. It should be more familiar with slaked lime and slaked lime, especially in chemical experiments and physical experiments. So, in addition to being able to do experiments, do you know any other uses for this calcium hydroxide?

What is calcium hydroxide

Calcium hydroxide is a fine white powder produced by a professional calcium hydroxide production line, which is odorless and slightly bitter in taste. It is easy to absorb carbon dioxide and become calcium carbonate when placed in the air. It is made of calcium oxide, that is, quicklime, digested with water, dried, sieved, and air-selected (or crushed by an extension machine).

The chemical formula Ca(OH)2, commonly known as slaked lime and slaked lime, is formed into two layers after adding water. The upper aqueous solution is called clarified lime water, and the lower suspension is called lime milk or lime slurry.

The supernatant clear lime water can test carbon dioxide, and the lower turbid liquid lime milk is a building material. Calcium hydroxide is a binary medium and strong base (calcium hydroxide is considered to be a strong base in the middle school stage, but in fact it cannot be completely ionized in water. It has the property of alkali and has a corrosive effect on skin and fabrics. It has a wide range of applications in industry. It is a commonly used building material, and is also used as a fungicide and chemical raw materials.

Calcium hydroxide is a strong alkaline substance with irritating and corrosive effects. Inhalation of dust is highly irritating to the respiratory tract and may also cause pneumonia. Eye contact is also strongly irritating and can cause burns.

Uses of calcium hydroxide

With the development of modern industry, lime has opened up a variety of uses in many emerging industrial sectors besides the main material of civil engineering. Such as metallurgy, glass, alkali sugar, paper, food, medicine, feed, leather, calcium carbide and organic chemicals, carbonized bricks, carbonized plates and soil improvement, water treatment, gas purification, stone cutting aids, soil stabilizers, A large amount of lime is used in concrete conditioners, chemical reagents, gypsum board caulking coagulants, building adhesive ingredients, calcium alkane sulfonates, pharmaceutical acid stoppers, astringents, hard water softeners, and plastic fibers.

1. Chemistry: Calcium hydroxide is mainly used for scientific research and development. Its high quality, high content and high price.

2. Medical aspects: Calcium hydroxide is used as a root canal sealant, and it has shown good results in killing microorganisms and reducing the toxicity to root tip tissue. Calcium hydroxide has a high anti-anaerobic effect, has bactericidal effect on Actinomyces naeviteria and Actinomycetales ichthyosis, and can significantly reduce the biological activity of  G-endotoxin, can inhibit root apical tissue dissolution and periapical tissue absorption, induce Repair of periapical bone defects. Use calcium hydroxide powder and propylene glycol to make a thick paste, add an appropriate amount of iodoform to increase sterilization and make cells produce oxidation, and the effect is long-lasting, non-irritating to tissue, can promote the regression of inflammation in the apical area and the repair of lesions, prevent Pus regenerates and eventually eliminates inflammation and repairs root apical tissue.

3. Food industry: due to its strong activity and loose structure, calcium hydroxide is widely used in food additives

4. Industrial aspects: Calcium hydroxide is mainly used as an environmental neutralizer, acid waste water, sewage treatment, boiler flue gas desulfurization and building construction, as well as caustic soda and bleaching powder.

5. Agricultural aspects: it is used in agriculture to reduce soil acidity and improve soil structure; pesticide Bordeaux mixture is prepared with lime milk and copper sulfate aqueous solution in a certain proportion, so that it is used in sky blue viscous suspension pesticides for fruit trees and vegetables , is to eliminate pests and diseases through the copper element in it, which not only uses the properties of calcium hydroxide to react with copper sulfate, but also uses the point where calcium hydroxide is slightly soluble in water to make the liquid viscous, which is beneficial to the medicine The liquid adheres to the branches and leaves of plants. In addition, calcium hydroxide reacts with carbon dioxide in the air to form calcium carbonate that is slightly soluble in water, which is also beneficial for the liquid to adhere to the surface of branches and leaves and not be washed away by rainwater for a period of time.

6. Application in the construction industry: laying bricks, plastering walls, making three-compound soil, etc.

7. In terms of sewage treatment: calcium hydroxide can be used in wastewater to neutralize free acids and acid salts in wastewater; hydroxide ions in calcium hydroxide can react with metal ions to produce water-insoluble precipitates; Adjust the pH value of wastewater to alkaline, which can better precipitate metal hydroxide.

8. In coatings: calcium hydroxide reacts with carbon dioxide in the air to produce calcium carbonate, which is white and hard and can help coagulation.

9. Metallurgical industry: In this industry, in order to coat the metal surface, the impurities (containing metal oxides) on the surface of the metal plate must be removed first, so dilute sulfuric acid must be used to remove them first, and the wastewater generated in the production process should be neutralized with calcium hydroxide. .

10. On refractory materials: when producing silica bricks, it can be used as an additive to enhance the strength and viscosity of bricks. Silica bricks are made from silica with a SiO4 content of not less than 96%, adding mineralizers and binders, and going through processes such as mixing, molding, drying, and firing.

11. Application of calcium hydroxide in flue gas desulfurization : It is mainly used to neutralize acid gases such as sulfur dioxide, sulfur trioxide and a small part of fluoride ion chloride ions, etc., so that the sulfur content of discharged flue gas meets environmental protection standards.

12. Application of calcium hydroxide in leather manufacturing industry: mainly used for combing process in leather manufacturing industry.

13. Learning: applied to students’ classroom experiments.

Calcium hydroxide has a wide range of uses. It is used in medicine, food, construction, etc., and even in classroom experiments in schools. It can be said that it is ubiquitous.

Detailed explanation of high-purity calcium hydroxide processing process

Calcium hydroxide is obtained from the chemical reaction of calcium oxide and water, and is a traditional product of inorganic chemical industry. The processing method of high-purity calcium hydroxide is more complicated than that of ordinary calcium hydroxide, and it needs to use raw materials with high activity and low impurity content for processing. With the increase in market demand, the quality of calcium hydroxide on the market is also mixed, which needs to be carefully identified.

The process of high-purity calcium hydroxide processing

1. Primary screening

Take limestone and coke for calcination, and calcined calcium oxide with a vibrating screen of 5~15mm to remove the “plain ash” with more impurities, and then crush it to about 5~25mm to obtain more than 90% effective components. High-activity calcium oxide is supplied to the pre-digester through a constant-weight feeder through an air-tight regulator. To remove iron, sulfate and other impurities in slaked lime, first of all, the quality of raw and fuel materials must be strictly controlled, and raw and fuel materials with high iron content (including other oxides) are strictly prohibited from entering the site.

2. Preliminary digestion

According to the quality of calcium oxide and the ratio of supply, according to the range of water-to-calcium ratio of 0.55~0.80, use the control valve to automatically adjust the amount of water added, so that it is mixed and stirred in the pre-slider for 5~15 minutes for preliminary digestion, and the digestion temperature is controlled to 90 ~190°C, and then sent to the ripener for further digestion for 10~40 minutes to ensure complete digestion reaction.

3. Complete digestion

The completely digested calcium hydroxide enters the air separation separator for separation. According to the principle of centrifugal force and centripetal force, the large and small particles are separated by adjusting the separation value. point.

4. Screen again

The high or low calcium hydroxide content depends on the ore. First, the CaO content of limestone is required to be greater than or equal to 54%, and the content of other oxides cannot exceed the standard. Then, calcined and digested properly, calcium hydroxide with high calcium content can be obtained. For industrial calcium hydroxide, the effective calcium hydroxide content should be detected according to the product standard analysis method. The vibrating screen of 3mm~0.5mm or smaller can be exchanged according to the product’s requirements for purity, and the material under the sieve enters the vibrating mill and then undergoes air separation to improve the digestion yield of calcium oxide, and the material on the screen is used as coarse powder. The scum is drained.

Advantages of high purity calcium hydroxide

1. High activity, up to 300ml or more.

2. High purity, calcium oxide content is more than 72%.

3. Low impurity content, less than 1.70% of silica, alumina, iron oxide and magnesium oxide, and less than 1.10% of carbon dioxide.

3. The yield is high, can reach more than 95.1%, and can be mass-produced.

4. High fineness, low moisture content, use 590μm sieve with a sieve allowance of 0.00, 149μm sieve allowance <5%, and 44μm sieve allowance <10%.

5. It can meet the requirements of chemical production such as epichlorohydrin and high-efficiency bleaching powder, and can replace caustic soda, saving a lot of caustic soda and energy.

The above is the introduction of high-purity calcium hydroxide processing technology. In the process of calcium oxide digestion, it is also necessary to strengthen water quality management and calcium hydroxide line equipment management, improve calcium hydroxide production line, and produce high-purity calcium hydroxide.

The refinement of industrial production requires the production of higher-purity products. Only products that meet the development needs of the times can win the market competition and win market recognition. If you want to know about calcium hydroxide production line equipment, please call or leave a message on the website for details!